Controllable hybrid plasmonic integrated circuit

In this paper, a controllable hybrid plasmonic integrated circuit (CHPIC) composed of hybrid plasmonic waveguide (HPW)-based rhombic nano-antenna, polarization beam splitter, coupler, filter, and sensor has been designed and investigated for the first time. In order to control the power into a corresponding input port, a graphene-based 1 × 3 power splitter with switchable output has been exploited. The functionality of each device has been studied comprehensively based on the finite element method and the advantages over state-of-the-art have been compared. Moreover, the effect of connection of CHPIC to the photonic and plasmonic waveguides has been studied to exhibit the capability of variety excitation methods of the CHPIC. Furthermore, the performance of the proposed CHPIC connected to inter/intra wireless transmission links has been investigated. The wireless transmission link consists of two HPW-based nano-antennas as transmitter and receiver with the maximum gain and directivity of 10 dB and 10.2 dBi, respectively, at 193.5 THz. The suggested CHPIC can be used for applications such as optical wireless communication and inter/intra-chip optical interconnects.

Phenotypic and genotypic evaluation of ESBL- and AmpC-producing Escherichia coli isolated from chicken distributed in Birjand, East of Iran

The aims of the present study were to detect Escherichia coli in chicken distributed in Birjand, to investigate the prevalence of ESBL and AmpC beta-lactamases producers among them, and to identify their antibiotic resistance patterns. The study was conducted on 150 chicken samples, and the antimicrobial susceptibility patterns were determined by the Kirby–Bauer disk diffusion method. Phenotypic identification of ESBL and AmpC was performed by the combined disk test (CDT). The specific genes of ESBL and AmpC beta-lactamases were detected using two multiplex PCR (m-PCR) assays. According to our results, 116 out of 150 chicken samples were contaminated with E. coli. Moreover, the highest resistance of E. coli isolates was observed to trimethoprim/sulfamethoxazole (46%), ampicillin (40%), and amoxicillin (29.33%). In the molecular confirmation step, among 17 (11.33%) beta-lactamase producers, five samples contained the blaCTX-M14 gene (3.33%), two samples contained blaDHA (1.33%) and blaCTX-M3 gene (1.33%), and just one sample carried blaCMY-2 gene (0.66%). The blaSHV and blaTEM genes were not detected in any strains isolated from the chicken samples. This study showed the contamination of chicken with antibiotic-resistant E. coli. Therefore, it is recommended that veterinarians be more precautious in prescribing antibiotics.

Is periodontitis associated with obstructive sleep apnea? A systematic review and meta-analysis

Background

There are conflicting results on the association between periodontitis and obstructive sleep apnea (OSA). In the present study, we performed a contemporaneous systematic review and meta-analysis to clarify this issue. We also tried to find out whether periodontitis is associated with OSA severity.

Material and Methods

We searched the literature published from the inception to 31 December 2021 from the databases of Embase, PubMed, Scopus, and Web of Science, using a combination of suitable keywords, without language restriction. We included observational studies recruiting adults (≥18 years old) that evaluated the association between periodontitis and OSA. Two investigators screened independently the titles and abstracts of the identified articles for potential suitability. We compared the prevalence of periodontitis between OSA-positive and negative individuals using a pooled odds ratio (OR) with a 95% confidence interval (CI). The heterogeneity between the studies was examined by the I2 statistic.

Results

Of 265 citations, a total of 10 eligible studies containing 30,994 participants were finally included. Analysis of these studies showed that there was a significant association between periodontitis and OSA (OR=2.17, 95% CI: 1.66-2.83), with no significant heterogeneity between the studies (I2=42.7%, p=0.073). Analysis of three surveys indicated that periodontitis is significantly associated with mild-to-moderate OSA (OR=2.51, 95% CI: 1.32-4.78; I2=0.0%, p=0.527), but not with severe OSA (OR=1.58, 95% CI: 0.70-3.58; I2=0.0%, p=0.469).

Conclusions

According to the results, periodontitis has a direct association with OSA. Also, periodontitis has been shown to be associated with mild-to-moderate OSA, but not with severe OSA. Further studies are warranted to elucidate the mechanisms of these associations.

Key words:Periodontitis, obstructive sleep apnea, systematic review.

Theoretical analysis of ultra-fast multi-wavelength switch containing Kerr nonlinear material and its application as simultaneous AND and NOR logic gates

In this paper, an all-optical plasmonic multi-wavelength switch based on Kerr nonlinear material is proposed. It consists of circular waveguides wrapped around three side-coupled nano-ring resonators. Fundamentally, introducing the circular waveguide increases the coupling coefficient and switching modulation depth. The transmission response of the proposed multi-switching structure is studied theoretically based on coupled mode and transfer matrix theories. The validity of the derived transmission formula is confirmed by the numerical result obtained by the finite element method. Also, based on the self-phase modulation and cross-phase modulation (XPM) nonlinear effects, the resonance wavelengths are effortlessly tuned by changing the intensity of the incident lightwave without changing the dimensions of the structure. As a result, by utilizing the XPM effect, the required input signal intensity is significantly decreased to 6.5MW/cm². The obtained modulation depths are 18.08, 31.83, and 28.40 dB at wavelengths of 850, 1310, and 1550 nm, respectively. Finally, to show the application of the proposed switch, the simultaneous AND and NOR logic gates are designed with intensity contrast ratios of 78.81 and 85.49 dB, respectively. The proposed plasmonic switch has many advantages such as being multi-wavelength and having low required switching intensity, ultra-fast switching time of 23 fs, and optical bistability. These features are promising for future integrated plasmonic devices for applications such as communications, signal processing, and sensing.

Photocatalytic degradation of penicillin G from simulated wastewater using the UV/ZnO process: isotherm and kinetic study

PURPOSE

Pharmaceutical contaminants, including antibiotics, present in the environment, especially water resources, are a main concern for human and environmental health due to their stability and non-degradability. Accordingly, the purpose of this study was to investigate the photocatalytic removal of penicillin G antibiotic from simulated wastewater using a photocatalytic process [UV/ZnO] in an isotherm and kinetic study.

METHODS

In the current research, the ZnO nanoparticles [ZnO NPs] were initially characterized by scanning electron microscope [SEM] and X-ray diffraction [XRD]. Then, its efficiency was investigated in the photocatalytic degradation process of penicillin G. The evaluated parameters in the adsorption process penicillin G antibiotic were pH [1-5], penicillin G concentration [10-30 mgL-1], NP dosage [0.5-4.5 gL-1] and contact time [5 to 200 min]. Then, the effect of pH [3, 5, 7, 9, 11, and], penicillin G concentration [10-30 mgL-1], NP dosage [0.01-1.5 gL-1] and contact time [5 to 200 min] in the photocatalytic degradation (UV/ZnO) was studied. The residual penicillin G concentration was measured using a spectrophotometery at a wavelength of 283 nm.

RESULTS

The results indicated that the penicillin G removal efficiency of photocatalytic process [UV/ZnO] using ZnO was 74.65% at the concentration of 10 mgL-1, the pH value of 5, the ZnO NP dosage of 0.1 gL-1 and the contact time of 180 min, as well as the kinetics of degradation followed the pseudo-first-order kinetic model.

CONCLUSION

It can be concluded that the use of this process is appropriate an effective for the removal of the antibiotic pollutants.

Correction to: Photocatalytic degradation of penicillin G from simulated wastewater using the UV/ZnO process: isotherm and kinetic study

[This corrects the article DOI: 10.1007/s40201-020-00442-7.].

Study of the effect individual, occupational and environmental factors on return to work (RTW ) among office workers with Low back pain in one of the oil company in southern part of Iran

Introduction: low back pain is one of the prevalent musculoskeletal disorders among working population including office workers. In this regard, various factors are important for low back pain reduction and return to work. The aim of this study was to investigate factors influencing return to work among employees with low back pain. Methods: About 303 administrative employees participated in this study from an oil company located in southern part of Iran in 1394. The study variables were a 4-part questionnaire including demographic, job related variables and information about low back pain and the interventions implemented for return work. Results: The majority of participants were male 35-47 years old, bachelor degrees. With 9-25 years job tenure. Most of the employees had medium to high mental, physical, and temporal demands. From 303 participants, about 85(28/1) had low back pain. The main cause of low back pain was mostly muscular spasm (52/9) and the physiotherapy was the most treatment method (51/8). About 91% of participants had individual intervention like changing the life style. About 88/2 of them had job interventions as body posture correction. Furthermore, 62/4 had organizational interventions as teamwork development. The age, physical activity, and the type of treatment showed significant relationship with return to work. Also, the individual, occupational, and organizational interventions had a significant relationship with RTW. Conclusion: The ability to return to work was seen mostly among the individuals with less physical activities in their working practices. Also, physiotherapy played better role in a rapid return to work comparing to other treatments. The individual interventions showed high impact on RTW. The issues such as individual interventions including change in lifestyle as well as doing particular exercises, job interventions including change in working stations, change in physical status during work and organizational interventions including special routine examinations, performing teamwork as well as particular training classes had played great impacts on RTW.

Analytic approach to study a hybrid plasmonic waveguide-fed and numerically design a nano-antenna based on the new director

In this paper, a wideband InP-based hybrid plasmonic nano-antenna (HPNA) operating at telecommunication wavelengths has been proposed. Monolithically integrating InP-based lasers with hybrid plasmonic waveguide (HPW) as a feed line of the proposed HPNA on the same InGaAsP/InP wafer can increase the antenna efficiency. A new vertical director has been employed to have a highly directive horizontal radiation pattern. This enhancement is attributed to the efficient coupling between the radiation patterns of arm elements as well as reduced side lobes and back-lobes levels due to the achieved impedance matching. As a result, the directivity has been increased considerably, 3.6 dBi at 193.5 THz (1550 nm) and 1.1 dBi at 229 THz (1310 nm). The HPNA shows the high directivity, total efficiency and quality factor of 11.8, 97.49% and 94.57, respectively. Further, to verify the validity of confining the fundamental TM mode to a thin layer with the lower refractive index, both theoretical and numerical methods have been employed. Therefore, we have derived an analytical formula to investigate the HPW dispersion relation based on the transfer matrix theory and genetic algorithm. Moreover, due to the HPNA ability to receive an optical signal from free space and transmit it to the waveguide based on the reciprocity theorem, the HPNA performance as an optical wireless on-chip nano-link has been investigated analytically and numerically. Additionally, to obtain a high optical power signal and steering the beam angle, the antenna gain and directivity have been calculated with two different types of array structure by controlling the relative phase shift between the array elements and elements number. To validate the array design performance, a three dimensional full-wave numerical simulation and array factor theory have been exploited. The HPNA fabrication is compatible with generic foundry technology.

β2 adrenergic receptors and leptin interplay to decrease food intake in chicken

1. The present study was designed to examine the effects of intracerebroventricular (ICV) injection of different α and [Formula: see text] adrenergic receptor antagonists on leptin-induced hypophagia in broiler chickens.2. The study consisted of six experiments. In all experiments, chickens were deprived of feed for 3 h prior to the ICV injections and thereafter were returned immediately to the individual cages and cumulative feed intake, based on the percentage of body weight, was measured at 30, 60 and 120 min post-injection.3. In experiment 1, leptin (2.5, 5 or 10 µg) were injected in birds. In experiment 2, groups received either control solution, prazosin (10 nmol), leptin (10 µg) or a co-injection of prazosin (10 nmol) and leptin (10 µg). The other experiments were conducted as experiment 2, but instead of prazosine (10 nmol), yohimbine (13 nmol) was used in experiment 3, metoprolol (24 nmol) in experiment 4, ICI 118,551 (5 nmol) in experiment 5 and SR 59230R (5 nmol) in experiment 6 were injected either in a group or in combination with leptin (10 µg).4. The results of this study revealed a dose-dependent hypophagic effect of leptin and, in experiment 5, ICV co-injection of ICI118, 551 (5 nmol) and leptin (10 µg) significantly attenuated this effect (P˂0.5). These results suggest that the hypophagic effect of leptin is probably mediated by β2 adrenergic receptors in chickens.

The practical utility of the synthesis FeNi3@SiO2@TiO2 magnetic nanoparticles as an efficient photocatalyst for the humic acid degradation

Humic acid (HA) compounds in drinking water and wastewater disinfection processes are viewed as precursors of highly toxic, carcinogenic, and mutagenic disinfection by-product chemicals. In recent times, these compounds have gained considerable attention of scientists for their successful removal from aqueous solutions to permissible limits. To achieve this aim, the present study investigated, for the first time, the photocatalytical performance of the synthesis FeNi₃@SiO₂@TiO₂ nanoparticles for the HA degradation under different environmental conditions. The photocatalytic reactions were performed using ultraviolet (UV) radiation, whose intensity was fixed at 2500 μW/cm² throughout the experimental study. The characterization study performed, using specific diagnostic techniques, revealed the presence of several good morphological, magnetic, and catalytic specifications of the synthesized nanoparticles. The use of the simplified form of the Langmuir-Hinshelwood equation sufficiently describes the experimental data of the HA kinetic degradation, as it shows a high coefficient of regression values. Furthermore, the complete HA degradation was reached under conditions of pH = 3; initial HA concentration = 10 mg/L; FeNi₃@SiO₂@TiO₂ nanoparticles dosage = 0.01 g/L; and reaction time >30 min. Thus, the results obtained from this research suggested that the catalyst of FeNi₃@SiO₂@TiO₂ nanoparticles was an attractive, novel, and effective agent, which could be used for the degradation of HA in the photocatalytic processes.

Synthesis and characteristics of a novel FeNi3/SiO2/TiO2 magnetic nanocomposites and its application in adsorption of humic acid from simulated wastewater: study of isotherms and kinetics

The presence of natural organic matter such as humic acid in water creates various problems in water purification. Humic acid can react with chlorine in the disinfection step and lead to the production of trihalomethanes and haloacetic acids that these compounds have carcinogenic and mutagenic properties; therefore, they must be removed before arriving to the disinfection stage. The purpose of this research was adsorption of humic acid from simulated wastewater by synthesized FeNi₃/SiO₂/TiO₂ magnetic nanocomposites. FeNi₃/SiO₂/TiO₂ magnetic nanocomposites were synthesized by sol-gel procedure and its characteristics were determined by TEM, VSM, BET, FESEM, and XRD techniques. Then, the effects of such pH (3-11), FeNi₃/SiO₂/TiO₂ dosage (0.005-0.1 g/L), contact time (0-200 min), and initial concentration (2-15 mg/L) were studied on humic acid adsorption using FeNi₃/SiO₂/TiO₂. The results of adsorption experiments revealed that the highest percentage of humic acid removal (94.4%) was achieved at pH 3, initial concentration of 5 ppm, FeNi₃/SiO₂/TiO₂ dose of 0.1 g/L, and contact time of 90 min. The analyses of experimental isotherm data showed that the humic acid adsorption was described by Langmuir model and also the kinetic studies represented that the process of adsorption of humic acid on FeNi₃/SiO₂/TiO₂ was followed by the pseudo-second kinetic. According to the results, it can be concluded that FeNi₃/SiO₂/TiO₂ magnetic nanocomposites have a high ability to absorb humic acid from simulated wastewater.

A comparative study of using barberry stem powder and ash as adsorbents for adsorption of humic acid

In the present research, investigation of the practical utility of barberry stem powder (BSP) and barberry stem ash (BSA) for humic acid (HA) removal from an aqueous medium by adsorption was carried out. The adsorption process was tested by varying of pH (3-11), reaction time (5-20 min), initial HA concentration (5-40 mg/L), adsorbent dosage (1-4 g/L), and temperature (15-35 °C). The isothermal results revealed that the adsorption process is favorable for both used adsorbents and it is highly described using the Freundlich and Langmuir models (R² > 0.960). Also, the maximum uptakes of BSP and BSA for HA were 20.220 and 16.950 mg/g at the abovementioned optimized conditions (pH = 7, reaction time = 10 min, temperature = 15 °C, initial HA concentration = 40 mg/L, and adsorbent amount = 1.0 g/L), respectively. The results achieved from the fitting of the experimental data with Dubinin-Radushkevich isotherm model showed that the HA molecules are adsorbed onto the BSP and BSA by physiosorption process. From the thermodynamic study, it appeared that the biosorption process of the HA onto two studied adsorbents was of exothermic nature. The kinetics of the adsorption process of HA has been found to be pseudo-second-order model (R² = 0.930-0.999). Thus, the results obtained from this paper elucidated that the BSP exhibited higher adsorption capacity in comparison to BSA, for HA removal up to permissible concentrations.

Consequence of dopamine D2 receptor blockade on the hyperphagic effect induced by cannabinoid CB1 and CB2 receptors in layers

1. Endocannabinoids (ECBs) and their receptors play a regulatory function on several physiological processes such as feed-intake behaviour, mainly in the brain. This study was carried out in order to investigate the effects of the dopaminergic D1 and D2 receptors on CB1/CB2 ECB receptor-induced hyperphagia in 3-h feed-deprived neonatal layer chickens. 2. A total of 8 experiments were designed to explore the interplay of these two modulatory systems on feed intake in neonatal chickens. In Experiment 1, chickens were intracerebroventricular (ICV) injected with control solution, l-DOPA (levo-dihydroxyphenylalanine as precursor of dopamine; 125 nmol), 2-AG (2-arachidonoylglycerol as CB₁ receptor agonist; 2 µg) and co-administration of l-DOPA (125 nmol) plus 2-AG (2 µg). Experiments 2-4 were similar to Experiment 1 except birds were injected with either 6-OHDA (6-hydroxydopamine as dopamine synthesis inhibitor; 150 nmol), SCH23390 (D1 receptor antagonist; 5 nmol) and AMI-193 (D2 receptor antagonist; 5 nmol) instead of l-DOPA, respectively. Additionally, Experiments 5-8 followed the previous ones using the same dose of l-DOPA, 6-OHDA and dopamine antagonists except that birds were injected with CB65 (CB2 receptor agonist; 5 µg) instead of 2-AG. Coadministrations were at the same dose for each experiment. Cumulative feed intakes were measured until 120 min after each injection. 3. ICV administration of 6-OHDA and AMI-193 significantly attenuated 2-AG-induced hyperphagia. Interestingly, the hyperphagic effect of CB65 was significantly attenuated by administration of l-DOPA, whereas the administration of 6-OHDA and AMI-193 together amplified the hyperphagic effect of CB65. 4. It was concluded that cannabinoid-induced feeding behaviour is probably modulated by dopamine receptors in neonatal layer-type chickens. It seems that their interaction may be mediated by the D2-dopamine receptor.

Properties of Geobacillus stearothermophilus levansucrase as potential biocatalyst for the synthesis of levan and fructooligosaccharides

The production of levansucrase (LS) by thermophilic Geobacillus stearothermophilus was investigated. LS production was more effective in the presence of sucrose (1%, w/v) than fructose, glucose, glycerol or raffinose. The results (Top 57°C; stable for 6 h at 47°C) indicate the high stability of the transfructosylation activity of G. stearothermophilus LS as compared with LSs from other microbial sources. Contrary to temperature, the pH had a significant effect on the selectivity of G. stearothermophilus LS-catalyzed reaction, favoring the transfructosylation reaction in the pH range of 6.0-6.5. The kinetic parameter study revealed that the catalytic efficiency of transfructosylation activity was higher as compared with the hydrolytic one. In addition to levan, G. stearothermophilus LS synthesized fructooligosaccharides in the presence of sucrose as the sole substrate. The results also demonstrated the wide acceptor specificity of G. stearothermophilus LS with maltose being the best fructosyl acceptor. This study is the first on the catalytic properties and the acceptor specificity of LS from G. stearothermophilus.

The effect of nutrition and food hygieneeducation on the knowledge of female elementary school teachers in city of ferdows

INTRODUCTION

Teachers are one of the most influential groups in elevating social health, and their teaching nutritional points to the students can both affect students' awareness and the transferring of such nutritional education to the families. This study was undertaken tosurvey the influence of nutrition and nutritional health education on the awareness of female elementary school teachers.

MATERIALS AND METHODS

Fifty-seven female elementary school teachers were chosen from the Ferdows City for this quasi-experimental study. Prior to the outset of the educational workshop, they were asked to fill out a questionnaire about nutrition and nutritional health, which was followed by the two-day workshop. After two months, they were given a second questionnaire. The results were analyzed by paired t-test, ANOVA, and McNemar. In all the tests, a significance level α = 0.05 was considered.

RESULTS

Findings of the study showed that the mean score of awareness before interference was 10.98%, which reached up to 18.2% after the interference (P < 0.001). With regard to theimportance of breakfast intake, the teachers' awareness increased from 57.9 to 98.2% from before to after intervention, respectively.

CONCLUSION

Applying interventional methods of education in teacher training centers in conjunction with medical and educational centers, with regard to nutrition and nutritional health, can elevate the health of students.

Effect of lithium chloride on the luteal steroidogenesis in gonadotropin-stimulated rat

BACKGROUND

Main function of corpus luteum is progesterone synthesis that is significantly accompanied with an increase in levels of mRNA encoding of steroidogenic enzymes known as luteal markers.

OBJECTIVE

This study was designed to evaluate effects of lithium chloride on the release of steroid hormones and steroidogenic enzymes in gonadotropin-stimulated rats.

MATERIALS AND METHODS

Immature 23 days old Wistar rats were divided into 10 groups; each group comprised of 8 rats, and induced with single injection of pregnant mare's serum gonadotrophin (PMSG) and followed by single injection of human chorionic gonadotropin (hCG). Then, rats were given lithium chloride (LiCl) or saline at 12 hours post-hCG injection. Ovaries were collected in 4-hour interval from 8-24 hour post-hCG injection. Expression pattern of steroidogenic acute regulatory protein (StAR), side-chain cleavage cytochrome P450 (P450scc) and 3β-hydroxysteroid dehydrogenase (3β-HSD) genes were determined by semi-quantitative RT-PCR. In addition, serum levels of progesterone and 17β-estradiol were measured by ELISA.

RESULTS

Our results showed that hCG stimulation of progesterone was markedly diminished and transcript levels of key steroidogenic enzymes were altered in the hormone-stimulated rats following LiCl treatment.

CONCLUSION

These results suggest that critical steps in the function of corpus luteum are disrupted by lithium. It is concluded that LiCl is an effective factor for suppressing of steroid genes expression.

The effects of planting methods and head pruning on seed yield and yield components of medicinal pumpkin (Cucurbita pepo subsp. Pepo convar. Pepo var. styriaca) at low temperature areas

This experiment carried out to evaluate the effects of planting methods (seed sowing and transplanting) and head pruning (no pruning, pruning after 12th node and pruning after 16th node) on yield and yield components such as number of branches (sub-branches) per plant, fruits per plant, growth, fruit size, weight of fresh fruit, weight of seeds per fruit, number of seeds per fruit and seed yield of medicinal pumpkin. The experiment was carried out based of factorial experiment with Randomized Completely Blocks Design (RCBD) by three replications in Ardabil Agricultural and Natural Resources Researches Station at 2007. Seedlings were grown in heated greenhouse. When the climatic condition became suitable and seedlings were at the four leaves stage, both seeds and seedlings were planted at the same time in the farm. Maintenance operations were done during the growth season. Head pruning treatments were done the forecast time. The results showed that the planting methods had significant effect on the number of ripen fruits per plant, fruits diameter, weight of seeds per fruit, weight of 1000 seeds and seed yield and had no significant effect on the other traits. Also the results indicated that head pruning treatments had significant effects on the number of branches per plant, growth and seed yield and no significant on the other traits. In this experiment the most seed yield (997.8 kg ha(-1)) obtained from transplanting method with head pruning after 12th node and the least seed yield obtained from control.

The food habit of Epinephelus coioides (Hamilton, 1822) in Khuzestan coastal waters (Persian Gulf)

During January 2000 to March 2001, a large number of Epinephelus coioides species was captured in main fishing areas of Khuzestan province namely, Busafe-Liphe and Bahrakan, North of Persian Gulf. The stomach contents of 394 individuals were analysed, in which 226 individuals had contained (trace-full) stomachs while 168 individuals had empty stomachs. The percentages of CV in males were more than in females. Seventy three percent of stomachs contained fish 11% crab; 8.8% shrimp; 3.9% squid; 1.7% gastropod and 0.4% bivalves. The intensity of feeding in monthly sampling periods and length groups did not show a clear trend. The results of Fp index showed 73% for fish; crab 11%; shrimp 8.8%; squid 3.9%; gastropod 1.7 and 0.4% for bivalvia. Similar pattern of feeding was observed using CN index. The main food items for E. coioides were fish followed by crabs and accidental food items were shrimp, squid, gastropods and bivalvia.