On the Unit Graph of a Noncommutative Ring

Let $R$ be a ring (not necessary commutative) with non-zero identity. The unit graph of $R$, denoted by $G(R)$, is a graph with elements of $R$ as its vertices and two distinct vertices $a$ and $b$ are adjacent if and only if $a+b$ is a unit element of $R$. It was proved that if $R$ is a commutative ring and \fm is a maximal ideal of $R$ such that |R/\fm|=2, then $G(R)$ is a complete bipartite graph if and only if (R, \fm) is a local ring. In this paper we generalize this result by showing that if $R$ is a ring (not necessary commutative), then $G(R)$ is a complete $r$-partite graph if and only if (R, \fm) is a local ring and $r=|R/m|=2^n$, for some $n \in \N$ or $R$ is a finite field. Among other results we show that if $R$ is a left Artinian ring, $2 \in U(R)$ and the clique number of $G(R)$ is finite, then $R$ is a finite ring.Comment: 6 pages. To appear in Algebra Colloquiu

Evaluation of Physical Parameters of Skin by Consecutive Ultrasonic Image Processing During Ultraviolet Radiation in an Animal Model of Wrinkled Skin

BACKGROUND AND OBJECTIVE: Skin aging is divided into two categories of intrinsic and extrinsic aging. Skin aging due to repeated exposure to ultraviolet radiation (extrinsic aging) is different from aging caused by time (intrinsic aging). The appearance of wrinkles caused by sunlight is due to subcutaneous fat atrophy and reduced production of collagen and elastin, thereby altering the biomechanical properties of the skin tissue. This study was conducted to investigate the skin damage caused by ultraviolet B (UVB) radiation by consecutive ultrasonic image processing with high resolution. METHODS: In this experimental study, we evaluated the skin injury process among 25 C57BL/6 mice in healthy group (zero dose), and case group exposed to UVB radiation at 0.03 milliwatts per square centimeter (5 times a week for 5 weeks) due to differences in skin characteristics. Physical parameters of dermal and epidermal layers were measured and evaluated weekly from day 7 to day 35 using ultrasonic image processing. FINDINGS: The thickness of the dermal and epidermal layers obtained by ultrasonic processing during the process of ultraviolet radiation injury in the mouse model significantly increased during the 5 – week study (p < 0.05). In addition, the percentage of changes in the thickness of the epidermis layer (from 0.22±0.01 mm on day zero to 0.37 ± 0.02 mm on the thirty-fifth day) and the dermal layer (from 0.57 ± 0.05 on day zero to 0.90 ± 0.08 mm on the thirty-fifth day) showed 68% and 57% increase, respectively. CONCLUSION: The results showed that UVB radiation increased the thickness of the skin layers

Multiple Locus Variable Number Tandem Repeat Analysis (MLVA) for Typing Pseudomonas Aeruginosa Isolated from Urine Samples of Different Patients

BACKGROUND AND OBJECTIVE: Pseudomonas aeruginosa is considered as one of the important causes of urinary infections in hospitals. The aim of the current study is the genetic typing for the number of bacterial strains isolated from patients using MLVA technique. METHODS: In this study, 70 isolates were collected from different hospitals located in Tehran city. First, DNA extraction was conducted for genotyping analysis by MLVA method. Subsequently, VNTR sequences located in several genes of bacterial genomes such as MS-214, MS-215, MS-217, MS-222, MS-223, MS-142 and MS-173 were amplified by specific primers using PCR technique. After confirming the PCR amplification using electrophoresis and visualization of their bonds on agarose gel, relationship evolutionary graph for the different strains was constructed based on MLVA technique. FINDINGS: After the electrophoresis of PCR products and determination of VNTR copy-numbers, 70 strains were classified as 39 types and genetic evolutionary tree was also constructed based on VNTRs Data. According to the MST algorithm, 70 clinical strains divided into 11 clonal complexes which these criteria is interpreted as genetic distance based on the difference of VNTR copy numbers for each group. CONCLUSION: The present study showed that MLVA could be helpful for typing clinical strains of P. aeruginosa. The results also showed that this method had great potential to differentiate those strains with high phenotypic similarity

the effects of cool dialysate on quality of sleep among patients undergoing hemodialysis: A randomized clinical trial

INTRODUCTION: Low quality of sleep is a common problem among hemodialysis patients. This study was conducted to evaluate the effect of a cold dialysis solution on the quality of sleep in patients undergoing hemodialysis. METHODOLOGY: This double-blind clinical trial was performed on 26 hemodialysis patients with chronic renal failure and sleep disorders in the dialysis center of Sabzevar, Iran, in 2016–2017. Of the 26 patients, 13 each were allocated to the intervention and control groups. The patients in both groups received 4 weeks of hemodialysis (3 sessions per week) using a standard solution with a temperature of 37°C. In the next stage, the control group continued to receive the standard-temperature dialysis, while the intervention group received dialysis using a solution with a temperature of 35.5°C for 4 weeks (3 sessions per week). The Pittsburgh Sleep Quality Index was used to assess and compare the quality of sleep before and after the intervention in the two groups. Data were analyzed using R 1.2.3 software, at 95% confidence level. RESULTS: Although the mean scores of sleep quality were not significantly different between the intervention (9.53 ± 3.12) and control (11.23 ± 3.37) groups at baseline, postintervention, significant differences were observed (intervention group: 4.7 ± 4.55; control group: 10.61 ± 2.69; P < 0.001). CONCLUSION: This study showed that dialysis with cold solution is a simple, cost-effective, and nonpharmacological method that can be used to improve sleep quality in patients undergoing hemodialysis

Locally functionally countable subalgebra of R(L)\mathcal{R}(L)

summary:Let $L_c(X)= \lbrace f \in C(X) \colon \overline{C_f}= X\rbrace$, where $C_f$ is the union of all open subsets $U \subseteq X$ such that $\vert f(U) \vert \le \aleph _0$. In this paper, we present a pointfree topology version of $L_c(X)$, named $\mathcal{R}_{\ell c}(L)$. We observe that $\mathcal{R}_{\ell c}(L)$ enjoys most of the important properties shared by $\mathcal{R}(L)$ and $\mathcal{R}_c(L)$, where $\mathcal{R}_c(L)$ is the pointfree version of all continuous functions of $C(X)$ with countable image. The interrelation between $\mathcal{R}(L)$, $\mathcal{R}_{\ell c}(L)$, and $\mathcal{R}_c(L)$ is examined. We show that $L_c(X) \cong \mathcal{R}_{\ell c}\big (\mathfrak{O}(X)\big )$ for any space $X$. Frames $L$ for which $\mathcal{R}_{\ell c}(L)=\mathcal{R}(L)$ are characterized

Removal of Metronidazole Antibiotic from Hospital Wastewater by Biosorbent Prepared from Plantain Wood

BACKGROUND AND OBJECTIVE: The overuse of antibiotics in hospitals and the entry of these pollutants into water resources is one of the major challenges to the health of the community and the environment. Removal of antibiotics from hospital wastewater and other aquatic environments is possible through the adsorption process. This study was performed to evaluate antibiotic removal using plantain wood due to being cheapn and natural. METHODS: In this in vitro study, the effect of pH (2, 4, 6, 8, 10 and 12), contact time (5, 10, 20, 40, 60, 80, 100 and 120 minutes), initial metronidazole concentration (10, 50 and 100 mg/L) and biosorbent dose (0.2, 0.4, 0.6, 0.8, 1, 1.2 and 1.4 g) on metronidazole removal rate in synthetic solution were evaluated, and the isothermal kinetic and thermodynamic results of the adsorption process were investigated in this study. Concentration of metronidazole in aqueous solution was measured by Hach DR 5000 UV-Vis Laboratory Spectrophotometer. FINDINGS: Maximum removal of metronidazole (91%) was obtained at pH=6.5, 60 min, initial concentration of 50 mg/l, adsorbent dose of 0.8 g and 25 °C and maximum adsorption capacity (11.38 mg/g) was obtained at a dosage of 0.1 g. In this study, the reaction rate followed the pseudo-second order and adsorption isotherm followed Langmuir equation. The adsorption thermodynamic results showed that the adsorption process is physical in nature and is a spontaneous endothermic reaction. CONCLUSION: The results of the study showed that biosorbent prepared from plantain wood is a natural material and has the ability to remove metronidazole antibiotics from hospital wastewater and other aquatic environments

Genotypic identification of Pseudomonas aeruginosa strains isolated from patients with urinary tract infection

Background: Numerous nosocomial infections including urinary tract infection (UTI) have been reported to be linked to Pseudomonas aeruginosa (P. aeruginosa). This bacterium is one of the most common pathogen colonized in the urinary tract. The main purpose of this study was to evaluated the presence of antibiotic resistance genes and also the most frequent genotype patterns of P. aeruginosa in the patients with UTI hospitalized in different wards of hospitals. Materials and methods: In this study, 70 strains of P. aeruginosa isolated of urine samples from the patients with UTI were assessed. The isolated strains were genotyped using Multiple-Locus Variable Number Tandem Repeat Analysis (MLVA) method. We have also analyzed the presence of TEM and SHV resistant genes in the isolates. Results: A total of 70 P. aeruginosa strains was isolated from the UTI patients. Based on MLVA method, 61 various genotypes of P. aeruginosa were identified which grouped into two main clusters and 4 sub-clusters. Moreover, approximately 80 and 70 of isolated strains carried the TEM and SHV resistance genes, respectively. Conclusion: Our findings showed that the majority of patients hospitalized in different wards of hospitals have experienced the urinary tract infection caused by P. aeruginosa. According to the genotyping results, a high diversity of the P. aeruginosa population was observed in the patients with UTI. Our results can provide a better understanding of the P. aeruginosa genotype distribution and epidemiology of infection, which can be applied as basic data for future antibiotic therapies. © 2019 Elsevier Lt