Discover the most talked about and latest scientific content & concepts.

Concept: Steady state


PURPOSE: Pasireotide (SOM230), a novel multireceptor ligand somatostatin analog (SSA), binds with high affinity to four of the five somatostatin receptor subtypes (sst1-3, 5). This study evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics profiles of pasireotide long-acting release (LAR) formulation in patients with advanced gastroenteropancreatic neuroendocrine tumor (GEP NET) refractory to other SSAs. METHODS: In this randomized, multicenter, open-label, phase II study, patients with biopsy-proven primary or metastatic GEP NET refractory to available SSAs were randomly assigned 1:1:1 to receive pasireotide LAR by deep intragluteal injection at a dose of 20, 40, or 60 mg once every 28 days for 3 months. RESULTS: Forty-two patients received pasireotide LAR. Adverse events were reported by 34 (81 %) patients, with the most frequently reported including diarrhea, fatigue, abdominal pain, and nausea. Mean fasting glucose levels were increased compared with baseline at all points throughout the study. After the third injection of pasireotide LAR, the median trough plasma concentrations on day 84 were 4.82, 12.0, and 19.7 ng/mL in the 20-, 40-, and 60-mg treatment groups, respectively. Drug accumulation was limited for each dose based on the increase in trough concentrations after the first to third injections (accumulation ratios were approximately 1 from all dose levels). CONCLUSIONS: This study demonstrated that a new, once-monthly, intramuscular LAR formulation of pasireotide was well tolerated in patients with advanced GEP NET. Steady state levels of plasma pasireotide were achieved after three injections.

Concepts: Pharmacology, Clinical trial, Cancer, Oncology, Endocrinology, Neuroendocrine tumor, Randomness, Steady state


A chemical mixture that continually absorbs work from its environment may exhibit steady-state chemical concentrations that deviate from their equilibrium values. Such behavior is particularly interesting in a scenario where the environmental work sources are relatively difficult to access, so that only the proper orchestration of many distinct catalytic actors can power the dissipative flux required to maintain a stable, far-from-equilibrium steady state. In this article, we study the dynamics of an in silico chemical network with random connectivity in an environment that makes strong thermodynamic forcing available only to rare combinations of chemical concentrations. We find that the long-time dynamics of such systems are biased toward states that exhibit a fine-tuned extremization of environmental forcing.

Concepts: Energy, Chemical reaction, Chemistry, Chemical equilibrium, Thermodynamics, Systems theory, Steady state, Dynamic equilibrium


Background BTH1677 is a beta glucan pathogen associated molecular pattern (PAMP) currently being investigated as a novel cancer therapy. Here, the initial safety and pharmacokinetic (PK) results of BTH1677 in healthy subjects are reported. Subjects and Methods In the Phase 1a single-dosing study, subjects were randomized (3:1 per cohort) to a single intravenous (iv) infusion of BTH1677 at 0.5, 1, 2, 4, or 6 mg/kg or placebo, respectively. In the Phase 1b multi-dosing study, subjects were randomized (3:1 per cohort) to 7 daily iv infusions of BTH1677 at 1, 2, or 4 mg/kg or placebo, respectively. Safety and PK non-compartmental analyses were performed. Results Thirty-six subjects (N = 24 Phase 1a; N = 12 Phase 1b) were randomized to treatment. No deaths or serious adverse events occurred in either study. Mild or moderate adverse events (AEs) occurred in 67 % of BTH1677-treated subjects in both studies. Treatment-related AEs (occurring in ≥10 % of subjects) included dyspnea, flushing, headache, nausea, paraesthesia, and rash in Phase 1a and conjunctivitis and headache in Phase 1b. BTH1677 serum concentration was linear with dose. Clearance, serum elimination half-life (t1/2) and volume of distribution (Vss) were BTH1677 dose-independent. In Phase 1b, area under the curve, t1/2, and Vss values were larger at steady state on days 6-30 versus day 0. Conclusions BTH1677 was well tolerated after single doses up to 6 mg/kg and after 7 daily doses up to 4 mg/kg.

Concepts: Pharmacology, Clinical trial, Thermodynamics, Dose, Acupuncture, Pharmacokinetics, Steady state, Half-life


Boiling, a dynamic and multiscale process, has been studied for several decades; however, a comprehensive understanding of the process is still lacking. The bubble ebullition cycle, which occurs over millisecond time-span, makes it extremely challenging to study near-surface interfacial characteristics of a single bubble. Here, we create a steady-state vapor bubble that can remain stable for hours in a pool of sub-cooled water using a femtosecond laser source. The stability of the bubble allows us to measure the contact-angle and perform in-situ imaging of the contact-line region and the microlayer, on hydrophilic and hydrophobic surfaces and in both degassed and regular (with dissolved air) water. The early growth stage of vapor bubble in degassed water shows a completely wetted bubble base with the microlayer, and the bubble does not depart from the surface due to reduced liquid pressure in the microlayer. Using experimental data and numerical simulations, we obtain permissible range of maximum heat transfer coefficient possible in nucleate boiling and the width of the evaporating layer in the contact-line region. This technique of creating and measuring fundamental characteristics of a stable vapor bubble will facilitate rational design of nanostructures for boiling enhancement and advance thermal management in electronics.

Concepts: Water, Thermodynamics, Heat, Liquid, Heat transfer, Steady state


We have developed an asynchronous brain-machine interface (BMI)-based lower limb exoskeleton control system based on steady-state visual evoked potentials (SSVEPs).

Concepts: Thermodynamics, Systems theory, Evoked potential, Steady state


The purpose of this study was to analyze the effect of recovery type (passive vs. active) during prolonged intermittent exercises on the blood lactate concentration (MLSS) and work rate (MLSS(wint)) at maximal lactate steady state. Nineteen male trained cyclists were divided into 2 groups for the determination of MLSS(wint) using passive (maximal oxygen uptake = 58.1 ± 3.5 mL·kg(-1)·min(-1); N = 9) or active recovery (maximal oxygen uptake = 60.3 ± 9.0 mL·kg(-1)·min(-1); N = 10). They performed the following tests, on different days, on a cycle ergometer: (i) incremental test until exhaustion to determine maximal oxygen uptake; (ii) 2 to 3 continuous submaximal constant work rate tests (CWRT) for the determination of the work rate at continuous maximal lactate steady state (MLSS(wcont)); and (iii) 2 to 3 intermittent submaximal CWRT (7 × 4 min and 1 × 2 min, with 2-min recovery) with either passive or active recovery for the determination of MLSS(wint). MLSS(wint) was significantly higher when compared with MLSS(wcont) for both passive recovery (294.7 ± 32.2 vs. 258.7 ± 24.5 W, respectively) and active recovery groups (300.5 ± 23.9 vs. 273.2 ± 21.5 W, respectively). The percentage increments in MLSS(wint) were similar between conditions (passive = 13% vs. active = 10%). MLSS (mmol·L(-1)) was not significantly different between MLSS(wcont) and MLSS(wint) for either passive recovery (4.50 ± 2.10 vs. 5.61 ± 1.78, respectively) and active recovery (4.06 ± 1.49 vs. 4.91 ± 1.91, respectively) conditions. We can conclude that using a work/rest ratio of 2:1, MLSS(wint) was ∼10%-13% higher than MLSS(wcont), irrespective of the recovery type performed during prolonged intermittent exercises.

Concepts: Thermodynamics, Steady state, The Work, VO2 max


We propose the very first “Nernstian biosupercapacitor”, a biodevice based on only one redox polymer: poly(vinyl imidazole-co-allylamine)[Os(bpy)2 Cl], and two biocatalysts. At the bioanode PQQ-dependent glucose dehydrogenase reduces the Os(3+) moieties at the polymer to Os(2+) shifting the Nernst potential of the Os(3+) /Os(2+) redox couple to negative values. Concomitantly, at the biocathode the reduction of O2 by means of bilirubin oxidase embedded in the same redox polymer leads to the oxidation of Os(2+) to Os(3+) shifting the Nernst potential to higher values. Despite the use of just one redox polymer an open circuit voltage of more than 0.45 V was obtained during charging and the charge is stored in the redox polymer at both the bioanode and the biocathode. By connecting both electrodes via a predefined resistor a high power density is obtained for a short time exceeding the steady state power of a corresponding biofuel cell by a factor of 8.

Concepts: Adenosine triphosphate, Enzyme, Glucose, Redox, Electrochemistry, Nicotinamide adenine dinucleotide, Electrochemical cell, Steady state


OBJECTIVES: To compare the pharmacokinetics (PK), safety and efficacy of innovator infliximab (INX) and CT-P13, a biosimilar to INX, in patients with active ankylosing spondylitis (AS). METHODS: Phase 1 randomised, double-blind, multicentre, multinational, parallel-group study. Patients were randomised to receive 5 mg/kg of CT-P13 (n=125) or INX (n=125). Primary endpoints were area under the concentration-time curve (AUC) at steady state and observed maximum steady state serum concentration (Cmax,ss) between weeks 22 and 30. Additional PK, efficacy endpoints, including 20% and 40% improvement response according to Assessment in Ankylosing Spondylitis International Working Group criteria (ASAS20 and ASAS40), and safety outcomes were also assessed. RESULTS: Geometric mean AUC was 32 765.8 μgh/ml for CT-P13 and 31 359.3 μgh/ml for INX. Geometric mean Cmax,ss was 147.0 μg/ml for CT-P13 and 144.8 μg/ml for INX. The ratio of geometric means was 104.5% (90% CI 94% to 116%) for AUC and 101.5% (90% CI 95% to 109%) for Cmax,ss. ASAS20 and ASAS40 responses at week 30 were 70.5% and 51.8% for CT-P13 and 72.4% and 47.4% for INX, respectively. In the CT-P13 and INX groups more than one adverse event occurred in 64.8% and 63.9% of patients, infusion reactions occurred in 3.9% and 4.9%, active tuberculosis occurred in 1.6% and 0.8%, and 27.4% and 22.5% of patients tested positive for anti-drug antibodies, respectively. CONCLUSIONS: The PK profiles of CT-P13 and INX were equivalent in patients with active AS. CT-P13 was well tolerated, with an efficacy and safety profile comparable to that of INX up to week 30.

Concepts: Thermodynamics, Ratio, Arithmetic mean, Mean, Geometric mean, Ankylosing spondylitis, Steady state, Means


In humans, the monocyte pool comprises three subsets (classical, intermediate, and nonclassical) that circulate in dynamic equilibrium. The kinetics underlying their generation, differentiation, and disappearance are critical to understanding both steady-state homeostasis and inflammatory responses. Here, using human in vivo deuterium labeling, we demonstrate that classical monocytes emerge first from marrow, after a postmitotic interval of 1.6 d, and circulate for a day. Subsequent labeling of intermediate and nonclassical monocytes is consistent with a model of sequential transition. Intermediate and nonclassical monocytes have longer circulating lifespans (∼4 and ∼7 d, respectively). In a human experimental endotoxemia model, a transient but profound monocytopenia was observed; restoration of circulating monocytes was achieved by the early release of classical monocytes from bone marrow. The sequence of repopulation recapitulated the order of maturation in healthy homeostasis. This developmental relationship between monocyte subsets was verified by fate mapping grafted human classical monocytes into humanized mice, which were able to differentiate sequentially into intermediate and nonclassical cells.

Concepts: Inflammation, Monocyte, Bone marrow, Thermodynamics, Systems theory, Steady state, Fibonacci number, Dynamic equilibrium


Humans move frequently and tend to carry parasites among areas with endemic malaria and into areas where local transmission is unsustainable. Human-mediated parasite mobility can thus sustain parasite populations in areas where they would otherwise be absent. Data describing human mobility and malaria epidemiology can help classify landscapes into parasite demographic sources and sinks, ecological concepts that have parallels in malaria control discussions of transmission foci. By linking transmission to parasite flow, it is possible to stratify landscapes for malaria control and elimination, as sources are disproportionately important to the regional persistence of malaria parasites. Here, we identify putative malaria sources and sinks for pre-elimination Namibia using malaria parasite rate (PR) maps and call data records from mobile phones, using a steady-state analysis of a malaria transmission model to infer where infections most likely occurred. We also examined how the landscape of transmission and burden changed from the pre-elimination setting by comparing the location and extent of predicted pre-elimination transmission foci with modeled incidence for 2009. This comparison suggests that while transmission was spatially focal pre-elimination, the spatial distribution of cases changed as burden declined. The changing spatial distribution of burden could be due to importation, with cases focused around importation hotspots, or due to heterogeneous application of elimination effort. While this framework is an important step towards understanding progressive changes in malaria distribution and the role of subnational transmission dynamics in a policy-relevant way, future work should account for international parasite movement, utilize real time surveillance data, and relax the steady state assumption required by the presented model.

Concepts: Epidemiology, Malaria, Plasmodium, Plasmodium vivax, Thermodynamics, Change, Steady state