Over the last decade, a wide array of evidence has been accumulated that disruption of circadian clock is prone to cause age-related diseases and premature aging. On the other hand, aging has been identified as one of the risk factors linked to the alteration of circadian clock. These evidences suggest that the processes of aging and circadian clock feedback on each other at the animal level. However, at the cellular level, we recently revealed that the primary fibroblast cells derived from Bmal1 -/- mouse embryo, in which circadian clock is completely disrupted, do not demonstrate the acceleration of cellular aging, i.e., cellular senescence. In addition, little is known about the impact of cellular senescence on circadian clock. In this study, we show for the first time that senescent cells possess a longer circadian period with delayed peak-time and that the variability in peak-time is wider in the senescent cells compared to their proliferative counterparts, indicating that senescent cells show alterations of circadian clock. We, furthermore, propose that investigation at cellular level is a powerful and useful approach to dissect molecular mechanisms of aging in the circadian clock.

Ageing is one of the greatest risk factors for chronic non-communicable diseases, and cellular senescence is one of the major causes of ageing and age-related diseases. The persistent presence of senescent cells in late life seems to cause disarray in a tissue-specific manner. Ageing disrupts the circadian clock system, which results in the development of many age-related diseases such as metabolic syndrome, cancer, cardiac diseases and sleep disorders and an increased susceptibility to infections. In this review, we first discuss cellular senescence and some of its basic characteristics and detrimental roles. Then, we discuss a relatively unexplored topic on the link between cellular senescence and the circadian clock and attempt to determine whether cellular senescence could be the underlying factor for circadian clock disruption.

As 5G technology is advancing towards its final phase of development and the deployment of 5G networks is underway, academic, development and industrial communities are already moving towards the research and development of 6G wireless networks. While 5G technologies had been hauled as an enabler for Internet of Everything, many limitations of such cellular systems are coming to light as they are being deployed. These drawbacks of 5G networks have motivated worldwide interest on developing the next generation wireless system, 6G, with the capability to fully incorporate wide-ranging applications from virtual reality to autonomous systems. In this paper, an overview of the first five generations of wireless systems has been shown, followed by a survey on 6G wireless network along with a discussion on the possible requirements and challenges of 6G.

Senescent cells, which show the permanent growth arrest in response to various forms of stress, accumulate in the body with the progression of age, and are associated with aging and age-associated diseases. Although the senescent cells are growth arrested, they still demonstrate high metabolic rate and altered gene expressions, indicating that senescent cells are still active. We recently showed that the circadian clock properties, namely phase and period of the cells, are altered with the establishment of replicative senescence. However, whether cellular senescence triggers the alteration of circadian clock properties in the cells is still unknown. In this study we show that the oxidative stress-induced premature senescence induces the alterations of the circadian clock, similar to the phenotypes of the replicative senescent cells. We found that the oxidative stress-induced premature senescent cells display the prolonged period and delayed phases. In addition, the magnitude of these changes intensified over time, indicating that cellular senescence changes the circadian clock properties. Our current results corroborate with our previous findings and further confirm that cellular senescence induces altered circadian clock properties, irrespective of the replicative senescence or the stress-induced premature senescence.

A main feature of aged organisms is the accumulation of senescent cells. Accumulated senescent cells, especially stress‐induced premature senescent cells, in aged organisms lead to the decline of the regenerative potential and function of tissues. We recently reported that the over‐expression of NAMPT, which is the rate‐limiting enzyme in mammalian NAD+ salvage pathway, delays replicative senescence in vitro. However, whether Nampt‐overexpressing cells are tolerant of stress‐induced premature senescence remains unknown. Here, we show that primary mouse embryonic fibroblasts derived from Nampt‐overexpressing transgenic mice (Nampt Tg‐MEF cells) possess resistance against stress‐induced premature senescence in vitro. We found that higher oxidative or endoplasmic reticulum (ER) stress is required to induce premature senescence in Nampt Tg‐MEF cells compared to wild‐type cells. Moreover, we found that Nampt Tg‐MEF cells show acute expression of unfolded protein response (UPR)‐related genes, which in turn would have helped to restore proteostasis and avoid cellular senescence. Our results demonstrate that NAMPT/NAD+ axis functions to protect cells not only from replicative senescence, but also from stress‐induced premature senescence in vitro. We anticipate that in vivo activation of NAMPT activity or increment of NAD+ would protect tissues from the accumulation of premature senescent cells, thereby maintaining healthy aging.

Functional foods such as mushrooms are rich in polyphenolic compounds and secondary metabolites with health-promoting properties such as antioxidant, antimicrobial, antidiabetic and immunostimulatory effects. The present study is aimed to investigate the ethanolic extracts of three varieties of mushrooms, namely, G. lucidum, G. tropicum, and C. indica grown in Bangladesh for phenolic and flavonoid content and their antioxidant properties. Moreover, the phenolic composition of the extracts was analyzed by using the HPLC-DAD system. G. lucidum extract exhibited the highest antioxidant potential as evidenced by its lowest IC50 value in all the tested assay models ( 40.44 ± 2.09  μg/mL, 151.32 ± 0.35  μg/mL, 137.89 ± 1.85  μg/mL in DPPH, H2O2, and NO scavenging assay, respectively) along with the highest phenolic content ( 81.34 ± 0.68 GAE g-1 extract). G. tropicum and C. indica extracts also showed significant antioxidant properties and a good amount of phenolic content, 52.16 ± 0.25 GAE g-1 extract, and 47.1 ± 0.26 GAE g-1 extract, respectively. The scavenging activity increased with the increasing concentration of extracts in all cases. The total phenolic content of the ethanolic extracts of mushroom species was highly correlated with antioxidant effects with Pearson’s correlation coefficient ( r ) values ranging from 0.8883–0.9851. The α-amylase inhibitory and antibacterial activity of G. lucidum was evaluated by using 3,5-dinitrosalicylic acid and disc diffusion method, respectively. The maximum inhibitory activity recorded against α-amylase was 70.98 ± 0.042 % at a concentration of 500 μg/mL. G. lucidum extract exhibited the highest antibacterial activity against Pseudomonas aeruginosa with 23.00 ± 1.00  mm clear zone of inhibition and an MIC value of 3.5 mg/mL. The results indicate that the mushroom species tested in this study could serve as a potential source of natural antioxidants in the development of nutraceuticals and herbal drugs for the management of oxidative stress-associated diseases as well as infectious diseases.

Background: Zoonotic parasite species are those parasites of animal origin that can be transferred to human. They possess the threat of high infection rate among both animals and human and should be monitored carefully. Aims: The current study aimed to determine the prevalence of zoonotic parasite species in cats and dogs from a prominent pet market of Dhaka, Bangladesh. Methodology: A total of 60 animals (30 dogs and 30 cats) were selected from different pet shops in Katabon pet market, Nilkhet, Dhaka, Bangladesh. The hosts were dogs of foreign breed; German Spitz, German Shephed (Canis lupus familiaris) and cats of local breed (Felis catus). They were age matched: Puppies/Kittens (≥6 months - 1 year), young (>1- 2 years) and adults (>2 - 3 years) for both dogs and cats. Feces were collected and Formol Ether concentration technique was done prior to identify parasite’s egg, ova and larvae by microscopy. Results: We were able to identify 17 different parasite species of zoonotic importance in total 60 animals. 8 species were common in both animals (Taenia spp., Hymenolepis diminuta, H. nana, Ancylostoma spp., Ascaris lumbricoides, Capillaria spp., Toxascaris leonina and Trichuris vulpis). Apart from 8 common species, 2 more species were exclusively identified in dogs and 7 species in cats. Capillaria spp. had the highest prevalence in both dogs (86.67%) and cats (90%) followed by Trichuris vulpis (83.33% in dogs, 90% in cats). Other highly prevalent parasites in dogs were A. lumbricoides and Toxocara canis (prevalence 76.67% for both); in cats were - T. leonina, Toxocara cati, Sarcocystis spp. and Toxoplasma spp. (prevalence 76.67%, 73.33%, 60% and 60%, respectively). According to the age group of hosts, in both dogs and cats, puppies or kittens and young hosts had higher prevalence of parasites compared to adults. Conclusion: Proper training should be given to pet handlers when handling the food/feces of pets to reduce the risk of zoonotic infection and mass people should be aware about the risk of zoonotic parasite species to avoid potential health hazards.

The 6G wireless network with its superior capabilities must be considered to accommodate the much more stringent quality of service (QoS) requirements of the numerous emerging applications and services in the future. Attempting to adhere these constraints raise various challenges that are required to be addressed and solved in order to realize the vision of a fully intelligent and automated future society. This article provides the key enabling technologies and future applications for 6G networks followed by a discussion on QoS. It also presents a state-of-the-art survey on the challenges faced while trying to meet the QoS requirements regarding the time latency, throughput, connectivity, packet loss, and bandwidth, together with possible solutions to handle various constraints. A discussion on user satisfaction estimation from QoS analysis is also included. Finally, the article concludes with future research opportunities in meeting the QoS constraints of the 6G network.