Hypoxia is an important factor in forming multidrug resistance, recurrence and metastasis in solid tumors. Nanozymes respond to tumor microenvironment for tumor-specific treatment is a new and effective strategy. In this study, one-pot method was used to synthesize hollow Ru@CeO₂ yolk shell nanozymes (Ru@CeO₂ YSNs), which possess excellent light-to-heat conversion efficiency and catalytic performance. Antitumor drug ruthenium complex (RBT) and resveratrol (Res) were dual-loaded in Ru@CeO₂ YSNs, and a double outer layer structure using polyethylene glycol was constructed to form dual-drug delivery system (Ru@CeO₂-RBT/Res-DPEG) that was released on demand. The double outer layer structure increased the biocompatibility of Ru@CeO₂ YSNs and effectively prolong the circulation time in blood. Ru@CeO₂-RBT/Res-DPEG catalyzes endogenous H₂O₂ to produce oxygen, which achieve in situ oxygen supply and enhanced dual-chemotherapy and photothermal therapy (PTT) for colorectal cancer. In vitro studies found that Ru@CeO₂-RBT/Res-DPEG has good tumor penetration depth and antitumor effect. In addition, Ru@CeO₂-RBT/Res-DPEG can alleviate tumor hypoxia, and inhibit metastasis and recurrence of orthotopic and subcutaneous colorectal cancer. Accordingly, the study shows that yolk shell nanozymes can be used as an efficient synergistic system for dual-chemotherapy and PTT to kill tumor and inhibit orthotopic colorectal cancer metastasis and recurrence.

Social media are changing the way we do business and how leaders are perceived, from the shop floor to the CEO suite. But whereas the best businesses are creating comprehensive strategies in thi area, research suggests that few corporate Leaders have a social media presence--say, a Facebook or Linked in of page--and that those do don't use it strategically. Today's leaders must embrace social media for three reasons, First, they provide a low-cost, highly accessible platform on which to build your personal brand, communicating who you are both within and outside your company. Second, they allow you to engage rapidly and simultaneously with peers, employees, customers, and the broader public--in order to leverage relationships, show commitment to a cause, and demonstrate a capacity for reflection. Third, they give you an opportunity to learn from instant information and unvarnished feedback. To formulate your personal social media strategy, it helps to clarify your goals (personal, professional, or both), desired audience (private or public), and resources (can you justify using your company's?). You must also consider the risks of maintaining a large number of connections and of sharing content online. Active participation in social media can be a powerful tool--the difference between leading effectively and ineffectively, and between advancing and faltering in the pursuit of your goals.

A core-shell cerium oxide nanorod@polypyrrole (CeO₂-NR@Ppy) nanocomposite-based electrochemical DNA biosensor was studied for Salmonella detection. The core-shell CeO₂-NR@Ppy nanocomposite was prepared by in situ chemical oxidative polymerization of pyrrole monomer on CeO₂-NRs, which provided a suitable platform for electrochemical DNA biosensor fabrication. The immobilization of ss-DNA sequences onto nanocomposite-coated microelectrode was performed via covalent attachment method. DNA biosensor electrochemical responses were studied by cyclic voltammetry and electrochemical impedance spectroscopy with [Fe (CN)₆]^3-/4- as redox probe. Under optimal conditions, DNA biosensor response showed good linearity in the range of 0.01-0.4 nM with sensitivity of 593.7 Ω·nM^-1·cm^-2. The low limit of detection and limit of quantification for the DNA biosensor were 0.084 and 0.28 nM, respectively. The proposed DNA biosensor also showed good results when used in detecting actual Salmonella samples.

Alzheimer's disease (AD) is a chronic neurodegenerative disease leading to progressive dementia in elderly people. The disease is characterized, among others, by formation of amyloid-β (Aβ) polypeptide plaques in the brain. Although etiology of the disease is not fully understood, recent research suggest that nanomaterials may affect AD development. Here, we described the consequences of exposure of mouse BV-2 microglia to silver nanoparticles (AgNPs, 50 µg/mL), cerium oxide nanoparticles (CeO₂NPs, 100 µg/mL), and cadmium telluride quantum dots (CdTeQDs, 3 or 10 µg/mL) in the context of its ability to clear Aβ plaques. The brain microglial cells play an important role in removing Aβ plaques from the brain. Cell viability and cycle progression were assessed by trypan blue test and propidium iodide binding, respectively. The uptake of Aβ and NPs was measured by flow cytometry. Secretion of proinflammatory cytokines was measured with the use of cytometric bead array. Aβ (0.1 μM) did not affect viability, whereas NPs decreased microglia growth by arresting the cells in G1 phase (CdTeQDs) or in S phase (AgNPs and CeO₂NPs) of cell cycle. The uptake of Aβ was significantly reduced in the presence of AgNPs and CeO₂NPs. In addition, the least toxic CeO₂NPs induced the release of proinflammatory cytokine, tumor necrosis factor α. In summary, each of the NPs tested affected either the microglia phagocytic activity (AgNPs and CeO₂NPs) and/or its viability (AgNPs and CdTeQDs) that may favor the occurrence of AD and accelerate its development.

Inhalation is the most relevant entry point for nanoparticles (NPs) into the human body. To date, toxicity testing of nanomaterials in respect to oral, dermal and inhalative application is mainly based on animal experiments. The development of alternative test methods is the subject of current research. In vitro models can help to investigate mechanistic aspects, as e.g. cellular uptake or genotoxicity and might help to reduce in vivo testing. Lung cell lines are proper in vitro tools to assess NP toxicity. In respect to this, various cell models have been developed during the recent years, but often lack in a proper intact barrier function. However, besides other important in vivo criteria which are still missing like e.g. circulation, this is one basic prerequisite to come closer to the in vivo situation in certain mechanistic aspects such as particle translocation which is an important task for risk assessment of nanomaterials. Novel developed in vitro models may help to investigate the translocation of nanomaterials from the lung. We investigated the barrier function of the recently developed human lung cell lines CI-hAELVi and CI-huAEC. The cells were further exposed to CeO₂ NPs and ZnO NPs, and their suitability as in vitro models for toxicological investigations was proven. The obtained data were compared with data generated with the A549 cell line. Measurement of transepithelial resistance and immunohistochemical examination of tight junctions confirmed the formation of a functional barrier for both cell lines for submerged and air-liquid cultivation. For particle exposure, hAELVi and huAEC cells showed comparable results to A549 cells without losing the barrier function. CeO₂ NP exposure revealed no toxicity for all cell lines. In contrast, ZnO NPs was toxic for all cell lines at a concentration between 10-50 μg ml^-1. Due to the comparable results to A549 cells CI-hAELVi and CI-huAEC offer new opportunities to investigate nanoparticle cell interactions more realistic than recent 2D cell models.

In order to assess the potential hazards of nanoparticles (NPs) releasing, better knowledge about their toxicity to microbes is required. However, it remains controversial whether NPs could exert particles pecifictoxicity. In this study, the toxic impacts of four kinds of rare earth oxides (REO) NPs (La(2)O(3),CeO(2), Gd(2)O(3), and Yb(2)O(3)) on gram-negative Escherichia coli (E. coli) pBR322 were examined. The results indicate that all the tested NPs possessed cytotoxicity against E. coli. To evaluate the ion-related toxicity of REO NPs, the NPs dissolution in the presence of test organisms was quantitatively measured using X-ray absorption fine structure (XAFS) spectroscopy. Our results suggest that NPs-cell contact could facilitate the dissolution of NPs, and the additional ionic release at the particle-cell interface might result in a substantial increase in the ion-related toxicities towards the test organisms. Therefore, the ion-related toxicity of NPs might be grossly underestimated if the additional dissolution of NPs caused by particle-cell contact was overlooked, further leading to a false interpretation of particle-specific toxicity. To the best of our knowledge, this is the first determination of the total NPs dissolution after particle-cell contact. These findings are helpful to advance mechanistic understanding of the toxicity exerted by dissolvable metal-based NPs.

Antimicrobial medicine and food packages based on bio-based film containing essential oils have attracted great attention worldwide. However, the controlled release of essential oils from these film nanocomposites is still a big challenge. In this study, a long-term antibacterial film nanocomposite composed of zein film and cinnamon essential oil (CEO) loaded MCM-41 silica nanoparticles was prepared. The CEO was loaded into MCM-41 particles via modified supercritical impregnation efficiently with a high drug load (>40 wt%). The morphologies of the prepared nanoparticles and film nanocomposite were characterized by a scanning electron microscope. The release behaviors of CEO under different temperatures, high humidity, continuous illumination and in phosphate buffer solution (PBS) solution were investigated. The results showed that the film nanocomposite had an outstanding release-control effect. The addition of MCM-41 nanoparticles also improved the mechanical properties of zein films. The antibacterial effect of CEO was significantly prolonged by the film nanocomposite; indicating the CEO film nanocomposite fabricated via modified supercritical CO₂ impregnation was a potential long-term antibacterial medicine or food package material.

Several epidemiologic surveillance studies have implicated backyard flocks as a reservoir for poultry diseases; however, much debate still exists over the risk these small flocks pose. To evaluate this concern, the prevalence of Newcastle disease (ND), infectious laryngotracheitis (ILT), Mycoplasma gallisepticum (MG), and Salmonella was determined in 39 Maryland backyard flocks. Serum, tracheal, and cloacal swabs were randomly collected from 262 birds throughout nine counties in Maryland. Through PCR and ELISA analysis, disease prevalence and seroprevalence were determined in flocks, respectively, for the following: ND (0%, 23%); ILT (26%, 77%); MG (3%, 13%); and Salmonella (0%, not done). Vaccine status could not be accurately confirmed. Premise positives were further differentiated and identified by partial nucleotide sequencing. Screening of the 10 ILT premise positives showed that most were live attenuated vaccines: eight matched a tissue culture origin vaccine, one matched a chicken embryo origin (CEO) vaccine, and one was CEO related. The single MG-positive flock, also positive for the CEO-related sequence, was identified as the infectious S6 strain. The prevalence rates for these economically important poultry diseases ranged from none to relatively low, with the vast majority of sampled flocks presenting no clinical signs.

Two Indian spices, Trachyspermum ammi and Myristica fragrans, were studied for their essential oil (EO) yielding pattern, insecticidal activity, antibacterial activity, and composition. The essential oils (EOs) of T. ammi (1.94 ± 30 mL/100 gm) and M. fragrans (5.93 ± 90 mL/100 gm) were extracted using hydrodistillation method. In Gas Chromatography analysis, the beta-pinene, alpha-pinene, alpha-p-menth-1-en-4-ol, Limonene, and elemicin were found as major constituents of T. ammi essential oil whereas M. fragrans essential oil mostly contains Gamma-Terpinolene, p-Cymene, Thymol, and beta-pinene. The insecticidal activities of EO were demonstrated using LC50 values against Plodia interpunctella and EO of T. ammi was found comparatively more effective than EO of M. fragrans. Further, individual EO and combination of essential oil were examined for antibacterial activity against three Gram (-) bacterial strains (E. coli-MTCC 443, P. vulgaris-MTCC 1771, and K. pneumoniae-MTCC number 7028) and three Gram (+) bacterial strains (S. aureus-MTCC 3381, B. subtilis-MTCC 10619, and B. megaterium-MTCC 2412) by well agar diffusion method. The essential oil in combination (CEO) exhibited higher antibacterial activity as compared with individual essential oils.

Eco-friendly functional bionanocomposite films were prepared using sodium caseinate (SC) and guar gum (GG) as the polymer matrix and TiO₂ and cumin essential oil (CEO) as functional fillers. 0.2 vol% GG selected for the preparation of SC/GG composite film and various amount of TiO₂ and CEO (1 and 2 wt% based on SC) were incorporated into the SC/GG film either individually or in combination. The addition of TiO₂ and CEO significantly improved the water permeability and sensitivity properties and mechanical characteristics such as the strength (TS), stiffness (YM), and flexibility (EB) of the composite films. Also, the SC/GG films incorporated with TiO₂ and CEO exhibited remarkable antibacterial activity against both Gram-positive (L. monocytogenes and S. aureus) and Gram-negative (E. coli O157: H7 and S. enteritidis) bacteria. All the film properties were varied not only on the concentration of TiO₂ and CEO, but also increased synergistically when they were added together.

Dr Haseltine speaks to Emily Culme-Seymour, Assistant Commissioning Editor William A Haseltine, PhD has an active career in both Science and Business. He was a professor at Harvard Medical School and Harvard School of Public Health (MA, USA) from 1976 to 1993, where he was Founder and Chair of two academic research departments. He is well known for his pioneering work on cancer, HIV/AIDS and genomics. He has authored more than 200 manuscripts in peer-reviewed journals and is the author of several books. He is the founder of Human Genome Sciences, Inc. and served as the Chairman and CEO of the company until 2004. He is also the founder of several other successful biotechnology companies. William Haseltine is currently Chairman and President of ACCESS Health International, Inc., which supports access to affordable, high-quality health services in low, middle and high income countries, and Chairman of the Haseltine Foundation for Science and the Arts, which fosters a dialog between sciences and the arts. He is an Adjunct Professor at the Scripps Institute for Medical Research and the Institute of Chemical Engineering, the University of Mumbai, India. He is a member of the Advisory Board of the IE University, Madrid, the President's Council of the Cold Spring Harbor Laboratory, the Advisory Council for the Koch Institute of MIT, a member of the University Council Committee on technology transfer, Yale University, and is a Lifetime Governor of the New York Academy of Science (NY, USA). He is an honorary member of the Board of Trustees of the Brookings Institution, a member of the Board of Trustees of the Center for Emerging Markets of the Indian School of Business, a member of the Council on Foreign Relations, a member of the Board of AID for AIDS International, and a member of the Chairman's Circle of the Asia Society. He is a member of the Advisory Board of the Metropolitan Opera (NY, USA), the Chairman's Council of the Metropolitan Museum (NY, USA), the International Council of the Guggenheim Museum, the International Council of the Tate Modern, the Board of Directors of the Young Concert Artists, Inc. and the Youth Orchestra of the Americas.

The relation of surface science studies of single crystal metal oxides to gas sensing applications is reviewed. Most metal oxide gas sensors are used to detect oxidizing or reducing gases and therefore this article focuses on surface reduction processes and the interaction of oxygen with these surfaces. The systems that are discussed are: (i) the oxygen vacancy formation on the surface of the ion conductor CeO(2)(111); (ii) interaction of oxygen with TiO(2) (both adsorption processes and the incorporation of oxygen into the TiO(2)(110) lattice are discussed); (iii) the varying surface composition of SnO(2)(101) and its consequence for the adsorption of water; and (iv) Cu modified ZnO(0001)-Zn surfaces and its interaction with oxygen. These examples are chosen to give a comprehensive overview of surface science studies of different kinds of gas sensing materials and to illustrate the potential that surface science studies have to give fundamental insight into gas sensing phenomena.

Reflecting the increasing relevance of quality outcomes for hospital payments, some hospital boards have promoted physicians into top-management positions. So far, however, the literature regarding the impact of physician leadership on care quality or cost is limited. The aim of this study is to examine the link between the educational background of a hospital's CEO and its performance in terms of medical quality and financial success. Examining data of 370 German hospitals for the year 2016, this study uses the second largest sample of its kind and the largest for a single country. Multivariate regression analysis with matching is used to model the effect of the CEO's education, controlling for tenure, competition, hospital size and ownership. We find that physician-led hospitals have lower in-hospital mortality rates for pneumonia and higher patient satisfaction (at the 5% and 1% significance level, respectively). In contrast, institutions led by managers with economics or business degrees have better financial performance (at the 10% significance level) and superior outcomes for hip and knee surgeries (at the 1% and 10% significance level). Our findings support prior results regarding financial outcomes and mortality. However, including a broad spectrum of measures for clinical quality, we draw a more nuanced picture that does not point to the straightforward interpretation that physician CEOs lead to superior medical quality.

Doxorubicin (DOX) is considered as a backbone in several chemotherapeutic regimens. Nevertheless, the reported systemic toxicity usually hampers its broad application. Interestingly, Cerium oxide nanoparticles (CeONPs) depicted promising regenerative antioxidant and hepatoprotective potentials against multiple oxidative stress-induced pathologies. Thus, the aim of the present study was to determine either CeONPs would display hepatoprotective properties once concomitantly administered with DOX or not. Male Sprague Dawley rats were divided into four groups (n = 10) in a two weeks study: Control (received saline, IP injection thrice a week), CeO (0.5 mg/kg, IP injection once a week), DOX (2.5 mg/kg, IP injections thrice a week) and DOX + CeO (received both treatments). Hepatic toxicity was assessed by histological and ultrastructural studies. In addition, serum transaminases (ALT, AST) and malondialdehyde (MDA), an oxidative stress marker, were evaluated. CeONPs were not only proved to be safe at the proposed dose, but also their concomitant administration with DOX managed to mitigate DOX-induced hepatic insult on both histological and biochemical aspects. Such hepatoprotective behavior was referred to the noticed antioxidant action CeONPs as highlighted by the significant difference in MDA levels.

Realizing the full potential of oxide-supported single-atom metal catalysts (SACs) is key to successfully bridge the gap between the fields of homogeneous and heterogeneous catalysis. Here we show that the one-pot combination of Ru 1 /CeO 2 and Rh 1 /CeO 2 SACs enables a highly selective olefin isomerization-hydrosilylation tandem process, hitherto restricted to molecular catalysts in solution. Individually, monoatomic Ru and Rh sites show a remarkable reaction specificity for olefin double-bond migration and anti -Markovnikov α-olefin hydrosilylation, respectively. First-principles DFT calculations ascribe such selectivity to differences in the binding strength of the olefin substrate to the monoatomic metal center s. The single-pot cooperation of the two SACs allows the production of terminal organosilane compounds with high regio-selectivity (>95%) even from industrially-relevant complex mixtures of terminal and internal olefins, alongside a straightforward catalyst recycling and reuse. These results demonstrate the significance of oxide-supported single-atom metal catalysts in tandem catalytic reactions, which are central for the intensification of chemical processes.

The clean activation of methane at low temperatures remains an eminent challenge and a field of competitive research. In particular, on late transition metal surfaces such as Pt(111) or Ni(111), higher temperatures are necessary to activate the hydrocarbon molecule, but a massive deposition of carbon makes the metal surface useless for catalytic activity. However, on very low-loaded M/CeO₂ (M = Pt, Ni, or Co) surfaces, the dissociation of methane occurs at room temperature, which is unexpected considering simple linear scaling relationships. This intriguing phenomenon has been studied using a combination of experimental techniques (ambient-pressure X-ray photoelectron spectroscopy, time-resolved X-ray diffraction, and X-ray absorption spectroscopy) and density functional theory-based calculations. The experimental and theoretical studies show that the size and morphology of the supported nanoparticles together with strong metal-support interactions are behind the deviations from the scaling relations. These findings point toward a possible strategy for circumventing scaling relations, producing active and stable catalysts that can be employed for methane activation and conversion.

Anthropogenic nanoparticles (NPs) are emitted to the environment and may be present in vegetables for human consumption. However, the toxicity of NPs exposure through food lack systematical investigations. In order to propose a systematical study, lettuce grown in a Cerium- (IV), Copper- (II) and Zinc oxide NP contaminated environment were digested. This digestate was used to culture human intestine cells (i.e. epithelial colorectal adenocarcinoma cells, Caco-2). The basolateral juice produced by the intestinal cells was then used to culture normal human liver (HL-7702) cells. Bioavailability and biotoxicity of the NPs in the vitro models were assessed. NPs were found to be taken up from the environment by vegetables, and may thus be transferred to humans through oral exposure. Bioavailability and the effect of their concentration in the digestate medium differed in regards to NP materials. The levels of NPs found in the digestate were detrimental to intestine cells, while the liver cells exposed to lower concentrations of NP in the bodily fluid showed no statically significant change in cell necrosis. A closer assessment of the detrimental effect of the studied NPs to Caco-2 cells revealed that the damage was mainly related to the solubility of the NPs. This may partly be due to that the more soluble NP material (ZnO > CuO > CeO₂) render higher metal ion release and thus higher bioavailability. This appeared to cause more cell death, and even lead to local intestinal inflammation. Although no liver cells died, there was an increase of ROS level, causing ROS-related DNA damage prior to cell necrosis. The findings in this study enhances our understanding of the relative detrimental effect of different types of NPs, and the mechanisms causing their biotoxicity in human cells through food.

Cerium oxide (CeO2) and 1%, 5% and 10% zirconium/tin-dual doped CeO2 nanoparticles (Zr/Sn-dual doped CeO2 NPs) were synthesized using an aqueous leaf extract of Pometia pinnata. By using UV-visible diffuse reflectance spectroscopy, the band gap energies of these materials were found to be in the range of ∼2.49 to 2.66 eV. The average crystallite sizes of the fluorite phase obtained from X-ray diffraction were between 7 and 16 nm. X-ray photoelectron spectroscopy (XPS) analysis further confirmed the synthesis of CeO2 and Sn-doped CeO2 NPs. Almost spherical shapes of the nanomaterials with an average particle size of 12-17 nm were determined using scanning electron microscopy and transmission electron microscopy studies. Photoantioxidant activities of the synthesized materials showed enhanced photoantioxidant response under visible light irradiation in comparison with those under dark conditions in both dose- and time-dependent manner. The CeO2 NPs exhibited a significant concentration-dependent antibiofilm activity against the Gram-positive bacteria Staphylococcus aureus (S. aureus) and Listeria monocytogenes (L. monocytogenes). Only the 10% Zr/Sn-dual doped-CeO2 NPs were found to inhibit S. aureus biofilm formation at higher concentrations. All Zr/Sn-dual doped CeO2 NPs exhibited a concentration-dependent biofilm inhibition of L. monocytogenes and also bactericidal activity towards S. aureus. These nanomaterials exhibited enhanced photoantioxidant activities and antibacterial properties, which make them suitable for various biological applications.

In order to study the effect of cinnamon essential oil (CEO) on the microbiological and physiochemical characters of fresh Italian style sausage, CEO (0%, 0.1%, and 0.5%, v/w) was added into ground meat, cased, and stored at 4°C. Lipid oxidation, instrument color, total viable aerobic counts, Enterobacteriaceae, biogenic amines, and total volatile basic nitrogen (TVB-N) were investigated during 10 days (day). Results showed that CEO treatments had lower thiobarbituric acid reactive substances (TBARS), b* value, aerobic and Enterobacteriaceae counts, biogenic amine contents, and TVB-N and higher a* values at 4, 6, 8, and 10 days compared to the control, whereas 0.5% CEO treatment had better effect than 0.1% CEO. CEO improved color shelf-life by inhibiting lipid oxidation and prevented the increase in biogenic amines and TVB-N by reducing microbial counts of fresh sausage during storage. This study suggested that CEO could be applied in the food industry to improve the shelf-life of meat products.

Despite the availability of new generation drugs, hepatocellular carcinoma (HCC) is still the third most frequent cause of cancer-related deaths worldwide. Cerium oxide nanoparticles (CeO₂ NPs) have emerged as a novel antioxidant agent in experimental liver disease because of their antioxidant, anti-inflammatory and antisteatotic properties. In the present study, we aimed to elucidate the potential of CeO₂ NPs as therapeutic agent in HCC.

HCC was induced in 110 Wistar rats by intraperitoneal administration of diethylnitrosamine for 16 weeks. Animals were treated with vehicle or CeO₂ NPs at the week 16 and 17. At the 18th week, nanoceria biodistribution was assessed by mass spectrometry (MS). The effect of CeO₂ NPs on tumor progression and animal survival was investigated. Hepatic tissue MS-based phosphoproteomics as well as analysis of principal lipid components were performed. The intracellular uptake of CeO₂ NPs by human ex vivo perfused livers and human hepatocytes was analyzed. Nanoceria was mainly accumulated in the liver, where it reduced macrophage infiltration and inflammatory gene expression. Nanoceria treatment increased liver apoptotic activity while proliferation was attenuated. Phosphoproteomic analysis revealed that CeO₂ NPs affected the phosphorylation of proteins mainly related to cell adhesion and RNA splicing. CeO₂ NPs decreased phosphatidylcholine-derived arachidonic acid and reverted the HCC-induced increase of linoleic acid in several lipid components. Furthermore, CeO₂ NPs reduced serum alpha-protein levels and improved the survival of HCC-rats. Nanoceria uptake by ex vivo perfused human livers and in vitro human hepatocytes was also demonstrated.

These data indicate that CeO₂ NPs partially revert the cellular mechanisms involved in tumor progression and significantly increase survival in HCC-rats, suggesting that they could be effective in patients with HCC.

In the era of technology, nanotechnology has been introduced as a new window for agriculture. However, no attention has been paid to the effect of cerium dioxide nanoparticles (nCeO₂) on the reproductive stage of plant development to evaluate their toxicity and safety. To address this important topic, bean plants (Phaseolus vulgaris L.) treated aerially with nCeO₂ suspension at 250-2000 mg L^-1 were cultivated until flowering and seed production in the greenhouse condition. Microscopy analysis was carried out on sectioned anthers and ovules at different developmental stages. The pollen's mother cell development in nCeO₂ treatments was normal at early stages, the same as control plants. However, the results indicated that pollen grains underwent serious structural damages, including chromosome separation abnormality at anaphase I, pollen wall defect, and pollen grain malformations in nCeO₂-treated plants at the highest concentration, which resulted in pollen abortion and yield losses. On the ovule side, the progression of development only at the highest concentration was modified in the two-nucleated embryo sac stage, probably due to apoptosis in nuclei. Nevertheless, the findings confirmed the more pronounced vulnerability of male reproductive development under nCeO₂ exposure than female development. The higher concentration decreased seed productivity, including seed set in either pods or whole plant (13% and 18% compared to control, respectively). The data suggested the potential application of nCeO₂ at optimal dosages as a plant productivity ameliorative. However, a higher dosage is considered as an eco-environmental hazard. To our best knowledge, this is the first study analyzing reproductive plant response upon exposure to nCeO₂.

Keywords: cerium dioxide nanoparticles; food safety; pollen viability; reproductive phase; seed productivity.

Ceria (CeO₂) nanostructures are well-known in catalysis for energy and environmental preservation and remediation. Recently, they have also been gaining momentum for biological applications in virtue of their unique redox properties that make them antioxidant or pro-oxidant, depending on the experimental conditions and ceria nanomorphology. In particular, interest has grown in the use of biotemplates to exert control over ceria morphology and reactivity. However, only a handful of reports exist on the use of specific biomolecules to template ceria nucleation and growth into defined nanostructures. This review focusses on the latest advancements in the area of biomolecular templates for ceria nanostructures and existing opportunities for their (bio)applications.

Keywords: anti-oxidant; biomolecule; catalysis; ceria; nanoparticles; nanorods; nanosheets; nanozyme; oxygen radicals; template.

Monitoring carbon dioxide (CO₂) levels is extremely important in a wide range of applications. Although metal oxide-based chemoresistive sensors have emerged as a promising approach for CO₂ detection, the development of efficient CO₂ sensors at low temperature remains a challenge. Herein, we report a low-temperature hollow nanostructured CeO₂-based sensor for CO₂ detection. We monitor the changes in the electrical resistance after CO₂ pulses in a relative humidity of 70% and show the high performance of the sensor at 100 °C. The yolk-shell nanospheres have not only 2 times higher sensitivity but also significantly increased stability and reversibility, faster response times, and greater CO₂ adsorption capacity than commercial ceria nanoparticles. The improvements in the CO₂ sensing performance are attributed to hollow and porous structure of the yolk-shell nanoparticles, allowing for enhanced gas diffusion and high specific surface area. We present an easy strategy to enhance the electrical and sensing properties of metal oxides at a low operating temperature that is desirable for practical applications of CO₂ sensors.