36 research outputs found
Phase behaviour and miscibility studies of collagen/silk fibroin macromolecular system in dilute solutions and solid state
Miscibility is an important issue in biopolymer blends for analysis of the behavior of polymer pairs through the detection of phase separation and improvement of the mechanical and physical properties of the blend. This study presents the formulation of a stable and one-phase mixture of collagen and regenerated silk fibroin (RSF), with the highest miscibility ratio between these two macromolecules, through inducing electrostatic interactions, using salt ions. For this aim, a ternary phase diagram was experimentally built for the mixtures, based on observations of phase behavior of blend solutions with various ratios. The miscibility behavior of the blend solutions in the miscible zones of the phase diagram was confirmed quantitatively by viscosimetric measurements. Assessing the effects of biopolymer mixing ratio and salt ions, before and after dialysis of blend solutions, revealed the importance of ion-specific interactions in the formation of coacervate-based materials containing collagen and RSF blends that can be used in pharmaceutical, drug delivery, and biomedical applications. Moreover, the conformational change of silk fibroin from random coil to beta sheet, in solution and in the final solid films, was detected by circular dichroism (CD) and Fourier transform infrared spectroscopy (FTIR), respectively. Scanning electron microscopy (SEM) exhibited alterations of surface morphology for the biocomposite films with different ratios. Surface contact angle measurement illustrated different hydrophobic properties for the blended film surfaces. Differential scanning calorimetry (DSC) showed that the formation of the beta sheet structure of silk fibroin enhances the thermal stability of the final blend films. Therefore, the novel method presented in this study resulted in the formation of biocomposite films whose physico-chemical properties can be tuned by silk fibroin conformational changes by applying different component mixing ratios228sem informaçãosem informaçã
Lineage Abundance Estimation for SARS-CoV-2 in Wastewater Using Transcriptome Quantification Techniques
Effectively monitoring the spread of SARS-CoV-2 mutants is essential to efforts to counter the ongoing pandemic. Predicting lineage abundance from wastewater, however, is technically challenging. We show that by sequencing SARS-CoV-2 RNA in wastewater and applying algorithms initially used for transcriptome quantification, we can estimate lineage abundance in wastewater samples. We find high variability in signal among individual samples, but the overall trends match those observed from sequencing clinical samples. Thus, while clinical sequencing remains a more sensitive technique for population surveillance, wastewater sequencing can be used to monitor trends in mutant prevalence in situations where clinical sequencing is unavailable
Time arc hybrid petri net based scheduling of mixed batch/continuous plants
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Petri-net based formulation and algorithm for short-term scheduling of batch plants
Effective scheduling of operations in batch plants has a great potential for high economic returns, in which the formulation and optimal solution algorithm are the main issues of study. Petri-nets have proven to be a promising technique to solve many difficult problems associated with the modeling, formal analysis, design and coordination control of discrete event systems. One of the major advantages of using a Petri-net model is that the same model can be used for the analysis of behavioral properties and performance evaluation, as well as for the systematic construction of discrete event simulators and controllers. This paper aims to present a Petri-net based approach for the scheduling of operations in batch plants. Firstly, the short-term scheduling of batch plants is formulated using timed Petri-net. Secondly, the heuristic search algorithm for scheduling of batch plants is given, which is based on generating and checking the markings in the reachability tree of the Petri-net model. Finally, the novel formulation and algorithm are tested using two simulation case studies, and compared against traditional methods
Comparison of clinical efficacy of carbamazepine and haloperidol as adjuncts to lithium in patients with acute manic phase: A double-blind clinical trial
Copyright © Masood Zangeneh, Editor-in-Chief, International Journal of Mental Health & AddictionThere is abundant evidence that the efficacy of the carbamazepine-lithium combination in acute manic episodes is comparable to that of other custom medications (e.g., a haloperidol-lithium combination). The aim of the current investigation was to compare the clinical efficacy and side effects of lithium combined with carbamazepine versus lithium combined with haloperidol and biperiden in patients with bipolar disorder. In the present study, 24 patients in an acute manic phase were randomly assigned to receive either lithium-carbamazepine (Li-CBZ) or lithium-haloperidol (Li-Hal) combinations for 8 weeks. Clinical (including ESRS, MRS, CBZ side effect profile, and HAM-D) and laboratory measurements were regularly performed on all patients. Both therapeutic regimens were effective in alleviating manic symptoms, whether psychotic features were present or not (p<.001). However, there was a faster response to treatment for the Li-CBZ group compared to the Li-Hal group, as revealed by a lower mean MRS score on day 14 in the former group (p=.018). HAM-D scores revealed significantly better outcomes for the Li-CBZ group. A higher mean HAM-D score on day 56, as well as a higher mean alteration in HAM-D scores throughout the study period, were noted in the Li-Hal group (p=.008 and p=.011, respectively). Dropouts in the Li-Hal group were considerable due to noncompliance resulting from neuroleptic-induced side effects (depressive and extrapyramidal). Similarly, several subjects in the Li-CBZ group had to end the study prematurely as a result of developing side effects for which drug discontinuation is indicated. It may be prudent to reevaluate neuroleptic medications in manic patients, specifically for long-term management.Ye