Search

Abstract Carbon nanotube (CNT) has fostered research as a promising nanomaterial for a variety of applications due to its exceptional mechanical, optical, and electrical characteristics. The present article proposes a novel and comprehensive micromechanical framework to assess the viscoelastic properties of a multiscale CNT-reinforced two-dimensional (2D) woven hybrid composite. It also focuses on demonstrating the utilisation of the proposed micromechanics in the dynamic analysis of shell structure. First, the detailed constructional attributes of the proposed trans-scale composite material system are described in detail. Then, according to the nature of the constructional feature, mathematical modelling of each constituent phase or building block’s material properties is established to evaluate the homogenised viscoelastic properties of the proposed composite material system. To highlight the novelty of this study, the viscoelastic characteristics of the modified matrix are developed using the micromechanics method of Mori–Tanaka (MT) in combination with the weak viscoelastic interphase (WI) theory. In the entire micromechanical framework, the CNTs are considered to be randomly oriented. The strength of the material (SOM) approach is used to establish mathematical frameworks for the viscoelastic characteristics of yarns, whereas the unit cell method (UCM) is used to determine the viscoelastic properties of the representative unit cell (RUC). Different numerical results have been obtained by varying the CNT composition, interface conditions, agglomeration, carbon fibre volume percentage, excitation frequency, and temperature. The influences of geometrical parameters like yarn thickness, width, and the gap length to yarn width ratio on the viscoelasticity of such composite material systems are also explored. The current study also addresses the issue of resultant anisotropic viscoelastic properties due to the use of dissimilar yarn thickness. The results of this micromechanical analysis provide valuable insights into the viscoelastic properties of the proposed composite material system and suggest its potential applications in vibration damping. To demonstrate the application of developed novel micromechanics in vibration analysis, as one of the main contributions, comprehensive numerical experiments are conducted on a shell panel. The results show a significant reduction in vibration amplitudes compared to traditional composite materials in the frequency response and transient response analyses. To focus on the aspect of micromechanical behaviour on dynamic response and for the purpose of brevity, only linear strain displacement relationships are considered for dynamic analysis. These insights could inform future research and development in the field of composite materials.

Immunotherapy is now established as a potent therapeutic paradigm engendering antitumor immune response against a wide range of malignancies and other diseases by modulating the immune system either through the stimulation or suppression of immune components such as CD4+ T cells, CD8+ T cells, B cells, monocytes, macrophages, dendritic cells, and natural killer cells. By targeting several immune checkpoint inhibitors or blockers (e.g., PD-1, PD-L1, PD-L2, CTLA-4, LAG3, and TIM-3) expressed on the surface of immune cells, several monoclonal antibodies and polyclonal antibodies have been developed and already translated clinically. In addition, natural killer cell-based, dendritic cell-based, and CAR T cell therapies have been also shown to be promising and effective immunotherapeutic approaches. In particular, CAR T cell therapy has benefited from advancements in CRISPR-Cas9 genome editing technology, allowing the generation of several modified CAR T cells with enhanced antitumor immunity. However, the emerging SARS-CoV-2 infection could hijack a patient’s immune system by releasing pro-inflammatory interleukins and cytokines such as IL-1β, IL-2, IL-6, and IL-10, and IFN-γ and TNF-α, respectively, which can further promote neutrophil extravasation and the vasodilation of blood vessels. Despite the significant development of advanced immunotherapeutic technologies, after a certain period of treatment, cancer relapses due to the development of resistance to immunotherapy. Resistance may be primary (where tumor cells do not respond to the treatment), or secondary or acquired immune resistance (where tumor cells develop resistance gradually to ICIs therapy). In this context, this review aims to address the existing immunotherapeutic technologies against cancer and the resistance mechanisms against immunotherapeutic drugs, and explain the impact of COVID-19 on cancer treatment. In addition, we will discuss what will be the future implementation of these strategies against cancer drug resistance. Finally, we will emphasize the practical steps to lay the groundwork for enlightened policy for intervention and resource allocation to care for cancer patients.

First, second, third, and fourth-generation biofuels are continuously evolving as a promising substitute to petrodiesel catalyzed by energy depletion, economic and environmental considerations. Bio-diesel can be synthesized from various biomass sources, which are commonly divided into FAME and renewable biodiesel. FAME biodiesel is generally produced by the transesterification of vegetable oils and fats while renewable diesel is produced by hydro-deoxygenation of vegetable and waste oils and fats. The different generation, processing technologies and standards for FAME and renewable biodiesel are reviewed. Finally, the life cycle analysis and production cost of conventional and renewable biodiesel are described.

Growth of rice (Oryza sativa L.) is severely affected by drought stress, which leads to decreased rice production in rainfed ecosystems worldwide. Particularly, modern rice varieties are more susceptible to drought stress rather than traditional rice varieties. In the present study, a modern short-term rice variety, ADT37, abundantly cultivated in the Cauvery delta region of the southern part of India, was improved for grain yield by introducing qDTY1.1 through the conventional backcross method. Positive F1 progenies were identified using RM431 linked with qDTY1.1 in PCR amplification. In phenotypic selection, rice progenies with suitable plant height to avoid linkage drag as well as high degree of drought tolerance to manage the drought stress were selected and advanced through the backcrossing process up to the BC3 generation. Finally, two near isogenic lines with equal plant height to the recurrent parent and high degree of drought tolerance were selected. A positive effect of qDTY1.1 on plant height and fertile seeds was revealed. In the future, the selected superior near isogenic lines would be useful to rice researchers and farmers facing unexpected water crises. Moreover, the morphological marker associated with the performance of crops according to the intensity of stress will support climate resilient agriculture. [ABSTRACT FROM AUTHOR]

Salmonella enterica is a leading cause of foodborne illness in the U.S. In the meat industry, one action taken to address pathogen contamination incidence is an intense sanitization (IS) of the entire processing plant that many large processors perform annually or semiannually. However, this procedure’s immediate and long-term impact on environment microbial community and pathogen colonization are unknown. Here we investigated the impact of IS procedure on environmental biofilms and the subsequent S. enterica colonization and stress tolerance. Environmental samples were collected from floor drains at various areas 1 week before, 1 week, and 4 weeks after the IS procedure at a beef plant with sporadic S. enterica prevalence. Biofilm formation by microorganisms in the drain samples without S. enterica presence was tested under processing temperature. The ability of the biofilms to recruit and/or protect a co-inoculated S. enterica strain from quaternary ammonium compound (QAC) treatment was determined. The community structure of each drain sample was elucidated through 16S rRNA amplicon community sequencing. Post-IS samples collected from 8 drains formed significantly stronger biofilms than the respective pre-IS samples. S. enterica colonization was not different between the pre- and post-IS biofilms at all drain locations. S. enterica survival in QAC-treated pre- and post-IS mixed biofilms varied depending upon the drain location but a higher survival was associated with a stronger biofilm matrix. The 16S rRNA amplicon gene community sequencing results exhibited a decrease in community diversity 1 week after IS treatment but followed by a significant increase 4 weeks after the treatment. The IS procedure also significantly altered the community composition and the higher presence of certain species in the post-IS community may be associated with the stronger mixed biofilm formation and Salmonella tolerance. Our study suggested that the IS procedure might disrupt the existing environmental microbial community and alter the natural population composition, which might lead to unintended consequences as a result of a lack of competition within the multispecies mixture. The survival and recruitment of species with high colonizing capability to the post-IS community may play crucial roles in shaping the ensuing ecological dynamics.

ABSTRACT Salmonella enterica is a prominent cause of foodborne disease in the United States. However, the mechanism and route of pathogen transmission that leads to Salmonella infection in commercial processing plants are poorly understood. This study aimed to investigate the effect of mixed-species biofilms on S. enterica survival and persistence under sanitizer stress [Quaternary ammonium compounds (QACs)] by analyzing 78 floor drain samples from a meat processing facility and three S. enterica strains (serovars Cerro, Montevideo, and Typhimurium) isolated from that facility and an unrelated source. The four test groups were as follows: control, QAC treatment, Salmonella addition, and QAC treatment with Salmonella addition. DNAs were extracted, and 16S rRNA gene based on the variable region V4 amplicon sequencing was performed to analyze the relative abundance, core microbiome, and Alpha and Beta diversity using the qiime2 pipeline. At the genus level, the Brochothrix (45.56%), Pseudomonas (38.94%), Carnobacterium (6.18%), Lactococcus (4.68%), Serratia (3.14%), and Staphylococcus (0.82%) were shown to be the most prevalent in all drain samples. The results demonstrate that the relative abundance of different bacterial genera was affected by both QAC treatment and Salmonella addition, with some genera showing increases or decreases in abundance. Notably, the correlation network was constructed to understand the relationships between the different bacteria. Nitrospira had the greatest number of connections in the floor drain environment network, with two negative and eight positive correlations. The results suggest that Nitrospira in the mixed-species biofilm community may play a role in converting ammonium in the QAC sanitizer into nitrites. Thus, Nitrospira could be a potentially important genus in providing sanitizer resistance to pathogen-encompassed mixed-species biofilms.IMPORTANCESalmonella contamination in meat processing facilities can lead to foodborne illness outbreaks. Our study characterized the microbiome dynamics in beef facility drains and their response to Salmonella addition and common sanitizer (QAC). Nitrospira could be an important genus in providing sanitizer resistance to pathogen-encompassed mixed-species biofilms. The results provide insight into the impact of mixed-species biofilms on Salmonella survival and persistence under sanitizer stress in meat processing facilities. The results highlight the need to consider mixed-species biofilm effects when developing targeted interventions to enhance food safety.

BackgroundMulti-species biofilms pose a problem in various environments, especially food-processing environments. The diversity of microorganisms in these biofilms plays a critical role in their integrity and protection against external biotic and abiotic factors. Compared to single-species biofilms, mixed-species biofilms are more resistant to various stresses, including antimicrobials like sanitizers. Therefore, understanding the microbiome composition and diversity in biofilms and their metabolic potential is a priority when developing intervention techniques to combat foodborne pathogens in food processing environments. MethodsThis study aimed to describe and compare the microbiome profile of 75 drain biofilm samples obtained from five different locations (Hotscale, Hotbox, Cooler, Processing, & Grind room) of three beef-processing plants (Plant A, B & C) taken over two timepoints 2017-18 (T1) and 2021 (T2) by shotgun sequencingResultsCore microbiome analysis found Pseudomonas, Psychrobacter, and Acinetobacter to be the top three prevalent genera among the plants and locations. Alpha diversity analysis demonstrated a high diversity of microbiome present in all the plants and locations across the time points. Functional analysis showed the high metabolic potential of the microbial community with abundance of genes in metabolism, cell-adhesion, motility, and quorum sensing. Moreover, Quaternary Ammonium Compound (QAC) resistance genes were also observed, this is significant as QAC sanitizers are commonly used in many food processing facilities. Multi-functional genes such as transposases, polymerases, permeases, flagellar proteins, and Mobile Genetic Elements (MGEs) were found suggesting these are dynamic microbial communities that work together to protect themselves against environmental stresses through multiple defense mechanisms.ConclusionThis study provides a framework for understanding the collective microbial network spanning a beef processing system. The results can be used to develop intervention strategies to best control these highly communicative microbial networks.

Background: Growth can be one of the most uncertain variations, but understanding the same is very important for diagnosis and treatment planning. Skeletal age and dental age have been used to determine a child′s developmental age. Several researchers have evaluated the association between dental and skeletal maturity with chronologic age on different population. The purpose of the present study was to find out whether dental age estimation can be replaced for skeletal age estimation in the Dakshina Kannada population. Methods: A total of 104 samples equally distributed among both genders in the age group of 9-14 years were selected. Skeletal age was estimated using hand-wrist radiographs and Fishman′s skeletal maturation index and dental age was measured using Demirjian′s method. Results: Spearman′s rank-order correlation coefficients were used to measure the association between the skeletal maturity and dental maturity. The mean ages of male and female samples were determined as 11.89 ± 1.867 years and 12.21 ± 1.473 years, respectively. Chronological age was found to be positively correlated to dental age and skeletal age and found to be statistically significant (P < 0.01). The correlation between dental age and skeletal age was also found to be statistically significant with P < 0.001 and correlation coefficient of 0.683 and 0.704 for males and females. Conclusion: The present study showed a strong relation between the developmental ages in mixed dentition population; hence, dental age can be considered as a replacement in the study population.