Metallofullerenes as Robust Single-Atom Catalysts for Adsorption and Dissociation of Hydrogen Molecules: A Density Functional Study.

Hydrogen is currently considered as the best alternative for traditional fuels due to its sustainable and ecofriendly nature. Additionally, hydrogen dissociation is a critical step in almost all hydrogenation reactions, which is crucial in industrial chemical production. A cost-effective and efficient catalyst with favorable activity for this step is highly desirable. Herein, transition-metal-doped fullerene (TM@C60) complexes are designed and investigated as single-atom catalysts for the hydrogen splitting process. Interaction energy analysis (Eint) is also carried out to demonstrate the stability of designed TM@C60 metallofullerenes, which reveals that all the designed complexes have higher thermodynamic stability. Furthermore, among all the studied metallofullerenes, the best catalytic efficiency for hydrogen dissociation is seen for the Sc@C60 catalyst Ea = 0.13 eV followed by the V@C60 catalyst Ea = 0.19 eV. The hydrogen activation and dissociation processes over TM@C60 metallofullerenes is further elaborated by analyzing charge transfer via the natural bond orbital and electron density difference analyses. Additionally, quantum theory of atoms in molecule analysis is carried out to investigate the nature of interatomic interactions between hydrogen molecules and TMs@C60 metallofullerenes. Overall, results of the current study declare that the Sc@C60 catalyst can act as a low cost, highly efficient, and noble metal-free single-atom catalyst to efficiently catalyze hydrogen dissociation reaction.

Detection of linezolid resistance cfr gene among MRSA isolates.

BACKGROUND: Linezolid (Oxazolidinones) is commonly used against a variety of Gram-positive infections, especially methicillin-resistant Staphylococcus aureus (MRSA). The emerging resistance to linezolid curtail the treatment of infections caused by MRSA and other Gram-positive bacteria. Presence of cfr gene plays a crucial role in Linezolid resistance. OBJECTIVE: Present study was aimed to detect cfr gene among clinical MRSA isolates. MATERIALS AND METHODS: The suspected Staphylococcus aureus isolates were processed through Kirby Bauer disc diffusion methods for the confirmation of MRSA strains. Phenotypic Linezolid resistance was determined through broth micro-dilution method. The plasmid and DNA of Linezolid resistant isolates were subjected to molecular characterization for the presence of cfr gene. RESULTS: Among 100 Staphylococcus aureus isolates, 85 of them were confirmed as MRSA isolates. Categorically, 65% MRSA isolates were sensitive to linezolid with MIC lower than 8 µg/ml, whereas, 35% of them were resistant to linezolid having MIC greater than 8 µg/ml. MIC level of 128 µg/ml was observed among 3.5% of the resistant isolates. Similarly, MIC level of 64 µg/ml, 32 µg/ml, 16 µg/ml and 8 µg/ml were noted for 3.5%, 4.7%, 8.2% and 15.3% isolates respectively. Linezolid resistance cfr gene was detected only in 9.4% of the resistant isolates. CONCLUSION: Multi drug resistance among MRSA isolates is keenly attributed to the presence of cfr gene as evident in the present study, and horizontal dissemination of cfr gene among MRSA strains is accredited to cfr-carrying transposons and plasmids.

Computational investigation of a covalent triazine framework (CTF-0) as an efficient electrochemical sensor.

In the current study, a covalent triazine framework (CTF-0) was evaluated as an electrochemical sensor against industrial pollutants i.e., O3, NO, SO2, SO3, and CO2. The deep understanding of analytes@CTF-0 complexation was acquired by interaction energy, NCI, QTAIM, SAPT0, EDD, NBO and FMO analyses. The outcome of interaction energy analyses clearly indicates that all the analytes are physiosorbed onto the CTF-0 surface. NCI and QTAIM analysis were employed to understand the nature of the non-covalent interactions. Furthermore, SAPT0 analysis revealed that dispersion has the highest contribution towards total SAPT0 energy. In NBO analysis, the highest charge transfer is obtained in the case of SO3@CTF-0 (-0.167 e-) whereas the lowest charge transfer is observed in CO2@CTF-0. The results of NBO charge transfer are also verified through EDD analysis. FMO analysis revealed that the highest reduction in the HOMO-LUMO energy gap is observed in the case of O3 (5.03 eV) adsorption onto the CTF-0 surface, which indicates the sensitivity of CTF-0 for O3 analytes. We strongly believe that these results might be productive for experimentalists to tailor a highly sensitive electrochemical sensor using covalent triazine-based frameworks (CTFs).

Biogenic Synthesis of Silver Nanoparticles Using Phagnalon niveum and Its In Vivo Anti-Diabetic Effect against Alloxan-Induced Diabetic Wistar Rats.

Background: Type-2 diabetes mellitus (T2DM) is a non-communicable, life-threatening syndrome that is present all over the world. The use of eco-friendly, cost-effective and green synthesised nanoparticles (NPs) as a medicinal therapy in the treatment of T2DM is an attractive option. Aim: The present study aimed to evaluate the anti-diabetic potential of the phyto-synthesised silver nanoparticles (AgNPs) obtained from Phagnalon niveum plant methanolic extract. Methods: The green synthesised AgNPs made from Phagnalon niveum plant methanolic extract were analysed by Ultraviolet-Visible (UV-Vis) spectroscopy, and the functional groups involved in the reduction of the silver ions (Ag+) were characterised by Fourier Transform Infrared (FTIR) spectroscopy. The size and crystallinity were assessed via X-ray Diffraction (XRD). The morphology of AgNPs was confirmed using Scanning Electron Microscopy (SEM). The amount of silver (Ag) was estimated via energy dispersive X-ray (EDX) analysis. An intraperitoneal injection of 200 mg alloxan per kg albino Wistar rats' body weight, at eight weeks old and weighing 140-150 g, was used to induce diabetes mellitus (N = 25; n = 5/group). Group C: untreated normal control rats that only received distilled water, group DAC: diabetic control rats that received alloxan 200 mg/Kg body weight, DG: diabetic rats treated with glibenclamide at 0.5 mg/kg body weight, DE: diabetic rats that received methanolic P. niveum extract at 10 mg/Kg body weight, and DAgNPs: diabetic rates that received AgNPs synthesised from P. niveum at 10 mg/kg body weight. The blood glucose levels were monitored on days 0, 7, and 14, while lipid, liver, and kidney profiles were checked after dissection at the end of treatment (day 21). On the final day of the period study (day 21), an oral glucose tolerance test was carried out by administering orally 2 g/kg body weight of glucose to the respective groups, and the blood glucose level was checked. A fasting glucose level was measured using a glucometer. Urine samples were collected from each animal and analysed using lab-made assay kits for glucose, bilirubin, pH, leukocytes, and nitrite, among other factors. For statistical analyses, a one-way ANOVA and Dunnett's test were applied. Results: The green-mediated synthesis of AgNPs using P. niveum methanolic extract produced spherical and mono-dispersed NPs with a size ranging from 12 to 28 nm (average: 21 nm). Importantly, a significant reduction of blood glucose levels and an increase in body weight, as well as a remarkable improvement in lipid, liver, and kidney profiles, were noticed. Conclusions: The biosynthesised AgNPs significantly improved the abnormalities in body weight, urine, and serum levels, indicating that it is a promising anti-diabetic agent.

Association of Virulence Genes with Antibiotic Resistance in Pakistani Uropathogenic E. coli Isolates.

BACKGROUND: Escherichia coli various strains can cause alarmingly serious infections. Countries like Pakistan harbour the class of bacteria with one of the highest rates of resistance, but very little has been done to explore their genetic pool. OBJECTIVES: This study was designed to find out the frequency of virulence genes of Uropathogenic E. coli and their association with antibiotic resistance along with the evolutionary adaptation of the selected gene through the phylogenetic tree. METHODS: Isolates from 120 urinary tract infected patients were collected. Antibiotic sensitivity was detected by the disk diffusion method and DNA extraction was done by the boiling lysis method followed by PCR-based detection of virulence genes. The final results were analysed using the chi-square test. RESULTS: The isolates were found to be least susceptible to nalidixic acid, followed by ampicillin, cotrimoxazole, cefotaxime, ciprofloxacin, aztreonam, amoxicillin, gentamycin, nitrofurantoin and imipenem. The iucC was the most common virulence gene among the resistant isolates. About 86% of the collected samples were found to be multi-drug resistant. Statistical analysis revealed a significant association between the iucC gene and resistance to ampicillin (P=0.03) and amoxicillin (P=0.04), and also between fimH and resistance to aztreonam (P=0.03). CONCLUSION: This study unravels the uncharted virulence genes of UPEC in our community for the very first time. We report a high frequency of the iucC and fimH virulence genes. This, along with their positive association with resistance to beta-lactam antibiotics in the studied community, indicates their important role in the development of complicated UTIs.

Molecular Heterogeneity of ß-Thalassemia in the Kohat Region, Khyber Pakhtunkhwa Province, Pakistan.

The present study was intended to report the incidence of the most frequently occurring ß-thalassemia (ß-thal) mutations in the Kohat region [Khyber Pakhtunkhwa (KP) Province, Pakistan], their inheritance pattern in patients, and consanguinity in the parents. Moreover, this study could provide valuable information regarding thalassemia diagnoses such as prenatal diagnosis (PND), genetic counseling and carrier screening for controlling the affected births in the population. During this study, 160 peripheral blood samples of affected patients, their parents and siblings were collected from 25 discrete families having at least one child needing regular blood transfusions from different areas of the Kohat region. ß-Thalassemia mutations found in the population were screened via the amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). A total of 320 alleles was evaluated for the presence of six ß-thal mutations. Of these six ß-thal mutations, the frameshift codons (FSC) 8/9 (+G) (HBB: c.27_28insG) was found to be the most frequent in the studied population, and more interestingly, followed by IVS-I-5 (G>C) (HBB: c.92+5G>C) and FSC 5 (-CT) (HBB: c.17_18delCT). The findings of the present study show differences with previous results from other regions of the Pashtun population, which demarcates the heterogeneity in mutations found in the Pashtun ethnicity. These observations may help in implementing parental meetings about disease recurrence in future, large scale mutation screening and PND for the population of the Kohat region and also the whole Pashtun ethnicity.

Hexane soluble extract of Mallotus philippensis (Lam.) Muell. Arg. root possesses anti-leukaemic activity.

BACKGROUND: Mallotus philippensis (Lam.) Muell. Arg. is a well known medicinal plant of Asia and Australia. Various compounds from different aerial parts of the plant have been reported possessing potent pharmacological, antiviral, antibacterial and cytotoxic activities. We were interested to determine the effects of some root extracts from M. philippensis on human promyelocytic leukemia HL-60 cell proliferation, cell cycle regulators and apoptosis in order to investigate its anti-leukemic potential. RESULTS: Root extract of M. philippensis was initially extracted in organic solvents, hexane, ethyl acetate, and n-butanol. The hexane extract showed highest toxicity against p53-deficient HL-60 cells (IC50 1.5 mg dry roots equivalent/ml medium) after 72 h and interestingly, inhibition of cell proliferation was preceded by the upregulation of the proto-oncogenes Cdc25A and cyclin D1 within 24 h. The hexane extract induced 18% apoptosis after 48 h of treatment. Chemical composition of the hexane extract was analyzed by GC-MS and the 90% fragments were matched with polyphenolic compounds. CONCLUSIONS: The present study confirms that the hexane fraction of M. philippensis root extract possesses anti-leukemic activity in HL-60 cells. The polyphenols were the main compounds of the hexane extract that inhibited proliferation and induced apoptosis.

Prevalence of class A and AmpC ß-lactamases in clinical Escherichia coli isolates from Pakistan Institute of Medical Science, Islamabad, Pakistan.

In this study, 121 Escherichia coli samples isolated from clinical specimens obtained from Pakistan Institute of Medical Science, Islamabad, Pakistan, were analyzed for extended-spectrum ß-lactamases (ESBLs) and AmpC ß-lactamases using disk-diffusion assay and polymerase chain reaction. Of the isolates, 78 and 43 were identified as ESBL and AmpC producers, respectively. The highest resistance (89%) was observed against cefotaxime, followed by ciprofloxacin (87.6%) and cefepime (87%). Genetic analysis showed the presence of different class A and class C ß-lactamase genes, either alone (44.7%) or in combination (53.6%). CTX-M (57.7%) was the most prevalent among class A, followed by TEM (20.3%) and SHV (15.4%). CIT (including LAT-1 to LAT-4, CMY-2 to CMY-7, and BIL-1) and MOX (including MOX-1, MOX-2, CMY-1, and CMY-8 to CMY-11) family-specific plasmid-mediated AmpC ß-lactamases were the most prevalent among these isolates. Our study showed that both class A and class C ß-lactamases contributed to cephalosporin resistance in the E. coli isolates, thereby limiting therapeutic options. Co-expression of these enzymes may further hinder the identification of ESBLs, which is a critical step for designing a successful treatment for multidrug-resistant E. coli.