Eco-friendly approach for the determination of moxifloxacin in pharmaceutical formulations and biological fluids based on fluorescence quenching of l-tryptophan.

A rapid, novel and cost-effective spectrofluorimetric method developed to determine moxifloxacin (MFX) in pharmaceutical preparations because MFX in a pH 10 medium could reduce the fluorescence intensity of l-tryptophan. The maximum fluorescence excitation and emission wavelengths were found to be 280 and 363 nm respectively. A range of factors affecting fluorescence quenching and the effect of co-existing substances were investigated. Fluorescence quenching values (ΔF = FL-tryptophan - FMoxi-L-tryptophan ) displayed a strong linear relationship with the MFX concentration ranging from 0.2 to 8.0 µg/ml under optimum conditions. The limit of detection was found to be 6.1 × 10-4  µg/ml. The proposed method was shown to be suitable for MFX determination in pharmaceutical tablets and biological fluids by the linearity, recovery and limit of detection. The spectrofluorimetric approach that has been developed is extremely eco-friendly, as evidenced by the fact that all the experimental components and solvents were safe for the environment.

Ecofriendly Approach for the Determination of Selected Aldehydes by Fluorescence Quenching of L-Tryptophan.

It is a fluorescence-based study to examine the interaction between L-tryptophan and a selection of aldehydes, namely furfural (furan-2-carbaldehyde), 3-hydroxybenzaldehyde, salicylaldehyde (2-hydroxybenzaldehyde), 3-nitrobenzaldehyde, and 4-bromobenzaldehyde. The investigation took place in an aqueous environment, revealing that all five aldehydes induced quenching of the fluorescence intensity of L-tryptophan. By employing the Stern-Volmer equation to describe the quenching process, we constructed Stern-Volmer plots and derived Stern-Volmer constants. These constants (KSV) ranged from 2.87 × 104 mol L- 1 to 5.75 × 104 mol L- 1. Notably, the values of the Stern-Volmer constants varied among the different aldehydes, with the following order: 3-hydroxybenzaldehyde(3-HBA) > 4-bromobenzaldehyde (4-BBA) > 3-nitrobenzaldehyde > furan-2-carbaldehyde > salicylaldehyde. Consequently, our findings highlighted 3-hydroxybenzaldehyde as the most potent quencher, while 2-hydroxybenzaldehyde displayed the least sensitivity to quenching. Additionally, we determined the detection and quantification limits for the investigated aldehydes, resulting in ranges of 3.87 × 10- 12 to 8.25 × 10- 6 and 1.29 × 10- 11 to 2.75 × 10- 5, respectively. This research paves the way for the development of novel fluorescence probe-based sensors and offers valuable techniques for analyzing aldehydes within environmental and biological samples.

Enhancements in yield, agronomic, and zinc recovery efficiencies of rice-wheat system through bioactive zinc coated urea application in Aridisols.

BACKGROUND: Zinc (Zn) deficiency and source-dependent Zn fertilization to achieve optimum Zn levels in rice and wheat grains remain global concern for human nutrition, especially in developing countries. To-date, little is known about the effectiveness of bioactive Zn-coated urea (BAZU) to enhance the concentration, uptake, and recovery of Zn in relation to agronomic efficiency in paddy and wheat grains. RESULTS: Field experiments were carried out during 2020-21 on the rice-wheat system at Lahore, Faisalabad, Sahiwal, and Multan, Punjab, Pakistan using four treatments viz.T1 (Urea 46% N @ 185 kg ha-1 + zero Zn), T2 (Urea 46% N @ 185 kg ha-1 + ZnSO4 33% Zn @ 15 kg ha-1), T3 (BAZU 42% N @ 103 kg ha-1 + Urea 46% N @ 62 kg ha-1 + 1% bioactive Zn @ 1.03 kg ha-1) and T4 (BAZU 42% N @ 125 kg ha-1 + Urea 46% N @ 62 kg ha-1 + 1% bioactive Zn @ 1.25 kg ha-1) in quadruplicate under Randomized Complete Block Design. Paddy yield was increased by 13, 11, 12, and 11% whereas wheat grain yield was enhanced by 12, 11, 11, and 10% under T4 at Multan, Faisalabad, Sahiwal, and Lahore, respectively, compared to T1. Similarly, paddy Zn concentration was increased by 58, 67, 65 and 77% (32.4, 30.7, 31.1, and 34.1 mg kg-1) in rice whereas grain Zn concentration was increased by 90, 87, 96 and 97% (46.2, 43.9, 46.7 and 44.9 mg kg-1) in wheat by the application of BAZU (T4) at Multan, Faisalabad, Sahiwal, and Lahore, respectively, in comparison to T1. Zinc recovery was about 9-fold and 11-fold higher in paddy and wheat grains, respectively, under BAZU (T4) treatment relative to T2 while, the agronomic efficiency was enhanced up to 130% and 141% in rice and wheat respectively as compared to T2. CONCLUSION: Thus, T4 application at the rate of 125 kg ha-1 could prove effective in enhancing the rice paddy and wheat grain yield along with their Zn biofortification (∼34 mg kg-1 and ∼47 mg kg-1, respectively) through increased agronomic and Zn recovery efficiencies, the underlying physiological and molecular mechanisms of which can be further explored in future.

Efficacy Of Sub-Tenon's Block In Paediatric Strabismus Surgery In Terms Of Reduction In Oculocardiac Reflex.

Background: Strabismus is a common disease entity in paediatric age group usually requiring surgical intervention under general anaesthesia and Oculocardiac reflex is the most dangerous complications intraoperatively. Various anaesthetic options have been evaluated to mitigate this complication. The objective of this study was to assess the efficacy of sub-tenon's block in paediatric strabismus surgery in terms of reduction in oculocardiac reflex. Methods: This prospective Randomized control trial was conducted at Department of ophthalmology, MTI, Hayatabad Medical complex, Peshawar over a period of six months from 1st July to 31st December 2021. A total of 124, were equally divided in subtenon's group (Group A) and placebo group (Group B). Intraoperatively, patients were assessed for Bradycardia and development of OCR. Data including demographics, intraoperative BP, HR and OCR development were noted and analysed with SPSS version 22. Results: The total number of patients were 124, 62 in each group with a mean age of 9.45±1.61. Sixty-six (53.22%) patients were males and 58 (46.87%) patients were females. At 10-, 20- and 30-minutes interval, the SBP and DBP has no significant difference. At 10, 20, 30 minutes interval, the HR differed significantly (79.33±7.36 vs 66.65±6.83 (p˂0.05), 79.78±7.63 vs 66.57±7.06 (p˂0.05), 79.80±7.78 vs 66.52±7.01 (p˂0.05), respectively. Intraoperative OCR was recorded in 13 (21%) patients in sub-tenon's (Group A) versus 56 (90.30%) patients in placebo (Group B) with statistically significant difference between the two (p<0.05). Conclusion: Sub-tenon's injection of bupivacaine reduces the incidence of Bradycardia and OCR in squint surgery patients after general anaesthesia induction and usage is recommended in routine.

Eco-friendly approach for determination of moxifloxacin in pharmaceutical preparations and biological fluids through fluorescence quenching of eosin Y.

An easy, verified spectrofluorimetric approach was established for the investigation of moxifloxacin in pure forms, pharmaceutical preparations, and biological fluids. The approach involves forming a binary complex of moxifloxacin and eosin Y in an acetate buffer with a pH of 3.6. The highest quenching of eosin Y with moxifloxacin occurs at 545 nm. Several factors, such as pH, buffer type and concentration, and eosin Y concentration, were carefully studied. The calibration graph showed a linear relationship between fluorescence intensity and moxifloxacin concentrations between 0.2 and 10 µg mL-1 with a correlation coefficient of 0.998. It was determined that the detection and quantification limits were 0.0322 µg mL-1 and 0.0976 µg mL-1, respectively. The impact of common excipients was investigated, but no interferences were discovered. Standard forms of moxifloxacin, pharmaceuticals, and biological samples have all been studied using the established methodology. The method, which successfully complied with ICH requirements, was used for the analysis of moxifloxacin in its pure form, pharmaceutical dosage forms, and biological samples. The percentage recoveries obtained were ranged from 99.50 to 102.50% for pharmaceutical preparations and from 100.50 to 102.50% for human blood plasma and urine. Proposed mechanisms for the reaction between moxifloxacin and eosin Y.

Assessment of Attitudes and Intentions towards COVID-19 Vaccines and Associated Factors among General Populations of Pakistan: A Cross-Sectional Study.

OBJECTIVE: The goal of public health in combatting COVID-19 is to increase herd immunity. However, vaccine reluctance makes attaining herd immunity a worldwide challenge. This investigation aimed to identify negative and positive attitudes and intentions about COVID-19 vaccinations. METHODS: A cross-sectional online survey was conducted once free COVID-19 vaccines became available in Pakistan in 2021. 4392 Pakistanis aged 18 and older were surveyed from seven administrative units between 1 July and 30 August 2021. Online structured questionnaires were utilized to collect data using a simple sampling procedure. The questionnaires were divided into three major sections: sociodemographic, health factors, and attitudes toward COVID-19. RESULTS: The survey link was shared with approximately 4500 participants. 97.6%(4392) completed the survey once begun. Frequency, percentage and Chi-square tests were used to analyze statistical data. Most of the participants in the research were men (2703 (61.54%)), 3277 (74.61%) were aged 18-29 years, and 1824 (41.53%) were residents of the Khyber Pakhtunkhwa province. (18.69%) Respondents expressed COVID-19 vaccine hesitancy, whereas 36.66% of participants liked getting the Sinopharm and Sinovac vaccines and (35.84%) of participants preferred the Pfizer vaccine. A significant number of participants (38.05%) were concerned about the vaccine's unexpected side effects Thus, it is essential to realize that many participants were concerned about the vaccine's unexpected side effects. CONCLUSIONS: The overall high level of concern about the unforeseen side effects of COVID-19 vaccines, as well as widespread vaccine hesitancy among Pakistani populations and its predictors, should be taken into account if public health intervention campaigns in Pakistan are changing negative attitudes and improving compliance with regard to COVID-19 vaccines.

Medication Errors and Type 2 Diabetes Management: A Qualitative Exploration of Physicians' Perceptions, Experiences and Expectations From Quetta City, Pakistan.

Background: Type 2 Diabetes-related medication errors are frequently reported from the hospitals and consequently are of major concern. However, such reports are insufficient when developing healthcare settings are pursued in literature. Keeping this inadequacy in mind, we therefore aimed to explore physicians' perceptions, experiences and expectations of medication errors when managing patients with Type 2 Diabetes Mellitus. Methods: A qualitative design was adopted. By using a semi-structured interview guide through the phenomenology-based approach, in-depth, face-to-face interviews were conducted. Physicians practicing at the medicine ward of Sandeman Provincial Hospital, Quetta, were purposively approached for the study. All interviews were audio-taped, transcribed verbatim, and were then analyzed for thematic contents by the standard content analysis framework. Results: Although the saturation was reached at the 13th interview, we conducted additional two interviews to ensure the saturation. Fifteen physicians were interviewed, and thematic content analysis revealed six themes and nine subthemes. Mixed conceptualization and characterization of medication errors were identified. Medication errors were encountered by all physicians however poor understanding of the system, deficiency of logistics and materials were rated as barriers in reporting medication errors. Among contributors of medication errors, physicians themselves as well as dispensing and patient-related factors were identified. Physicians suggested targeted training sessions on medication error-related guidelines and reporting system. Parallel, establishment of an independent unit, involving the pharmacists, and strict supervision of paramedics to minimize medication errors was also acknowledged during data analysis. Conclusion: With a longer life expectancy and a trend of growing population, the incidences of medication errors are also expected to increase. Our study highlighted prescribing, dispensing and administration phases as contributing factors of medication errors. Although, physicians had poor understanding of medication errors and reporting system, they believed getting insights on guidelines and reporting system is essential. A review of admission and discharge reconciliation must be prioritized and a culture of teamwork, communication and learning from mistakes is needed.

Social Media Improves Students' Academic Performance: Exploring the Role of Social Media Adoption in the Open Learning Environment among International Medical Students in China.

Numerous studies have examined the role of social media as an open-learning (OL) tool in the field of education, but the empirical evidence necessary to validate such OL tools is scant, specifically in terms of student academic performance (AP). In today's digital age, social media platforms are most popular among the student community, and they provide opportunities for OL where they can easily communicate, interact, and collaborate with each other. The authors of this study aimed to minimize the literature gap among student communities who adopt social media for OL, which has positive impacts on their AP in Chinese higher education. We adopted social constructivism theory (SCT) and the technology acceptance model (TAM) to formulate a conceptual framework. Primary data containing 233 questionnaires of international medical students in China were collected in January 2021 through the survey method. The gathered data were analyzed through structural equation modeling techniques with SmartPLS 3. The results revealed that perceived usefulness, perceived ease of use, and interactions with peers have positive and significant influence on OL. In addition, OL was found to have positive and significant influence on students' AP and engagement. Lastly, engagement showed a positive impact on students' AP. Thus, this study shows that social media serves as a dynamic tool to expedite the development of OL settings by encouraging collaboration, group discussion, and the exchange of ideas between students that reinforce their learning behavior and performance.

Performance, Health, and Psychological Challenges Faced by Students of Physical Education in Online Learning during COVID-19 Epidemic: A Qualitative Study in China.

The spread of COVID-19 has led students to take classes online (rather than face-to-face) worldwide, including in China. For this study, we conducted qualitative focus group discussions to identify the experience of and difficulties faced by online physical education students in higher education taking online classes, including the impact on their physical activity performance, as well as some health problems they face while taking online classes during the quarantine period, such as weight gain, depression, and anxiety. Finally, utilizing Mayer's learning model as a conceptual framework, we propose a method that addresses how to effectively manage an optimal future learning system for physical education students, both during and after the COVID-19 outbreak situation. During the isolation period of COVID-19, the required equipment for the participants was rarely available at home while attending the online classes, which inevitably reduced the number of physical education units that could be conveyed. This resulted in a transfer of attention from competition to underperformance, weight gain, and adverse psychological conditions. We conclude that it is important to review and systematize the methods of online physical education learning, particularly highlighting the cultural and educational characteristics of different countries, and to investigate the effectiveness of online physical education as a whole.

Social Media for Knowledge Acquisition and Dissemination: The Impact of the COVID-19 Pandemic on Collaborative Learning Driven Social Media Adoption.

During the COVID-19 outbreak, educational institutions were closed, and students worldwide were confined to their homes. In an educational environment, students depend on collaborative learning (CL) to improve their learning performance. This study aimed to increase the understanding of social media adoption among students during the COVID-19 pandemic for the purpose of CL. Social media provides a learning platform that enables students to easily communicate with their peers and subject specialists, and is conducive to students' CL. This study addresses the key concept of CL during the COVID-19 pandemic by assessing social media use among students in higher education. The relationship between social media use and students' performance is crucial to understanding the role of social media during a pandemic. This study is based on constructivism theory and the technology acceptance model. Structural equation modeling was used to analyze the conceptual model using SmartPLS. The research findings indicate that social media plays an important role during the pandemic because it provides opportunities for students to enhance CL under the aforementioned situations. This study makes noteworthy theoretical and practical contributions.

A characteristic study of Zea mays L. (sweet corn) cobs for synthetic dye degradation from aqueous media.

The current study reports a systematic methodology of Zea mays L. (sweet corn) cobs (ZMLC) for the sequestration of synthetic dye (gentian violet) from aqueous solutions. Adsorbent was scrutinized by using scanning electron microscopy, Fourier transform infra-red spectrometry with pHpzc determination. The impact of various adsorption parameters including pH effect, ZMLC (sorbent) dosage, temperature, concentration and shaking time was examined. The equilibrium sorption isotherms were determined by the batch method from 283 to 303 K at pHpzc. Adsorption data were adjusted to four isothermal models: Langmuir, Freundlich, Dubinin-Radushkevich and Temkin's models, which presented the best adjustment to Freundlich, Dubinin-Radushkevich and Temkin's at 283 K. The kinetic profile fitted well to the pseudo-second order kinetic equation at three distinct concentrations 600, 700, 800 mg/L. Maximum sorption capacity was gained up to 700 mg.g-1 for gentian violet at pH 3, respectively. The adsorption process is endothermic, non-spontaneous, favorable thermodynamically due to positive values of entropy and Gibbs free energy and randomness decreases during the adsorption process. Furthermore, after biosorption onto ZMLC the dye can be desorbed effectively by using mineral base KOH solution. Consequently, the ZMLC is said to be a promising biosorbent to remediate gentian violet-contaminated water as well as wastewater.

False negative rate of COVID-19 PCR testing: a discordant testing analysis.

BACKGROUND: COVID-19 is diagnosed via detection of SARS-CoV-2 RNA using real time reverse-transcriptase polymerase chain reaction (rtRT-PCR). Performance of many SARS-CoV-2 rtRT-PCR assays is not entirely known due to the lack of a gold standard. We sought to evaluate the false negative rate (FNR) and sensitivity of our laboratory-developed SARS-CoV-2 rtRT-PCR targeting the envelope (E) and RNA-dependent RNA-polymerase (RdRp) genes. METHODS: SARS-CoV-2 rtRT-PCR results at the Public Health Laboratory (Alberta, Canada) from January 21 to April 18, 2020 were reviewed to identify patients with an initial negative rtRT-PCR followed by a positive result on repeat testing within 14 days (defined as discordant results). Negative samples from these discordant specimens were re-tested using three alternate rtRT-PCR assays (targeting the E gene and N1/N2 regions of the nucleocapsid genes) to assess for false negative (FN) results. RESULTS: During the time period specified, 95,919 patients (100,001 samples) were tested for SARS-CoV-2. Of these, 49 patients were found to have discordant results including 49 positive and 52 negative swabs. Repeat testing of 52 negative swabs found five FNs (from five separate patients). Assuming 100% specificity of the diagnostic assay, the FNR and sensitivity in this group of patients with discordant testing was 9.3% (95% CI 1.5-17.0%) and 90.7% (95% CI 82.6-98.9%) respectively. CONCLUSIONS: Studies to understand the FNR of routinely used assays are important to confirm adequate clinical performance. In this study, most FN results were due to low amounts of SARS-CoV-2 virus concentrations in patients with multiple specimens collected during different stages of infection. Post-test clinical evaluation of each patient is advised to ensure that rtRT-PCR results are not the only factor in excluding COVID-19.

Impact of Physical Activity on Challenging Obesity in Pakistan: A Knowledge, Attitude, and Practice (KAP) Study.

Physical activity (PA) refers to any action produced by skeletal muscle that consumes energy. According to the World Health Organization (WHO), PA is the primary element that can improve health at the community level. Obviously, PA plays an important role in the social, physical, and mental development of men and women, as well as in balancing weight. However, the large-scale negative impacts of physical inactivity on health-related issues are also recognized globally, such as obesity, which is the source of many non-communication diseases (NCDs). In Pakistan alone, 46% of deaths occur due to NCD. The majority of NCD deaths are linked to obesity, and Pakistan is the ninth most obese country in the world. Research on obesity caused by sedentary work in Pakistan is lacking, especially among university employees. To fill this gap, the current study mainly focuses on the rising non-communicable disease (NCD) rates among university employees in Pakistan due to a lack of exercise (obesity, in this case), with the help of a self-designed knowledge, attitude, and practice (KAP) questionnaire. Five universities in the Sindh province of Pakistan were surveyed (n = 276), following the concept of Yin-Yang as a theoretical lens. The results of the current study show that the knowledge, behaviors, and attitudes of university employees have a great influence on their body mass index (BMI). The study shows that Pakistani residents' (especially teaching staff) perceptions and attitudes towards obesity and PA have been instructive, but their practices need to be improved.

Designing Star-Shaped Subphthalocyanine-Based Acceptor Materials with Promising Photovoltaic Parameters for Non-fullerene Solar Cells.

Star-shaped three-dimensional (3D) twisted configured acceptors are a type of nonfullerene acceptors (NFAs) which are getting considerable attention of chemists and physicists on account of their promising photovoltaic properties and manifestly promoted the rapid progress of organic solar cells (OSCs). This report describes the peripheral substitution of the recently reported highly efficient 3D star-shaped acceptor compound, STIC, containing a 2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile (IC) end-capped group and a subphthalocyanine (SubPc) core unit. The 3D star-shaped SubPc-based NFA compound STIC is peripherally substituted with well-known end-capped groups, and six new molecules (S1-S6) are quantum chemically designed and explored using density functional theory (DFT) and time-dependent DFT (TDDFT). Density of states (DOS) analysis, frontier molecular orbital (FMO) analysis, reorganization energies of electrons and holes, open-circuit voltage, transition density matrix (TDM) surface, photophysical characteristics, and charge-transfer analysis of selected molecules (S1-S6) are evaluated with the synthesized reference STIC. The designed molecules are found in the ambience of 2.52-2.27 eV with a reduction in energy gap of up to 0.19 eV compared to R values. The designed molecules S3-S6 showed a red shift in the absorption spectrum in the visible region and broader shift in the range of 605.21-669.38 nm (gas) and 624.34-698.77 (chloroform) than the R phase values of 596.73 nm (gas) and 616.92 nm (chloroform). The open-circuit voltages are found with the values larger than R values in S3-S6 (1.71-1.90 V) and comparable to R in the S1 and S2 molecules. Among all investigated molecules, S5 due to the combination of extended conjugation and electron-withdrawing capability of end-capped acceptor moiety A5 is proven as the best candidate owing to promising photovoltaic properties including the lowest band gap (2.27 eV), smallest λe = 0.00232 eV and λh = 0.00483 eV, highest λmax values of 669.38 nm (in gas) and 698.77 nm (in chloroform), and highest V oc = 1.90 V with respect to HOMOPTB7-Th-LUMOacceptor. Our results suggest that the selected molecules are fine acceptor materials and can be used as electron and/or hole transport materials with excellent photovoltaic properties for OSCs.

Design, synthesis, and spasmolytic activity of thiophene-based derivatives via Suzuki cross-coupling reaction of 5-bromothiophene-2-carboxylic acid: their structural and computational studies.

In the current research work, a facile synthesis of a series of novel thiophene-based derivatives of 5-bromothiophene-2-carboxylic acid ( 1 ) have been synthesized. All analogs ( 5a - 5e , 10a - 10f ) were obtained from the coupling reaction of 5-bromothiophene-2-carboxylic acid ( 1 ) and different arylboronic acids with moderate-to-good yields under controlled and optimal conditions. The structures of the newly synthesized compounds were characterized through spectral analysis and their spasmolytic activity, and most of the compounds exhibited potentially good spasmolytic effect. Among the synthesized analogs, compound phenethyl 5-(3,4-dichlorophenyl)thiophene-2-carboxylate ( 10d ) particular showed an excellent spasmolytic effect with an EC 50 value of 1.26. All of the compounds were also studied for their structural and electronic properties by density functional theory (DFT) calculations. Through detailed insight into frontier molecular orbitals of the compounds and their different reactivity descriptors, it was found that the compounds 10c and 5c are the most reactive, while 10a is the most stable in the series. Furthermore, compounds 10c and 5c showed a very good NLO response with the highest ß values.

Prevalence of Depressive Symptoms Among University Students in Pakistan: A Systematic Review and Meta-Analysis.

Background: In Pakistan, almost 30% population is between 15 to 29 years of age, with university enrollment rates of 10-15%. Although there is a growing concern on mental health of university students across the globe, studies from low and middle income countries such as Pakistan are scarce. We conducted a systematic review and meta-analysis of prevalence of depressive symptoms among Pakistani university students. Methods: PubMed, Web of Science, PsycInfo and Google Scholar were searched between 15 to 30th January 2020. Cross-sectional and longitudinal studies, published till 31st December 2019 were included. Data on study characteristics and prevalence of depressive symptoms were extracted. Meta-analysis was conducted using random effects models. To estimate subgroup difference based on study characteristics, meta-regression and sub-group analyses were conducted. Results: In total, 26 studies involving 7,652 participants were included in review. Overall prevalence of depressive symptoms was 42.66% (95% CI: 34.82% to 50.89%), with significant heterogeneity among studies. Subgroup analyses revealed a significant difference in prevalence estimates based on depression screening instrument and study major. Statistically significant differences were observed among studies employing different psychometric scales (test for subgroup differences, Q = 21.92, p < 0.05) and between students from different study majors (test for subgroup differences, Q = 3.76, p = 0.05). Conclusion: Our study found that overall prevalence of depressive symptoms among university students in Pakistan was 42.66%, however, findings should be interpreted with caution. Large scale epidemiological surveys using valid and reliable tools are needed to better estimate prevalence of depression among Pakistani university students.

A Validated Spectrofluorimetric Method for the Determination of Moxifloxacin in Its Pure Form, Pharmaceutical Preparations, and Biological Samples.

This research work presents a simple, sensitive, selective, economic, and widely applicable and interferences-free spectrofluorimetric method estimating moxifloxacin in the pure form, commercial formulations and biological samples. The method is based on the reaction of moxifloxacin with Ce(IV) in an acidic medium to generate fluorescent active species Ce(III). The excitation and emission of the fluorescent species are 250 and 362 nm, respectively. Different variables that might influence the oxidation of moxifloxacin, including the Ce(IV) concentration and volume, the effect of temperature and the heating time, the type of acids and its concentration were analyzed and boosted. The linearity was observed in the concentration range of 0.2 - 5.0 µg mL-1 with a correlation coefficient of 0.9991. The limit of detection and the limit of quantification were calculated and observed to be 0.016 and 0.056 µg mL-1 respectively. The effects of the common excipients and some co-administrated drugs usually used in the determination of moxifloxacin were investigated, and no interferences were noted. The planned method has been successfully practical for the analysis of moxifloxacin in its pure form, in pharmaceutical products and in biological samples. The obtained percent recoveries ranged from 95.50 to 101.37% for pharmaceutical products and from 95.15 to 103.18% for human blood plasma and urine.

Phenanthrene Fluorescence Quenching in Aqueous Sodium Dodecyl Sulphate (SDS) and Determination of Important Metal Ions.

In this work fluorescence quenching of phenanthrene by heavy metal ions (Fe3+, Cu2+, Cr3+ Pb2+, Ni2+) was studied in aqueous solution of sodium dodecyl sulphate (SDS). Fluorescence quenching was higher in lower SDS concentration and decreased with the increase in SDS concentration. Phenanthrene quenching by heavy metal ions were explained by Stern-Volmer equations and the Stern-Volmer constants were observed in the order Fe3+ > Cu2+ > Cr3+ > Pb2+ > Ni2+ respectively. Stern-Volmer constants reflect the sensitivity of the method for the studied metal ions. Limit of detection which was calculated as three time standard deviation of the blank for n = 10 (3×SD) ranged from 1.504×10-6-1.113×10-5 molL-1and limit of quantification which was calculated as ten times standard deviation of the blank for n = 10 (10×SD) ranged from 5.013×10-6-3.371×10-5 mol L-1. Phenanthrene fluorescence quenching by the studied metal ions shows good reproducibility and the used of anionic surfactant increases the fluorescence quenching of phenanthrene by heavy metal ions. This method could be very effective for the determination of metal ions.

Evaluating toxicity of copper(II) oxide nanoparticles (CuO-NPs) through waterborne exposure to tilapia (Oreochromis mossambicus) by tissue accumulation, oxidative stress, histopathology, and genotoxicity.

Metal oxide nanoparticles are widely used in industries, and peak level can be confirmed in their surroundings. In the present study, the sub-lethal effects of CuO-NPs from low to high concentration as 0.5 to 1.5 mg/L were observed in tilapia (Oreochromis mossambicus). Accumulation of copper from CuO-NPs was increased with the increase in doses, and maximum accumulation was found in the gill than liver and muscles. The increased lipid peroxidation level was observed in the gill as compared to liver, and the similar results were obtained in catalase and glutathione while superoxide dismutase level was higher in the liver than gills. In histological alterations, gill edema, curved tips, fusion of gill lamellae, and thickening of primary and secondary gill lamellae were observed. Necrosis and apoptosis with condensed nuclear bodies and pyknotic nuclei were observed in the liver at the highest dose concentration. In a genotoxic study, the highest value of % tail DNA and olive tail movement was observed with increasing concentrations. Copper oxide nanoparticles has greater potential to accumulate in the soft tissues, which may cause respiratory distress such as oxidative stress, induction of antioxidant defense by raising glutathione, organ pathology, and genotoxicity.