Utility-Driven End-to-End Network Slicing for Diverse IoT Users in MEC: A Multi-Agent Deep Reinforcement Learning Approach.

Mobile Edge Computing (MEC) is crucial for reducing latency by bringing computational resources closer to the network edge, thereby enhancing the quality of services (QoS). However, the broad deployment of cloudlets poses challenges in efficient network slicing, particularly when traffic distribution is uneven. Therefore, these challenges include managing diverse resource requirements across widely distributed cloudlets, minimizing resource conflicts and delays, and maintaining service quality amid fluctuating request rates. Addressing this requires intelligent strategies to predict request types (common or urgent), assess resource needs, and allocate resources efficiently. Emerging technologies like edge computing and 5G with network slicing can handle delay-sensitive IoT requests rapidly, but a robust mechanism for real-time resource and utility optimization remains necessary. To address these challenges, we designed an end-to-end network slicing approach that predicts common and urgent user requests through T distribution. We formulated our problem as a multi-agent Markov decision process (MDP) and introduced a multi-agent soft actor-critic (MAgSAC) algorithm. This algorithm prevents the wastage of scarce resources by intelligently activating and deactivating virtual network function (VNF) instances, thereby balancing the allocation process. Our approach aims to optimize overall utility, balancing trade-offs between revenue, energy consumption costs, and latency. We evaluated our method, MAgSAC, through simulations, comparing it with the following six benchmark schemes: MAA3C, SACT, DDPG, S2Vec, Random, and Greedy. The results demonstrate that our approach, MAgSAC, optimizes utility by 30%, minimizes energy consumption costs by 12.4%, and reduces execution time by 21.7% compared to the closest related multi-agent approach named MAA3C.

Metagenomic approaches and opportunities in arid soil research.

Arid soils present unique challenges and opportunities for studying microbial diversity and bioactive potential due to the extreme environmental conditions they bear. This review article investigates soil metagenomics as an emerging tool to explore complex microbial dynamics and unexplored bioactive potential in harsh environments. Utilizing advanced metagenomic techniques, diverse microbial populations that grow under extreme conditions such as high temperatures, salinity, high pH levels, and exposure to metals and radiation can be studied. The use of extremophiles to discover novel natural products and biocatalysts emphasizes the role of functional metagenomics in identifying enzymes and secondary metabolites for industrial and pharmaceutical purposes. Metagenomic sequencing uncovers a complex network of microbial diversity, offering significant potential for discovering new bioactive compounds. Functional metagenomics, connecting taxonomic diversity to genetic capabilities, provides a pathway to identify microbes' mechanisms to synthesize valuable secondary metabolites and other bioactive substances. Contrary to the common perception of desert soil as barren land, the metagenomic analysis reveals a rich diversity of life forms adept at extreme survival. It provides valuable findings into their resilience and potential applications in biotechnology. Moreover, the challenges associated with metagenomics in arid soils, such as low microbial biomass, high DNA degradation rates, and DNA extraction inhibitors and strategies to overcome these issues, outline the latest advancements in extraction methods, high-throughput sequencing, and bioinformatics. The importance of metagenomics for investigating diverse environments opens the way for future research to develop sustainable solutions in agriculture, industry, and medicine. Extensive studies are necessary to utilize the full potential of these powerful microbial communities. This research will significantly improve our understanding of microbial ecology and biotechnology in arid environments.

Ascorbic acid assisted photodegradation of methylcobalamin using corrective irrelevant absorption spectrophotometric assay: A kinetic study.

Photodegradation of drug substances leads to the formation of known and unknown degradation products. These unknown degradation products interfere and give erroneous results because of absorption on analytical wavelengths. This interference could be eliminated using the correction of irrelevant absorbancies. This study is based on the application of linear and non-linear correction of irrelevant absorption for the determination of methylcobalamin (MC) and hydroxocobalamin in the photolytic degradation assisted by ascorbic acid (AH2). MC follows first-order degradation kinetics and the rate of degradation (kobs) ranges from 1.99-2.34 × 10-2, min-1 at pH 2.0-12.0. The second-order rate constants (k2) for the photochemical interaction of MC and AH2 are in the range of 17.9-60.3 × 10-2 M-1, min-1 (acidic region) and 10.3-24.6 × 10-2 M-1, min-1 (alkaline region). The k2-pH profile was found to be bell-shaped and the maximum rate of degradation in the presence of AH2 is at pH 5.0 (60.3 × 10-2 M-1, min-1) due to the protonation of MC. However, in alkaline pH, the rate of photodegradation decreases due to the ionization form of AH2 which is AH- species.

Prevalence of Metabolic Syndrome and Its Risk Factors Influence on Microvascular Complications in Patients With Type 1 and Type 2 Diabetes Mellitus.

BACKGROUND: Diabetes mellitus (DM) long-term macrovascular and microvascular complications pose significant health risks and increase mortality. In DM patients, metabolic syndrome (MetSy) either precedes or coexists with the condition. Central obesity, poor glycemic control, hypertension, elevated triglycerides (TG), and low high-density lipoproteins (HDL-C) are the components of MetSy. The purpose of this study is to investigate related diabetic microvascular complications in type 1 DM (T1DM) by comparing them with type 2 DM (T2DM), determine potential risk factors, and estimate prevalence based on the diagnosis of MetSy. METHODOLOGY: This study included 160 T1DM and 160 T2DM patients, totaling 320 DM patients. It was carried out from April 20, 2022, to September 31, 2023, at the Sheikh Zayed Hospital, Rahim Yar Khan, in the Outdoor Diabetic Clinic and Medicine Department. A unique questionnaire was utilized to gather socio-demographic, general, clinical, and laboratory data for the MetSy criteria set forth by the International Diabetes Federation (IDF). The blood pressure, BMI, and waist circumference (WC) were measured, while venous fasting blood was used to assess biochemical markers such as HDL-C, TG, and fasting blood sugar. The microvascular diabetes complications were identified using abdominal ultrasound, fundus ophthalmoscopy, and routine laboratory tests. We quantified and analyzed these variables individually for T1DM and T2DM patients with or without MetSy and compared them in the presence or absence of diabetes microvascular complications. RESULTS: MetSy prevalence was 25.62% (41, n=160) for T1DM and 60.62% (97, n=160) for T2DM, totaling 43.12%. Among T1DM patients with MetSy, the majority were married males, aged 36-49 years, with a BMI of 26.69±2.20 kg/m2 and a WC of 85.12±4.23, and 67.5% (108) patients had diabetes microvascular complications. Comparatively, in T2DM with MetSy, the majority were married females aged 50-59 years with a BMI of 29.79 ± 4.65 kg/m² and a large WC of 93.43±4.49, and 75% (123) patients had diabetes microvascular complications. Overall, this study noted significant p-values for hypertension, elevated TG, low HDL-c, high WC, obesity, female gender in T2DM, and above 36 years of age in both groups with MetSy. Diabetic retinopathy (DR) at 32.4% (p<0.001) was the most prevalent T1DM microvascular complication, followed by nephropathy (30.6%), neuropathy (DN) at 28.1%, and gastroparesis (DG) at 22.3%. Whereas in T2DM, the prevalence of DN was 36.3% (p<0.001), followed by DKD (29.3%), DG (28.9%), and DR (24.9%). CONCLUSION: Nearly a quarter of T1DM patients had MetSy, with increasing percentages of overweight and obese patients who are more likely to have DR, DKD, or DN. MetSy affects two-thirds of T2DM patients, with married obese females aged 50-59 being more susceptible than males, who are more likely to suffer DN, DKD, or DG. Risk factors that contribute to the MetSy burden in T1DM and T2DM include hypertension, poor glycemic management, low HDL-C, high TG, and a higher BMI or WC. Increasing age, female gender in T2DM, longer diabetes duration, and co-morbid hypertension were independent predictors of microvascular complications. DR, DN, DKD, and gastroparesis are the most prevalent diabetic microvascular sequelae. The clinical management of diabetic patients with healthy lifestyle adaptations, good glycemic control, antihypertensives, and statins will contribute greatly to MetSy prevention.

Insight into carbohydrate metabolism, protein quantification and mineral regulation in wheat (Triticum aestivum L.) by the action of green synthesized silver nanoparticles (AgNPs) against heat stress.

In the present investigation, the role of GS-AgNPs treatment in wheat plants was carried out in reducing heat stress with the aim of facilitating scientists on this topic. The effect of GS-AgNPs against heat stress has rarely been deliberated in wheat plants, and only a few studies have been established earlier in this scenario. This work illustrated the effect of GS-AgNPs on the regulation of carbohydrates metabolism, SOD, proteins, crude fibers, and minerals changes in wheat plants. Data were analysed using PCA analysis, correlation parameters, and normal probability distribution in PAST 3 software. The results indicated that heat stress alone caused severe changes in carbohydrates metabolism, SOD, proteins, crude fibers, and minerals immediately so that plants could not recover without foreign stabilizers such as GS-AgNPs. The application of GS-AgNPs increases the flux of carbohydrates metabolism, SOD, and proteins, including HSPs, crude fibers, and minerals, in wheat plants to reduce the effect of heat stress. The 50 mg/l concentration of GS-AgNPs has shown an increase in carbohydrates metabolism and SOD activity, while crude fibres have shown a significant enhancement at 100 mg/l of GS-AgNPs. The crude and true proteins were also shown pronounced increase in treatment to a concentration of 50 mg/l of GS-AgNPs. GS-AgNPs stimulated HSP production; most importantly, smHSP production was observed in the present results with other HSPs in wheat plants treated with a 50 mg/l concentration of GS-AgNPs. The mineral distribution was also regulated by the respective treatment of GS-AgNPs, and the highest amounts of Ca, P and Fe were found to be highest in wheat under heat stress. In general, we computed the expected model based on GS-AgNPs on the genes/factors that respond to heat stress and their potential role in mitigating heat stress in wheat. In addition, we discussed the prospective signalling pathway triggered by GS-AgNPs in wheat against heat stress. In the future, this work might be helpful in distinguishing the genetic variation due to GS-AgNPs in promoting tolerance in wheat against heat stress.Communicated by Ramaswamy H. Sarma.

Riboflavin (vitamin B2) sensitized photooxidation of ascorbic acid (vitamin C): A kinetic study.

Ascorbic acid (AH2) photoxidation sensitized by riboflavin (RF) has been studied between pH 2.0 and 12.0 in ambient air and anaerobic environment using UV and visible irradiation sources. The kinetics of AH2 degradation in aqueous medium along with RF is found to be first-order for its photodegradation. AH2 photolysis rate constants in aerobic and anaerobic conditions with RF (1.0-5.0 × 10-5 M) are 0.14-3.89 × 10-2 and 0.026-0.740 × 10-2 min-1, respectively. The rate constants (k2) of second-order kinetics for AH2 and RF photochemical interaction in aerobic and anaerobic conditions are in the range of 0.24-3.70 to 0.05-0.70 × 10-3 M-1 min-1, respectively, which manifests that increasing the RF concentration also increases the rate of photodegradation (photooxidation) of AH2. The k2 versus pH graph is bell-shaped which indicates that increasing the pH increases photolytic degradation rate of AH2 with RF. Increasing the pH results in the increased ionization of AH2 (ascorbyl anion, AH-) and redox potential which leads to the higher rates of photodegradation of AH2. Two-component spectrophotometric (243 and 266 nm, AH2 and RF, respectively) and high-performance liquid chromatography (HPLC) methods have been used to determine the concentration of AH2 and RF in pure and degraded solutions. The results obtained from these two methods are compared using a student t-test which showed no noteworthy difference between them.

Association of IL-17A promoter region SNP-rs2275913 with urinary bladder cancer.

Objective: Urinary bladder cancer (UBC) is the fourth most common cancer among men and tenth most common cancer in women. This study investigated an association of interleukins -17A promoter region single nucleotide polymorphism (SNP)-rs2275913 with UBC in Pakistani population. Methods: Population-based study was designed with 127 UBC patients and 100 healthy individuals. Only UBC Patients were included and other diseases hepatitis or any other malignancy/cancer were excluded from the study. Polymerase chain reaction Restriction fragment length polymorphism technique was used to genotype the rs2275913 SNP in patients and control. Linear regression analysis was performed on the genotype data and allelic frequency data. Online statistical tool was used to calculate ratio of odds. Results: Linear regression analysis showed that there was no association between rs2275913 SNP and UBC patients in the dominant model (OR = 0.815, CI = 0.415-1.6), recessive model (OR = 0.389, CI = 0.014-5.565), codominant model (OR = 0.376, CI=0.013-5.420) and (OR = 0.855, CI = 0.427-1.713). Moreover, among the UBC samples, low-grade non-muscle invasive UBC samples dominant model (OR = 0.722, CI = 0.316-1.637), recessive model (OR = 0.000, CI = 0.000-5.864), codominant model (OR = 0.864, CI = 0.030-12.668), and (OR = 0.788, CI = 0.341-1.806) did also not show any association. When same analysis was performed for high-grade muscle invasive UBC, dominant (OR = 0.936, CI = 0.403-2.155), recessive model (OR = 0.875, CI = 0.031-12.696), and codominant model (OR = 0.864, CI = 0.030-12.668,), and (OR = 0.942, CI = 0.394-2.232) did not show any association. Conclusion: Results revealed that rs2275913 did not show any associated with the high risk of UBC in Pakistani population. Some limitations of the studies are firstly, the samples size and other are detailed information on UBC and role of inflammation.

APACHE scoring as an indicator of mortality rate in ICU patients: a cohort study.

Predictive scoring systems are tools that assess the magnitude of a patient's illness and forecast disease prognosis, usually in the form of mortality, in the ICU. We aimed to determine the mortality rate among patients admitted to ICU using the Acute Physiology and Chronic Health Evaluation II (APACHE II) scoring system correlating with lengths of stay in the ICU. Methodology: A cohort study using team approach to care was conducted from July 2021 through July 2022 at KRL Hospital. Five hundred fifty-two patients aged 18-40 years, admitted for medical or surgical reasons (other than cardiac) who stayed in the ICU for more than 24 h were included. The APACHE II score was determined using 12 physiological variables at the end of the first 24 h of ICU admission. Data were analyzed using IBM Corp. released in 2015 (IBM SPSS Statistics for Windows, Version 23.0, Armonk, New York). Results: The average age of study participants was 36.34±2.77, ranging from 18 to 40 years. Three hundred fifteen participants were males and 237 were females. Patients were categorized into four separate groups as per their respective APACHE II scores. Patients with an APACHE II score of 31-40 were assigned to group 1. Patients with an APACHE II score of 21-30 were assigned to group 2. Patients with an APACHE II score of 11-20 were assigned to group 3. Lastly, patients with an APACHE II score of 3-10 were assigned to group 4. All patients in group 1 and group 2 died and none survived. Groups 1 and 2 contained a sum of 228 patients. A total of 123 patients were assigned to group 3, out of which 88 patients (71.54%) survived and 35 patients (28.45%) died. From these observations, it is evident that a higher APACHE II score is correlated with increased mortality. Conclusion: APACHE II scoring serves as an early warning indication of death and prompts clinicians to upgrade their treatment protocol. This makes it a useful tool for the clinical prediction of ICU mortality.

Carbonate Reservoir Quality Variations in Basins with a Variable Sediment Influx: A Case Study from the Balkassar Oil Field, Potwar, Pakistan.

The carbonate reservoir quality is strongly reliant on the compaction process during sediment burial and other processes such as cementation and dissolution. Porosity and pore pressure are the two main factors directly affected by mechanical and chemical compactions. Porosity reduction in these carbonates is critically dependent on the overburden stress and subsidence rate. A variable sediment influx in younger basins may lead to changes in the reservoir quality in response to increasing lithostatic pressure. Deposition of molasse sediments as a result of the Himalayan orogeny caused variations in the sedimentation influx in the Potwar Basin of Pakistan throughout the Neogene times. The basic idea of this study is to analyze the carbonate reservoir quality variations induced by the compaction and variable sediment influx. The Sakesar Limestone of the Eocene age, one of the proven carbonate reservoirs in the Potwar Basin, shows significant changes in the reservoir quality, specifically in terms of porosity and pressure. A 3D seismic cube (10 km2) and three wells of the Balkassar field are used for this analysis. To determine the vertical and lateral changes of porosity in the Balkassar area, porosity is computed from both the log and seismic data. The results of both the data sets indicate 2-4% porosities in the Sakesar Limestone. The porosity reduction rate with respect to the lithostatic pressure computed with the help of geohistory analysis represents a sharp decrease in porosity values during the Miocene times. Pore pressure predictions in the Balkassar OXY 01 well indicate underpressure conditions in the Sakesar Limestone. The Eocene limestones deposited before the collision of the Indian plate had enough time for fluid expulsion and show underpressure conditions with high porosities.

ReSTiNet: An Efficient Deep Learning Approach to Improve Human Detection Accuracy.

Human detection is an important task in computer vision. It is one of the most important tasks in global security and safety monitoring. In recent days, Deep Learning has improved human detection technology. Despite modern techniques, there are very few optimal techniques to construct networks with a small size, deep architecture, and fast training time while maintaining accuracy. ReSTiNet is a novel small convolutional neural network that overcomes the problems of network size, detection speed, and accuracy. The developed ReSTiNet contains fire modules by evaluating their number and position in the network to minimize the model parameters and network size. To improve the detection speed and accuracy of ReSTiNet, the residual block within the fire modules is carefully designed to increase the feature propagation and maximize the information flow in the network. The developed approach compresses the well-known Tiny-YOLO architecture while improving the following features: (i) small model size, (ii) faster detection speed, (iii) resolution of overfitting, and (iv) better performance than other compact networks such as SqueezeNet and MobileNet in terms of mAP on the Pascal VOC and MS COCO datasets. ReSTiNet is 10.7 MB, five times smaller than Tiny-YOLO. On Tesla k80, mAP is 27.3% for MS COCO and 63.74% for PASCAL VOC. The validation of the proposed ReSTiNet model has been done on INRIA person dataset using the Tesla K80.•All the necessary steps, algorithms, and mathematical formulas for building the net- work are provided.•The network is small in size but has a faster detection speed with high accuracy.

The global emergence of Chikungunya infection: An integrated view.

Chikungunya virus (CHIKV) is one of the emerging viruses around the globe. It belongs to the family Togaviridae and genus Alphavirus and is an arthropod borne virus that transmits by the bite of an infected mosquito, mainly through Aedes aegypti and Aedes albopcitus. It is a spherical, enveloped virus with positive single stranded RNA genome. It was first discovered during 1952-53 in Tanganyika, after which outbreaks were documented in many regions of the world. CHIKV has two transmission cycles; an enzootic sylvatic cycle and an urban cycle. CHIKV genome contains 11,900 nucleotides and two open reading frames and shows great sequence variability. Molecular mechanisms of virus host-cell interactions and the pathogenesis of disease are not fully understood. The disease involves three phases; acute, post-acute and chronic with symptoms including high-grade fever, arthralgia, macupapular rashes and headache. There is no licensed vaccine or specific treatment for CHIKV infection. This lack of specific interventions combined with difficulties in making a precise diagnosis together make the disease difficult to manage. In this review we aim to present the current knowledge of global epidemiology, transmission, structure, various aspects of diagnosis as well as highlight potential antiviral drugs and vaccines against CHIKV.

Clinical manifestations, associated risk factors and treatment outcomes of Chronic Pulmonary Aspergillosis (CPA): Experiences from a tertiary care hospital in Lahore, Pakistan.

BACKGROUND: Chronic pulmonary aspergillosis (CPA) has a wide spectrum of illnesses depending on the progression of the disease and comorbid conditions. However, there is an inadequacy of investigations regarding clinical, laboratory, risk factor and prognostic data on CPA. The current study is aimed to consider the clinical manifestations, risk factors and outcomes of CPA. METHODOLOGY: Retrospective records of all patients with a confirmed diagnosis of CPA who sought treatment at Gulab Devi Chest Hospital Lahore, Pakistan from January 2017 to December 2019 were evaluated. Data regarding demographics, clinical manifestations, comorbidities, radiographic and microbiological findings, length of hospital stay (LOS) and intensive care unit (ICU) admission was collected and analyzed to identify the factors associated with mortality. The independent factors associated with mortality were also identified by appropriate analyses. RESULTS: A total of 218 CPA patients were included in this study. The mean age was 45.75 ± 6.26 years. Of these, 160 (73.4%) were male, and 65 (29.8%) had diabetes. The mean LOS was 18.5 ± 10.9 days. The most common type of CPA was simple aspergilloma (56%) followed by chronic cavitary pulmonary aspergillosis (CCPA) (31.2%). About one half of the patients had a history of pulmonary tuberculosis (TB) and treatment response rates were low in patients with active TB. The overall mortality rate was 27.1%. ICU admission was required for 78 (35.8%) patients. Diabetes mellitus (DM), hematological malignancies and chronic kidney disease (CKD) were the common underlying conditions predicting a poor outcome. Mean LOS, hematological malignancies, consolidation and ICU admission were identified as the independent factors leading to mortality. CONCLUSIONS: CPA had a significant association with TB in the majority of cases. Treatment response rates in cases with active TB were comparatively low. Cases with high mean LOS, hematological malignancies, consolidation, ICU admission, CKD and DM experienced poor outcomes. High mean LOS, hematological malignancies, consolidation and ICU stay were identified as independent risk factors for mortality. Future large prospective studies, involving aspergillus specific immunoglobulin G (IgG) antibody testing, are required for a better understanding of CPA in Pakistan.

EGFRvIII expression and isocitrate dehydrogenase mutations in patients with glioma.

Molecular pathology and personalized medicine are still being evolved in Saudi Arabia, and genetic testing for the detection of mutations as cancer markers have not been established in the diagnostics laboratories in Saudi Arabia. The aim of the present study was to determine the prevalence of isocitrate dehydrogenase (IDH1 and IDH2) mutations and epidermal growth factor receptor variant (EGFRv)III transcript expression in Saudi Arabian patients with glioma. Out of 117 brain tumors tested by reverse transcription-quantitative PCR for EGFRvIII, 41 cases tested positive. In the glioblastoma (GBM) category, 28/55 tumors were positive, in astrocytoma tumors 5/22, and in oligodendrogliomas 4/13 cases were positive respectively. EGFRvIII transcript was sequenced by capillary electrophoresis to demonstrate the presence of EGFRvIII-specific junction where exons 2-7 were deleted. In the present study 106 tumors were sequenced for IDH1 exon-4 mutations using the capillary sequencing method. The most common substitution missense mutation c.395G>A was found in 16 tumors. In the case of adamantinomatous craniopharyngioma, a novel missense mutation in c.472C>T was detected in IDH2 gene. Using next-generation sequencing (NGS), 74 tumors were sequenced for the IDH1 gene, and a total of 8 missense variants were identified in 36 tumors in a population of Saudi Arabia. The missense mutation (c.395G>A) was detected in 29/36 of tumors. A novel intronic mutation in c.414+9T>A was found in 13 cases in the IDH1 gene. In addition, one case exhibited a novel synonymous mutation in c.369A>G. Eleven tumors were found to have compound mutations in the IDH1 gene. In IDH2 gene, out of a total of 16 variants found in 6 out of 45 tumors, nine were missense, five were synonymous and one was intronic. This is the first report from Saudi Arabian laboratories analyzing glioma tumors for EGFRvIII expression, and the first study from Saudi Arabia to analyze IDH mutations in gliomas using the capillary and NGS methods.

Genome-wide association study identifies five new cadmium uptake loci in wheat.

Cadmium (Cd) toxicity is a serious threat to future food security and health safety. To identify genetic factors contributing to Cd uptake in wheat, we conducted a genome-wide association study with genotyping from 90K SNP array. A spring wheat diversity panel was planted under normal conditions and Cd stress (50 mg Cd/kg soil). The impact of Cd stress on agronomic traits ranged from a reduction of 16% in plant height to 93% in grain iron content. Individual genotypes showed a considerable variation for Cd uptake and translocation subdividing the panel into three groups: (1) hyper-accumulators (i.e. high Leaf_Cd and low Seed_Cd ), (2) hyper-translocators (i.e. low Leaf_Cd and high Seed_Cd ), and (3) moderate lines (i.e. low Leaf_Cd and low Seed_Cd ). Two lines (SKD-1 and TD-1) maintained an optimum grain yield under Cd stress and were therefore considered as Cd resistant lines. Genome-wide association identified 179 SNP-trait associations for various traits including 16 for Cd uptake at a significance level of P < .001. However, only five SNPs were significant after applying multiple testing correction. These loci were associated with seed-cadmium, grain-iron, and grain-zinc: qSCd-1A, qSCd-1D, qZn-2B1, qZn-2B2, and qFe-6D. These five loci had not been identified in the previously reported studies for Cd uptake in wheat. These loci and the underlying genes should be further investigated using molecular biology techniques to identify Cd resistant genes in wheat.

Toxicity assessment of a novel oil dispersant based on silica nanoparticles using Fathead minnow.

Oil spill accidents are a major concern for aquatic organisms. In recent history, the Deepwater Horizon blowout spilled 500 million liters of crude oil into the Gulf of Mexico. Corexit 9500A was used to disperse the oil since it was the method approved at that time, despite safety concerns about its use. A better solution is necessary for dispersing oil from spills that reduces the toxicity to exposed aquatic organisms. To address this challenge, novel engineered nanoparticles were designed using silica cores grafted with hyperbranched poly(glycidol) branches. Because the silica core and polymers are known to be biocompatible, we hypothesized that these particles are nontoxic to fathead minnows (Pimephales promelas) and would decrease their exposure to oil polyaromatic hydrocarbons. Fathead minnow embryos, juveniles and adult stages were exposed to the particles alone or in combination with a water-accommodated fraction of oil. Acute toxicity of nanoparticles to fish was tested by measuring mortality. Sub-lethal effects were also measured including gene expression of cytochrome P450 1a (cyp1a) mRNA and heart rate in embryos. In addition, a mixture of particles plus the water-accommodated fraction was directly introduced to adult female fathead minnows by gavage. Three different nanoparticle concentrations were used (2, 10, and 50 mg/L) in either artificial fresh water or the water-accommodated fraction of the oil. In addition, nanoparticle-free controls were carried out in the two solutions. No significant mortality was observed for any age group or nanoparticle concentration, suggesting the safety of the nanoparticles. In the presence of the water-accommodated fraction alone, juvenile and adult fathead minnows responded by increasing expression of cyp1a. The addition of nanoparticles to the water-accommodated fraction reduced cyp1a gene expression in treatments. Heart rate was also restored to normal parameters in embryos co-exposed to nanoparticles and to the water-accommodated fraction. Measurement of polyaromatic hydrocarbons confirmed their presence in the tested solutions and the reduction of available PAH in WAF treated with the nanoparticles. Our findings suggest the engineered nanoparticles may be protecting the fish by sequestering polyaromatic hydrocarbons from oil, measured indirectly by the induction of cypa1 mRNAs. Furthermore, chemical analysis showed a reduction in PAH content in the water accommodated fraction with the presence of nanoparticles.

Silver nanoparticles and silver salt (AgNO3) elicits morphogenic and biochemical variations in callus cultures of sugarcane.

The research work was arranged to check the role of AgNPs and silver ions on callus cells of sugarcane (Saccharum spp. cv CP-77,400). AgNPs were synthesized chemically and characterized by UV-Vis spectra, XRD and SEM. AgNPs and silver ions were applied in various concentrations (0, 20, 40, 60 ppm) to sugarcane calli and the induced stress was characterized by studying various morphological and biochemical parameters. AgNPs and silver ions treatments produced high levels of malondialdehyde, proline, proteins, TP and TF contents. Similarly, CAT, SOD and POX activity was also significant in both treatments. The lower concentration of AgNPs and silver ions (20 ppm) provided maximum intracellular GSH level. This work mainly showed effects of AgNPs and silver ions on sugarcane calli in terms of morphological aberrations and cell membrane damage due to severe oxidative stress and production of enhanced levels of enzymatic and non-enzymatic antioxidants as self-defence to tolerate oxidative stress by scavenging reactive oxygen species. These preliminary findings will provide the way to study ecotoxicity mechanism of the metal ions and NPs in medicine industry and in vitro toxicity research. Furthermore, silver ions alone and their chemically synthesised AgNPs can be used for various biomedical applications in future.

Assessment of AgNPs exposure on physiological and biochemical changes and antioxidative defence system in wheat (Triticum aestivum L) under heat stress.

The present study was designed to check the role of silver nanoparticles (AgNPs) on physiological, biochemical parameters and antioxidants of wheat (Triticum aestivum L.) under heat stress. Plant extract of Moringa oleifera was used for AgNPs synthesis followed by characterization through UV-Vis spectroscopy, SEM, XRD and Zeta analyser. Heat stress was applied in range of 35-40°C for 3 hrs/ day for 3 days to wheat plants at trifoliate stage. Heat stress decreased the RWC (13.2%), MSI (16.3%), chl a (5.2%), chl b (4.1%) and TCCs (9.9%). Wheat plants treated with AgNPs showed significant increase in RWC (12.2%), MSI (26.5%), chl a (10%), chl b (16.4%), TCCs (19%), TPC (2.4%), TFC (2.5%), TASC (2.5%), SOD (1.3%), POX (1.5%), CAT (1.8%), APX (1.2%) and GPX (1.4%), under heat stress. Lower concentration of AgNPs (50 mg/l) decreased the sugar (5.8%) and proline contents (4%), while increase was observed in higher AgNPs concentrations. Overall, AgNPs treatment enhanced thermo-tolerance in wheat plants, but the mechanism of AgNPs action needs further investigation at genome and proteome level in wheat plants under heat stress.

Green synthesis and evaluation of silver nanoparticles for antimicrobial and biochemical profiling in Kinnow (Citrus reticulata L.) to enhance fruit quality and productivity under biotic stress.

Green synthesis of silver nanoparticles (AgNPs) by utilising plant extract is an emerging class of nanotechnology. It revolutionizes all the field of biological sciences by synthesizing chemical free AgNPs. In the present study, AgNPs were synthesised by utilising Moringa oleifera leaves as the main reducing and stabilising agent and characterised through UV-visible spectroscopy, zeta analyser, X-ray diffraction spectroscopy (XRD), energy dispersive X-ray (EDX), and scanning electron microscopy (SEM). The different concentrations of biosynthesised AgNPs (10, 20, 30, and 40 ppm) were exogenously applied on the already infected plants (canker) of Citrus reticulata at different day intervals. The AgNPs at a concentration of 30 ppm was found to be most suitable concentration for creating the resistance against canker disease in Citrus reticulata. The enzymatic activities were also explored and it was found that 30 ppm concentration of biosynthesised AgNPs significantly reduced the biotic stress. Fruit quality and productivity parameters were also assessed and it was found that fruit quality and productivity were significant in response to 30 ppm concentration of biosynthesised AgNPs. The present work highlights the potent role of biosynthesised AgNPs, which can be used as biological control of citrus diseases and ultimately improving the quality and productivity of Citrus.

Photolysis of carboxymethylflavin in aqueous and organic solvent: a kinetic study.

This is the first study on the photolysis of carboxymethylflavin (CMF), an intermediate in the photolysis of riboflavin (RF). CMF is photodegraded by removal of side-chain to lumichrome (LC) in acid solution and to LC and lumiflavin (LF) in alkaline solution. It also undergoes alkaline hydrolysis to 1,2-dihydro-1-methyl-2-keto-3-quinoxaline carboxylic acid (KA) and 1,2,3,4-tetrahydro-1-methyl-2,3-dioxoquinoxaline (DQ) by cleavage of isoalloxazine ring. CMF degrades to LC in organic solvents. The formation of LC in acid solution and organic solvents takes place by second-order reaction and those of LC, LF, KA and DQ in alkaline solution by first-order reactions. The values of second-order rate constants for the photolysis of CMF at pH 2.0 to 7.0 are in the range of 1.13 to 2.45 M-1 s-1 and those of first-order rate constants (k obs) at pH 8.0-12.0 from 1.53 to 4.18 × 10-4 s-1 and for the formation of photoproducts from 0.37 to 16.6 × 10-5 s-1. The photolysis of CMF is enhanced, with pH, in the alkaline region since the excited state is sensitive to alkaline hydrolysis. The photolysis and fluorescence quantum yields of CMF in aqueous and organic solvents have been reported. CMF and photoproducts have been assayed spectrofluorimetrically. The mode of CMF photolysis is discussed.

Multicomponent spectrofluorimetric method for the assay of carboxymethylflavin and its hydrolytic products: kinetic applications.

The simultaneous assay of carboxymethylflavin (CMF), an intermediate in the photolysis of riboflavin, and its hydrolytic side-chain cleavage products, lumichrome (LC) (acid solution) and LC and lumiflavin (LF) as well as isoalloxazine ring cleavage products, 1,2-dihydro-1-methyl-2-keto-3-quinoxaline carboxylic acid (KA) and 1,2,3,4-tetrahydro-1-methyl-2,3-dioxo-quinoxaline (DQ) (alkaline solution) has been carried out by a multicomponent spectrofluorimetric method. The method is based on the adjustment of pH of the degraded solutions to 2.0 and extraction of LC and LF with chloroform. The chloroform extract is evaporated to dryness under reduced pressure, the residue dissolved in pH 6.5 citro-phosphate buffer and LC and LF determined at their fluorescence maxima at 478 and 530 nm, respectively. The pH of the aqueous phase is re-adjusted to 6.5 and the solution used for the determination of CMF, KA and DQ at the wavelengths of 530, 443 and 420 nm, respectively. The proposed method has been validated according to ICH guidelines. The calibration curves for CMF and its hydrolytic products are linear in the concentration range of 0.5-5.0 × 10-6  M. The mean recovery ranges from 99.0-102.0% with relative standard deviation (RSD) of 0.19-0.99%. The limit of detection (LOD) and the limit of quantification (LOQ) are in the range of 1.17-1.78 × 10-7  M and 3.55-5.40 × 10-7  M, respectively. The uniformity of molar balance of CMF and degradation products during hydrolytic reactions indicates the accuracy of the proposed method for the spectrofluorimetric assay of the compounds. It has been applied to study the kinetics of hydrolytic reactions of CMF.