A decay-modeled compressed sensing reconstruction approach for non-Cartesian hyperpolarized 129Xe MRI.

PURPOSE: Hyperpolarized 129Xe MRI benefits from non-Cartesian acquisitions that sample k-space efficiently and rapidly. However, their reconstructions are complex and burdened by decay processes unique to hyperpolarized gas. Currently used gridded reconstructions are prone to artifacts caused by magnetization decay and are ill-suited for undersampling. We present a compressed sensing (CS) reconstruction approach that incorporates magnetization decay in the forward model, thereby producing images with increased sharpness and contrast, even in undersampled data. METHODS: Radio-frequency, T1, and T 2 * $$ {\mathrm{T}}_2^{\ast } $$ decay processes were incorporated into the forward model and solved using iterative methods including CS. The decay-modeled reconstruction was validated in simulations and then tested in 2D/3D-spiral ventilation and 3D-radial gas-exchange MRI. Quantitative metrics including apparent-SNR and sharpness were compared between gridded, CS, and twofold undersampled CS reconstructions. Observations were validated in gas-exchange data collected from 15 healthy and 25 post-hematopoietic-stem-cell-transplant participants. RESULTS: CS reconstructions in simulations yielded images with threefold increases in accuracy. CS increased sharpness and contrast for ventilation in vivo imaging and showed greater accuracy for undersampled acquisitions. CS improved gas-exchange imaging, particularly in the dissolved-phase where apparent-SNR improved, and structure was made discernable. Finally, CS showed repeatability in important global gas-exchange metrics including median dissolved-gas signal ratio and median angle between real/imaginary components. CONCLUSION: A non-Cartesian CS reconstruction approach that incorporates hyperpolarized 129Xe decay processes is presented. This approach enables improved image sharpness, contrast, and overall image quality in addition to up-to threefold undersampling. This contribution benefits all hyperpolarized gas MRI through improved accuracy and decreased scan durations.

Electrochemical C-H/C-C Bond Oxygenation: A Potential Technology for Plastic Depolymerization.

Herein, we provide eco-friendly and safely operated electrocatalytic methods for the selective oxidation directly or with water, air, light, metal catalyst or other mediators serving as the only oxygen supply. Heavy metals, stoichiometric chemical oxidants, or harsh conditions were drawbacks of earlier oxidative cleavage techniques. It has recently come to light that a crucial stage in the deconstruction of plastic waste and the utilization of biomass is the selective activation of inert C(sp3 )-C/H(sp3 ) bonds, which continues to be a significant obstacle in the chemical upcycling of resistant polyolefin waste. An appealing alternative to chemical oxidations using oxygen and catalysts is direct or indirect electrochemical conversion. An essential transition in the chemical and pharmaceutical industries is the electrochemical oxidation of C-H/C-C bonds. In this review, we discuss cutting-edge approaches to chemically recycle commercial plastics and feasible C-C/C-H bonds oxygenation routes for industrial scale-up.

Diversity in Phytochemical Composition and Medicinal Value of Murraya paniculata.

Murraya paniculata is herbal medicinal plant which is traditionally being used for management of cardiovascular, intestinal and respiratory (air way) disorders. This evergreen plant of tropical regions is a member of Rutaceace family. The goal of this review is to analyze and report the biological activities and active phytochemicals reported from Murraya paniculata (M. paniculata) extracts and essential oil. The data was searched using different search engines and using specific key words including M. paniculata, herbal medicine, phytochemicals, extract, essential oil, pharmacological activities. M. paniculata has been found to have wide range of pharmacological activities, including antinociceptive, antianxiety, antioxidant, antidepressant, antibacterial, analgesic and anti-diabetic properties. A diverse range of phytochemicals, including phenols, coumarins, terpenoids, flavonoids, and alkaloids have been isolated from various portions of the plant and tested for a variety of biological activities. This review will provide more information and stimulate additional research to develop more effective and cost-efficient alternative medicine from this plant.

Designing Electron-Deficient Diketone Unit Based Non-Fused Ring Acceptors with Amplified Optoelectronic Features for Highly Efficient Organic Solar Cells: A DFT Study.

Organic solar cells (OSCs) made of electron-acceptor and electron-donor materials have significantly developed in the last decade, demonstrating their enormous potential in cutting-edge optoelectronic applications. Consequently, we designed seven novel non-fused ring electron acceptors (NFREAs) (BTIC-U1 to BTIC-U7) using synthesized electron-deficient diketone units and reported end-capped acceptors, a viable route for augmented optoelectronic properties. The DFT and TDDFT approaches were used to measure the power conversion efficiency (PCE), open circuit voltage (Voc), reorganization energies (λh, λe), fill factor (FF), light harvesting efficiency (LHE) and to evaluate the potential usage of proposed compounds in solar cell applications. The findings confirmed that the photovoltaic, photophysical, and electronic properties of the designed molecules BTIC-U1 to BTIC-U7 are superior to those of reference BTIC-R. The TDM analysis demonstrates a smooth flow of charge from the core to the acceptor groups. Charge transfer analysis of the BTIC-U1:PTB7-Th blend revealed orbital superposition and successful charge transfer from HOMO (PTB7-Th) to LUMO (BTIC-U1). The BTIC-U5 and BTIC-U7 outperformed the reference BTIC-R and other developed molecules in terms of PCE (23.29% and 21.18%), FF (0.901 and 0.894), normalized Voc (48.674 and 44.597), and Voc (1.261 eV and 1.155 eV). The proposed compounds enclose high electron and hole transfer mobilities, making them the ideal candidate for use with PTB7-Th film. As a result, future SM-OSC design should prioritize using these constructed molecules, which exhibit excellent optoelectronic properties, as superior scaffolds.

Synthesis, Crystal Structure, DFT Calculations, Hirshfeld Surface Analysis and In Silico Drug-Target Profiling of (R)-2-(2-(1,3-Dioxoisoindolin-2-yl)propanamido)benzoic Acid Methyl Ester.

The work here reflects synthesis, DFT studies, Hirshfeld charge analysis and crystal data exploration of pharmacologically important (R)-2-(2-(1,3-dioxoisoindolin-2-yl)propanamido)benzoic acid methyl ester (5) to understand its properties for further chemical transformations. The methyl anthranilate (2) was produced by the esterification of anthranilic acid in an acidic medium. The phthaloyl-protected alanine (4) was rendered by the fusion of alanine with phthalic anhydride at 150 °C, followed by coupling with (2) furnished isoindole (5). The characterization of products was performed using IR, UV-Vis, NMR and MS. Single-crystal XRD also verified the structure of (5) in which N-H⋯O bonding stabilizes the molecular configuration of (5), resulting in the formation of S(6) hydrogen-bonded loop. The molecules of isoindole (5) are connected in the form of dimers, and the π⋯π stacking interaction between aromatic rings further stabilizes the crystal packing. DFT studies suggest that HOMO is over the substituted aromatic ring, the LUMO is present mainly over the indole side, and nucleophilic and electrophilic corners point out the reactivity of the product (5). In vitro and in silico analysis of (5) shows its potential as an antibacterial agent targeting DNA gyrase and Dihydroorotase from E. coli and tyrosyl-tRNA synthetase and DNA gyrase from Staphylococcus aureus.

The potential role of dietary plant ingredients against mammary cancer: a comprehensive review.

Breast cancer is known as the most devastating cancer in the global female community and is considered as one of the severe health care burdens in both developed and developing countries. In many cases, breast cancer has shown resistance to chemotherapy, radiotherapy and hormonal therapy. Keeping in view these limitations, there is an urgent need to develop safe, readily available and effective breast anticancer treatments. Therefore, the scientists are keen in the extraction of plant-based phytochemicals (organosulfur compounds, betalains, capsaicinoids, terpenes, terpenoids, polyphenols, and flavonoids) and using them as breast anticancer agents. Results of numerous epidemiological investigations have revealed the promising role of phytochemicals in the prevention and treatment of breast cancer. The diverse classes of plant bioactive metabolites regulate different metabolic and molecular processes, which can delay the proliferation of cancers. These phytochemicals possess chemo-preventive properties as they down-regulate the expression of estrogen receptor-α, inhibit the proliferation of cancer cells, and cause cell cycle arrest by inducing apoptotic conditions in tumor cells. This review article discusses the potent role of various plant-based phytochemicals as potential therapeutic agents in the treatment or prevention of breast cancer along with the proposed mechanisms of action.

Resource Allocation in Spectrum Access System Using Multi-Objective Optimization Methods.

The paradigm of dynamic shared access aims to provide flexible spectrum usage. Recently, Federal Communications Commission (FCC) has proposed a new dynamic spectrum management framework for the sharing of a 3.5 GHz (3550-3700 MHz) federal band, called a citizen broadband radio service (CBRS) band, which is governed by spectrum access system (SAS). It is the responsibility of SAS to manage the set of CBRS-SAS users. The set of users are classified in three tiers: incumbent access (IA) users, primary access license (PAL) users and the general authorized access (GAA) users. In this article, dynamic channel assignment algorithm for PAL and GAA users is designed with the goal of maximizing the transmission rate and minimizing the total cost of GAA users accessing PAL reserved channels. We proposed a new mathematical model based on multi-objective optimization for the selection of PAL operators and idle PAL reserved channels allocation to GAA users considering the diversity of PAL reserved channels' attributes and the diversification of GAA users' business needs. The proposed model is estimated and validated on various performance metrics through extensive simulations and compared with existing algorithms such as Hungarian algorithm, auction algorithm and Gale-Shapley algorithm. The proposed model results indicate that overall transmission rate, net cost and data-rate per unit cost remain the same in comparison to the classical Hungarian method and auction algorithm. However, the improved model solves the resource allocation problem approximately up to four times faster with better load management, which validates the efficiency of our model.

Phytochemical Screening, Anti-Inflammatory, and Antidiabetic Activities of Different Extracts from Caralluma edulis Plant.

The plant Caralluma edulis is traditionally used against diabetes and inflammatory conditions in Pakistan. This study was designed to provide scientific validation of the traditional use of Caralluma edulis. Phytochemicals were extracted from the plant by different solvents (distilled water, methanol, ethanol, and acetone) using the Soxhlet's extraction method. Bioactive compounds were detected by gas chromatography-mass spectrometry (GC-MS). The in vitro anti-inflammatory activities (albumin denaturation, membrane stabilization, and proteinase inhibition) and antioxidant capacity (DPPH scavenging activity, FRAP reducing activity) of different extracts from Caralluma edulis were assessed. The antidiabetic potential of Caralluma edulis plant extracts was determined in acute and subacute diabetic rabbit models. Oxidative stress and enzymatic antioxidant status were also estimated in MDA, CAT, and SOD levels. Results showed that the methanol extract yielded the highest contents of phenolics, flavonoids, alkaloids, and terpenoids. The in vitro anti-inflammatory activity and antioxidant potential of the methanol extract were the highest among the tested solvents. The tested extracts did not show any remarkable antidiabetic activity in the acute diabetic model. However, all tested extracts demonstrated antidiabetic potential in the subacute diabetic model. No adverse effect was observed at the tested dose (200 mg/kg) of Caralluma edulis extracts in experimental animals. It is concluded that methanol is the key solvent for extracting bioactive compounds from Caralluma edulis. The plant can be used against inflammatory disorders and may prove a potential candidate for drug development. Long-term use of Caralluma edulis at the tested dose (200 mg/kg) showed antidiabetic properties in the animal model.

Comparative analysis of fecal microbiota composition diversity in Tibetan piglets suffering from diarrheagenic Escherichia coli (DEC).

This study was ascertained to investigate the adverse effects of pathogenic E. coli on gut microbiota of Tibetan piglets with history of yellow and white dysentery. For this purpose, a total of 18 fecal samples were collected from infected and healthy Tibetan piglets for 16S rRNA gene amplification and sequencing of V3-V4 region. Results showed that Firmicutes, Bacteroidia Fusobacteriota, Proteobacteria and Actinobacteriota were the predominant bacteria in Tibetan piglets at the level of phylum classification. Results on classification at family level showed that Lactobacillus, Bacteroidota, Fusobacteriota and Enterobacteriaceae were the dominant bacteria. Results on classification of bacteria at phylum level compared with normal piglets indicated that Bacteroidota, Actinobacteriota, Euryarchaota and Spirochaetota in fecal microbial community in Tibetan piglets showing yellow dysenteric and diarrhea group were significantly decreased (P ≤ 0.05). Compared with the feces of healthy Tibetan piglets, the abundance of Escherichia-Shigella, Lactobacillus and Enterococcus increased significantly in feces of Tibetan piglets having yellow dysentery and white dysentery. Moreover, results exhibited that the Proteobacteria and Fusobacteriota were significantly increased (P ≤ 0.05) suggesting dominant microbial community. Results revealed that E. coli induced different pathological alterations in intestine including damage to intestinal epithelial cells, infiltration of inflammatory cells, presence of red blood cells in spaces of tissues, hemorrhages and necrosis of intestinal villi in piglets with history of yellow dysentery. This study for the first time reported the composition, characteristics, and differences of the fecal microflora diversity of Tibetan piglets with yellow and white dysentery in Qinghai-Tibet Plateau, which can provide a suitable support for effective control of diarrhoeal disease in these animals.

Long-term exposure to the fluoride blocks the development of chondrocytes in the ducks: The molecular mechanism of fluoride regulating autophagy and apoptosis.

Long-term exposure to excessive fluoride causes chronic damage in the body tissues and could lead to skeletal and dental fluorosis. Cartilage damage caused by excessive fluoride intake has gained wide attention, but how fluoride accumulation blocks the development of chondrocytes is still unclear. Here, we report a negative correlation between the length and growth plate width after NaF treatments via apoptosis and autophagy, with shrinkage of cells, nuclear retraction, dissolution of chondrocytes. Whereas, fluoride exposure had no significant effect on the number and distribution of the osteoclasts which were well aligned. More importantly, fluoride exposure induced apoptosis of tibial bone through CytC/Bcl-2/P53 pathways via targeting Caspase3, Caspase9, Bak1, and Bax expressions. Meanwhile, the Beclin1, mTOR, Pakin, Pink, and p62 were elevated in NaF treatment group, which indicated that long-term excessive fluoride triggered the autophagy in the tibial bone and produced the chondrocyte injury. Altogether, fluoride exposure induced the chondrocyte injury by regulating the autophagy and apoptosis in the tibial bone of ducks, which demonstrates that fluoride exposure is a risk factor for cartilage development. These findings revealed the essential role of CytC/Bcl-2/P53 pathways in long-term exposure to fluoride pollution and block the development of chondrocytes in ducks, and CytC/Bcl-2/P53 can be targeted to prevent fluoride induced chondrocyte injury.

Exposure to Fluoride induces apoptosis in liver of ducks by regulating Cyt-C/Caspase 3/9 signaling pathway.

Fluorine being a well-known and essential element for normal physiological functions of tissues of different organisms is frequently used for growth and development of body. The mechanisms of adverse and injurious impacts of fluoride are not clear and still are under debate. Therefore, this study was executed to ascertain the potential mechanisms of sodium fluoride in liver tissues of ducks. For this purpose, a total of 14 ducks were randomly divided and kept in two groups including control group and sodium fluoride treated group. The ducks in control group were fed with normal diet while the ducks in other group were exposed to sodium fluoride (750 mg/kg) for 28 days. The results showed that exposure to sodium fluoride induced deleterious effects in different liver tissues of ducks. The results indicated that mRNA levels of Cas-3, Cas-9, p53, Apaf-1, Bax and Cyt-c were increased in treated ducks with significantly higher mRNA level of Cas-9 and lower levels of the mRNA level of Bcl-2 as compared to untreated control group (P < 0.01). The results showed that protein expression levels of Bax and p53 were increased while protein expression level of Bcl-2 was reduced in treated ducks. No difference was observed in protein expression level of Cas-3 between treated and untreated ducks. The results of this study suggest that sodium fluoride damages the normal structure of liver and induces abnormal process of apoptosis in hepatocyte, which provide a new idea for elucidating the mechanisms of sodium fluoride induced hepatotoxicity in ducks.

Metabolomics and transcriptomics indicated the molecular targets of copper to the pig kidney.

Copper poses huge environmental and public health concerns due to its widespread and persistent use in the past several decades. Although it is well established that at higher levels copper causes nephrotoxicity, the exact mechanisms of its toxicity is not fully understood. Therefore, this experimental study for the first time investigates the potential molecular mechanisms including transcriptomics, metabolomics, serum biochemical, histopathological, cell apoptosis and autophagy in copper-induced renal toxicity in pigs. A total of 14 piglets were randomly assigned to two group (7 piglets per group) and treated with a standard diet (11 mg CuSO4 per kg of feed) and a high copper diet (250 mg CuSO4 per kg of feed). The results of serum biochemical tests and renal histopathology suggested that 250 mg/kg CuSO4 in the diet significantly increased serum creatinine (CREA) and induced renal tubular epithelial cell swelling. Results on transcriptomics and metabolomics showed alteration in 804 genes and 53 metabolites in kidneys of treated pigs, respectively. Combined analysis of transcriptomics and metabolomics indicated that different genes and metabolism pathways in kidneys of treated pigs were involved in glycerophospholipids metabolism and glycosphingolipid metabolism. Furthermore, copper induced mitochondrial apoptosis characterized by increased bax, bak, caspase 3, caspase 8 and caspase 9 expressions while decreased bcl-xl and bcl2/bax expression. Exposure to copper decreased the autophagic flux in terms of increased number of autophagosomes, beclin1 and LC3b/LC3a expression and p62 accumulation. These results indicated that the imbalance of glycosphingolipid metabolism, the impairment of autophagy and increase mitochondrial apoptosis play an important role in copper induced renal damage and are useful mechanisms to understand the mechanisms of copper nephrotoxicity.

In situ reduced graphene-based aerogels embedded with gold nanoparticles for real-time humidity sensing and toxic dyes elimination.

Hybrid aerogels are promising candidates for energy storage, biosensing, and medical applications, but the conventional fabrication methods, being time-consuming and complex, limit their widespread utilization. The critical issues affecting their functionality include the un-controllable particle dispersity, loading of active materials, and the porosity. We report a simple and efficient method to synthesize in situ reduced Au nanoparticles@graphene (Au@graphene) hybrid aerogel using near-infrared radiation (NIR), resulting the uniform loading of well-dispersed Au nanoparticles (Au-NPs) as well as in situ reduction of graphene oxide (GO) with enhanced conductivity. The concentration of iso-propylacrylamide and GO can be adjusted to control the aerogel pore size during the freeze-drying process. Reduction of HAuCl4 and GO to high extent under NIR light was confirmed with advanced characterization techniques. Density functional theory based calculations with generalized gradient-corrected functional (GGA/PW91) in the hybrid aerogel system, and dnd basis sets are used for the confirmation of possible interactions between the GO, Au-NPs, and the polymer. The as-designed highly porous and conductive aerogel shows an excellent humidity response (30-97%) and successfully removes the methylene blue pollutant from the aqueous solution to a high extent (90%). Therefore, Au@graphene hybrid aerogel is potentially an exciting candidate for a wide range of applications in the humidity sensing and biomedical disease detection.

Key Electronic, Linear and Nonlinear Optical Properties of Designed Disubstituted Quinoline with Carbazole Compounds.

Organic materials development, especially in terms of nonlinear optical (NLO) performance, has become progressively more significant owing to their rising and promising applications in potential photonic devices. Organic moieties such as carbazole and quinoline play a vital role in charge transfer applications in optoelectronics. This study reports and characterizes the donor-acceptor-donor-π-acceptor (D-A-D-π-A) configured novel designed compounds, namely, Q3D1-Q3D3, Q4D1-Q1D2, and Q5D1. We further analyze the structure-property relationship between the quinoline-carbazole compounds for which density functional theory (DFT) and time-dependent DFT (TDDFT) calculations were performed at the B3LYP/6-311G(d,p) level to obtain the optimized geometries, natural bonding orbital (NBO), NLO analysis, electronic properties, and absorption spectra of all mentioned compounds. The computed values of λmax, 364, 360, and 361 nm for Q3, Q4, and Q5 show good agreement of their experimental values: 349, 347, and 323 nm, respectively. The designed compounds (Q3D1-Q5D1) exhibited a smaller energy gap with a maximum redshift than the reference molecules (Q3-Q5), which govern their promising NLO behavior. The NBO evaluation revealed that the extended hyperconjugation stabilizes these systems and caused a promising NLO response. The dipole polarizabilities and hyperpolarizability (ß) values of Q3D1-Q3D3, Q4D1-Q1D2, and Q5D1 exceed those of the reference Q3, Q4, and Q5 molecules. These data suggest that the NLO active compounds, Q3D1-Q3D3, Q4D1-Q1D2, and Q5D1, may find their place in future hi-tech optical devices.

Distribution and antimicrobial susceptibility profile of bacterial and fungal pathogens isolated from burn wounds in hospitalized patients.

OBJECTIVE: Current study was designed to isolate the pathogens from burn wounds and determine the antibiogram of these isolates. METHODS: A total of 85 samples were collected from burn patients with the history of different weeks of hospitalization in various public and private hospitals of Faisalabad during September 2017-July 2019 and shifted to Department of Microbiology, Government College University, Faisalabad for further processing. Isolation and identification of the pathogens was done through conventional microbiological procedures. Disc diffusion method was used for the determination of antibacterial and antifungal activity. RESULTS: A total of 40(91%) samples were found positive for the presence of bacterial or fungal pathogens. Commonly isolated pathogens were Staphylococcus aureus 15 (21.4%), Pseudomonas aeruginosa 15 (21.4%), Bacillus subtilis 11(15.7%), Escherichia coli 10(14.2%), Candida albicans 8(11.4%), Aspergillus flavus 6(8.5%) and Salmonella Typhi 5(7.1%). Highest resistance was found against S. aureus and P. aeruginosa. Cefotaxime was the least effective antibiotic, while Gentamicin and Amphotericin-B were the mosteffective antimicrobial drugs against bacterial and fungal pathogens, respectively. CONCLUSIONS: Taking together it was concluded that most isolated pathogen was S. aureus and P. aeruginosa followed by B. subtilis, E. coli, C. albicans, A. flavus and S. typhi from burn wound in hospitalized patients. Anti-biogram studies showed S. aureus and P. aeruginosa were the most resistant pathogens whereas S. typhi, C. albicans and A. flavus were susceptible to various commonly used antibiotics. Cefotaxime was the least effective antibiotic, while Gentamicin and Amphotericin-B were the most effective antimicrobial drugs against bacterial and fungal pathogens, respectively. It is suggested that alternate anti-microbial agents should be investigated to control the infections.

Gut microbial dysbiosis and its association with esophageal cancer.

Due to its aggressive nature and low survival rate, esophageal cancer is one of the deadliest cancer. While the intestinal microbiome significantly influences human health and disease. This research aimed to investigate and characterize the relative abundance of intestinal bacterial composition in esophageal cancer patients. The fecal samples were collected from esophageal cancer patients (n = 15) and healthy volunteers (n = 10). The PCR-DGGE was carried out by focusing on the V3 region of the 16S rRNA gene, and qPCR was performed for Bacteroides vulgatus, Escherichia coli, Bifidobacterium, Clostridium leptum and Lactobacillus. High-throughput sequencing of the 16S rRNA gene targeting the V3+V4 region was performed on 20 randomly selected samples. PCR-DGGE and High-throughput diversity results showed a significant alteration of gut bacterial composition between the experimental and control groups, which indicates the gut microbial dysbiosis in esophageal cancer patients. At the phylum level, there was significant enrichment of Bacteroidetes, while a non-significant decrease of Firmicutes in the experimental group. At family statistics, a significantly higher level of Bacteroidaceae and Enterobacteriaceae, while a significantly lower abundance of Prevotellaceae and Veillonellaceae were observed. There was a significantly high prevalence of genera Bacteroides, Escherichia-Shigella, while a significantly lower abundance of Prevotella_9 and Dialister in the experimental group as compared to the control group. Furthermore, the species analysis also showed significantly raised level of Bacteroides vulgatus and Escherichia coli in the experimental group. These findings revealed a significant gut microbial dysbiosis in esophageal cancer patients. So, the current study can be used for the understanding of esophageal cancer treatment, disease pathway, mechanism, and probiotic development.

Transcriptional Response of Multidrug-Resistant Klebsiella pneumoniae Clinical Isolates to Ciprofloxacin Stress.

BACKGROUND: The term "persisters" refers to a small bacterial population that persists during treatment with high antibiotic concentration or dose in the absence of genetic resistance. The present study was designed to investigate the transcriptional response in indigenous Klebsiella pneumoniae under the ciprofloxacin stress. METHODS: Isolation and identification of K. pneumoniae were carried out through standard microbiological protocols. The characterization of quinolone resistance was performed by estimating the quinolone susceptibility testing, MIC estimation, and detecting the QRDR and PMQR. Transcriptional response of the isolates to ciprofloxacin was determined using qPCR. RESULTS: Among 34 isolates, 23 (67%) were resistant to ciprofloxacin. Both QRDR (gyrA and gyrB) and PMQR (qnrA, qnrB, and qnrS) were detected in the isolates, and all were found resistant to ciprofloxacin. The mRNA levels of both mutS and euTu under the influence of ciprofloxacin were significantly increased. On ciprofloxacin exposure, the mRNA levels of the DNA damage response element (mutS) were raised in a time-dependent fashion. K. pneumoniae showed high-level resistance to ciprofloxacin in the presence of mutations in QRDR and PMQR genes. CONCLUSION: The transcriptional response revealed the upregulation of DNA repair and protein folding elements (mutS and euTu) in ciprofloxacin stress and delayed cell division. The ciprofloxacin was found to trigger various stress responses in a time- and concentration-dependent manner.

Chemical Composition and Bioactivities of Essential Oil from Leaves of Syzygium cumini (L.) Skeels Native to Punjab, Pakistan.

Herbal medicines are widely used for the treatment of different types of diseases like skin and throat infections and other diseases in developing countries. Syzygium cumini (L.) Skeels fruit, leaves and bark were used for the remedies of different diseases anciently. The aim of the present study was to evaluate the chemical profile of Syzygium cumini leaves essential oil (EO) from Punjab, Pakistan. The essential oil was isolated using hydrodistillation technique and analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS). Free radical scavenging capacity and antioxidant activity were assessed by using DPPH radical scavenging ability, inhibition of linoleic acid peroxidation, bleaching of ß-carotene in linoleic acid system and reducing power assays. Antimicrobial potential was assessed by disc diffusion assay and measurement of minimum inhibitory concentration (MIC) using resazurin microtiter-plate assay. The anti-heme biocrystallization activity of EO was also assessed. The major components (>3%) found in Syzygium cumini leaves EO were ß-farnesene (3.42 %), caryophyllenol (3.46 %), terpinen-4-ol (3.61 %), ß-myrcene (3.90 %), γ-cadinene (4.09 %), fenchol (4.22 %), cis-ß-ocimene (4.40 %) and 5-methyl-1,3,6-heptatriene (4.90 %). Excellent antioxidant, antimicrobial and weak antimalarial potential was observed. It can be concluded that Syzygium cumini leaves EO has potential application for food and pharmaceutical industries.

Efficient Channel Allocation using Matching Theory for QoS Provisioning in Cognitive Radio Networks.

The focus of research efforts in cognitive radio networks (CRNs) has primarily remained confined to maximizing the utilization of the discovered resources. However, it is also important to enhance the user satisfaction in CRNs by finding a suitable match between the secondary users and the idle channels available from the primary network while taking into consideration not only the quality of service (QoS) requirements of the secondary users but the quality of the channels as well. In this work, the Gale Shapley matching theory was applied to find the best match, so that the most suitable channels from the available pool were allocated that satisfy the QoS requirements of the secondary users. Before applying matching theory, two objective functions were defined from the secondary user's perspective as well as from the channel's perspective. The objective function of secondary users is the weighted sum of the data rate of the secondary users and the probability of reappearance of the primary user on the channel. Whereas, the objective function of the channel is the maximum utilization of the channel. The weight factors included in the objective functions allow for diverse service classes of secondary users (SUs) or varying channel quality characteristics. The objective functions were used in developing the preference lists for the secondary users and the idle channels. The preference lists were then used by the Gale Shapely matching algorithm to determine the most suitably matched SU-channel pairs. The performance of the proposed scheme was evaluated using Monte-Carlo simulations. The results show significant improvement in the overall satisfaction of the secondary users with the proposed scheme in comparison to other contemporary techniques. Further, the impact of changing the weight factors in the objective functions on the secondary user's satisfaction and channel utilization was also analyzed.

Analysis of Efficient Spectrum Handoff in a Multi-Class Hybrid Spectrum Access Cognitive Radio Network Using Markov Modelling.

Cognitive radio networks (CRNs) rely on sensing of the licensed spectrum of a primary network to dynamically ascertain underutilized portion of the spectrum, thus affording additional communication opportunities. In a CRN, a single homogeneous spectrum access, such as interweave only deprives the secondary users (SUs) of channel access during handoff, particularly at high primary network traffic. Therefore, providing quality-of-service (QoS) to multi-class SUs with diverse delay requirements during handoff becomes a challenging task. In this paper, we have evolved a Markov-based analytical model to ascertain the gain in non-switching spectrum handoff scheme for multi-class SUs employing hybrid interweave-underlay spectrum access strategy. To satisfy the QoS requirements of the delay-sensitive traffic, we have analyzed the impact of hybrid spectrum access scheme for prioritized multi-class SUs traffic. The results show substantial improvement in spectrum utilization, average system throughput and extended data delivery time compared to conventional CRN using interweave only spectrum access. This demonstrates the suitability of the proposed scheme towards meeting QoS requirements of the delay-sensitive SU traffic while improving the overall performance for delay-tolerant SU traffic as well.