Benzimidazole as a Privileged Scaffold in Drug Design and Discovery.

Benzimidazole is a privileged drug design and discovery scaffold with various phar-macological activities, including antimicrobial, anticancer, antitubercular, anti-inflammatory, an-tidiabetic, antihypertensive, antimalarial, and many more. This scaffold can be observed in the structure of numerous FDA-approved drugs and employed in medicinal chemistry to develop novel bioactive compounds through rational drug design. Its broad pharmacological significance is due to physicochemical attributes, including H-bond donor-acceptor efficiency, π-π stacking interactions, and hydrophobic interactions; these characteristics enable benzimidazole derivatives to bind with macromolecules efficiently. This article emphasizes mechanisms, SAR, and docking studies to unveil benzimidazole's various active hybrids accountable for diversified activities. It will assist researchers in strategically designing various novel benzimidazole-endowed hybrids to develop clinically active therapeutic candidates.

Aerosol-PM2.5 Dynamics: In-situ and satellite observations under the influence of regional crop residue burning in post-monsoon over Delhi-NCR, India.

The increasing air pollution in the urban atmosphere is adversely impacts the environment, climate and human health. The alarming degradation of air quality, atmospheric conditions, economy and human life due to air pollution needs significant in-depth studies to ascertain causes, contributions and impacts for developing and implementing an effective policy to combat these issues. This work lies in its multifaceted approach towards comprehensive understanding and mitigating severe pollution episodes in Delhi and its surrounding areas. We investigated the aerosol dynamics in the post-monsoon season (PMS) from 2019 to 2022 under the influence of both crop residue burning and meteorological conditions. The study involves a broad spectrum of factors, including PM2.5 concentrations, active fire events, and meteorological parameters, shedding light on previously unexplored studies. The average AOD550 (0.79) and PM2.5 concentration (140.12 µg/m³) were the highest in 2019. PM2.5 was higher from mid-October to mid-November each year, exceeding the WHO guideline of 15 µg/m³ (24 h) by 27-34 times, signifying a public health emergency. A moderate to strong correlation between PM2.5 and AOD was found (r = 0.65) in 2021. The hotspot region accounts for almost 50% (2019), 47.51% (2020), 57.91% (2021) and 36.61% (2022) of the total fire events. A statistically significant negative non-linear correlation (r) was observed between wind speed (WS) and both AOD and PM2.5 concentration, influencing air quality over the region. HYSPLIT model and Windrose result show the movement of air masses predominated from the North and North-West direction during PMS. This study suggest to promotes strategies such as alternative waste management, encouraging modern agricultural practices in hot-spot regions, and enforcing strict emission norms for industries and vehicles to reducing air pollution and its detrimental effects on public health in the region and also highlights the need for future possibilities of research to attract the global attention.

Biomechanical Analysis of Trapezoidal Thread Screw-Rod Fixation in Pedicle Section of Cervical Spine: A Finite-Element Analysis.

Background: Cervical pedicle screw-rod fixation presents a complex approach in spinal surgery, offering enhanced spine stabilization in variable conditions considering traumatic injuries, degenerative changes, as well as orthopaedic and oncological ailments. This technique employs small diameter screw implants strategically placed to bolster the mechanical integrity of the spine. Notably, it involves minimally invasive procedures, resulting in smaller incisions and reduced patient discomfort. This study aims to assess the effects of trapezoidal thread screws in pedicle sections of the cervical spine during flexion-extension loadings, focusing on factors such as range of motion (ROM), implant stress, and stress on adjacent bone. Methods: Utilizing CT scan data, a finite element model of the cervical spine (C2-C7 vertebrae) was prepared. Trapezoidal thread screws were integrated into a single-level pedicle screw-rod fixation at the C5-C6 vertebrae. The C2 vertebra were given a compressive load of 50 N along with a moment of 1 Nm, resulting in the immobilization of the C7. Results and Discussion: The results indicate a reduction in ROM at the C5-C6 level by 69% to 77% compared to the intact spine during flexion-extension loading, with a slight increase in ROM observed at adjacent cervical spine levels. Stress analysis revealed that the trapezoidal thread screws induced stresses ranging from 24 MPa to 29 MPa in PEEK trapezoidal screw-rod implants, which fall below the material's yield stress. Conclusions: This suggests that the trapezoidal thread profile may be advantageous in minimizing stress concentration, attributed to its larger contact area with the vertebrae bone between the threads.

Reversible Intrapore Redox Cycling of Platinum in Platinum-Ion-Exchanged HZSM-5 Catalysts.

Isolated platinum(II) ions anchored at acid sites in the pores of zeolite HZSM-5, initially introduced by aqueous ion exchange, were reduced to form platinum nanoparticles that are stably dispersed with a narrow size distribution (1.3 ± 0.4 nm in average diameter). The nanoparticles were confined in reservoirs within the porous zeolite particles, as shown by electron beam tomography and the shape-selective catalysis of alkene hydrogenation. When the nanoparticles were oxidatively fragmented in dry air at elevated temperature, platinum returned to its initial in-pore atomically dispersed state with a charge of +2, as shown previously by X-ray absorption spectroscopy. The results determine the conditions under which platinum is retained within the pores of HZSM-5 particles during redox cycles that are characteristic of the reductive conditions of catalyst operation and the oxidative conditions of catalyst regeneration.

Oral Hygiene Status, Salivary and Microbiological Parameters Among Visually Impaired and Normal-Sighted Children After Specialized Oral Health Education: An Interventional Study.

Aim and objectives To assess oral hygiene status and salivary and microbiological parameters among 12 to 15-year-old visually impaired and normal-sighted children before and after oral health education (OHE). Methodology An interventional study was conducted among 25 visually impaired children (Group A) and 25 normal-sighted children (Group B) in the age range of 12 to 15 years. Simple random sampling was used to select the study participants. A questionnaire was designed to record socio-demographic data and the dietary habits of the children on pre-decided days. The oral hygiene practices and the Decayed Missing Filled Teeth (DMFT) index were recorded, and salivary physicochemical parameters for all the selected children were evaluated, followed by saliva collection for microbial analysis. After baseline assessment, the Audio-Tactile Performance technique for Group A and the animated visual performance technique for Group B children were used to impart OHE. Periodic assessments of salivary parameters were conducted at one-month and three-month intervals. Unpaired T test/Mann-Whitney U test, repeated measures analysis of variance (ANOVA)/Friedman test, followed by Bonferroni's post hoc test were carried out to determine the difference between and within groups, respectively. All statistical tests were performed at a significance level of 5%. Results Group A demonstrated a greater change in salivary pH (6.20 ± 0.41 to 6.96 ± 0.20), salivary buffering capacity (5.80 ± 0.82 to 7.20 ± 0.65), and Streptococcus mutans count (9.36 ± 0.41 to 8.7 ± 0.45 x 104 CFU/mL) when compared to Group B. Group B demonstrated a greater Lactobacillus acidophilus count reduction (7.96 ± 0.66 to 7.50 ± 0.64 x 104 CFU/mL) when compared to Group A. Conclusion The appropriate use of specialized OHE holds particular significance in the improvement of oral hygiene status and salivary parameters, along with a reduction in the bacterial count in both visually impaired children and normal-sighted children.

Hesperetin blocks poxvirus replication with a low tendency to select for drug-resistant viral variants.

In this study, we demonstrated the antiviral efficacy of hesperetin against multiple poxviruses, including buffalopox virus (BPXV), vaccinia virus (VACV), and lumpy skin disease virus (LSDV). The time-of-addition and virus step-specific assays indicated that hesperetin reduces the levels of viral DNA, mRNA, and proteins in the target cells. Further, by immunoprecipitation (IP) of the viral RNA from BPXV-infected Vero cells and a cell-free RNA-IP assay, we demonstrated that hesperetin-induced reduction in BPXV protein synthesis is also consistent with diminished interaction between eukaryotic translation initiation factor eIF4E and the 5' cap of viral mRNA. Molecular docking and MD simulation studies were also consistent with the binding of hesperetin to the cap-binding pocket of eIF4E, adopting a conformation similar to m7GTP binding. Furthermore, in a BPXV egg infection model, hesperetin was shown to suppress the development of pock lesions on the chorioallantoic membrane and associated mortality in the chicken embryos. Most importantly, long-term culture of BPXV in the presence of hesperetin did not induce the generation of drug-resistant viral mutants. In conclusion, we, for the first time, demonstrated the antiviral activity of hesperetin against multiple poxviruses, besides providing some insights into its potential mechanisms of action.

Carbon Dots: Synthesis, Characterizations, and Recent Advancements in Biomedical, Optoelectronics, Sensing, and Catalysis Applications.

Carbon nanodots (CNDs), a fascinating carbon-based nanomaterial (typical size 2-10 nm) owing to their superior optical properties, high biocompatibility, and cell penetrability, have tremendous applications in different interdisciplinary fields. Here, in this Review, we first explore the superiority of CNDs over other nanomaterials in the biomedical, optoelectronics, analytical sensing, and photocatalysis domains. Beginning with synthesis, characterization, and purification techniques, we even address fundamental questions surrounding CNDs such as emission origin and excitation-dependent behavior. Then we explore recent advancements in their applications, focusing on biological/biomedical uses like specific organelle bioimaging, drug/gene delivery, biosensing, and photothermal therapy. In optoelectronics, we cover CND-based solar cells, perovskite solar cells, and their role in LEDs and WLEDs. Analytical sensing applications include the detection of metals, hazardous chemicals, and proteins. In catalysis, we examine roles in photocatalysis, CO2 reduction, water splitting, stereospecific synthesis, and pollutant degradation. With this Review, we intend to further spark interest in CNDs and CND-based composites by highlighting their many benefits across a wide range of applications.

Breast cancer derived exosomes: Theragnostic perspectives and implications.

Breast cancer (BC) is the most prevalent malignancy affecting women worldwide. Although conventional treatments such as chemotherapy, surgery, hormone therapy, radiation therapy, and biological therapy are commonly used, they often entail significant side effects. Therefore, there is a critical need to investigate more cost-effective and efficient treatment modalities in BC. Extracellular vesicles (EVs), including exosomes, microvesicles, and apoptotic bodies, play a crucial role in modulating recipient cell behaviour and driving cancer progression. Among the EVs, exosomes provide valuable insights into cellular dynamics under both healthy and diseased conditions. In cancer, exosomes play a critical role in driving tumor progression and facilitating the development of drug resistance. BC-derived exosomes (BCex) dynamically influence BC progression by regulating cell proliferation, immunosuppression, angiogenesis, metastasis, and the development of treatment resistance. Additionally, BCex serve as promising diagnostic markers in BC which are detectable in bodily fluids such as urine and saliva. Targeted manipulation of BCex holds significant therapeutic potential. This review explores the therapeutic and diagnostic implications of exosomes in BC, underscoring their relevance to the disease. Furthermore, it discusses future directions for exosome-based research in BC, emphasizing the necessity for further exploration in this area.

Identification of miR-29a as a novel biomarker for lumpy skin disease virus exposure in cattle.

Micro RNAs (miRNAs) have been implicated in the regulation of maturation, proliferation, differentiation, and activation of immune cells. In this study, we demonstrated that miR-29a antagonizes IFN-γ production at early times post-LSDV infection in cattle. miR-29a was predicted to target upstream IFN-γ regulators, and its inhibition resulted in enhanced IFN-γ production in sensitized peripheral blood mononuclear cells (PBMCs). Further, stimulation of PBMCs with LSDV antigen exhibited lower levels of miR-29a, concomitant with a potent cell-mediated immune response (CMI), characterized by an increase in LSDV-specific CD8+ T cell counts and enhanced levels of IFN-γ, which eventually facilitated virus clearance. In addition, a few immunocompromised cattle (developed secondary LSDV infection at ~ 6 months) that failed to mount a potent cell-mediated immune response, were shown to maintain higher miR-29a levels. Furthermore, as compared to the sensitized crossbred cattle, PBMCs from sensitized Rathi (a native Indian breed) animals exhibited lower levels of miR-29a along with an increase in CD8+ T cell counts and enhanced levels of IFN-γ. Finally, we analysed that a ≥ 60% decrease in miR-29a expression levels in the PBMCs of sensitized cattle correlated with a potent CMI response. In conclusion, miR-29a expression is involved in antagonizing the IFN-γ response in LSDV-infected cattle and may serve as a novel biomarker for the acute phase of LSDV infection, as well as predicting the functionality of T cells in sensitized cattle. In addition, Rathi cattle mount a more potent CMI response against LSDV than crossbred cattle.

The GATA transcriptional program dictates cell fate equilibrium to establish the maternal-fetal exchange interface and fetal development.

The placenta establishes a maternal-fetal exchange interface to transport nutrients and gases between the mother and the fetus. Establishment of this exchange interface relies on the development of multinucleated syncytiotrophoblasts (SynT) from trophoblast progenitors, and defect in SynT development often leads to pregnancy failure and impaired embryonic development. Here, we show that mouse embryos with conditional deletion of transcription factors GATA2 and GATA3 in labyrinth trophoblast progenitors (LaTPs) have underdeveloped placenta and die by ~embryonic day 9.5. Single-cell RNA sequencing analysis revealed excessive accumulation of multipotent LaTPs upon conditional deletion of GATA factors. The GATA factor-deleted multipotent progenitors were unable to differentiate into matured SynTs. We also show that the GATA factor-mediated priming of trophoblast progenitors for SynT differentiation is a conserved event during human placentation. Loss of either GATA2 or GATA3 in cytotrophoblast-derived human trophoblast stem cells (human TSCs) drastically inhibits SynT differentiation potential. Identification of GATA2 and GATA3 target genes along with comparative bioinformatics analyses revealed that GATA factors directly regulate hundreds of common genes in human TSCs, including genes that are essential for SynT development and implicated in preeclampsia and fetal growth retardation. Thus, our study uncovers a conserved molecular mechanism, in which coordinated function of GATA2 and GATA3 promotes trophoblast progenitor-to-SynT commitment, ensuring establishment of the maternal-fetal exchange interface.

Malate:quinone oxidoreductase knockout makes Mycobacterium tuberculosis susceptible to stress and affects its in vivo survival.

Mycobacterium tuberculosis H37Ra (Mtb-Ra) ORF MRA_2875, annotated as malate:quinone oxidoreductase (mqo), is thought to have a role in TCA cycle in converting malate to oxaloacetate. To study its physiological relevance, we developed mqo knockout (KO) in Mtb-Ra. A KO complemented (KOC) strain was also developed by complementing the KO with mqo over-expressing construct. Under normal in vitro conditions, KO does not show any growth defect but showed reduced CFU burden in macrophages and in mice lungs. In vitro studies with KO showed reduced fitness under oxidative and low pH stress, and also increased susceptibility to levofloxacin and D-cycloserine. Transcript analysis of mqo showed increased expression levels under oxidative and low pH stress. This is the first study to show physiological relevance of mqo encoded by MRA_2875 in Mtb-Ra under oxidative and low pH stress. In summary, the present study shows that MRA_2875 encoded malate:quinone oxidoreductase is a functional enzyme which contributes to oxidative stress and low pH tolerance, and survival in macrophages and in mice.

Piceatannol improved cerebral blood flow and attenuated JNK3 and mitochondrial apoptotic pathway in a global ischemic model to produce neuroprotection.

Cerebral ischemia is one of the leading causes of death and disability worldwide. The only FDA-approved treatment is recanalization with systemic tissue plasminogen activators like alteplase, although reperfusion caused by recanalization can result in neuroinflammation, which can cause brain cell apoptosis. Therefore, after an ischemic/reperfusion injury, interventions are needed to minimize the neuroinflammatory cascade. In the present study, piceatannol (PCT) was studied for its neuroprotective efficacy in a rat model of global ischemic injury by attenuating c-Jun N-terminal kinase 3 (JNK3) downstream signaling. PCT is a resveratrol analog and a polyphenolic stilbenoid naturally occurring in passion fruit and grapes. The neuroprotective efficacy of PCT (1, 5, 10 mg/kg) in ischemic conditions was assessed through pre- and post-treatment. Cerebral blood flow (CBF) and tests for functional recovery were assessed. Protein and gene expression were done for JNK3 and other inflammatory markers. A docking study was performed to identify the amino acid interaction. The results showed that PCT improved motor and memory function as measured by a functional recovery test believed to be due to an increase in cerebral blood flow. Also, the caspase signaling which promotes apoptosis was found to be down-regulated; however, nitric oxide synthase expression was up-regulated, which could explain the enhanced cerebral blood flow (CBF). According to our findings, PCT impeded c-Jun N-terminal kinase 3 (JNK3) signaling by suppressing phosphorylation and disrupting the mitochondrial apoptotic pathway, which resulted in the neuroprotective effect. Molecular docking analysis was performed to investigate the atomic-level interaction of JNK3 and PCT, which reveals that Met149, Leu206, and Lys93 amino acid residues are critical for the interaction of PCT and JNK3. According to our current research, JNK3 downstream signaling and the mitochondrial apoptosis pathway are both inhibited by PCT, which results in neuroprotection under conditions of global brain ischemia. Piceatannol attenuated JNK3 phosphorylation during the ischemic condition and prevented neuronal apoptosis.

Characterization, Antioxidant, and Antimicrobial Properties of Mulberry Lattices.

In order to find the most advantageous bioactive compounds from mulberry latex for drug development in the near future, this study was conducted to characterize and evaluate antioxidant and antimicrobial properties from four different mulberry lattices (BR-2, S-1, AR-14, and S-146). The characterization of the lattices was performed by scanning electron microscopy with energy-dispersive X-ray spectroscopy, gas chromatography coupled to mass spectroscopy, and Fourier transform infrared spectroscopy. Further, screenings of the antioxidant and antimicrobial potential of selected lattices were performed in vitro using 2,2-diphenyl-1-picrylhydrazyl assay and agar well diffusion methods, respectively. Interestingly, the outcome of the current study revealed that tested mulberry lattices contain a considerable amount of bioactive phytoconstituents, particularly antimicrobial and antioxidant compounds, as revealed by chromatographic analysis. BR-2 latex was found to have significant antioxidant activity (75%) followed by S-146 (64.6%) and AR-14 (52.9%). The maximum antimicrobial activity was found in BR-2 latex compared to other tested latex varieties. The results of this investigation showed that mulberry latex from the BR-2 type may successfully control both bacterial and fungal infections, with the added benefit of having enhanced antioxidant capabilities.

The Utility of Methylphenidate for Fatigue in Long-Term Neurological Conditions: A Meta-analytical Review.

OBJECTIVE: Fatigue is a chronic and debilitating symptom of many long-term neurological conditions (LTNCs). Although methylphenidate provides some promise in alleviating fatigue in other clinical groups, little work has explored its potential utility within LTNCs. The current systematic review and meta-analysis evaluates the utility of methylphenidate for symptoms of fatigue in LTNCs. METHODS: Five databases (PsycINFO, MEDLINE, Embase, Scopus, and Cochrane Library) were searched for relevant articles from their inception to February 2022. A purpose-developed evaluation tool was used to assess each study's research quality (QuEST:F). RESULTS: Of the 1698 articles identified, 11 articles were included within this review (n = 370). Meta-analytical findings reported an overall significant benefit of methylphenidate for symptoms of fatigue across a mixed neurological sample ( g = -0.44; 95% confidence interval, -0.77 to -0.11). Subgroup analyses identified a significantly greater benefit ( P < 0.001) of methylphenidate for fatigue in LTNCs with static pathogenic trajectories (eg, traumatic brain injury) (number needed to treat = 2.5) compared with progressive conditions (eg, multiple sclerosis) (number needed to treat = 40.2). CONCLUSIONS: Methylphenidate may pose an effective intervention for the treatment of fatigue in a number of LTNCs. Nonetheless, given the quality of the current evidence base, there exists a clear need for further robust assessment of the utility of methylphenidate-with a focus on subgroup-specific variability.

miRNA profiling of primary lamb testicle cells infected with lumpy skin disease virus.

In this study, miRNA profiling of cells infected with lumpy skin disease virus (LSDV) was conducted for the first time. When compared to mock-infected cells, LSDV-infected primary lamb testicle (LT) cells showed dysregulation of 64, 85, and 85 miRNAs at 12 hours postinfection (hpi), 48 hpi, and 72 hpi, respectively. While some of these miRNAs were found to be dysregulated at a particular time point following LSDV infection, others were dysregulated at all three time points. Analysis of the differentially expressed miRNA-mRNA interaction networks, Gene Ontology analysis of the predicted targets, and KEGG analysis of highly enriched pathways revealed several cellular factors/pathways involved in protein/ion/enzyme binding, cell differentiation, movement of subcellular components, calcium reabsorption, aldosterone synthesis and secretion, and melanogenesis. Some selected upregulated (oar-mir-379-5p, oar-let-7d, Chr10-18769, Chr2_5162 and oar-miR-493-5p) and downregulated (ChrX-33741, Chr3_8257 and Chr26_32680) miRNAs were further confirmed by quantitative real-time PCR. These findings contribute to our understanding of virus replication, virus-host interactions, and disease pathogenesis, and the differentially expressed miRNAs and their cellular targets may serve as biomarkers as well as novel targets for therapeutic intervention against LSDV.

Assessment of potential antimicrobial activity of Ocimum basilicum extract and chlorhexidine against Socransky's complex pathogens of oral cavity: An in vitro study.

Background and Objective: Periodontitis is a multifactorial disease initiated by periodontal pathogens and progresses further in destruction of periodontium. Hence, the objective of this study was to test the efficacy of Ocimum basilicum seeds extract on periodontal pathogens. Materials and Methods: O. basilicum seeds were authenticated from a recognized taxonomist. They were coarsely powdered; ethanol-based extract preparation was done by the Soxhlet method and aqueous-based extract by hot infusion procedure. Extracts so obtained were assessed for minimum inhibitory concentration, minimum bactericidal concentration, zone of inhibition, and time-kill assay of O. basilicum seeds extract on periodontal pathogens, and comparatively evaluated the effectiveness against 0.12% chlorhexidine (CHX) gluconate in triplicates. Kruskal-Wallis Test was employed wherein the statistical significance was set at P ≤ 0.05. Results: The concentration of O. basilicum ethanolic extract against periodontal pathogens was determined to be 10 mg/ml, whereas 4.7 mg/ml of aqueous extract was proven effective against periodontal pathogens. Similarly, aqueous extract of O. basilicum developed a wider zone against periodontal pathogens compared to ethanol-based O. basilicum extract. Statistically significant difference found in the effectiveness between both extract and CHX. Conclusion: The antibacterial activity was evident in both the extracts of O. basilicum against anaerobic periodontal pathogens. However, it was more pronounced in aqueous extract, but lower compared to CHX.

Care and three-year outcomes of children with Benign Epilepsy with Centro-Temporal Spikes in England.

PURPOSE: Benign Epilepsy with Centro-Temporal Spikes (BECTS) is a pediatric epilepsy with typically good seizure control. Although BECTS may increase patients' risk of developing neurological comorbidities, their clinical care and short-term outcomes are poorly quantified. METHODS: We retrospectively assessed adherence to National Institute for Health and Care Excellence (NICE) guidelines relating to specialist referral, electroencephalogram (EEG) conduct and annual review in the care of patients with BECTS, and measured their seizure, neurodevelopmental and learning outcomes at three years post-diagnosis. RESULTS: Across ten centers in England, we identified 124 patients (74 male) diagnosed with BECTS between 2015 and 2017. Patients had a mean age at diagnosis of 8.0 (95% CI = 7.6-8.4) years. 24/95 (25%) patients were seen by a specialist within two weeks of presentation; 59/100 (59%) received an EEG within two weeks of request; and 59/114 (52%) were reviewed annually. At three years post-diagnosis, 32/114 (28%) experienced ongoing seizures; 26/114 (23%) had reported poor school progress; 15/114 (13%) were diagnosed with a neurodevelopmental disorder (six autism spectrum disorder, six attention-deficit/hyperactivity disorder); and 10/114 (8.8%) were diagnosed with a learning difficulty (three processing deficit, three dyslexia). Center-level random effects models estimated neurodevelopmental diagnoses in 9% (95% CI: 2-16%) of patients and learning difficulty diagnoses in 7% (95% CI: 2-12%). CONCLUSIONS: In this multicenter work, we found variable adherence to NICE guidelines in the care of patients with BECTS and identified a notable level of neurological comorbidity. Patients with BECTS may benefit from enhanced cognitive and behavioral assessment and monitoring.

Replication cycle timing determines phage sensitivity to a cytidine deaminase toxin/antitoxin bacterial defense system.

Toxin-antitoxin (TA) systems are ubiquitous two-gene loci that bacteria use to regulate cellular processes such as phage defense. Here, we demonstrate the mechanism by which a novel type III TA system, avcID, is activated and confers resistance to phage infection. The toxin of the system (AvcD) is a deoxycytidylate deaminase that converts deoxycytidines (dC) to dexoyuridines (dU), while the RNA antitoxin (AvcI) inhibits AvcD activity. We have shown that AvcD deaminated dC nucleotides upon phage infection, but the molecular mechanism that activated AvcD was unknown. Here we show that the activation of AvcD arises from phage-induced inhibition of host transcription, leading to degradation of the labile AvcI. AvcD activation and nucleotide depletion not only decreases phage replication but also increases the formation of defective phage virions. Surprisingly, infection of phages such as T7 that are not inhibited by AvcID also lead to AvcI RNA antitoxin degradation and AvcD activation, suggesting that depletion of AvcI is not sufficient to confer protection against some phage. Rather, our results support that phage with a longer replication cycle like T5 are sensitive to AvcID-mediated protection while those with a shorter replication cycle like T7 are resistant.

Uniform titania-supported Ce(iii) carbonate cluster catalysts for degradation of reactive oxygen species.

We report the synthesis of uniform 2.5 ± 0.4 nm diameter Ce(iii) carbonate clusters deposited on the surface of TiO2 nanoparticles and characterize them using HAADF-STEM and EELS, as well as UV-Vis and FTIR spectroscopies. This material is a highly proficient catalytic antioxidant for the degradation of photocatalytically generated reactive oxygen species (ROS). We observed an unusual U-shaped pH-dependence in its photoprotection catalytic activity, with an optimum function in the near-neutral pH range of 7.7 ± 0.7. This sharp pH dependence is not observed in previously reported bulk Ce(iii) carbonate materials, and it is also not a consequence of Ce(iii) carbonate cluster decomposition. However, it is consistent with a tandem reaction sequence consisting of a biomimetic superoxide dismutase and catalase function, which is dependent on a balance of protons and hydroxide anions for function. Our dissolution-deposition approach for synthesizing nanoscale Ce(iii) carbonate clusters on TiO2 should be generalizable to other carbonates and metal-oxide supports.