Selective leaching kinetics of calcareous phosphate rock in succinic acid solution was investigated. Using a known particle size range of the sample, liquid/solid ratio and acid concentration, the ...influence of various reaction temperatures was studied in order to elucidate the kinetics of calcareous material in the rock. The leaching rate increased with increasing temperature. A kinetic model was suggested to describe the selective leaching process of calcareous material analyzing the kinetic data. The selective leaching curves were evaluated in order to check the validity of shrinking core models for liquid–solid systems. The experimental data were tested by graphical and statistical methods and it was found that the leaching of calcareous material in the rock was controlled by chemical reaction, i.e., 1
−
(1
−
x)
1/3
=
1.47
×
10
6e
−64.92/
RT
t. The apparent activation energy of the leaching process was found as 64.92 kJ mol
−1 over the reaction temperature range from 313 to 353 K.
Let
σ
be a partition of the set of all primes
P
. Let
G
be a finite group and
F
be a Fitting class of finite groups. In the theory of formations of finite soluble groups, a well known result of Bryce ...and Cossey is: a local formation
F
is a Fitting class if and only if every value of the canonical formation function
F
of
F
is a Fitting class. In this paper, we give the dual theory of the result of Bryce and Cossey. We proved that an
σ
-local Fitting class
F
is a formation if and only if every value of the canonical
σ
-local
H
σ
-function of
F
is a formation.
Aims
Carotid artery disease (CAD) is an important risk factor for stroke. We first evaluated CAD and stroke pathology in elderly post‐stroke survivors. To simulate CAD, we assessed long‐term ...consequences of bilateral common carotid artery stenosis (BCAS) in mice and exposed them to environmental enrichment (EE).
Methods
Histopathological methods were used to determine degrees of CAD (% area stenosis), brain infarct types, sizes and distribution in post‐stroke survivors and BCAS mice. Adult male C57BL/6J mice after BCAS or sham surgery were randomly assigned to standard housing (Std) or limited (3 h) or full‐time (Full) exposure to EE per day for 12 weeks.
Results
High frequencies of moderate carotid artery stenosis (51–75%) were evident in post‐stroke survivors whereas those with severe CAD (>75% stenosis) exhibited greater numbers of cortical rather than subcortical infarcts and, were at higher risk of developing dementia. BCAS in mice reduced cerebral blood flow by 52% (P < 0.01) and thickened carotid artery walls, regardless of EE duration. Remarkably, the total and cortical infarcts declined by >50% in BCAS mice exposed to EE compared with BCAS‐Std (P < 0.01). Frontal lobe and cortical strokes were associated with worsening working memory tested in a radial maze paradigm. Proteomic analysis revealed EE, both BCAS‐3 h and BCAS‐Full attenuated coagulation cascade factors including fibrinogen and von Willebrand factor, markers of blood–brain barrier damage.
Conclusion
Small cortical and subcortical infarcts were evident in both post‐stroke survivors with CAD and BCAS mice. Experimental evidence suggested that moderate exposure to EE is sufficient to reduce subsequent stroke lesions.
The complete genome sequence of Geobacter sulfurreducens, a δ-proteobacterium, reveals unsuspected capabilities, including evidence of aerobic metabolism, one-carbon and complex carbon metabolism, ...motility, and chemotactic behavior. These characteristics, coupled with the possession of many two-component sensors and many c-type cytochromes, reveal an ability to create alternative, redundant, electron transport networks and offer insights into the process of metal ion reduction in subsurface environments. As well as playing roles in the global cycling of metals and carbon, this organism clearly has the potential for use in bioremediation of radioactive metals and in the generation of electricity.
Natural fiber reinforced biocomposites have recently attracted many researchers because of their biodegradability, cost effectiveness and ecofriendliness. The present study investigates the ...properties of willow-fiber reinforced poly(lactic acid) based composites and their foam processability. Microcellular foams of the composites were prepared by foam injection moulding using nitrogen gas as the blowing agent. The effects of willow-fiber addition on the morphology, mechanical properties, thermal stability, crystallization, and heat deflection temperature (HDT) were studied. At 30 weight percent wt% willow-fiber content, unfoamed composites showed good improvement in specific tensile and flexural moduli. Addition of willow-fiber increased crystallinity and the rate of crystallization and yielded narrow crystallite size distribution as observed by differential scanning calorimetry (DSC). Scanning electron microscopy (SEM) results of the foamed composites revealed that increase in willow-fiber content caused smaller average cell size and higher cell density. Specific notch impact strength of foamed composites at both 20 and 30 wt% willow-fiber content showed increasing trend compared to that of their unfoamed counterparts.
In order to select effective samples in the large number of data of PV power generation years and improve the accuracy of PV power generation forecasting model, this paper studies the application of ...clustering analysis in this field and establishes forecasting model based on neural network. Based on three different types of weather on sunny, cloudy and rainy days, this research screens samples of historical data by the clustering analysis method. After screening, it establishes BP neural network prediction models using screened data as training data. Then, compare the six types of photovoltaic power generation prediction models before and after the data screening. Results show that the prediction model combining with clustering analysis and BP neural networks is an effective method to improve the precision of photovoltaic power generation.
Display omitted
In the current study, sustained release salicylic acid (SA) and ketoconazole (KCZ) loaded silica nanoparticles (SiO2-NPs) were encapsulated in natural macromolecule-alginate (ALG) ...based scaffold through freeze gelation method for an effective treatment of commonly prevailed fatal fungal infections. After statistical optimization by central composite rotatable design (CCRD), the optimized scaffold was subjected to comparative in vitro/in vivo antifungal, skin irritation, wound healing, cytotoxicity, and histopathological evaluations. In physico-chemical characterization performed through X-ray diffraction (p-XRD), Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA), an absolute lack of structural interactions was found between drugs and formulation components. The zeta potential and scanning electron microscopy (SEM) revealed spherical, highly porous negatively charged (–23.1) SiO2-NPs having a size distribution of 40–80 nm with successful encapsulation in negatively charged scaffold (-20.2 mV). The entrapment efficiency and drugs release exhibited visible quadratic influence of formulation variables on scaffold. The optimized ALG-scaffold demonstrated comparatively an enhanced in vitro, in vivo antifungal activity, least cytotoxicity and rapid wound healing efficacy in histopathological evaluation by sustained drugs release up to 14-days without any skin irritation effect. The study suggested the potential of alginate scaffold for not only the endurance of drugs loaded SiO2-NPs but also for the simultaneous co-delivery of medicaments fulfilling the need of consistent prolonged availability of drugs for better fungal therapeutics.
Opioids evoke analgesia through activation of opioid receptors (predominantly the μ opioid receptor) in the central nervous system. Opioid receptors are abundant in multiple regions of the central ...nervous system and the peripheral nervous system including enteric neurons. Opioid-related adverse effects such as constipation, nausea, and vomiting pose challenges for compliance and continuation of the therapy for chronic pain management. In the post-operative setting opioid-induced depression of respiration can be fatal. These critical limitations warrant a better understanding of their underpinning cellular and molecular mechanisms to inform the design of novel opioid analgesic molecules that are devoid of these unwanted side-effects. Research efforts on opioid receptor signalling in the past decade suggest that differential signalling pathways and downstream molecules preferentially mediate distinct pharmacological effects. Additionally, interaction among opioid receptors and, between opioid receptor and non-opioid receptors to form signalling complexes shows that opioid-induced receptor signalling is potentially more complicated than previously thought. This complexity provides an opportunity to identify and probe relationships between selective signalling pathway specificity and in vivo production of opioid-related adverse effects. In this review, we focus on current knowledge of the mechanisms thought to transduce opioid-induced gastrointestinal adverse effects (constipation, nausea, vomiting) and respiratory depression.
•Review of currently understood mechanisms of opioid-related gastrointestinal and respiratory side-effects.•The cellular mechanisms underpinning these opioid related side-effects are poorly understood.•New insight on these mechanisms is opening new frontiers for discovery of novel opioids with improved side effects profile.
antibiotic resistant infections in high-risk patients are a great challenge for researchers and clinicians worldwide. In an effort to achieve potent bactericidal outcomes, a novel chitosan-mastoparan ...nanoconstruct (Mast-Cs NC) was designed and assessed for its therapeutic potential through in silico, in vitro and in vivo experimentation against clinical multidrug-resistant (MDR)
.
Optimized 3D structures of mastoparan and chitosan were coupled computationally through an ionic cross-linker to generate a circular ring of chitosan encasing mastoparan. The complex was assessed for interactions and stability through molecular dynamic simulation (MDS). Binding pocket analysis was used to assess the protease-peptide interface. Mast-Cs NC were prepared by the ionic gelation method. Mast-Cs NC were evaluated in vitro and in vivo for their therapeutic efficacy against drug-resistant clinical
.
MDS for 100 ns showed stable bonds between chitosan and mastoparan; the first at chitosan oxygen atom-46 and mastoparan isoleucine carbon atom with a distance of 2.77 Å, and the second between oxygen atom-23 and mastoparan lysine nitrogen atom with a distance of 2.80 Å, and binding energies of -3.6 and -7.4 kcal/mol, respectively. Mast-Cs complexes approximately 156 nm in size, with +54.9 mV zeta potential and 22.63% loading capacity, offered >90% encapsulation efficiency and were found to be geometrically incompatible with binding pockets of various proteases. The MIC
of Mast-Cs NC was significantly lower than that of chitosan (4 vs 512 μg/mL, respectively,
<0.05), with noticeable bacterial damage upon morphological analysis. In a BALB/c mouse sepsis model, a significant reduction in bacterial colony count in the Mast-Cs treated group was observed compared with chitosan and mastoparan alone (
<0.005). Mast-Cs maintained good biocompatibility and cytocompatibility.
Novel mastoparan-loaded chitosan nanoconstructs signify a successful strategy for achieving a synergistic bactericidal effect and higher therapeutic efficacy against MDR clinical
isolates. The Mast-Cs nano-drug delivery system could work as an alternative promising treatment option against MDR
.
PDF
