119 research outputs found

    Pathological studies on Pteris cretica (L.) fern-Bovine Papilloma Virus infection in Syrian Golden Hamsters (Mesocricetus auratus)

    Get PDF
    Pteris cretica (L.) commonly known as Cretan brake is widely distributed in nature and considered as potential environmental carcinogen. However, only limited literature is available on this fern commonly taken by cattle while grazing. It is known that in cattle Bovine papilloma virus (BPV) induced benign tumours are converted into malignant with interaction of ptaquiloside (Pta) present in ferns. In the present investigation, we evaluated the pathological effects of P. cretica (PC)-BPV infection in laboratory model hamster. Though toxic principle Pta was detected in fern samples but quercetin could not be found. Tumours were successfully induced in hamsters by cutaneous wart suspension and histopathologically diagnosed as fibroma and lipofibroma. Histopathologically, hamsters showed mild to moderate vascular changes in vital organs, multiple cysts, degenerative changes, bile duct hyperplasia and necrosis in liver, haemorrhages and haemosiderosis in spleen, hypersecretory activity and prominent Peyerā€™s patches in ileum, degenerative changes and presence of eosinophilic casts in renal tubules. Ultrastructural study revealed apoptosis in hepatocytes, abundance of variable shaped mitochondria in renal tubular lining epithelial cells and enterocytes showed abundance of mitochondria and cytoplasmolysis in the fern fed groups. Almost all the hamsters from BPV, fern and virus infection (PC+BPV) groups developed similar type of tumorous growths. The visible growths in the hamsters of these groups were either single or double large sized except multiple tumorous growths in one hamster from PC+BPV group. However, multiple palpable subcutaneous nodules were developed at the site of scarification in all the hamsters of BPV and PC+BPV groups. Our findings suggest that the Pta containing P. cretica feeding induced hepatotoxic and nephrotoxic lesions in hamsters, but effects of P. cretica-BPV infection were found negligible

    Pathological studies on Pteris cretica (L.) fern-Bovine Papilloma Virus infection in Syrian Golden Hamsters (Mesocricetus auratus)

    Get PDF
    597-608Pteris cretica (L.) commonly known as Cretan brake is widely distributed in nature and considered as potential environmental carcinogen. However, only limited literature is available on this fern commonly taken by cattle while grazing. It is known that in cattle Bovine papilloma virus (BPV) induced benign tumours are converted into malignant with interaction of ptaquiloside (Pta) present in ferns. In the present investigation, we evaluated the pathological effects of P. cretica (PC)-BPV infection in laboratory model hamster. Though toxic principle Pta was detected in fern samples but quercetin could not be found. Tumours were successfully induced in hamsters by cutaneous wart suspension and histopathologically diagnosed as fibroma and lipofibroma. Histopathologically, hamsters showed mild to moderate vascular changes in vital organs, multiple cysts, degenerative changes, bile duct hyperplasia and necrosis in liver, haemorrhages and haemosiderosis in spleen, hypersecretory activity and prominent Peyer’s patches in ileum, degenerative changes and presence of eosinophilic casts in renal tubules. Ultrastructural study revealed apoptosis in hepatocytes, abundance of variable shaped mitochondria in renal tubular lining epithelial cells and enterocytes showed abundance of mitochondria and cytoplasmolysis in the fern fed groups. Almost all the hamsters from BPV, fern and virus infection (PC+BPV) groups developed similar type of tumorous growths. The visible growths in the hamsters of these groups were either single or double large sized except multiple tumorous growths in one hamster from PC+BPV group. However, multiple palpable subcutaneous nodules were developed at the site of scarification in all the hamsters of BPV and PC+BPV groups. Our findings suggest that the Pta containing P. cretica feeding induced hepatotoxic and nephrotoxic lesions in hamsters, but effects of P. cretica-BPV infection were found negligible

    Regulatory fine-tuning of mcr-1 increases bacterial fitness and stabilises antibiotic resistance in agricultural settings

    Get PDF
    Antibiotic resistance tends to carry fitness costs, making it difficult to understand how resistance can be maintained in the absence of continual antibiotic exposure. Here we investigate this problem in the context of mcr-1, a globally disseminated gene that confers resistance to colistin, an agricultural antibiotic that is used as a last resort for the treatment of multi-drug resistant infections. Here we show that regulatory evolution has fine-tuned the expression of mcr-1, allowing E. coli to reduce the fitness cost of mcr-1 while simultaneously increasing colistin resistance. Conjugative plasmids have transferred low-cost/high-resistance mcr-1 alleles across an incredible diversity of E. coli strains, further stabilising mcr-1 at the species level. Regulatory mutations were associated with increased mcr-1 stability in pig farms following a ban on the use of colistin as a growth promoter that decreased colistin consumption by 90%. Our study shows how regulatory evolution and plasmid transfer can combine to stabilise resistance and limit the impact of reducing antibiotic consumption

    MaOMFO: Many-objective moth flame optimizer using reference-point based non-dominated sorting mechanism for global optimization problems

    Get PDF
    Many-objective optimization (MaO) deals with a large number of conflicting objectives in optimization problems to acquire a reliable set of appropriate non-dominated solutions near the true Pareto front, and for the same, a unique mechanism is essential. Numerous papers have reported multi-objective evolutionary algorithms to explain the absence of convergence and diversity variety in many-objective optimization problems. One of the most encouraging methodologies utilizes many reference points to segregate the solutions and guide the search procedure. The above-said methodology is integrated into the basic version of the Moth Flame Optimization (MFO) algorithm for the first time in this paper. The proposed Many-Objective Moth Flame Optimization (MaOMFO) utilizes a set of reference points progressively decided by the hunt procedure of the moth flame. It permits the calculation to combine with the Pareto front yet synchronize the decent variety of the Pareto front. MaOMFO is employed to solve a wide range of unconstrained and constrained benchmark functions and compared with other competitive algorithms, such as non-dominated sorting genetic algorithm, multi-objective evolutionary algorithm based on dominance and decomposition, and novel multi-objective particle swarm optimization using different performance metrics. The results demonstrate the superiority of the algorithm as a new many-objective algorithm for complex many-objective optimization problems

    Role of diffusion weighted MR imaging in differentiating benign from malignant prostate lesions

    Get PDF
    Background: The purpose of the study was to determine the diagnostic accuracy of diffusion weighted MR imaging and to propose a cut off ADC value in differentiating benign from malignant prostatic lesions considering histopathology as gold standard.Methods: It is a descriptive type of observational study done on 40 patients with clinical suspicion of prostate carcinoma and elevated PSA level more than 4ng/ml. The patients underwent Multiparametric prostate MRI and ADC values were calculated using ADC maps.Results: Of the 40 cases included in the study histopathology revealed a diagnosis of abscess (1), chronic prostatitis (2), BPH with chronic prostatitis (4), BPH (12), and malignancy (21). The mean and standard deviation (SD) of ADC values for the abscess (0.59), CP (0.83+0.16), BPH with CP (0.94+0.22), BPH (1.14+0.14) and malignancy (0.72+0.15) (x10-3mm2/s) were found in our study. The mean ADC value of malignant lesion was lower (0.727+0.149) as compare to benign lesion (1.034+0.216) and this difference was found to be statistically significant with p<0.001. By using ROC curve, ADC cut off value was calculated as 0.92 x 10-3mm2/s and sensitivity, specificity at this cut off value of ADC were 95.24% and 73.68% respectively. The PPV, NPV, diagnostic accuracy of at this cut off value of ADC were 80%, 93.33%, 85% respectively.Conclusions: Our study shows that DWI with ADC calculation helps in differentiation of Benign from Malignant prostatic lesions with high accuracy and this quantitative analysis should be incorporated in routine MRI evaluation of prostatic lesion

    An enhanced gradient-based optimizer for parameter estimation of various solar photovoltaic models

    Get PDF
    The performance of a PhotoVoltaic (PV) system could be inferred from the features of its currentā€“voltage relationships, but the PV model parameters are uncertain. Because of its multimodal, multivariable, and nonlinear properties, the PV model requires that its parameters be extracted with high accuracy and efficiency. Therefore, this paper proposes an enhanced version of the Gradient-Based Optimizer (GBO) to estimate the uncertain parameters of various PV models. The Criss-Cross (CC) algorithm and Nelderā€“Mead simplex (NMs) strategy are hybridized with the GBO to improve its performance. The CC algorithm maximizes the effectiveness of the population and avoids local optima trapping. The NMs strategy enhances the individual search capabilities during the local search and produces optimum convergence speed; therefore, the proposed algorithm is called a Criss-Cross-based Nelderā€“Mead simplex Gradient-Based Optimizer (CCNMGBO). The primary objective of this study is to propose a simple and reliable optimization algorithm called CCNMGBO for the parameter estimation of PV models with five, seven, and nine unknown parameters. Firstly, the performance of CCNMGBO is validated on 10 benchmark numerical optimization problems, and secondly, applied to the parameter estimation of various PV models. The performance of the CCNMGBO is compared to several other state-of-the-art optimization algorithms. The results proved that the proposed algorithm is superior in handling the numerical optimization problem and obtaining the uncertain parameters of various PV models and performs better during different operating conditions. The convergence speed of the proposed CCNMGBO is also better than selected optimization algorithms with highly reliable output solutions. The average objective function value for case 1 is 9.83Eāˆ’04, case 2 is 2.43Eāˆ’04, and the average integral absolute error and relative error values are 1.05Eāˆ’02 and 3.51Eāˆ’03, respectively, for all case studies. With Friedmanā€™s rank test values of 2.21 for numerical optimization and 1.66 for parameter estimation optimization, the CCNMGBO stood first among all selected algorithms

    An efficient and reliable scheduling algorithm for unit commitment scheme in microgrid systems using enhanced mixed integer particle swarm optimizer considering uncertainties

    Get PDF
    The use of an electrical energy storage system (EESS) in a microgrid (MG) is widely recognized as a feasible method for mitigating the unpredictability and stochastic nature of sustainable distributed generators and other intermittent energy sources. The battery energy storage (BES) system is the most effective of the several power storage methods available today. The unit commitment (UC) determines the number of dedicated dispatchable distributed generators, respective power, the amount of energy transferred to and absorbed from the microgrid, as well as the power and influence of EESSs, among other factors. The BES deterioration is considered in the UC conceptualization, and an enhanced mixed particle swarm optimizer (EMPSO) is suggested to solve UC in MGs with EESS. Compared to the traditional PSO, the acceleration constants in EMPSO are exponentially adapted, and the inertial weight in EMPSO decreases linearly during each iteration. The proposed EMPSO is a mixed integer optimization algorithm that can handle continuous, binary, and integer variables. A part of the decision variables in EMPSO is transformed into a binary variable by introducing the quadratic transfer function (TF). This paper also considers the uncertainties in renewable power generation, load demand, and electricity market prices. In addition, a case study with a multiobjective optimization function with MG operating cost and BES deterioration defines the additional UC problem discussed in this paper. The transformation of a single-objective model into a multiobjective optimization model is carried out using the weighted sum approach, and the impacts of different weights on the operating cost and lifespan of the BES are also analyzed. The performance of the EMPSO with quadratic TF (EMPSO-Q) is compared with EMPSO with V-shaped TF (EMPSO-V), EMPSO with S-shaped TF (EMPSO-S), and PSO with S-shaped TF (PSO-S). The performance of EMPSO-Q is 15%, 35%, and 45% better than EMPSO-V, EMPSO-S, and PSO-S, respectively. In addition, when uncertainties are considered, the operating cost falls from 8729.87to8729.87 to 8986.98. Considering BES deterioration, the BES lifespan improves from 350 to 590, and the operating cost increases from 8729.87to8729.87 to 8917.7. Therefore, the obtained results prove that the EMPSO-Q algorithm could effectively and efficiently handle the UC problem

    Preparation of amino-substituted indenes and 1,4-dihydronaphthalenes using a one-pot multireaction approach: total synthesis of oxybenzo[c]phenanthridine alkaloids

    Get PDF
    Allylic trichloroacetimidates bearing a 2-vinyl or 2-allylaryl group have been designed as substrates for a one-pot, two-step multi-bond-forming process leading to the general preparation of aminoindenes and amino-substituted 1,4-dihydronaphthalenes. The synthetic utility of the privileged structures formed from this one-pot process was demonstrated with the total synthesis of four oxybenzo[c]phenanthridine alkaloids, oxychelerythrine, oxysanguinarine, oxynitidine, and oxyavicine. An intramolecular biaryl Heck coupling reaction, catalyzed using the Hermannā€“Beller palladacycle was used to effect the key step during the synthesis of the natural products

    Monitoring the reversible B to A-like transition of DNA in eukaryotic cells using Fourier transform infrared spectroscopy

    Get PDF
    The ability to detect DNA conformation in eukaryotic cells is of paramount importance in understanding how some cells retain functionality in response to environmental stress. It is anticipated that the B to A transition might play a role in resistance to DNA damage such as heat, desiccation and toxic damage. To this end, conformational detail about the molecular structure of DNA has been derived primarily from in vitro experiments on extracted or synthetic DNA. Here, we report that a B- to A-like DNA conformational change can occur in the nuclei of intact cells in response to dehydration. This transition is reversible upon rehydration in air-dried cells. By systematically monitoring the dehydration and rehydration of single and double-stranded DNA, RNA, extracted nuclei and three types of eukaryotic cells including chicken erythrocytes, mammalian lymphocytes and cancerous rodent fibroblasts using Fourier transform infrared (FTIR) spectroscopy, we unequivocally assign the important DNA conformation marker bands within these cells. We also demonstrate that by applying FTIR spectroscopy to hydrated samples, the DNA bands become sharper and more intense. This is anticipated to provide a methodology enabling differentiation of cancerous from non-cancerous cells based on the increased DNA content inherent to dysplastic and neoplastic tissue

    The evolution of colistin resistance increases bacterial resistance to host antimicrobial peptides and virulence

    Get PDF
    Antimicrobial peptides (AMPs) offer a promising solution to the antibiotic resistance crisis. However, an unresolved serious concern is that the evolution of resistance to therapeutic AMPs may generate cross-resistance to host AMPs, compromising a cornerstone of the innate immune response. We systematically tested this hypothesis using globally disseminated mobile colistin resistance (MCR) that has been selected by the use of colistin in agriculture and medicine. Here, we show that MCR provides a selective advantage to Escherichia coli in the presence of key AMPs from humans and agricultural animals by increasing AMP resistance. Moreover, MCR promotes bacterial growth in human serum and increases virulence in a Galleria mellonella infection model. Our study shows how the anthropogenic use of AMPs can drive the accidental evolution of resistance to the innate immune system of humans and animals. These findings have major implications for the design and use of therapeutic AMPs and suggest that MCR may be difficult to eradicate, even if colistin use is withdrawn
    • ā€¦
    corecore