61 research outputs found
Kinetic modeling of biosorption for hydrocarbons removal from wastewater using modified logistic equation
Application of raw and modified biomass to remove hydrocarbons from wastewater by adsorption is a common practice. A mathematical modeling of biosorption kinetics is a crucial step to optimize the remediation process. In the present study, kinetic studies were carried out to describe the sorption process of crude oil and water on waste sunflower pith. To increase sorption capacity the pith surface was modified with polydimethylsiloxane (PDMS) and hydrophobic SiO2 nanoparticles. The maximum sorption capacity of raw and modified material was 17.76 and 19.62 g/g for crude oil, respectively. The system reached the equilibrium stage after 24 hours. The uptake profiles have been described by the pseudo-first order rate equation and the pseudo-second order rate equation. The calculated results were compared with experimental data and their fit was poor. To predict biosorption kinetics a new mathematically efficient procedure based on modified logistic equation was developed. The results indicate that the sunflower pith has a great potential for the removal of crude oil from water phase as an eco-friendly process
Precompetitional Weight Reduction Modifies Prooxidative-Antioxidative Status in Judokas
The main aim of the study was an assessment of the influence of rapid weight loss on oxidative stress parameters
in judokas differing in weight reduction value. Materials and Methods. The study included 30 judokas with an age range of
18-30 years (mean age: 22 4 ± 3 40 years). Enzymatic and nonenzymatic antioxidative markers, lipid peroxidation markers,
and total oxidative stress were assessed three times: one week before a competition (the first stage), after gaining the
desired weight (the second stage), and one week after the competition (the third stage). Results. Between the first and the
second stage, the concentration of lipid hydroperoxides (LPH) decreased significantly. The superoxide dismutase (SOD),
copper- and zinc-containing superoxide dismutase (Cu,Zn-SOD), ceruloplasmin (CER), malondialdehyde (MDA), LPH, and
total oxidative stress (TOS) concentrations were the lowest one week after the competition. Linear regression indicated that
the emphases on increased weight reduction increased the activity of glutathione peroxidase (GPx), glutathione reductase (GR),
glutathione S-transferase (GST), and protein sulfhydryl (PSH) between the first and the second stage of the study. Moderate
weight reduction (2-5%) resulted in elevated levels of SOD, Mn-SOD, LPH, MDA, and TOS in comparison to low and high
reductions. An opposite relation was observed in PSH. In judokas, the precompetitional weight reduction range was 0.44-6.10%
(mean: 2 93% ± 1 76%) of the initial body weight. Concentrations of superoxide dismutase (SOD; p < 01), manganesedependent
superoxide dismutase (Mn-SOD; p < 001), and ceruloplasmin (CER; p < 05) decreased between the first and the
third stage of the study as well between the second and third one. Before competitions, a decrease in lipid hydroperoxide
(LPH; p < 01) concentration was observed. A reduction of malondialdehyde (MDA; p < 05), LPH (p < 01), and total oxidative
stress (TOS; p < 05) levels between the first and the final stage occurred. The increase in weight reduction was linearly
correlated with the rise of glutathione peroxidase (GPx; p < 05), glutathione reductase (GR; p < 05), glutathione Stransferase
(GST; p < 05), and protein sulfhydryl (PSH; p < 05) concentrations between the first and the second stage of
the study. Moderate weight reduction (2-5%) resulted in elevated levels of SOD (p < 05), Mn-SOD (p < 05), LPH
(p < 05), MDA (p < 05), and TOS (p < 05) in comparison to low and high reductions. An opposite relation was
observed in PSH (p < 005). Conclusions. The effect of weight reduction in judo athletes on prooxidative-antioxidative
system diversity depends on the weight reduction value
High-Pressure Dielectric Studies—a Way to Experimentally Determine the Solubility of a Drug in the Polymer Matrix at Low Temperatures
In this work, we employed broad-band dielectric spectroscopy to
determine the solubility limits of nimesulide in the Kollidon VA64 matrix at ambient
and elevated pressure conditions. Our studies confirmed that the solubility of the drug
in the polymer matrix decreases with increasing pressure, and molecular dynamics
controls the process of recrystallization of the excess of amorphous nimesulide from
the supersaturated drug−polymer solution. More precisely, recrystallization initiated at
a certain structural relaxation time of the sample stops when a molecular mobility
different from the initial one is reached, regardless of the temperature and pressure
conditions. Finally, based on the presented results, one can conclude that by
transposing vertically the results obtained at elevated pressures, one can obtain the
solubility limit values corresponding to low temperatures. This approach was validated
by the comparison of the experimentally determined points with the theoretically
obtained values based on the Flory−Huggins theory
Implantacja Andrastentu XL u osoby dorosłej z zaawansowaną niewydolnością serca w przebiegu koarktacji aorty
We report the case of a 49 year-old-man with congenital coarctation of the aorta (CoA), admitted in a critical clinical condition
due to advanced secondary cardiomyopathy and chronic heart failure. An Andrastent XL was implanted successfully in
the CoA. The procedure resulted in an almost completely resolved CoA and prompt clinical improvement in the patient.
Kardiol Pol 2011; 69, 9: 983–98
Compression-Induced Phase Transitions of Bicalutamide
The formation of solid dispersions with the amorphous drug dispersed in the polymeric
matrix improves the dissolution characteristics of poorly soluble drugs. Although they provide an
improved absorption after oral administration, the recrystallization, which can occur upon absorption
of moisture or during solidification and other formulation stages, serves as a major challenge.
This work aims at understanding the amorphization-recrystallization changes of bicalutamide.
Amorphous solid dispersions with poly(vinylpyrrolidone-co-vinyl acetate) (PVP/VA) were obtained
by either ball milling or spray drying. The applied processes led to drug amorphization as confirmed
using X-ray diffraction and differential scanning calorimetry. Due to a high propensity towards
mechanical activation, the changes of the crystal structure of physical blends of active pharmaceutical
ingredient (API) and polymer upon pressure were also examined. The compression led to drug
amorphization or transition from form I to form II polymorph, depending on the composition
and applied force. The formation of hydrogen bonds confirmed using infrared spectroscopy and
high miscibility of drug and polymer determined using non-isothermal dielectric measurements
contributed to the high stability of amorphous solid dispersions. They exhibited improved wettability
and dissolution enhanced by 2.5- to 11-fold in comparison with the crystalline drug. The drug
remained amorphous upon compression when the content of PVP/VA in solid dispersions exceeded
20% or 33%, in the case of spray-dried and milled systems, respectively.Polish National Science Centre
2015/16/W/NZ7/0040
Clinical Outcomes of Extracranial Carotid Artery-Related Stroke Eligible for Mechanical Reperfusion on Top of Per-Guidelines Thrombolytic Therapy:Analysis from a 6-Month Consecutive Patient Sample in 2 Centers
BACKGROUND: Systemic intravenous thrombolysis and mechanical thrombectomy (MT) are guideline-recommended reperfusion therapies in large-vessel-occlusion ischemic stroke. However, for acute ischemic stroke of extracranial carotid artery origin (AIS-CA) there have been no specific trials, resulting in a data gap. MATERIAL/METHODS: We evaluated referral/treatment pathways, serial imaging, and neurologic 90-day outcomes in consecutive patients, presenting in a real-life series in 2 stroke centers over a period of 6 months, with AIS-CA eligible for emergency mechanical reperfusion (EMR) on top of thrombolysis as per guideline criteria. RESULTS: Of 30 EMR-eligible patients (33.3% in-window for thrombolysis and thrombolysed, 73.3% male, age 39-87 years, median Alberta Stroke Program Early Computed Tomography Score (ASPECTS) 10, pre-stroke mRS 0–1 in all, tandem lesions 26.7%), 20 (66.7%) were EMR-referred (60% – endovascular, 6.7% – surgery referrals). Only 40% received EMR, nearly exclusively in stroke centers with carotid artery stenting (CAS) expertise (100% eligible patient acceptance rate, 100% treatment delivery involving CAS±MT with culprit lesion sequestration using micronet-covered stents). The emergency surgery rate was 0%. Baseline clinical and imaging characteristics did not differ between EMR-treated and EMR-untreated patients. Ninety-day neurologic status was profoundly better in EMR-treated patients: mRS 0–2 (91.7% vs 0%; P<0.001); mRS 3–5 (8.3% vs 88.9%; P<0.001), mRS 6 (0% vs 11.1%; P<0.001). CONCLUSIONS: In a real-life AIS-CA setting, the referral rate of EMR-eligible patients for EMR was low, and the treatment rate was even lower. AIS-CA revascularization was delivered predominantly in stroke thrombectomy-capable cardioangiology centers, resulting in overwhelmingly superior patient outcome. Large vessel occlusion stroke referral and management pathways should involve centers with proximal-protected CAS expertise. AIS-CA, irrespective of any thrombolysis administration, is a hyperacute cerebral emergency and EMR-eligible patients should be immediately referred for mechanical reperfusion
- …