High-purity alkaline lignin extraction from Saccharum ravannae and optimization of lignin recovery through response surface methodology

Saccharum ravannae, known as "Ekra" in the Northeast region of India, is an elephant grass species that abundantly grows in the natural habitat of Assam. This study aims to utilize this wild grass species and extract alkaline lignin of high purity through KOH-mediated alkaline hydrothermal pretreatment using the Oil bath process. Lignin recovery was optimized using RSM (response surface methodology) combined with a central composite model. Three process parameters, namely KOH concentration (1-3 %), reaction time (50-200 min), and solid loading (5-15 %), varied to optimize the combined effect of these parameters. RSM predicted a maximum lignin recovery of 15.38 g/100 g of raw biomass at optimum conditions (2.4 % KOH, 6.41 % solid loading, 176.57 min). Three experimental runs were performed at optimum conditions, and 15.81 ± 0.32 g/100 g lignin recovery was obtained, thus verifying the predicted result. Maximum 93.7 % purity of extracted lignin was achieved in a different operating condition (3 % KOH, 10 % solid loading, 125 min). The commercial and extracted alkaline lignin with maximum purity was characterized by Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The extracted lignin shows higher phenolic content and more functional groups than commercial lignin and can be used for future applications.

Combinatorial optimality of functional groups, process parameters, and Pd(II) adsorption-desorption characteristics for commercial anion exchange resins-synthetic electroless plating systems

Considering combinatorial optimality of functional group analysis, speciation, solution chemistry complexity, Pd(II) adsorption-desorption characteristics, this article addresses the competence and efficacy of anion exchange resins namely Amberlite IRA958, Dowex Marathon MSA, Lewatit TP214, and Amberlyst A21 commercial resins. Based on preliminary batch adsorption experiments conducted in the range of 2-10 pH, 0.2-2 g L^-1 adsorbent dosage, and 5-1080-min contact time, the optimal adsorption process parameters refer to 4 pH, 1.6, and 1.4 g L^-1 adsorbent dosage, and 840- and 720-min contact time for Amberlite IRA958 and Dowex Marathon MSA resins, respectively. Among alternate models, the best-fit models refer to the Freundlich isotherm and pseudo-second-order kinetic models to represent Pd(II) adsorption data obtained for both Dowex Marathon MSA and Amberlite IRA958 resins. Based on the Langmuir isotherm, the maximum monolayer adsorption capacity was evaluated to be 185.16 and 166.67 mg g^-1 for Dowex Marathon MSA and Amberlite IRA958 resins, respectively. For model electroless plating solutions as adsorbate system possessing desired solution chemistry complexity and resin cost, nitrogen- and oxygen-containing Amberlyst A21 resin is concluded to be optimal resin. This is not in agreement with the generalized rule of thumb that considers sulfur-nitrogen functional group containing commercial resins to be effective than resins with nitrogen-oxygen functional groups. Due to functional group interactions with the noble metal, no other by-products or exchanged chemicals have been produced in due course of Pd(II) adsorption process, which can be also regarded as an added advantage of the process. Graphical abstract.

Role of EDTA on the Pd(II) adsorption characteristics of chitosan cross-linked 3-amino-1,2,4-triazole-5-thiol derivative from synthetic electroless plating solutions

This article targets the efficacy of chitosan cross-linked 3-Amino-1,2,4-triazole-5-thiol derivative for the recovery of Pd from synthetic electroless plating solutions (ELP) whose solution chemistry complexity is brought forward with ethylenediaminetetraacetic acid (EDTA), ammonium hydroxide (NH₄OH), and surfactant (cetyl trimethyl ammonium bromide (CTAB)). Batch adsorption characteristics of the resin were investigated in the parametric range of 2-10 pH, 0.2-2 g L^-1 adsorbent dosage, 5-1080 min contact time, 50-300 mg L^-1 Pd concentration and 25-60 °C operating temperature. Equilibrium, kinetic and thermodynamic model fitness studies were also considered. Pd(II) adsorption characteristics were determined using NaOH, KOH and HCl solutions with variant eluent concentrations (0.1-2 N). The solution chemistry complexity has been evaluated to have profound impact in detrimentally influencing Pd sorption characteristics of the CH-AZ resin. The resin has been characterized to be highly effective for Pd removal from synthetic ELP solutions but with moderate efficacy towards the noble metal recovery and reuse.

Efficacy of reducing agent and surfactant contacting pattern on the performance characteristics of nickel electroless plating baths coupled with and without ultrasound

This article addresses furthering the role of sonication for the optimal fabrication of nickel ceramic composite membranes using electroless plating. Deliberating upon process modifications for surfactant induced electroless plating (SIEP) and combined surfactant and sonication induced electroless plating (SSOEP), this article highlights a novel method of contacting of the reducing agent and surfactant to the conventional electroless nickel plating baths. Rigorous experimental investigations indicated that the combination of ultrasound (in degas mode), surfactant and reducing agent pattern had a profound influence in altering the combinatorial plating characteristics. For comparison purpose, purely surfactant induced nickel ELP baths have also been investigated. These novel insights consolidate newer research horizons for the role of ultrasound to achieve dense metal ceramic composite membranes in a shorter span of total plating time. Surface and physical characterizations were carried out using BET, FTIR, XRD, FESEM and nitrogen permeation experiments. It has been analyzed that the SSOEP baths provided maximum ratio of percent pore densification per unit metal film thickness (PPDδ) and hold the key for further fine tuning of the associated degrees of freedom. On the other hand SIEP baths provided lower (PPDδ) ratio but higher PPD. For SSOEP baths with dropwise reducing agent and bulk surfactant, the PPD and metal film thickness values were 73.4% and 8.4 μm which varied to 66.9% and 13.3 μm for dropwise reducing agent and drop surfactant case.

Oxidative desulfurization: kinetic modelling

Increasing environmental legislations coupled with enhanced production of petroleum products demand, the deployment of novel technologies to remove organic sulfur efficiently. This work represents the kinetic modeling of ODS using H(2)O(2) over tungsten-containing layered double hydroxide (LDH) using the experimental data provided by Hulea et al. [V. Hulea, A.L. Maciuca, F. Fajula, E. Dumitriu, Catalytic oxidation of thiophenes and thioethers with hydrogen peroxide in the presence of W-containing layered double hydroxides, Appl. Catal. A: Gen. 313 (2) (2006) 200-207]. The kinetic modeling approach in this work initially targets the scope of the generation of a superstructure of micro-kinetic reaction schemes and models assuming Langmuir-Hinshelwood (LH) and Eley-Rideal (ER) mechanisms. Subsequently, the screening and selection of above models is initially based on profile-based elimination of incompetent schemes followed by non-linear regression search performed using the Levenberg-Marquardt algorithm (LMA) for the chosen models. The above analysis inferred that Eley-Rideal mechanism describes the kinetic behavior of ODS process using tungsten-containing LDH, with adsorption of reactant and intermediate product only taking place on the catalyst surface. Finally, an economic index is presented that scopes the economic aspects of the novel catalytic technology with the parameters obtained during regression analysis to conclude that the cost factor for the catalyst is 0.0062-0.04759 US $ per barrel.

Management of pediatric radiation dose using GE's Revolution digital radiography systems

Digital flat-panel x-ray detectors offer excellent image quality and dose efficiency in addition to clinical productivity, connectivity, and adaptability to advanced clinical applications. GE's Revolution systems provide two modes of exposure control for setting the dose operating point, fixed time and automatic exposure control, the latter of which maintains high image signal-to-noise ratio for the given technique settings. In addition to enhancing detail contrast and compressing the dynamic range, postprocessing automatically determines the best window level and width for display, taking into account the dose at which the image was acquired. Several studies have examined the reduction in patient dose achievable with Revolution systems as compared to competing technologies, and results indicate significant dose savings with equivalent or superior image quality. For pediatric exams, pediatric default techniques provide for a lower patient dose as compared to adult techniques. Therefore, GE's Revolution systems can achieve a high image quality-to-dose ratio for pediatric imaging using the combined advantages of dose-efficient detection, advanced postprocessing, and independently adjustable pediatric techniques.

Transcript map of the 8p23 putative tumor suppressor region

Cancers of the head and neck, prostate, liver, and bladder exhibit minimal regions of deletion within chromosomal band 8p23 that either overlap or map very close to one another. We previously refined a minimal region of deletion in squamous cell carcinomas to a 112-kb interval within 8p23. There seems to be only a single gene within this region that is expressed in normal upper aerodigestive tract epithelium. This candidate for the squamous cancer suppressor, CUB and sushi multiple domains-1 (CSMD1), extends into the minimal regions of deletions defined for the other types of cancer with 8p23 deletions. RT-PCR and EST data indicate that CSMD1 is also expressed in those organs,making this gene a candidate for a suppressor of multiple types of cancer. Both the sequence of the gene and the organization of the protein are highly conserved in the mouse.

Pulmonary CT image classification with evolutionary programming

RATIONALE AND OBJECTIVES

It is often difficult to classify information in medical images from derived features. The purpose of this research was to investigate the use of evolutionary programming as a tool for selecting important features and generating algorithms to classify computed tomographic (CT) images of the lung.

MATERIALS AND METHODS

Training and test sets consisting of 11 features derived from multiple lung CT images were generated, along with an indicator of the target area from which features originated. The images included five parameters based on histogram analysis, 11 parameters based on run length and co-occurrence matrix measures, and the fractal dimension. Two classification experiments were performed. In the first, the classification task was to distinguish between the subtle but known differences between anterior and posterior portions of transverse lung CT sections. The second classification task was to distinguish normal lung CT images from emphysematous images. The performance of the evolutionary programming approach was compared with that of three statistical classifiers that used the same training and test sets.

RESULTS

Evolutionary programming produced solutions that compared favorably with those of the statistical classifiers. In separating the anterior from the posterior lung sections, the evolutionary programming results were better than two of the three statistical approaches. The evolutionary programming approach correctly identified all the normal and abnormal lung images and accomplished this by using less features than the best statistical method.

CONCLUSION

The results of this study demonstrate the utility of evolutionary programming as a tool for developing classification algorithms.

Computer recognition of regional lung disease patterns

We have developed an objective, reproducible, and automated means for the regional evaluation of the pulmonary parenchyma from computed tomography (CT) scans. This method, known as the Adaptive Multiple Feature Method (AMFM) assesses as many as 22 independent texture features in order to classify a tissue pattern. In this study, the six tissue patterns characterized were: honeycombing, ground glass, bronchovascular, nodular, emphysemalike, and normal. The lung slices were evaluated regionally using 31 x 31 pixel regions of interest. In each region of interest, an optimal subset of texture features was evaluated to determine which of the six patterns the region could be characterized as. The computer output was validated against experienced observers in three settings. In the first two readings, when the observers were blinded to the primary diagnosis of the subject, the average computer versus observer agreement was 44.4 +/- 8.7% and 47.3 +/- 9.0%, respectively. The average interobserver agreement for the same two readings were 48.8 +/- 9.1% and 52.2 +/- 10.0%, respectively. In the third reading, when the observers were provided the primary diagnosis, the average computer versus observer agreement was 51.7 +/- 2.9% where as the average interobserver agreement was 53.9 +/- 6.2%. The kappa statistic of agreement between the regions, for which the majority of the observers agreed on a pattern type, versus the computer was found to be 0.62. For regional tissue characterization, the AMFM is 100% reproducible and performs as well as experienced human observers who have been told the patient diagnosis.

Interstitial lung disease: A quantitative study using the adaptive multiple feature method

We have previously described an adaptive multiple feature method (AMFM) for the objective assessment of global and regional changes in pulmonary parenchyma to detect emphysema. This computerized method uses a combination of statistical and fractal texture features for characterization of lung tissues based upon high resolution computed tomography (HRCT) scans. This present study was a substantial extension of the AMFM to simultaneously discriminate between multiple pulmonary disease processes. Normal subjects and those with emphysema, idiopathic pulmonary fibrosis (IPF), or sarcoidosis were studied. The AMFM was compared with two currently utilized computer-based methods: mean lung density (MLD) and the histogram analysis (HIST). Globally, when comparing two-subject groups the AMFM overall accuracy was 2 to 18% better than the overall accuracy of MLD and as much as 36% better than the accuracy of the HIST methods. In three-subject group discrimination tasks, the AMFM performed 7 to 27% better than the MLD and 4 to 36% better than the HIST methods. Finally, in discriminating all four subject groups at a time, the AMFM overall accuracy was 81%, which was 21% better than the MLD and 25% better than the HIST method. In most three-subject group comparisons and in the four-subject group comparison, the AMFM was significantly (p < 0.01) better than the MLD and HIST methods. Next, the AMFM was applied to local discrimination between normal and each disease group individually. The normal versus emphysema, normal versus IPF, and normal versus sarcoidosis samples were discriminated with an accuracy of 95, 86, and 77%, respectively. The AMFM is an objective quantitative method that can be adapted for successful discrimination of multiple parenchymal lung diseases.

Quantification of pulmonary emphysema from lung computed tomography images

A texture-based adaptive multiple feature method (AMFM) for evaluating pulmonary parenchyma from computed tomography (CT) images is described. This method incorporates multiple statistical and fractal texture features. The AMFM was compared to two previously published methods, namely, mean lung density (MLD) and the lowest fifth percentile of the histogram (HIST). First, the ability of these methods to detect subtle differences in ventral-dorsal lung density gradient in the prone normal lung was studied. Second, their abilities to differentiate between normal and emphysematous whole lung slices were compared. Finally, regional analyses comparing normal and emphysematous regions were performed by dividing the lungs. In the CT slices into six equal regions, ventral to dorsal, and analyzing each region separately. The results demonstrated that the AMFM could separate the ventral from the dorsal one-third of the normal prone lung with 89.8% accuracy, compared to an accuracy of 74.6% with the MLD and 64.4% with the HIST methods. The normal and emphysematous slices were separated on a global basis with 100.0% accuracy using the AMFM as compared to an accuracy of 94.7% and 97.4% using the MLD and HIST methods, respectively. The regional normal and emphysematous tissues were discriminated with an average accuracy of 97.9%, 89.9%, and 99.1% with the AMFM, MLD, and HIST methods, respectively. The three methods and the pulmonary function tests in the normal and emphysema groups were poorly correlated. Quantitative texture analysis using adaptive multiple features holds promise for the objective noninvasive evaluation of the pulmonary parenchyma.

Genetic dissection of thyroid hormone receptor beta: identification of mutations that separate hormone binding and transcriptional activation

The thyroid hormone receptors (TR) are members of the nuclear receptor family of ligand-mediated transcription factors. The large region of TR that lies C-terminal to its DNA-binding domain subserves functions of ligand binding, dimerization, and transactivation. Little is known regarding the structural or functional determinants of these processes. We have utilized genetic screening in the yeast Saccharomyces cerevisiae to identify residues involved in these functions. Random mutations of the rat TR beta 1 isoform between amino acid residues 179 and 456 were screened, and mutants with reduced hormone-dependent activation of reporter gene activity were isolated. In this paper we describe the characterization of a class of mutants that exhibit a dissociation between hormone binding and transcriptional activation. These mutants retained hormone binding (> 15% of the wild-type level) yet failed to transactivate a reporter gene. A number of these mutations occurred within the D region, which links the DNA-binding and ligand-binding domains of the receptor. One subset of these mutations abrogated DNA binding, supporting a role of the D region in this process. The remainder retain DNA binding and thus highlight residues critical for receptor activation. In addition, an unexpected group of "superactivator" mutations that led to enhanced hormone-dependent activation in S. cerevisiae were found. These mutations localized to the carboxy-terminal portion of the receptor in a region which contains elements conserved across the superfamily of nuclear receptors. The hormone-dependent phenotype of these superactivator mutations suggests an important role of this segment in ligand-mediated transcriptional activation.

Isolation of ribonucleic acid from the unactivated rat liver glucocorticoid receptor

We have reported that the 7-8S form of the rat liver glucocorticoid receptor is associated with RNA. Whether the unactivated 9-10S form of the glucorticoid receptor is also associated with RNA is less clear. Here we provide evidence that the unactivated 9-10S receptor is indeed associated with RNA. Unactivated 9-10S receptor was partially purified by diethylaminoethyl (DEAE)-cellulose chromatography in the presence of molybdate, an activation inhibitor. This preparation was then bound to BuGR-2, a mouse monoclonal antibody of the immunoglobulin G (IgG)-2 class to the rat liver glucocorticoid receptor, or to nonspecific mouse IgG-2. The antibody-antigen complex was then bound to protein A sepharose and washed to remove extraneous RNA. When the receptor was dissociated from the antibody and the RNA extracted and end-labeled, a distinct band of approximately 170 nucleotide (nt) was found that was specific for the BuGR-2 purified receptor. This band could also be found in DEAE-cellulose receptor that had been isolated from sucrose gradients. The DEAE-cellulose receptor was then cross-linked with formaldehyde before mixing with BuGR-2 in order to permit more vigorous washing of the antigen-antibody complex. In addition to the 170 nt RNA band, another distinct band at approximately 400 nt was seen that was specific to the BuGR-2 derived isolate. These results provide evidence that the 9-10S form of the glucocorticoid receptor from rat liver is associated with RNA.