Further results on outer independent 22-rainbow dominating functions of graphs

Let $G=(V(G),E(G))$ be a graph. A function $f:V(G)\rightarrow \mathbb{P}(\{1,2\})$ is a $2$-rainbow dominating function if for every vertex $v$ with $f(v)=\emptyset$, f\big{(}N(v)\big{)}=\{1,2\}. An outer-independent $2$-rainbow dominating function (OI$2$RD function) of $G$ is a $2$-rainbow dominating function $f$ for which the set of all $v\in V(G)$ with $f(v)=\emptyset$ is independent. The outer independent $2$-rainbow domination number (OI$2$RD number) $\gamma_{oir2}(G)$ is the minimum weight of an OI$2$RD function of $G$. In this paper, we first prove that $n/2$ is a lower bound on the OI$2$RD number of a connected claw-free graph of order $n$ and characterize all such graphs for which the equality holds, solving an open problem given in an earlier paper. In addition, a study of this parameter for some graph products is carried out. In particular, we give a closed (resp. an exact) formula for the OI$2$RD number of rooted (resp. corona) product graphs and prove upper bounds on this parameter for the Cartesian product and direct product of two graphs

Injective coloring of product graphs

The problem of injective coloring in graphs can be revisited through two different approaches: coloring the two-step graphs and vertex partitioning of graphs into open packing sets, each of which is equivalent to the injective coloring problem itself. Taking these facts into account, we observe that the injective coloring lies between graph coloring and domination theory. We make use of these three points of view in this paper so as to investigate the injective coloring of some well-known graph products. We bound the injective chromatic number of direct and lexicographic product graphs from below and above. In particular, we completely determine this parameter for the direct product of two cycles. We also give a closed formula for the corona product of two graphs

Limited packings: related vertex partitions and duality issues

A $k$-limited packing partition ($k$LP partition) of a graph $G$ is a partition of $V(G)$ into $k$-limited packing sets. We consider the $k$LP partitions with minimum cardinality (with emphasis on $k=2$). The minimum cardinality is called $k$LP partition number of $G$ and denoted by $\chi_{\times k}(G)$. This problem is the dual problem of $k$-tuple domatic partitioning as well as a generalization of the well-studied $2$-distance coloring problem in graphs. We give the exact value of $\chi_{\times2}$ for trees and bound it for general graphs. A section of this paper is devoted to the dual of this problem, where we give a solution to an open problem posed in $1998$. We also revisit the total limited packing number in this paper and prove that the problem of computing this parameter is NP-hard even for some special families of graphs. We give some inequalities concerning this parameter and discuss the difference between $2$TLP number and $2$LP number with emphasis on trees

Simultaneous in situ synthesis of nanosilver and dyeing of polyamide 6 fabric

In this research, in situ synthesis of silver nanoparticles (Ag NPs) has been established in an aqueous solution alongwith the dyeing of polyamide 6 fabric through a simple chemical reduction method by using silver nitrate (AgNO3),stannous chloride (SnCl2) and cetyltrimethylammonium bromide (CTAB). SnCl2 is used as a reducing agent in synthesis ofAg NPs and also as mordant in the dyeing of polyamide 6 fabric. The formation and distribution of Ag NPs on surface of thefabric are characterized by X-ray diffraction, scanning electron microscope and energy dispersive X-ray. The SEM imagesindicate the covering of fabric surface with Ag NPs. Loading of Ag NPs on the fabric surface leads to higher color strengthand change in colour. The presence of stannous and silver ions also leads to change in the reflectance behaviour of the dyedfabrics. CTAB has antibacterial properties and shows stabilizing effects in synthesis of Ag NPs, which further showssynergistic effect in antibacterial activities of Ag NPs loaded fabrics

Association of the single nucleotide polymorphism C1858T of the PTPN22 gene with unexplained recurrent pregnancy loss: A case-control study

Background: Lymphoid-tyrosine-phosphatase which is encoded by the protein tyrosine phosphatase non-receptor 22 (PTPN22) gene plays a pivotal role in the regulation of immune responses by dephosphorylating several signaling intermediates of immune cells. Objective: Since a balanced immune response has been shown to be important during pregnancy, the purpose of this research was to compare the frequency of the PTPN22 C1858T polymorphism in women with unexplained recurrent pregnancy loss (URPL) vs. in a control group for the first time. Materials and Methods: Genomic DNA from 200 individuals with URPL and 200 individuals without URPL (the control group) at the infertility center in Yazd, Iran was isolated using the salting-out method. The PTPN22 C1858T polymorphism of the two groups was analyzed using polymerase chain reaction-restriction fragment length polymorphism. Genotype frequencies in the women with URPL and the fertile control group were compared using the Chi-square test. Results: There were significant differences in the frequency of the PTPN22 1858T polymorphism in the URPL individuals vs. the healthy controls, i.e. 32.0% and 21.5%, respectively (p = 0.01). Conclusion: Our findings suggest that the PTPN22 1858T polymorphism could play a role in recurrent pregnancy loss. Therefore, genotyping of the mentioned polymorphism can help clinicians to predict the probable risk of URPL. Key words: Recurrent pregnancy loss, PTPN22 protein, Single nucleotide polymorphism

Antibacterial activity of endemic Satureja Khuzistanica Jamzad essential oil against oral pathogens

INTRODUCTION: To assess the antibacterial effects of an Iranian endemic essential oil, Satureja Khuzistanica Jamzad (SKJ) when used as an intracanal antiseptic and interappointment medicament. MATERIALS AND METHODS: Antimicrobial activity and minimum inhibition concentrations (MICs) of SKJ essential oil with and without calcium hydroxide (CH) against eleven aerobic, microaerophilic and anaerobic bacteria were assessed. The evaluation was carried out by agar dilution and well diffusion methods. The results were measured and recorded by an independent observer. Data were analyzed statistically using student t-test. RESULTS: The MIC for eight species was recorded in 0.31 mg/mL of essential oil. Pseudomonas aeruginosa with a MIC value of 1.25 mg/mL appeared to be the most resistant bacterium; while only 0.16 mg/mL of essential oil was sufficient to inhibit the growth of Bacillus subtilis and Staphylococcus aureus. The inhibition zone of the antiseptic oil (at 0.31 mg/mL) with E. faecalis in the well diffusion method was 13 mm; this was comparable with 12.5 mm inhibition zone value of the tetracycline disc (30 µg). No synergistic effect was found in combination of essential oil and CH powder. CONCLUSION: SKJ essential oil with the concentration of 0.31 mg/mL is effective against most of oral pathogens including E. faecalis

Association of M55L and Q192R polymorphisms of paraoxonase 1 gene (PON1) with recurrent pregnancy loss risk: A case–control study

Background: Recurrent pregnancy loss (RPL) refers to the incidence of two or more abortions before the first half of pregnancy. Oxidative stress has been hypothesized to play a central role in RPL. Objective: To investigate the relationship between Q192R and L55M polymorphisms of PON1 as antioxidant enzyme and the risk of RPL. Materials and Methods: In this case–control study, 110 women with RPL (case) and 110 healthy fertile women (control) referred to the Research and Clinical Center for Infertility, Shiraz, Iran were enrolled. Genomic DNA was extracted from the peripheral blood in all participants. Polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism method. Results: Statistical analysis of Q192R polymorphism showed a significant difference for the RR genotype between the case and control group (OR = 11, CI = 1.39–86.87, p = 0.005) but none for the QR and QQ genotypes. No significant association was observed between the R and Q allelic frequency in the RPL participants compared to the control group (p = 0.53). Also, statistical analysis of the L55M polymorphism for MM genotype in the case group compared with the control group showed a significant difference (OR = 3.59, CI = 0.97–13.30, p = 0.042), but none for the LM and LL genotypes. Conclusion: The findings showed a significant correlation between the Q192R polymorphisms and the L55M PON1 enzyme and RPL in this study population. Key words: Pregnancy, Abortion, PON1, Polymorphism, Recurrent pregnancy loss

Enhancement of Antibiotic Activity and Reversal of Resistance in Clinically Isolated Methicillin-Resistant Staphylococcus aureus by Trachyspermum ammi Essential Oil

Background and objectives: Methicillin-resistant Staphylococcus aureus (MRSA) has resulted in a worldwide threat due to the virulence and broad distribution in the hospital and community. Novel antibiotics are required to combat the emergence of multidrug-resistant bacteria such as MRSA. In the present study, the antibacterial activity of Trachyspermum ammi essential oil alone and in combination with fifteen antibiotics of different classes against a standard and five clinical strains of MRSAs was investigated. Methods: Chemical composition of the essential oil was investigated by using gas chromatography-mass spectrometry (GC-MS). The possible synergistic interaction of several antibiotics in combination with essential oil was screened by disc diffusion method. Interaction of the essential oil and the candidate antibiotic was investigated by checkerboard assay. Results: The essential oil was rich in thymol (74.2%), p-cymene (16%), and γ-terpinene (7.1%). Combination of sub-inhibitory concentrations of essential oil with vancomycin or gentamicin increased their inhibition zones against MRSA ATCC 33591 and clinically isolated MRSAs. All of the clinically isolated MRSAs were resistant to gentamicin, while combination of gentamicin with the essential oil caused augmentation of the antibacterial activity and 4 to 520-fold decrease in gentamicin minimum inhibitory concentrations was observed against different MRSA strains with fractional inhibitory concentration indices ranging from 0.50 to 0.75. Combination of essential oil with ciprofloxacin or imipenem increased the inhibition zones against some clinically isolated MRSAs. Conclusion: Combination of sub-inhibitory concentrations of T. ammi essential oil and gentamicin could be considered as a new choice for treatment of infectious diseases caused by MRSA strains.  </strong

Elucidation of Apigenin Derivatives from Ethyl Acetate Fraction of Stachys byzantina with Potent Antioxidant and Anti-Staphylococcus aureus Properties

The Stachys genus is a medicinal plant, with 34 different species, from Lamiaceae family that grows in Irano-Anatolian plateau. There are 12 species of Stachys native to Iran. Some species of Stachys have been used in traditional medicine of Iran, Turkey, Italy, Greece, China, and Japan for the treatment of various diseases like inflammation, common cold, and etc. Some researchers have noted many biological effects, such as cytotoxic, antioxidant, immunomodulator, anti-inflammatory and anti-bacterial effects for the members of this genus. There are a few evidences on phytochemical constituents of S. byzanthinaThe aim of this study was phytochemical investigation of various extracts of this plant to obtain the most efficient fractions and compound(s) to study the antimicrobial effects of this plant. Separation and isolation of compounds was performed by various methods of chromatography. The structure of each compound was identified by spectroscopic methods.Antimicrobial studies were performed on different fractions of S. byzantina by microdilution method and to determine the Minimum Inhibitory Concentration (MIC), agar well diffusion was done.Ethyl acetate fraction has the highest total phenol contents (1082.05 mg GAE/g fraction) and antioxidant capacity (IC50= 1.23 mg/ml). Also, ethyl acetate fraction, the most potential fraction of S. byzanthina, was demonstrated the largest inhibition zone (17.5 ± 0.7 mm) with 5 mg/ml in MIC against Staphylococcus auresus.Apigenin and its derivatives were isolated from this fraction and according to literature; they can be responsible for antibacterial activity of this fraction of S. byzanthina

Evaluation of phytochemicals, antioxidant and burn wound healing activities of Cucurbita moschata Duchesne fruit peel

Objective(s): Cucurbita moschata Duchesne (pumpkin) is a well-known plant with several pharmacological effects. The aim of the present study was to assess burn wound healing activity of C. moschata peel extract (CE). Also, standardized CE was assessed for antioxidant activity and antibacterial effects against major pathogens of burns. Materials and Methods: Healing properties of topical preparation of 10% and 20% concentrations of CE were assessed on second degree burn in rats during a 14-day period as well as histological studies, total antioxidant power, lipid peroxidation and total thiol content of skin tissue samples. Results: Radical scavenging IC50 and ferric-reducing antioxidant power value were 4.015±0.20 mg/ml and 142.63±2.65 mmol Fe2+/g, respectively. Total mucilage content was 13.8%. The optimal results were obtained by 20% CE that showed 90.80±5.86 % wound closure and tissue repair as well as significant reduction of tissue oxidative stress biomarkers. Histological analyses confirmed wound healing activity of pumpkin peel extract. Conclusion: Considering the high mucilage content of the plant, providing a moist environment for wound, C. moschata peel extract could be a natural remedy for treatment of burns. Further clinical studies are suggested to confirm C. moschata peel extract as a wound healing agent