381 research outputs found

    Serum hyaluronate as a non-invasive marker of hepatic fibrosis and inflammation in HBeAg-negative chronic hepatitis B

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    Background: HBV infection is a serious global heath problem. It is crucial to monitor this disease more closely with a non-invasive marker in clinical trials. We aimed to evaluate the predictive value of serum hyaluronate for the presence of extensive liver fibrosis and inflammation. Methods: 28 healthy volunteers and 65 patients with HBeAg negative chronic hepatitis B were enrolled. Liver biopsies scored according to Ishak system. Association of serum hyaloronate with liver fibrosis and inflammation were assessed, and cut off points for serum hyaluronate levels were identified by receiver operating characteristics (ROC) curves and their values for prediction of fibrosis and inflammation were assessed. Results: In patients with CHB serum hyaluronate had the most significant correlation and predictive values for the liver fibrosis and inflammation comparing to the other variables. At the cut off point of 126.4 ngm/ml it could discriminate extensive fibrosis from milder ones with sensitivity of 90.9% and specificity of 98.1%. With the same value it could discriminate extensive inflammation from their milder counterparts with sensitivity of 63.6% and specificity of 92.6%. Conclusion: Serum hyaluronate was the best predictor of extensive liver fibrosis and inflammation and it could discriminate subgroups of patients with chronic hepatitis B. It could be used as a non-invasive test to monitor these patients more closely with developing anti viral agents in clinical trials

    High-entropy high-hardness metal carbides discovered by entropy descriptors

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    High-entropy materials have attracted considerable interest due to the combination of useful properties and promising applications. Predicting their formation remains the major hindrance to the discovery of new systems. Here we propose a descriptor - entropy forming ability - for addressing synthesizability from first principles. The formalism, based on the energy distribution spectrum of randomized calculations, captures the accessibility of equally-sampled states near the ground state and quantifies configurational disorder capable of stabilizing high-entropy homogeneous phases. The methodology is applied to disordered refractory 5-metal carbides - promising candidates for high-hardness applications. The descriptor correctly predicts the ease with which compositions can be experimentally synthesized as rock-salt high-entropy homogeneous phases, validating the ansatz, and in some cases, going beyond intuition. Several of these materials exhibit hardness up to 50% higher than rule of mixtures estimations. The entropy descriptor method has the potential to accelerate the search for high-entropy systems by rationally combining first principles with experimental synthesis and characterization.Comment: 12 pages, 2 figure

    Origin of the Joumand fluorite and barite(Pb-Zn) veins of northwest Gonabad, Iran. Evidence from trace-element and stable (S) isotope data

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    The Joumand fluorite deposit is located 15 Km northwest of Gonabad, Eastern Iran. The fluorite mineralization mainly occurs within metasedimentary rocks (Shemshak formation). The intrusive rocks consist of dykes with porphyritic texture and granitic composition crosscutting the Shemshak formation. These dykes outcrop near the deposit. Fluorite veins are controled by fractures and faults. The most common primary (hypogene) minerals are fluorite, barite, galena, and quartz, with minor amounts of other sulfide minerals (chalcopyrite and pyrite). The samples show a pattern characterized by an increase from the LREE to the HREE. Fluorites exhibit high Y contents, strong positive Y anomalies, slightly positive Ce and negative Eu anomalies. 34δS measurements (-2.7 to +0.25‰) are an evidence for a primary source of sulphur derived from magmas. Microthermometric measurement, as well as geological and mineralogical evidence (for example Mn oxide crusts) indicate epithermal environment for flourite

    Modelling and synthesis of high-entropy refractory carbides

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    Bulk samples of equiatomic, hexanery (5-metal), high-entropy refractory carbides were fabricated using a combination of high-energy ball milling (HEBM), spark plasma sintering (SPS), and hot pressing (HP) annealing. To select candidate composition that are likely to form single phase high-entropy materials at lower processing temperatures (\u3c2500°C), a novel, first-principles materials design method was developed. The theory follows that for low temperature single phase formation, the different configurations should have similar energies to increase the number of thermodynamically accessible states. A partial occupation method was implemented within AFLOW to automate the generation and calculation of the different configurations. The energy distributions were then used to construct a descriptor of Entropy Forming Ability (EFA) to predict the formation of high-entropy materials. CALPHAD results were found to agree with the configuration energy range descriptor for each composition, and these carbides exhibited broad, single-phase solubility across each system, making processing possible at reasonable temperatures. Many of the complex carbide compositions, including (Hf0.2Nb0.2Ta0.2Ti0.2Zr0.2)C, (Hf0.2Nb0.2Ta0.2Ti0.2V0.2)C, (Hf0.2Nb0.2Ta0.2Ti0.2W0.2)C, and (Nb0.2Ta0.2Ti0.2V0.2W0.2)C demonstrated virtually single-phase, solid-solution compounds with the NaCl crystal structure as determined by x-ray diffraction (XRD) and energy dispersive x-ray spectroscopy (EDS), while some compositions, including (Hf0.2Mo 0.2Ta0.2W0.2Zr0.2)C and (Hf0.2Mo0.2V0.2W0.2Zr0.2)C, exhibited multiple phases. Results were found to be in good agreement with the ab initio based formulation of entropic stability, where the compositions with the highest EFA values were found to form a single rocksalt structure and compositions with the lower EFA values were found to exhibit multiple phases. Further, among the systems that were found to form single phase materials at 2500°C, artificial segregation was introduced via lower processing temperatures. In these artificially segregated samples, the extent of mixing was analyzed via peak broadening in XRD according to the formulation of Williamson and Hall [1] and compositional mapping in EDS. Results of artificially segregated samples provide continued support for the viability of the EFA formulation, where broadening was found to be more pronounced (i.e. more chemical segregation) in samples that were determined to have a lower EFA value. This work demonstrates the extension of entropic-stabilization into refractory interstitial carbides, paving the way for development of an entirely new class of UHTCs. This work is supported by the U.S. Office of Naval Research MURI program (Grant No. N00014-15- 1-2863). [1] G.. Williamson, W.. Hall, X-ray line broadening from filed aluminium and wolfram, Acta Metall. 1 (1953) 22–31. doi:10.1016/0001-6160(53)90006-6

    Methadone dosing strategies in preterm neonates can be simplified

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    Aims: A dramatic increase in newborn infants with neonatal abstinence syndrome has been observed and these neonates are frequently treated with complex methadone dosing schemes to control their withdrawal symptoms. Despite its abundant use, hardly any data on the pharmacokinetics (PK) of methadone is available in preterm neonates. Therefore we investigated developmental PK of methadone and evaluated current dosing strategies and possible simplification in this vulnerable population. Methods: A single-centre open-label prospective study was performed to collect PK data after a single oral dose of methadone in preterm neonates. A population PK model was built to characterize developmental PK of (R)- and (S)-methadone. Model-based simulations were performed to identify a simplified dosing strategy to reach and maintain target methadone exposure. Results: A total of 121 methadone concentrations were collected from 31 preterm neonates. A one-compartment model with first order absorption and elimination kinetics best described PK data for (R)- and (S)-methadone. Clearance increases with advancing gestational age and differs between R- and S-enantiomer, being slightly higher for the former (0.244 vs 0.167 L/h). Preterm neonates reached target exposure after 48 hours with currently used dosing schedules. Output from simulations revealed that target exposures can be achieved with a simplified dosing strategy during the first 4 days of treatment. Conclusion: Methadone clearance in preterm neonates increases with advancing gestational age and its disposition is influenced by its chirality. Simulations that account for developmental PK changes indicate a shorter methadone dosing strategy can maintain target exposure to control withdrawal symptoms. © 2019 The British Pharmacological Societ

    Continues renal replacement therapy (CRRT) with disposable hemoperfusion cartridge: A promising option for severe COVID-19

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    Cytokine release syndrome is prevalent in severe cases of COVID-19. In this syndrome, an uncontrolled response of immune system occurs. Extracorporeal blood purification has been proven to effectively remove the released inflammatory cytokines. Here, we reported a successful case to represent our experience of extracorporeal blood purification in a patient with severe COVID-19. © 2020 The Author

    Oral ibuprofen is more effective than intravenous ibuprofen for closure of a patent ductus arteriosus: can pharmacokinetic modeling help us to understand why?

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    Introduction: Oral ibuprofen is more effective than intravenous (IV) ibuprofen for closure of a patent ductus arteriosus (PDA). This study explored whether higher concentrations of the biologically active S-enantiomer or increased R- to S-conversion following oral dosing could explain this finding. Methods: Two datasets containing 370 S- and R-ibuprofen concentrations from 95 neonates with PDA treated with oral (n = 27, 28%) or IV ibuprofen were analyzed using nonlinear mixed effects modeling. Concentration-time profiles in typical neonates were explored and compared in different dosing or R- to S-conversion scenarios. Results: Postnatal age (PNA), gestational age (GA), and being small for GA impacted S- and R-ibuprofen clearance. Upon oral dosing, S-ibuprofen concentrations were lower compared to IV ibuprofen for a large part of the dosing interval. We could show that R- to Sconversion will not exceed 45%. Exploration of a 30% presystemic R- to S-conversion resulted in a 25-32% increase in S-ibuprofen exposure following oral administration with AUC(72h) values varying between 700-2,213 mg*h/L (oral) and 531-1,762 (IV) for the standard or 1,704-2,893 (oral) and 1,295-2,271 mg*h/L (IV) for PNA-based dosing. Discussion: The absence of higher S-ibuprofen concentrations does not support a beneficial concentration-time profile after oral dosing. While a fraction of up to 45% presystemic R- to S-conversion could not be ruled out, the impact of such a low conversion might be only relevant for the standard but not high dosing regimens, considering reported exposure-response targets. Perhaps, the lack of high peak concentrations observed following IV dosing may play a role in the observed effects upon oral dosing. 1.% 2022 The Author(s).Pharmacolog

    Insight into blood pressure targets for universal coverage of hypertension services in Iran: the 2017 ACC/AHA versus JNC 8 hypertension guidelines

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    BACKGROUND: We compared the prevalence, awareness, treatment, and control of hypertension in Iran based on two hypertension guidelines; the 2017 ACC/AHA -with an aggressive blood pressure target of 130/80 mmHg- and the commonly used JNC8 guideline cut-off of 140/90 mmHg. We shed light on the implications of the 2017 ACC/AHA for population subgroups and high-risk individuals who were eligible for non-pharmacologic and pharmacologic therapies. METHODS: Data was obtained from the Iran national STEPS 2016 study. Participants included 27,738 adults aged ≥25 years as a representative sample of Iranians. Regression models of survey design were used to examine the determinants of prevalence, awareness, treatment, and control of hypertension. RESULTS: The prevalence of hypertension based on JNC8 was 29.9% (95% CI: 29.2-30.6), which soared to 53.7% (52.9-54.4) based on the 2017 ACC/AHA. The percentage of awareness, treatment, and control were 59.2% (58.0-60.3), 80.2% (78.9-81.4), and 39.1% (37.4-40.7) based on JNC8, which dropped to 37.1% (36.2-38.0), 71.3% (69.9-72.7), and 19.6% (18.3-21.0), respectively, by applying the 2017 ACC/AHA. Based on the new guideline, adults aged 25-34 years had the largest increase in prevalence (from 7.3 to 30.7%). They also had the lowest awareness and treatment rate, contrary to the highest control rate (36.5%) between age groups. Compared with JNC8, based on the 2017 ACC/AHA, 24, 15, 17, and 11% more individuals with dyslipidaemia, high triglycerides, diabetes, and cardiovascular disease events, respectively, fell into the hypertensive category. Yet, based on the 2017 ACC/AHA, 68.2% of individuals falling into the hypertensive category were eligible for receiving pharmacologic therapy (versus 95.7% in JNC8). LDL cholesterol< 130 mg/dL, sufficient physical activity (Metabolic Equivalents≥600/week), and Body Mass Index were found to change blood pressure by - 3.56(- 4.38, - 2.74), - 2.04(- 2.58, - 1.50), and 0.48(0.42, 0.53) mmHg, respectively. CONCLUSIONS: Switching from JNC8 to 2017 ACC/AHA sharply increased the prevalence and drastically decreased the awareness, treatment, and control in Iran. Based on the 2017 ACC/AHA, more young adults and those with chronic comorbidities fell into the hypertensive category; these individuals might benefit from earlier interventions such as lifestyle modifications. The low control rate among individuals receiving treatment warrants a critical review of hypertension services

    Is salt intake reduction a universal intervention for both normotensive and hypertensive people: a case from Iran STEPS survey 2016

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    Purpose: There is a direct association between salt intake and blood pressure (BP), one of the main risk factors for CVDs. However, yet there has been a debate that how strong is this association in people with and without hypertension. This study was conducted to evaluate the magnitude of the association between salt intake and BP in hypertensive and normotensive population among a nationally representative population. Methods: The study was conducted on a nationally representative sample of 18,635 Iranian adults aged 25 years and older who participated in the STEPS survey 2016 and provided urine sample. Salt intake was estimated through spot urine sample and Tanaka equation. Multiple linear regression model in survey data analysis was used to assess the independent effect of salt intake on BP. Results: After adjusting for covariates, there was a significant association between salt intake and SBP in hypertensive (p ' 0.001) and normotensive people (p ' 0.001). In hypertensive people, with 1 g of increase in salt intake, the SBP and DBP increased 0.37 mmHg and 0.07 mmHg, respectively. Whereas in normotensive people, with 1 g of increase in salt intake, the SBP and DBP increased 0.26 mmHg and 0.05 mmHg, respectively. Moreover, there was a significant trend toward an increase of SBP across salt intake quartiles in both hypertensive (p ' 0.001) and normotensive people (p = 0.002), though the slope was steeper in hypertensive than in normotensive people. Conclusions: The present study demonstrated that salt intake significantly increased SBP in both hypertensive and normotensive people, though the magnitude of this increase was greater in hypertensive people as compared with normotensive people
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