Gymnemic acids inhibit hyphal growth and virulence in Candida albicans

Candida albicans is an opportunistic and polymorphic fungal pathogen that causes mucosal, disseminated and invasive infections in humans. Transition from the yeast form to the hyphal form is one of the key virulence factors in C. albicans contributing to macrophage evasion, tissue invasion and biofilm formation. Nontoxic small molecules that inhibit C. albicans yeast-to-hypha conversion and hyphal growth could represent a valuable source for understanding pathogenic fungal morphogenesis, identifying drug targets and serving as templates for the development of novel antifungal agents. Here, we have identified the triterpenoid saponin family of gymnemic acids (GAs) as inhibitor of C. albicans morphogenesis. GAs were isolated and purified from Gymnema sylvestre leaves, the Ayurvedic traditional medicinal plant used to treat diabetes. Purified GAs had no effect on the growth and viability of C. albicans yeast cells but inhibited its yeast-to-hypha conversion under several hypha-inducing conditions, including the presence of serum. Moreover, GAs promoted the conversion of C. albicans hyphae into yeast cells under hypha inducing conditions. They also inhibited conidial germination and hyphal growth of Aspergillus sp. Finally, GAs inhibited the formation of invasive hyphae from C. albicans-infected Caenorhabditis elegans worms and rescued them from killing by C. albicans. Hence, GAs could be useful for various antifungal applications due to their traditional use in herbal medicine

On Lh,k-Labeling Index of Inverse Graphs Associated with Finite Cyclic Groups

An Lh,k-labeling of a graph G=V,E is a function f:V⟶0,∞ such that the positive difference between labels of the neighbouring vertices is at least h and the positive difference between the vertices separated by a distance 2 is at least k. The difference between the highest and lowest assigned values is the index of an Lh,k-labeling. The minimum number for which the graph admits an Lh,k-labeling is called the required possible index of Lh,k-labeling of G, and it is denoted by λkhG. In this paper, we obtain an upper bound for the index of the Lh,k-labeling for an inverse graph associated with a finite cyclic group, and we also establish the fact that the upper bound is sharp. Finally, we investigate a relation between Lh,k-labeling with radio labeling of an inverse graph associated with a finite cyclic group

Underwater wireless sensor network-based multihop data transmission using hybrid cat cheetah optimization algorithm

Abstract For the conservation and sustainable use of the oceanic environment, monitoring of underwater regions is ineluctable and is effectuated with the aid of an underwater wireless sensor network. It is accoutered with smart equipment, vehicles and sensors and utilized for the transmission of acquired data from the monitoring region and forwarded to the sink nodes (SN) where the data are retrieved. Moreover, data transmission from sensor nodes to SN is complicated by the aquatic environment's inherent complexities. To surpass those issues, the work in this article focusesto propose a Hybrid Cat Cheetah optimization algorithm (HC2OA) that purveys the energy efficient clustering based routing. The network is then partitioned into numerous clusters, each of which is led by a cluster head (CH) and comprised of many sub-clusters (CM). Based on the factors such as distance and residual energy the CH selection is optimized and collects data from the respective CMs and forwarded to the SN with a multi-hop transmission approach. The proposed HC2OA chooses the optimized multi-hop route from the CH to SN. Thus mitigates the complexities over multi-hop routing and CH selection. Simulations are effectuated in the NS2 simulator and analyzed the performance. The results of the study show that the proposed work has significant advantages over state-of-the-art works in terms of network lifetime, packet delivery ratio, and energy consumption. The energy consumption of the proposed work is 0.2 J with a packet delivery ratio is 95%.The network life time of proposed work, with respect to the coverage area around 14 km is approximately 60 h

Defect Passivation by Pyridine-Carbazole Molecules for Efficient and Stable Perovskite Solar Cells

The defects in the light-harvesting perovskite absorber layer play a key role in limiting power conversion efficiencies (PCEs) and long-term stability of lead halide perovskite solar cells (PSCs). Although organic ammonium halides have been used for defect passivation in high-performance PSCs, the stability issue is still a challenge. Herein, we develop a novel material of pyridine-carbazole (Py-Cz) to passivate defects via coordination bonding. With this passivation, the photoluminescence intensity of perovskite films was increased. In addition, the formation of under-coordinated Pb2+defects in perovskite films was reduced significantly, enabling high-performance and long-term stable PSCs. Three different sets of PSCs were constructed, namely, without passivation, with phenethylammonium iodide (PEAI) (commonly used for passivation), and with Py-Cz passivation. Remarkably, the PSCs fabricated using the Py-Cz passivation not only achieved PCEs of over 20% but also retained 85% of their initial performances over more than 5000 h. In contrast, the PSCs without or with PEAI passivation degraded quickly during the long-term operational stability test under light illumination. This method opens up a new opportunity to develop highly efficient and operationally stable PSCs

Oral candidosis – clinical challenges of a biofilm disease

This review summarizes the impact of biofilms in oral candidosis with special emphasis on medically compromised patients. The concept of oral candidosis as a mixed candidal-bacterial biofilm infection has changed our understanding of its epidemiology and diagnosis as well as approach to its treatment. Candida albicans is the most common causative agent of oral candidosis although Candida species other than C. albicans are often seen in medically compromised patients with a history of multiple courses of azole antifungals. Although C. albicans is usually susceptible to all commonly used antifungals when tested in vitro, their biofilm form are highly resistant to most antifungals. Therefore, treatment consists of mechanical destruction of the biofilm in combination with topical drugs. Azole antifungals should be avoided for patients suffering from recurrent oral yeast infections due to a risk of selection and enrichment of resistant strains within the biofilm. Oral candidosis can also be a symptom of an undiagnosed or poorly controlled systemic disease such as HIV infection or diabetes. If the response to appropriate treatment is poor, other causes of oral mucositis should be excluded. Oral candidosis arises from the patient's mixed candidal-bacterial biofilm, i.e., dental plaque, whereby good self-care is important for successful therapy