Petri Dishes Research Articles

Antimicrobial Properties of Newer Calcium Silicate-Based Pulp-Capping Agents Against Enterococcus Faecalis and Streptococcus Mutans: An In-Vitro Evaluation.

This study aimed to evaluate the antibacterial activity of calcium silicate-based pulp-capping agents against Enterococcus faecalis and Streptococcus mutans using an agar diffusion test. The agar diffusion method was used to evaluate the antibacterial properties of pulp-capping agents. The materials used included Bio-C® Temp (Angelus, Brazil), Dia-Root™ Bio mineral trioxide aggregate (MTA) (Diadent Europe B.V., Almere, Netherlands), Biodentine™ (Septodont, Saint-Maur-des-Fossés, France), and TheraCal LC (Bisco Inc., Schaumburg, IL). Eighteen petri dishes, nine for S. mutans and nine for E. faecalis, were divided into four parts each (one for each agent), for a total sample size of 72. The bacterial suspensions were transferred to the petri dishes using a sterile swab. Four wells with a diameter of 4 mm were then punched in each petri dish. The wells were filled with the pulp-capping agents, which had been mixed according to the manufacturer's instructions, and the petri dishes were incubated. The zone of inhibition was measured at 24 and 48 hours to assess the pulp-capping agents' antimicrobial efficacy against E. faecalis and S. mutans. The readings were tabulated and subjected to statistical analysis. At 24 hours, the highest zone of inhibition was found in the Biodentine™ group (15.83 ± 0.79 mm), followed by Dia-Root™ Bio MTA (14.5 ± 0.88 mm), TheraCal LC® (12.56 ± 0.53 mm), and the shortest in the Bio-C Temp (9.61 ± 0.70 mm) against S. mutans. Analysis of variance (ANOVA) test showed a high statistical significance. After 48 hours, there was no statistically significant difference in the mean zone of inhibition. At 24 hours, the highest zone of inhibition was found in the Biodentine™ group (20.56 ± 0.73 mm), followed by Dia-Root™ Bio MTA (20.06 ± 1.33 mm), TheraCal LC® (18.22 ± 0.97 mm), and the shortest in the Bio-C Temp (14.11 ± 0.78 mm) against E. faecalis. The ANOVA test indicated no statistically significant difference between the Biodentine™ and the Dia-Root™ Bio MTA groups. After 48 hours, there was no statistically significant difference in the mean zone of inhibition. Biodentine™ has higher antibacterial efficacy against S. mutans, while Biodentine™ and Dia-Root™ Bio MTA have comparably high antibacterial activity against S. mutans and E. faecalis at 24 and 48 hours.

Biodeterioration Risk Assessment in Libraries by Airborne Fungal Spores.

Fungal growth on cellulose-based materials in libraries can have detrimental effects on books and documents. This biodeterioration affects their physical, chemical, and esthetical characteristics. Thus, this work aimed to assess fungal aerosols' concentrations and biodeterioration risk in two public libraries with artificial ventilation: the Banco de la República and CAJAMAG libraries. Air sampling was performed using a two-stage viable Andersen cascade impactor with Sabouraud dextrose agar at 4% on Petri dishes. Also, the temperature and relative humidity were measured with a digital thermo-hygrometer HOBO U12 Data Logger. The concentrations were low, with values of around 35 CFU/m3. Aspergillus, Cladosporium, and Penicillium were the predominant genera in the two libraries, with A. niger being the most abundant species. The thermo-hygrometric conditions inside the libraries were stable, with a mean temperature of 25.2 °C and a mean relative humidity of 52.1%. The calculated potential risk associated with fungal aerosols was seen to be medium in both libraries, where Aspergillus genera reported the highest cellulosic activity and hence had a higher risk of biodeterioration.

INFLUENCE OF DISINFECTANTS ON THE TOTAL BACTERIAL CONTAMINATION OF DUCK EGGSHELLS

The role of the total viable microbial count on eggshells is of significant interest, as it relates to egg safety and product shelf life.The aim of this study was to assess the influence of various disinfectants on the overall bacterial contamination of duck eggshells. For this purpose, fresh high-quality duck eggs were obtained from a farm, and solutions of disinfectants were prepared: 6% hydrogen peroxide, 4% calcium hydroxide, 4% sodium carbonate, and 3% acetic acid. When disinfecting duck or goose eggs, the dosage of substances is doubled compared to chicken eggs. The eggs were treated with prepared disinfectant solutions, with varying exposure times. The exposure times for hydrogen peroxide were 4 and 8 minutes, for calcium hypochlorite – 2 and 5 minutes, for sodium carbonate – 10 and 30 minutes, and for acetic acid – 5 and 15 minutes. Samples of washings from the eggshells were collected both before and after disinfection. Dilutions were prepared and subsequently plated on Petri dishes with non-selective media, followed by incubation at 30°C for 72 hours. As a result of colony counting, the number of mesophilic aerobic and facultatively anaerobic microorganisms (CFU/egg) was determined.The results of the study showed a direct correlation between the inactivation of microorganisms and exposure time when using acetic acid, hydrogen peroxide, and calcium hypochlorite. A longer contact period of the eggs with sodium carbonate did not result in a measurable reduction in the number of viable microorganisms. It was also found that 4% calcium hypochlorite could completely inactivate microbes on the eggshell within 5 minutes. With a 2-minute exposure, the total microbial contamination was 9.2*10¹±0.7 CFU/egg.Thus, in this study, solutions of calcium hypochlorite, hydrogen peroxide, and acetic acid demonstrated high bactericidal properties and can be considered effective agents for disinfecting duck eggshells.Most scientific articles are devoted to the study of chicken eggs. In this work, the object of research is duck eggs, the best disinfectants for processing eggshells have been identified, which is an urgent task in poultry farming.The obtained results can help farmers implement more effective strategies for combating foodborne infections.

Assessing of sugar beet Seed adaptation under salt and drought stress conditions with coating technology based on Fuzzy inference system

Sustainability in crop production is highly dependent on favorable indicators of germination and seedling establishment. In this research seed coating different treatments data prepared and membership function defined in fuzzy inference system then used rule editor tool for determining parameters weight for achieved the best coating treatment in salinity and drought stress conditions. Seed coating formulations were investigated in laboratory and greenhouse experiments for their potential to increase maximum germination, germination rate, germination uniformity, and seedling growth of sugar beet seeds. Sugar beet seeds were coated with different compounds and combinations, including micro- (Fe, Zn, Cu, Mn, Co, Mo) and macro- (N, P, K) nutrients, humic acid, gibberellic acid, kaolin, and chitosan. Coated and non-coated sugar beet seeds were evaluated for germination and seedling growth after 10 and 21 days, respectively. In total, 30 different treatments were used to assess the effects of seed coating treatments. In laboratory experiments, sugar beet seeds were placed on paper in Petri dishes and maintained in a germinator at 25 °C. Sodium chloride and polyethylene glycol 8000 were used to apply salinity and drought stresses at three levels each and achieve the results of seed coatings on reducing the effects of salinity and drought stresses. To determine the indices related to emergence and establishment, cultivation trays were utilized with four replications for each treatment. The trays were kept inside a greenhouse. Coating treatments significantly improved total germination percentage, germination rate, seedling growth, and uniformity compared with the non-treated controls. In all treatments, polyvinylpyrrolidone was utilized as a binder. The best treatment with respect to germination and seedling growth indices was number 21 (micro and macronutrients, humic acid, gibberellic acid) in salinity and drought stress conditions. The results by fuzzy inference system illustrated that micronutrients, humic acid, and gibberellic acid create the best seed coating for sugar beet seeds, especially when combined at the specified amounts.

Assessment of Piper longum L. (Piperaceae) leaves toxicity on the adults of Tribolium castaneum (Herbst, 1797) (Coleoptera: Tenebrionidae)

BackgroundNumerous insect pests attack stored grains causing both qualitative and quantitative losses. The most damaging pest that infests dry stored produce is the red flour beetle, Tribolium castaneum, a secondary pest of stored goods. This pest, especially in its adult stage, exhibits resistance to chemical insecticides, thereby rendering the traditional pesticides ineffective in controlling it. Phyto-derivatives, which are strong insecticides and also ecologically benign, have gained interest as non-chemical solutions for controlling this pest. Hence, the objective of this study was to investigate the potential of Piper longum leaf extract insecticidal action as an environmentally benign insecticide for the first time against the adults of T. castaneum. In this study, P. longum leaf ethanol extract was tested against the adults of T. castaneum by petri dish bioassay method. Ad hoc studies to verify significant mortality for the initial confirmation of adulticidal activity were conducted for 24 h at different dosages of 62.5, 125, 250, 500 and 1000 mg/L of P. longum leaf ethanol extract. Thereafter, dosages set at 10, 20, 30 and 40 mg/L for the fractions of P. longum leaf ethanol extract were conducted. Prior to this, the leaf extract of this plant was subjected to column chromatography for fractionation. The fractions tested for adulticidal activity were subjected to gas chromatography–mass spectroscopy.ResultsSignificant adulticidal action with 100% adult mortality was observed in ethanol extract of P. longum leaves. Among the fourteen fractions (F0–F13) obtained tested, only fractions, F5, F10 and F13, demonstrated adulticidal activity, and the remaining fractions displayed poor activity. One hundred per cent morality was noted in T. castaneum adults after 96 h at 40 mg/L in F5 and F10, and in F13 at 20 mg/L, and their respective LD50 values were 17.6, 26.6 and 10.0 mg/L. The fractions F5, F10 and F13 contained fatty acids, viz., hexadecanoic acid, dotriacontane and heptacosane in F5; tetradecanoic acid and nonadecanoic acid in F10; and octadecanoic acid, aspartame and tridecanoic acid in F13, revealed through gas chromatography–mass spectroscopy.ConclusionsThe results of the study showed that P. longum ethanol leaf extract revealed significant adulticidal activity and is a promising toxic agent to the adults of T. castaneum. The fatty acids in the ethanolic leaf extract fractions of P. longum could have caused toxicity to the adults of T. castaneum. According to the current literature survey, this is the first research report on the adulticidal activity of P. longum leaf extracts against the adults of T. castaneum.

Resistance of Bt and Non-Bt Soybean Cultivars Adapted to Novel Growing Regions of Brazil to Chrysodeixis includens and Spodoptera frugiperda.

Soybean is a highly valuable commodity crop for Brazil's economy. However, it faces significant threats from the attack of a complex of lepidopteran pests, particularly Chrysodeixis includens (Walker) and Spodoptera frugiperda (J. E. Smith). These pests have been managed primarily using transgenic Bt soybeans, but limited knowledge exists about the resistance levels of Bt and non-Bt cultivars adapted to novel soybean-growing areas in Brazil, such as the Minas Gerais state. This study evaluated the resistance levels of Bt and non-Bt soybean cultivars to C. includens and S. frugiperda, and whether the Bt cultivars can differentially affect these pests across larval stages. No-choice bioassays were conducted using Bt (NS6010 IPRO and P97R50 IPRO) and non-Bt soybeans (UFLA 6301 RR, P96R90 RR, and ANsc 80111 RR) at V4-stage in the laboratory with neonate (24 h) and third-instar larvae. Larvae were fed leaf discs in Petri dishes, recording the mortality, leaf consumption, and weight gain after 7 days. There was high mortality of C. includens neonates on the Bt cultivars, but this trend was not observed for older larvae. For S. frugiperda neonates, there was high mortality on the Bt cultivar NS 6010 IPRO and non-Bt cultivar UFLA 6301 RR, but only the former was effective for older larvae. Although the Bt cultivars did not kill the third instars, antinutritional effects were found, such that leaf tissue consumed was not converted to larval weight gain. These findings are important for defining regional strategies of integrated and resistance management of C. includens and S. frugiperda in expanding regions of soybean cultivation in Brazil.

Characterization of Bipolaris bicolor germination: effects of a physical factor on fungal adaptability.

Studies on physiological responses to stimuli from physical factors are essential for understanding the dynamics of the microorganisms and higly important for the management of plant diseases. Besides, the development of an epidemiological model for pathogen populations requires studying their physiological responses to physical stimuli. The objective of this study was to evaluate the germination dynamics of spores from six isolates of Bipolaris bicolor under effects of light at 25°C. Suspensions of 1.6 × 105 conidia mL- 1 from the B. bicolor isolates were inoculated onto Petri dishes containing agar-water culture medium and incubated in a BOD chamber under two physical conditions: (a) constant darkness and (b) constant light for five hours. The study was conducted in a completely randomized design, with a 6 × 2 factorial arrangement (six B. bicolor isolates and two physical conditions) and five replications. The length of the germ tube was measured hourly. The constant darkness resulted in higher mean germ tube growth for the pathogen; however, differences in the final germination percentage were found among the isolates. The isolate F-24-02 exhibited the highest germination adaptability to constant darkness, presenting the longest germ tube length.

First Report of Leaf Blight of Syringa oblata Caused by Botryosphaeria dothidea in China.

As an important landscaping plant, Syringa oblata is widely planted in northern China with high ornamental, medicinal, and edible value (Men et al. 2023). In September 2023, a new leaf blight disease on S. oblata was observed in Tianjin (39.0916°N, 117.1019°E), China. The onset of foliar symptoms was marked by the appearance of yellow-brown spots that originated from the tip and margin, subsequently evolving into irregularly shaped brown lesions. Finally, the lesions are distributed throughout the leaf surface, causing the leaf to wilt and seriously affecting photosynthesis. To identify the pathogen responsible for leaf blight of S. oblata, symptomatic leaves were collected and cut into square leaf blocks with a size of 0.3 cm², which were sterilized by immersion in 75% ethanol for 60 s and 5% NaClO for 30 s, and rinsed three times with sterile distilled water. The sterilized leaf pieces were then placed on potato dextrose agar (PDA) and incubated at 25 °C for 3-5 days. The peripheral hyphae of the fungal colony which developed from the infected tissues were isolated onto PDA plates. The fungal cultures on PDA plates were used for morphological observation and identification of the fungus. Colonies of B. dothidea on PDA medium were initially off-white, batting-shaped and gradually grayish-black. Aerial hyphae were well developed and could reach the tip of the petri dish. To induce sporulation, the hyphae were picked into medium containing sterilized pine needles. Conidia were found on pine needles after 30 d of incubation at 25°C. Conidia were hyaline, unicellular, oblong to spindle-shaped, and 17.5-23.0 µm in size × 6.1-8.5 µm(n=50). Based on these characteristics, the isolates were preliminarily identified as B. dothidea (Phillips et al. 2005). To provide additional evidence for the classification of the isolate, genomic DNA was extracted from the isolates of B. dothidea and used for Polymerase Chain Reaction (PCR). The internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (GPDH), and actin (ACT) were amplified with the primer pairs ITS1/ITS4, GDP1/GDP2, and ACT-512F/ACT-783R, respectively (Jiang et al. 2022). A BLAST search of sequences showed the ITS, GPDH, and ACT sequences had >99% identity with homologous sequences from B. dothidea isolates Bb158-4(HQ392696.1), PPO-46523(MG761771.1), and CMW7779 (AY972117.1), respectively. Phylogenetic analysis determined that the isolate was in the same clade position as B. dothidea, which confirmed the above morphological identification. To assess pathogenicity, the fungal cakes (6 mm diameter) were obtained from the edge of a fresh colony (cultured on a PDA plate for 7 days) using a sterile perforator. Ten surface-sterilized leaves of healthy S. oblata with uniform growth condition were collected and inoculated with fungal cakes after wounding. Ten leaves were inoculated with sterile PDA medium blocks as control. The test was repeated three times. All leaves were kept at 25°C and sterile H2O was sprayed daily to keep leaves surface moist. After five days, all vaccination sites showed lesions similar to those of the S. oblata diseased leaves in the field, while the controls were asymptomatic. B. dothidea was reisolated from symptomatic tissues, thus fulfilling Koch's postulates. B. dothidea is a member of Botryosphaeriaceae. Currently, B. dothidea infection of Syringa spp. plants has not been reported. However, in China, it has been reported to cause stem rot on Forsythia suspense (He et al. 2022) and leaf dieback on sweet osmanthus (Ling et al. 2010), demonstrating that B. dothidea can infect Oleaceae species. This study found that S. oblata could be infected by B. dothidea. To the best of our knowledge, this is the first report of B. dothidea causing leaf blight on S. oblata in China. Identifying the pathogen of S. oblata leaf blight is essential for the prevention and management of disease associated with S. oblata.

Morpho-physiological and biochemical responses of radish (Raphanus sativus L.) under cadmium stress

The accumulation of cadmium (Cd) in plants poses a major risk to consumer health, in addition to affecting plant growth, development and quality. The study aimed to examine the effects of cadmium on the plants' ability for photosynthesis and antioxidant enzyme activity. In this study, radishes were planted in Petri dishes and pots containing soil supplemented with different concentrations of cadmium sulphate (25, 50, and 100 mg Cd kg-1 soil). The results showed that the percentage of germination, seedlings length, and fresh and dry matter significantly declined its increasing cadmium concentrations. In addition, cadmium hindered plant growth, as evidenced by the fresh and dried weight of radish roots and leaves after a 100 mg Cd kg-1 soil treatment. There was also a notable decrease in chlorophyll a and chlorophyll b, total chlorophyll, and total leaf area per plant. The leaves of radish plant exhibited a significant increase in lipid peroxidation and electrolyte leakage contents under Cd stress, while, the relative water content (RWC) decreased. However, leaves and roots of radish plant showed a considerable increase in antioxidant enzymes (catalase; CAT, peroxidase; POD, and superoxide dismutase; SOD). Furthermore, radish showed a significant increase in Cd accumulation in all applications, however, there were no obvious symptoms of Cd toxicity following the 25 and 50 mg Cd kg-1 soil applications. In conclusion, the radish plants accumulated cadmium at higher concentrations (100 mg Cd kg-1 soil). So, we recommended cultivating the radish plants in soil that has low concentrations of cadmium.

Prospecting and Identification of Fungi Associated with the Rice Leaf Scald Disease in Togo

Leaf scald, caused by Rhynchosporium oryzae, is the third most damaging rice fungal disease worldwide after blast and helminthosporiosis. This study presents the first report of leaf scald on rice in Togo, based on a comprehensive survey of 93 rice plots across 28 out of 39 prefectures. The research aimed to identify, characterize, and test the pathogenicity of fungi associated with leaf scald symptoms, as well as determine the disease's distribution and severity in Togo. Samples were collected, processed in the laboratory, and cultured using blotting paper and potato dextrose agar media. Results revealed that 97,84% of surveyed plots exhibited symptoms related to leaf scald and severity of the disease record were most 5 except two plots which were recorded 9 on the scale of 1 to 9. Fungal isolates were confirmed as R. oryzae through macroscopic and microscopic analysis, adhering to criteria described in existing literature. Growth of mycelium where about 7,5 days in 90 mm petri dish from both paper blotting and PDA medium from initiative culture. Sporus where two or three septa and were obtained after 9 days. Koch's postulates were fulfilled by reproducing leaf scald symptoms using the isolated fungi on the variety IR 841 at 50 days stage. This study contributes valuable insights into the prevalence and characteristics of leaf scald in Togolese rice field.

Enhancing eco-friendly coatings: Aqueous olive leaves extract fortifies macroalgae-based packaging materials

This study incorporated bioactive compounds extracted from olive leaves (Olea europaea L.) into biodegradable films designed for preserving perishable food items like fruits and vegetables. Olive leaves, sourced from Lesvos island in Greece, yielded three aqueous extracts - OL1, OL2, and OL3 – representing different cultivated species. The antioxidant potential and phenolic compound profile of these extracts were analyzed. Subsequently, these extracts were integrated into 2% sodium alginate solutions, and the resulting mixtures were cast into 90 mm Petri dishes to form solid biofilms. Our findings reveal that the olive leaf extracts offer protection against UV–VIS radiation. Particularly, OL1 showcased the highest antioxidant capacity among the extracts examined. For the solid biofilms, various physical characteristics such as weight, diameter, density, and thickness were measured, alongside evaluating humidity, solubility in water, and water vapor permeability. The rheological properties of these solutions, influenced by temperature and extract addition, affect the viscosity, flow behavior, and gelation capacity, crucial for coating applications. Our research not only explores the impact of olive leaf extracts and glycerol as a plasticizer on biofilm solutions but also sheds light on increased opacity, reduced light absorption, and altered rheological properties. This endeavor aligns with the ongoing pursuit of sustainable packaging alternatives, emphasizing the crucial role of bioactive compounds in enhancing the functionality and eco-friendliness of biodegradable films.

Influence of Intraocular Pressure on the Expression and Activity of Sodium-Potassium Pumps in the Corneal Endothelium.

The corneal endothelium is responsible for pumping fluid out of the stroma in order to maintain corneal transparency, which depends in part on the expression and activity of sodium-potassium pumps. In this study, we evaluated how physiologic pressure and flow influence transcription, protein expression, and activity of Na+/K+-ATPase. Native and engineered corneal endothelia were cultured in a bioreactor in the presence of pressure and flow (hydrodynamic culture condition) or in a Petri dish (static culture condition). Transcription of ATP1A1 was assessed using qPCR, the expression of the α1 subunit of Na+/K+-ATPase was measured using Western blots and ELISA assays, and Na+/K+-ATPase activity was evaluated using an ATPase assay in the presence of ouabain. Results show that physiologic pressure and flow increase the transcription and the protein expression of Na+/K+-ATPase α1 in engineered corneal endothelia, while they remain stable in native corneal endothelia. Interestingly, the activity of Na+/K+-ATPase was increased in the presence of physiologic pressure and flow in both native and engineered corneal endothelia. These findings highlight the role of the in vivo environment on the functionality of the corneal endothelium.

Repellent Effects of Coconut Fatty Acid Methyl Esters and Their Blends with Bioactive Volatiles on Winged Myzus persicae (Sulzer) Aphids (Hemiptera: Aphididae).

Myzus persicae (Sulzer) (Hemiptera: Aphididae) is one of the most important aphid crop pests, due to its direct damage and its ability to transmit viral diseases in crops. The objective is to test whether spraying nanoemulsions of botanical products repels winged individuals of M. persicae in a bioassay in culture chambers. The bioactive volatiles were applied on pepper plants at a dose of 0.2% alone or at 0.1% of each component in blends. A treated plant and a control plant were placed at each side of an entomological cage inside a growth chamber. The winged individuals were released between the plants, in a black-painted Petri dish suspended by wires in the upper half of the cage. The most repellent products were farnesol (repellency index, RI = 40.24%), (E)-anethole (RI = 30.85%) and coconut fatty acid methyl ester (coconut FAME) (RI = 28.93%), alone or in the following blends: farnesol + (E)-anethole + distilled lemon oil (RI = 36.55%) or (E)-anethole + distilled lemon oil + coconut FAME (RI = 30.63%). The observed effect of coconut FAME on aphids is the first report of this product having a repellent effect on a crop pest. Repellent substances for viral disease vectors should be further investigated to develop new strategies for plant protection.

The sandwich feeding assay for use with first instar nymphs of the Asian citrus psyllid, Diaphorina citri confirms the high susceptibility of this life stage to bacterial pesticidal proteins

Citrus greening or huanglongbing is the most important disease of citrus and threatens citrus production worldwide. As nymphs of Diaphorina citri play a crucial role in the acquisition and transmission of the citrus greening bacterium, suppression of this life stage is particularly important. However, the lack of a tractable feeding assay for use with first instar D. citri nymphs has impeded assessment of the toxicity of bioactives. Of several bacterial pesticidal proteins (BPP) that are toxic to D. citri adults, Mpp51Aa1 and Cry1Ba1, which have LC50 values of 110 and 120 µg/mL respectively in adults, were fed to 1st instar nymphs in a newly developed assay. For this new sandwich feeding assay, parafilm layers containing feeding solution were placed on top of two 35 mm Petri dishes, with a concave surface created on each. Fifty nymphs were transferred to the membrane on one Petri dish, and the second Petri dish placed on the top to create a “sandwich” with the 1st instar nymphs in the middle. Nymphs were fed for four days and the LC50 values for Mpp51Aa1 and Cry1Ba1 were calculated at 6.7 and 41.6 µg/mL respectively. Bioassays with bioengineered plants expressing Cry1Ba1 confirmed that the majority of D. citri mortality occurs during the 1st instar nymph stage, while egg laying adults are much less susceptible. Taken together, these results confirm that 1st instar D. citri nymphs are more susceptible to BPP than adults and demonstrate the utility of the sandwich feeding assay for effective screening of BPPs prior to investment into production of transgenic plants.

Plantago Species Show Germination Improvement as a Function of Nitrate and Temperature

At the optimum temperature, which is the ideal range in which seeds germinate most efficiently, seed germination may be lower than expected under favorable conditions, and this is indicative of seed dormancy. Also, germination may be enhanced by additional and interacting factors, such as nitrate and light. However, little is known about the interplay between temperature, nitrate, and seed germination. Using seeds from 22 accessions of four Plantago species that occupy distinct pedoclimates, we applied a factorial experimental design to assess the relationship between exogenously applied nitrate (KNO3) and temperature on germination in a Petri dish experiment. The data explore the relationship between seed germination, temperatures, and seed- and maternal-source soil N content as either nitrite (NO2−), nitrate (NO3−), or ammonium (NH4+). The interpretation also considered the total N and C contents of seeds, and the soil of the maternal plant (of the test seed) sources. Significant interspecific effects of nitrate and temperature on seed germination were observed. The capacity of nitrate to enhance final germination may be diminished substantially at supra-optimum temperatures, e.g., P. lagopus germination at 15 °C was 7% lower than that seen for water-only treatment. In contrast, at sub-optimum and alternating temperatures, nitrate enhanced final germination differentially across the species tested. This suggests a shift to enhanced germination at lower temperatures in the presence of sufficient soil nitrate, facilitating seedling establishment earlier in the growing season. The seeds of some Plantago species showed increased germination as a function of nitrate and temperature, particularly those of P. lagopus. The findings indicate that species (and genotype) responses correlated with the prevailing temperature and rainfall patterns of the locality; such local adaptation would ensure that seed germination and establishment occur during a period when environmental conditions are optimal.

DEVELOPMENT OF FLUCONAZOLE-LOADED POLY(VINYL ALCOHOL)/POLY(ETHYLENE GLYCOL) BLENDED FILM FOR TREATMENT OF CANDIDA-INFECTED CUTANEOUS WOUNDS

In this work, we aimed to develop fluconazole (FLU)-loaded polymer blended film (FLU-film) for candidiasis wounds. The films were prepared from poly(vinyl alcohol) (PVA) and poly(ethylene glycol) 1000 (PEG 1000) mixed at different proportions by weight, casted on a petri dish, and dried at 60ºC for 12 h. Tensile strength, swelling ratio, and morphology were analyzed to determine an appropriate film for wound application. The selected film was loaded with 0.5% w/w FLU, where the drug homogeneity was ascertained. Then, the drug release profile, cytotoxicity of the films, and antifungal activity were determined. The findings revealed that the suitable film was PVA:PEG 1000 (95:5), showing anticipated flexibility and stretchability, as well as a soothing texture, while the swelling and molecular attributes were comparable to other films. FLU was homogenously loaded into the selected film and presented a prolonged release profile following Higuchi’s model. The film was found to be non-toxic to the human skin fibroblast. Lastly, the FLU-film presented 1.16-fold greater antifungal effectiveness than the free FLU. Overall, the FLU-film has been developed and proven to be effective for treating Candida-infected wounds.

On Seedling Morphoanatomy of Asteraceae Campestral Species: Some Adaptative and Taxonomic Considerations

Theoretical Framework: The vegetation of Parana State fields is composed mainly of woody grassy savanna, and one of the largest families in specific richness is Asteraceae. The campestral Asteraceae occurs in three microhabitats as dry fields (steppes “stricto sensu”), rocky outcrops (rupestrian vegetation refuges) and humid fields (higrophyllous steppes). Morphology and structure of Asteraceae seedlings can be useful for species recognition in the field at the juvenile stage, and to understand how seedlings establish themselves in different microhabitats. Objective: The aim of this paper was to analyze the seedling structure of 17 Asteraceae species, and to summarize some considerations on anatomical characters of the seedlings, which may be variations environmentally induced and they have some taxonomic or evolutionary value. Method: Cipselae of 17 species of Asteraceae were collected in the state parks of Paraná, Brazil, and placed to germinate in Petri plates. The seedling development occurred in greenhouse. Root, hypocotyl, cotyledons, epicotyl and eophylls were sectioned in rotation microtome, and analyzed in light microscope. Cotyledons and eophylls were investigated in a scanning electronic microscope. Results: Roots are diarch or tetrarch. Hypocotyl may have the root structure and partially or wholly as transition root-stem structure. Epicotyl shows the stem structure. Cotyledons and eophylls are dorsiventral. Trichome density and amphistomaty are xeromorphic characters that occur in the cotyledons and eophylls of the species. Conclusion: Some structural characters have diagnostic value for separation of investigated species, such as hypocotyl structure, root/stem transition type, epidermis, mesophyll tissues and midrib saliency of the cotyledons and eophylls, and presence of secretory ducts.

Height-Resolved Analysis of Indoor Airborne Microbiome: Comparison with Floor Dust-Borne Microbiome and the Significance of Shoe Sole Dust.

Exposure to the indoor airborne microbiome is closely related to the air that individuals breathe. However, the floor dust-borne microbiome is commonly used as a proxy for indoor airborne microbiome, and the spatial distribution of indoor airborne microbiome is less well understood. This study aimed to characterize indoor airborne microorganisms at varying heights and compare them with those in floor dust. An assembly of three horizontally and three vertically positioned Petri dishes coated with mineral oil was applied for passive air sampling continuously at three heights without interruption. The airborne microbiomes at the three different heights showed slight stratification and differed significantly from those found in the floor dust. Based on the apportionment results from the fast expectation-maximization algorithm (FEAST), shoe sole dust contributed approximately 4% to indoor airborne bacteria and 14% to airborne fungi, a contribution that is comparable to that from the floor dust-borne microbiome. The results indicated that floor dust may not be a reliable proxy for indoor airborne microbiome. Moreover, the study highlights the need for height-resolved studies of indoor airborne microbiomes among humans in different activity modes and life states. Additionally, shoe sole-dust-associated microorganisms could potentially be a source to "re-wild" the indoor microbiota.

Composting Cow Dung Enriched with Vivianite (Phosphocompost) for Agricultural Use in the Balaza Lawane Locality (Far North, Cameroon)

Aims: Soils in the Far North of Cameroon are deficient in organic matter and available phosphorus, making it difficult to intensify agricultural production. This affects the yield of several crops. With this in mind, a study has been carried out to produce cow dung compost enriched with vivianite, to improve soil quality in terms of organic matter and available phosphorus, and boost agricultural production. Study Design: A study was carried out to produce cow dung compost enriched with rock phosphate (Vivianite). Place and Duration of Study: Balaza Lawane in Far North Region of Cameroon. The sowing was done on January 15, 2021 until 20 april 2021. Methodology: To this end, we produced 3 organic amendments based on cow dung (a compost and two phospho-composts containing 10 and 20% of vivianite, respectively). Monitoring and chemical characterization of each of the three was carried out. A seed germination test was also carried out, on petri dishes in a completely randomized block design repeated three times. Results: Physico-chemical analyses reveal that the soil at the Balaza Lawane site has a Sandy clay loam granulometry and an acid pH (6.8); it is low in organic matter and available phosphorus. The monitoring of the amendments showed that the temperature, the pH, and even the moisture content of the amendments changed in the same way over time. The application of vivianite powder improved the nitrogen, potassium, and phosphorus content of the phosphocomposts compared to the compost. Phytotoxicity tests showed that our various amendments had no phytotoxic effects. The 20 and 10% phosphocomposts showed higher germination index than the other treatments (157.33±16.32% and 157.01±15.32% respectively). An analysis of variance revealed a significant difference (p < 0.05) threshold. Conclusion: Compost enriched with 20% vivianite produced more available phosphorus, and showed no phytotoxicity. This phosphocompost is proving to be the most effective crop amendment on Balaza Lawane soil.

Infiltrating monocytes drive cardiac dysfunction in a cardiomyocyte-restricted mouse model of SARS-CoV-2 infection.

Cardiovascular manifestations of coronavirus disease 2019 (COVID-19) include myocardial injury, heart failure, and myocarditis and are associated with long-term disability and mortality. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA and antigens are found in the myocardium of COVID-19 patients, and human cardiomyocytes are susceptible to infection in cell or organoid cultures. While these observations raise the possibility that cardiomyocyte infection may contribute to the cardiac sequelae of COVID-19, a causal relationship between cardiomyocyte infection and myocardial dysfunction and pathology has not been established. Here, we generated a mouse model of cardiomyocyte-restricted infection by selectively expressing human angiotensin-converting enzyme 2 (hACE2), the SARS-CoV-2 receptor, in cardiomyocytes. Inoculation of Myh6-Cre Rosa26loxP-STOP-loxP-hACE2 mice with an ancestral, non-mouse-adapted strain of SARS-CoV-2 resulted in viral replication within the heart, accumulation of macrophages, and moderate left ventricular (LV) systolic dysfunction. Cardiac pathology in this model was transient and resolved with viral clearance. Blockade of monocyte trafficking reduced macrophage accumulation, suppressed the development of LV systolic dysfunction, and promoted viral clearance in the heart. These findings establish a mouse model of SARS-CoV-2 cardiomyocyte infection that recapitulates features of cardiac dysfunctions of COVID-19 and suggests that both viral replication and resultant innate immune responses contribute to cardiac pathology.IMPORTANCEHeart involvement after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection occurs in multiple ways and is associated with worse outcomes in coronavirus disease 2019 (COVID-19) patients. It remains unclear if cardiac disease is driven by primary infection of the heart or immune response to the virus. SARS-CoV-2 is capable of entering contractile cells of the heart in a culture dish. However, it remains unclear how such infection affects the function of the heart in the body. Here, we designed a mouse in which only heart muscle cells can be infected with a SARS-CoV-2 strain to study cardiac infection in isolation from other organ systems. In our model, infected mice show viral infection, worse function, and accumulation of immune cells in the heart. A subset of immune cells facilitates such worsening heart function. As this model shows features similar to those observed in patients, it may be useful for understanding the heart disease that occurs as a part of COVID-19.