ABSTRACT
Volatile organic compound (VOC) sensors have a broad range of applications including healthcare monitoring, product quality control, and air quality management. However, many such applications are demanding, requiring sensors with high sensitivity and selectivity. 2D materials are extensively used in many VOC sensing devices due to their large surface-to-volume ratio and fascinating electronic properties. These properties, along with their exceptional flexibility, low power consumption, room-temperature operation, chemical functionalization potential, and defect engineering capabilities, make 2D materials ideal for high-performance VOC sensing. Here, a 2D MoS2/Te heterojunction is reported that significantly improves the VOC detection compared to MoS2 and Te sensors on their own. Density functional theory (DFT) analysis shows that the MoS2/Te heterojunction significantly enhances the adsorption energy and therefore sensing sensitivity of the sensor. The sensor response, which denotes the percentage change in the sensor's conductance upon VOC exposure, is further enhanced under photo-illumination and zero-bias conditions to values up to ≈7000% when exposed to butanone. The MoS2/Te heterojunction is therefore a promising device architecture for portable and wearable sensing applications.
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This research offers a comprehensive exploration of three pivotal aspects within the realm of fiber optics and piezoelectric materials. The study delves into the influence of voltage variation on piezoelectric displacement, examines the effects of bending multimode fiber (MMF) on data transmission, and scrutinizes the performance of an autoencoder in MMF image reconstruction with and without additional noise. To assess the impact of voltage variation on piezoelectric displacement, experiments were conducted by applying varying voltages to a piezoelectric material, meticulously measuring its radial displacement. The results revealed a notable increase in displacement with higher voltage, presenting implications for fiber stability and overall performance. Additionally, the investigation into the effects of bending MMF on data transmission highlighted that the bending process causes the fiber to become leaky and radiate power radially, potentially affecting data transmission. This crucial insight emphasizes the necessity for further research to optimize data transmission in practical fiber systems. Furthermore, the performance of an autoencoder model was evaluated using a dataset of MMF images, in diverse scenarios. The autoencoder exhibited impressive accuracy in reconstructing MMF images with high fidelity. The results underscore the significance of ongoing research in these domains, propelling advancements in fiber optic technology.
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Human T-cell lymphotropic virus type 1 (HTLV-1) is linked to two debilitating diseases, adult T-cell leukemia/lymphoma (ATLL) and HTLV-1 associated myelopathy tropical spastic paraparesis (HAM/TSP), which are prevalent in various parts of the world, including the Alborz province in Iran. Understanding the prevalence and evolutionary relationships of HTLV-1 infections in these endemic areas is of utmost importance. In the realm of phylogenetic studies, long terminal repeat (LTR) region of HTLV-1 stands out as highly conserved, yet more variable compared to other gene segments. Consequently, it is the primary focus for phylogenetic analyses. Additionally, trans-activator of transcription (Tax), an oncoprotein, holds a pivotal role in the regulation of gene expression. This cross-sectional study delved into the phylogenetic analysis of HTLV-1 among individuals in Alborz province of Iran. To confirm infection, we amplified partial sequence LTR (PLTR) and HTLV-1 bZIP factor (PHBZ). For phylogenetic analysis, we sequenced the full sequence LTR (FLTR) and full Tax sequence (FTax). The FLTR and FTax sequences underwent analysis using BioEdit, and phylogenetic trees were constructed using MEGA-X software. Out of the roughly 15,000 annual blood donors in Alborz, 19 samples tested positive for HTLV-1, indicating a 0.13% HTLV-1 positivity rate among blood donors. Furthermore, the HTLV-1 virus prevalent in the Alborz province belongs to subtype A (cosmopolitan) subgroup A. The findings revealed that while mutations were observed in both the LTR and Tax genes, they were not significant enough to bring about fundamental alterations. Despite positive selection detected in three Alborz isolates, it has not led to mutations affecting Tax function and virulence.
Subject(s)
Human T-lymphotropic virus 1 , Paraparesis, Tropical Spastic , Adult , Humans , Human T-lymphotropic virus 1/genetics , Phylogeny , Iran/epidemiology , Cross-Sectional Studies , Paraparesis, Tropical Spastic/epidemiologyABSTRACT
Contact-induced electrification, commonly referred to as triboelectrification, is the subject of extensive investigation at liquid-solid interfaces due to its wide range of applications in electrochemistry, energy harvesting, and sensors. This study examines the triboelectric between an ionic liquid and 2D MoS2 under light illumination. Notably, when a liquid droplet slides across the MoS2 surface, an increase in the generated current and voltage is observed in the forward direction, while a decrease is observed in the reverse direction. This suggests a memory-like tribo-phototronic effect between ionic liquid and 2D MoS2 . The underlying mechanism behind this tribo-phototronic synaptic plasticity is proposed to be ion adsorption/desorption processes resulting from pseudocapacitive deionization/ionization at the liquid-MoS2 interface. This explanation is supported by the equivalent electrical circuit modeling, contact angle measurements, and electronic band diagrams. Furthermore, the influence of various factors such as velocity, step size, light wavelength and intensity, ion concentration, and bias voltage is thoroughly investigated. The artificial synaptic plasticity arising from this phenomenon exhibits significant synaptic features, including potentiation/inhibition, paired-pulse facilitation/depression, and short-term memory (STM) to long-term memory (LTM) transition. This research opens up promising avenues for the development of synaptic memory systems and intelligent sensing applications based on liquid-solid interfaces.
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The cabbage aphid, Brevicoryne brassicae L. (Hemiptera: Aphididae), is one of the important pests of cruciferous plants throughout the world including Iran. In the present study, we grew cultivated canola plants under different fertilizers or distilled water and sprayed them with 100 µM abscisic acid (ABA) or a control solution (NaOH dissolved in water) to study (i) the antibiosis parameters of B. brassicae on these plants; (ii) the antixenosis of B. brassicae adults on these plants; (iii) the plant's peroxidase (POD), polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL) activity; and (iv) the plant's total phenolic and glucosinolate content. The results of antibiosis experiments showed that ABA and fertilizers have a profound and negative effect on the performance of B. brassicae. In the antixenosis experiment, control plants attracted a significantly higher number of adult females in comparison to treated plants. Also, B. brassicae had lower performance and preference when they were reared on the ABA-treated fertilized plants with higher levels of phenolic and glucosinolate content. These results prompted us to hypothesize that fertilizers enable canola plants to trigger a higher level of secondary metabolites. Our findings reveal that the type and level of nutrient availability may have different impacts on how the plant regulates its defense mechanisms.
Subject(s)
Aphids , Brassica napus , Female , Animals , Aphids/physiology , Abscisic Acid , Glucosinolates/metabolism , Fertilizers , Brassica napus/metabolism , Phenols , PhytochemicalsABSTRACT
Self-powered broadband photodetectors have attracted great interest due to their applications in biomedical imaging, integrated circuits, wireless communication systems, and optical switches. Recently, significant research is being carried out to develop high-performance self-powered photodetectors based on thin 2D materials and their heterostructures due to their unique optoelectronic properties. Herein, a vertical heterostructure based on p-type 2D WSe2and n-type thin film ZnO is realized for photodetectors with a broadband response in the wavelength range of 300-850 nm. Due to the formation of a built-in electric field at the WSe2/ZnO interface and the photovoltaic effect, this structure exhibits a rectifying behavior with a maximum photoresponsivity and detectivity of â¼131 mA W-1and â¼3.92 × 1010Jones, respectively, under an incident light wavelength ofλ= 300 nm at zero voltage bias. It also shows a 3-dB cut-off frequency of â¼300 Hz along with a fast response time of â¼496µs, making it suitable for high-speed self-powered optoelectronic applications. Furthermore, the facilitation of charge collection under reverse voltage bias results in a photoresponsivity as high as â¼7160 mA W-1and a large detectivity of â¼1.18 × 1011Jones at a bias voltage of -5 V. Hence, the p-WSe2/n-ZnO heterojunction is proposed as an excellent candidate for high-performance, self-powered, and broadband photodetectors.
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BACKGROUND: Vertebroplasty is a minimally invasive outpatient procedure to stabilize compression fractures in the spine. This procedure involves injecting bone cement into the vertebrae that have been cracked or broken, typically due to osteoporosis. The cement hardens inside the bones, providing stability to the fractures and supporting the spine. Additionally, radioactive bone cement and brachytherapy sources have been utilized to suppress tumor growth in the vertebral body. OBJECTIVE: We present a novel brachytherapy technique for treating vertebral body metastases using a liquid form of radioactive sources, Phosphorus-32 and Lutetium-177, separately mixed with bone cement and injected into vertebral body bone prostheses. We also investigated the dose distribution of the radioactive bone cement by theoretically calculating it using GEANT4 Monte Carlo and measuring it using TLD dosimeters for Phosphorus-32 and Lutetium-177 loaded in vertebral bodies. MATERIAL AND METHODS: CT-scanned images of each vertebral body (L2 and L3) were imported into GEANT4 for simulation purposes. Two simulations were performed to evaluate the possibility of using PLA prostheses in ex vivo measurements, using bone and PLA material as a bone substitute for brachytherapy of Lutetium-177 and Phosphorus-32. The simulations calculated the dose distribution, dose rates, and deposited dose to the spinal cord and aorta. Next, 3D-printed bone prostheses were drilled and separately filled with bone cement, including PMMA-P32 and PMMA-Lu177, in liquid form using the Vertebroplasty technique. The dose to regions of interest was measured using Thermoluminescence dosimeters. CONCLUSIONS: When comparing the simulated and measured results of dose rates, it was observed that P32 delivers higher doses to normal organs such as the spinal cord and aorta. At the same time, Lu177 has better sparing in these regions of interest. Therefore, while P32 and Lu177 are suitable for radioactive bone cement treatment, Lu177 delivers relatively lower doses to vital organs such as the spinal cord and aorta. Additionally, Lu177 has characteristics such as a shorter range and lower energies of beta particles in tissue and the presence of gamma rays that make it a better choice for the same treatments. It also provides the possibility of SPECT imaging.
Subject(s)
Spinal Fractures , Vertebroplasty , Humans , Bone Cements/therapeutic use , Polymethyl Methacrylate/therapeutic use , Vertebral Body , Vertebroplasty/methods , Polyesters , Treatment OutcomeABSTRACT
Volatile organic compounds (VOCs) sensors have a broad range of applications including healthcare, process control, and air quality analysis. There are a variety of techniques for detecting VOCs such as optical, acoustic, electrochemical, and chemiresistive sensors. However, existing commercial VOC detectors have drawbacks such as high cost, large size, or lack of selectivity. Herein, a new sensing mechanism is demonstrated based on surface interactions between VOC and UV-excited 2D germanium sulfide (GeS), which provides an effective solution to distinguish VOCs. The GeS sensor shows a unique time-resolved electrical response to different VOC species, facilitating identification and qualitative measurement of VOCs. Moreover, machine learning is utilized to distinguish VOC species from their dynamic response via visualization with high accuracy. The proposed approach demonstrates the potential of 2D GeS as a promising candidate for selective miniature VOCs sensors in critical applications such as non-invasive diagnosis of diseases and health monitoring.
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The elevation of cytokine levels in body fluids has been associated with numerous health conditions. The detection of these cytokine biomarkers at low concentrations may help clinicians diagnose diseases at an early stage. Here, we report an asymmetric geometry MoS2 diode-based biosensor for rapid, label-free, highly sensitive, and specific detection of tumor necrosis factor-α (TNF-α), a proinflammatory cytokine. This sensor is functionalized with TNF-α binding aptamers to detect TNF-α at concentrations as low as 10 fM, well below the typical concentrations found in healthy blood. Interactions between aptamers and TNF-α at the sensor surface induce a change in surface energy that alters the current-voltage rectification behavior of the MoS2 diode, which can be read out using a two-electrode configuration. The key advantages of this diode sensor are the simple fabrication process and electrical readout, and therefore, the potential to be applied in a rapid and easy-to-use, point-of-care, diagnostic tool.
Subject(s)
Aptamers, Nucleotide , Biosensing Techniques , Cytokines , Molybdenum , Tumor Necrosis Factor-alpha , Biosensing Techniques/methodsABSTRACT
INTRODUCTION: Radiation dermatitis (RD) is a side effect of radiation therapy (RT) which is experienced by over 90% of patients being treated for breast cancer. The current clinical trial was conducted to measure the preventative effects of a boron-based gel on several different clinical outcomes (dermatitis, erythema, dry desquamation, and moist desquamation) after 25 radiotherapy sessions. METHODS: This research used a double-blind parallel-group design with a placebo control (n = 76) and randomized group (n = 181), with all participants being between 18 and 75 years old. Fifteen minutes before each radiotherapy, participants in the intervention group were given a gel containing 3% sodium pentaborate pentahydrate, while those in the placebo group received a gel with no chemical substance. Dermatitis, erythema, dry desquamation, and moist desquamation were compared between the 2 groups. RESULTS: At baseline, there were no significant differences between the groups (p > 0.05), except for body mass index. After 14 days of treatment, dermatitis (98.7% vs. 9.9%; p < 0.001), erythema (96.1% vs. 12.2%; p < 0.001), dry desquamation (50% vs. 3.9%; p < 0.001), and moist desquamation (18.4% vs. 0.6%; p < 0.001) were much more common in the placebo group than the intervention group. To prevent dermatitis, erythema, dry desquamation, and moist desquamation in 1 patient, on average, 1.1 (95% confidence interval [CI]: 1.1-1.2), 1.2 (95% CI: 1.1-1.3), 2.2 (95% CI: 1.7-2.9), and 5.6 (95% CI: 3.8-11.0) patients need to be treated, respectively. CONCLUSION: The boron-based gel has a significant preventive effect on several categories of RD which might be used by clinicians in breast cancer.
Subject(s)
Breast Neoplasms , Radiodermatitis , Adolescent , Adult , Aged , Boron/therapeutic use , Breast Neoplasms/drug therapy , Breast Neoplasms/radiotherapy , Double-Blind Method , Female , Humans , Middle Aged , Radiodermatitis/drug therapy , Radiodermatitis/etiology , Radiodermatitis/prevention & control , Young AdultABSTRACT
As a new class of two-dimensional (2D) materials and a group-VI chalcogen, tellurium (Te) has emerged as a p-type semiconductor with high carrier mobility. Potential applications include high-speed opto-electronic devices for communication. One method to enhance the performance of 2D material-based photodetectors is by integration with a IV group of semiconductors such as silicon (Si). In this work, we demonstrate a self-powered, high-speed, broadband photodetector based on the 2D Te/n-type Si heterojunction. The fabricated Te/n-type Si heterojunction exhibits high performance in the UV-vis-NIR light with a high responsivity of up to â¼250 mA/W and a photocurrent-to-dark current ratio (I on/I off) of â¼106, fast response time of 8.6 µs, and superior repeatability and stability. The results show that the fabricated Te/n-type Si heterojunction photodetector has a strong potential to be utilized in ultrafast, broadband, and efficient photodetection applications.
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BACKGROUND: The first confirmed cases of COVID-19 in Iran were reported in Qom city. Subsequently, the neighboring provinces and gradually all 31 provinces of Iran were involved. This study aimed to investigate the case fatility rate, basic reproductive number in different period of epidemic, projection of daily and cumulative incidence cases and also spatiotemporal mapping of SARS-CoV-2 in Alborz province, Iran. METHODS: A confirmed case of COVID-19 infection was defined as a case with a positive result of viral nucleic acid testing in respiratory specimens. Serial interval (SI) was fitted by gamma distribution and considered the likelihood-based R0 using a branching process with Poisson likelihood. Seven days average of cases, deaths, doubling times and CFRs used to draw smooth charts. kernel density tool in Arc GIS (Esri) software has been employed to compute hot spot area of the study site. RESULTS: The maximum-likelihood value of R0 was 2.88 (95%, CI: 2.57-3.23) in the early 14 days of epidemic. The case fatility rate for Alborz province (Iran) on March 10, was 8.33% (95%, CI:6.3-11), and by April 20, it had an increasing trend and reached 12.9% (95%,CI:11.5-14.4). The doubling time has been increasing from about two days and then reached about 97 days on April 20, 2020, which shows the slowdown in the spread rate of the disease. Also, from March 26 to April 2, 2020 the whole Geographical area of Karj city was almost affected by SARS-CoV-2. CONCLUSIONS: The R0 of COVID-19 in Alborz province was substantially high at the beginning of the epidemic, but with preventive measures and public education and GIS based monitoring of the cases,it has been reduced to 1.19 within two months. This reduction highpoints the attainment of preventive measures in place, however we must be ready for any second epidemic waves during the next months.
Subject(s)
COVID-19 , Epidemics , Geographic Information Systems , Humans , Iran/epidemiology , Likelihood Functions , SARS-CoV-2ABSTRACT
Recently, atomically thin two-dimensional (2D) transition-metal dichalcogenides (TMDs) have attracted great interest in electronic and opto-electronic devices for high-integration-density applications such as data storage due to their small vertical dimension and high data storage capability. Here, we report a memristor based on free-standing multilayer molybdenum disulfide (MoS2) with a high current on/off ratio of â¼103 and a stable retention for at least 3000 s. Through light modulation of the carrier density in the suspended MoS2 channel, the on/off ratio can be further increased to â¼105. Moreover, the essential photosynaptic functions with short- and long-term memory (STM and LTM) behaviors are successfully mimicked by such devices. These results also indicate that STM can be transferred to LTM by increasing the light stimuli power, pulse duration, and number of pulses. The electrical measurements performed under vacuum and ambient air conditions propose that the observed resistive switching is due to adsorbed oxygen and water molecules on both sides of the MoS2 channel. Thus, our free-standing 2D multilayer MoS2-based memristors propose a simple approach for fabrication of a low-power-consumption and reliable resistive switching device for neuromorphic applications.
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BACKGROUND: Radiotherapy plays an important role in the treatment of breast cancer. In the process of radiotherapy, the underling lung tissue receives higher doses from treatment field, which led to incidence of radiation pneumonitis. OBJECTIVE: The present study aims to evaluate the predictive factors of radiation pneumonitis and related changes in pulmonary function after 3D-conformal radiotherapy of breast cancer. MATERIAL AND METHODS: In prospective basis study, thirty-two patients with breast cancer who received radiotherapy after surgery, were followed up to 6 months. Respiratory symptoms, lung radiologic changes and pulmonary function were evaluated. Radiation pneumonitis (RP) was graded according to common terminology criteria for adverse events (CTCAE) version 3.0. Dose-volume parameters, which included percentage of lung volume receiving dose of d Gy (V5-V50) and mean lung dose (MLD), were evaluated for RP prediction. Pulmonary function evaluated by spirometry test and changes of FEV1 and FVC parameters. RESULTS: Eight patients developed RP. Among the dose-volume parameters, V10 was associated to RP incidence. When V10<40% and V10≥40% the incidences of RP were 5.26% and 61.54%, respectively. The FEV1 and FVC had a reduction 3 and 6 months after radiotherapy, while only FEV1 showed significant reduction. The FEV1 had more reduction in the patients who developed RP than patients without RP (15.25±3.81 vs. 9.2±0.93). CONCLUSION: Pulmonary function parameters, especially FEV1, significantly decreased at 3 and 6 months after radiotherapy. Since most patients with breast cancer who developed RP did not show obvious clinical symptoms, so spirometry test is beneficial to identify patients with risk of radiation pneumonitis.
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Diabetic neuropathy is one of the most common complications of diabetes mellitus. Excess glutamate release and oxidative stress are hypothesized to be involved in the pathophysiology of diabetes-induced neuropathy. This study was designed to investigate the effect of clavulanic acid (CLAV), a competitive beta-lactamase inhibitor, on the streptozocin (STZ)-induced neuropathic pain and possible mechanisms in the spinal cord of rats. Male Wistar rats were divided into naive group; control group which got a single dose of STZ (50 mg/kg, i.p.), as a model of diabetic neuropathic pain; prophylactic groups: animals received CLAV (10, 20 and 40 mg/kg, i.p.) 1 week after STZ for 10 days; and therapeutic group: animals received 20 mg/kg CLAV, 21 days after STZ for 10 days. Study of pain behaviors was started on days 0, 7, 14, 21, 28, 35 and 42 after STZ. The expression of the glutamate transport 1 (GLT1), genes of oxidative stress including inducible nitric oxide synthase (iNOS), proinflammatory cytokine, tumor necrosis factor alpha (TNF-α), as well as genes involved in the apoptosis including bcl2, bcl2-associated x (bax) were measured in the spinal cord tissue by Real Time PCR, on day 42. On day 21 post injection of STZ, diabetic animals showed significant mechanical allodynia, cold allodynia and thermal hyperalgesia. CLAV in all doses of 10, 20 and 40 mg/kg reduced symptoms of allodynia and hyperalgesia, in both prophylactic and therapeutic regimens. While iNOS, TNF-α, bax/bcl2 were found significantly overexpressed in spinal cord of diabetic animals, their expression in animals received CLAV had been reduced. In contrast, GLT1 that had decreased in the spinal cord of diabetic animals, significantly increased in those received CLAV. CLAV was found a promising candidate for reliving neuropathic pain in diabetes mellitus. Such beneficial effect of CLAV could be, in part, attributed to the increased expression of GLT 1, inhibition of nitrosative stress, anti-inflammation, and inhibition of some apoptotic mediators followed by administration into diabetic animals.
Subject(s)
Analgesics/therapeutic use , Clavulanic Acid/therapeutic use , Diabetic Neuropathies/drug therapy , Neuralgia/drug therapy , Animals , Behavior, Animal/drug effects , Diabetes Mellitus, Experimental/chemically induced , Diabetes Mellitus, Experimental/complications , Diabetes Mellitus, Experimental/metabolism , Diabetic Neuropathies/etiology , Diabetic Neuropathies/metabolism , Gene Expression/drug effects , Hyperalgesia/drug therapy , Hyperalgesia/etiology , Hyperalgesia/metabolism , Male , Neuralgia/etiology , Neuralgia/metabolism , Open Field Test/drug effects , Rats, Wistar , Spinal Cord/drug effects , Spinal Cord/metabolism , StreptozocinABSTRACT
Exposure to polycyclic aromatic hydrocarbons (PAHs) has been associated with shorter telomere length (TL), a marker of ageing at cellular level. However, the available evidence on this association among children is still scarce. We therefore aimed to assess, the relationship between urinary 1-hydroxipayrene (1-OHP), a marker of exposure to PAHs, and relative leukocyte TL (LTL) in children at preschool age. Our study was based on 200 children enrolled from 27 randomly-selected kindergartens in the city of Sabzevar, Iran (2017). 1-OHP levels in the participants' urine samples were measured using solid phase extraction (SPE) method and high-performance liquid chromatography (HPLC). Moreover, real-time PCR was used to measure the LTL in the participants' blood samples. Linear mixed effects models, controlled for relevant covariates, were applied to investigate the association of 1-OHP concentration and LTL. The median (interquartile range (IQR)) of relative LTL and urinary 1-OHP were 0.83 (0.7) and 257 (375.5) ng/L, respectively. In the fully adjusted model, an IQR increase in urinary 1-OHP was related to -0.05 (95% confidence interval (CI): 0.09, -0.01, P-value = 0.02) decrease in relative LTL. This association was similar among boys and girls; however, we observed indications for a stronger association for those children whose parents had university education. Our study suggested an inverse relationship between urinary 1-OHP and LTL in children at preschool age. However, further longitudinal research with repeated measures of PAHs and LTL are needed to confirm these findings.
Subject(s)
Polycyclic Aromatic Hydrocarbons , Child, Preschool , Cross-Sectional Studies , Environmental Exposure/analysis , Female , Humans , Iran , Male , Polycyclic Aromatic Hydrocarbons/analysis , TelomereABSTRACT
BACKGROUND: Pseudomonas aeruginosa is an opportunistic pathogen that causes serious nosocomial infections, especially in immunodeficient patients and cystic fibrosis, cancer, and burned individuals. The biofilm that plays an important role in the virulence of P. aeruginosa is under the regulation of quorum sensing and two-component regulatory systems of bacteria. Curcumin, an active phenolic extract of turmeric has shown an inhibitory effect on the biofilm formation of some pathogenic bacteria. Thus, the present study aims to evaluate the effect of Nano-Curcumin on the expression of major regulatory genes involved in biofilm formation of P. aeruginosa. MATERIALS AND METHODS: The biofilm formation of P. aeruginosa ATCC 10145 was assessed in the presence of 15, 20, and 25 µg/mL concentrations of Nano-Curcumin using the microplate titer method. The effect of Nano-Curcumin on the expression level of regulatory genes were determined by relative reverse transcriptase-realtime PCR. RESULTS: In the absence of Nano-Curcumin, P. aeruginosa strain ATCC 10145 strongly produced biofilm (3+) and in the presence of 15 and 20 µg/mL, biofilm formation was reduced to moderate (2+) and weak biofilm producer (1+), respectively. Nano-Curcumin at a concentration of 25µg/mL inhibited biofilm formation in P. aeruginosa. The expression of regulatory genes was not affected by biofilm inhibitory concentrations of Nano-Curcumin. CONCLUSION: The antibiofilm mechanism of Curcumin is not related to the downregulation of regulatory systems of P. aeruginosa and probably it prevents the formation of a complete biofilm structure.
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OBJECTIVES: Ethanol withdrawal following chronic use, is an important challenge clinically. In this study, the effect of clavulanic acid was evaluated on the symptoms of ethanol withdrawal in rats. MATERIALS AND METHODS: Alcohol dependence was induced by the gavage of ethanol (10% v/v, 2 g/kg), twice daily for 10 days. Clavulanic acid (10, 20, 40, and 80 mg/kg) was administered concurrently with ethanol (sub-acute study), or a single dose after ethanol withdrawal (acute study). Six hours after the last dose of ethanol, anxiety was assessed by the elevated plus-maze (EPM). Seizure-like behavior was evaluated by a sub-convulsive dose of pentylenetetrazol (PTZ, 25 mg/kg/IP). Locomotor activity and motor coordination were measured by the open field and rotarod tests, respectively. Lipid peroxidation marker and antioxidant content were assessed through measuring malondialdehyde (MDA) and glutathione (GSH), respectively. RESULTS: The number of entries and time spent on the open arms of EPM decreased during the withdrawal state. Motor coordination and locomotor activity were significantly decreased. In the sub-acute study, clavulanic acid 80 mg/kg increased time spent and the number of entries to the open arms of EPM, in withdrawn animals. Both motor incoordination and locomotor activity reduction were normalized by clavulanic acid (10, 20, 40 and 80 mg/kg). Withdrawal-induced PTZ kindling seizure was also suppressed by all of the doses. MDA increased, while GSH decreased after withdrawal. Clavulanic acid attenuated such changes. CONCLUSION: Clavulanic acid could prevent the development of alcohol withdrawal-induced anxiety and seizure. Alcohol withdrawal causes oxidative stress which can be prevented by clavulanic acid.
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Aim: Multidrug-resistant Staphylococcus aureus isolates have become a serious concern in clinical microbiology. Antisense strategy, which specifically targets essential genes, could be helpful. Materials & methods:S. aureus cultures were treated with peptide conjugate-peptide nucleic acid (PPNA) specific for the gyrA gene. In addition, antimicrobial synergy with ciprofloxacin was tested. Results: The results indicated anti-gyrA-PPNA dramatically inhibited the growth of S. aureus isolates in Mueller Hinton Broth with complete elimination of bacteria observed on cell cultures. Specifically, PPNA reduced the gyrA transcripts up to 50%. With antisense interference, growth inhibition was augmented through combination with ciprofloxacin. Conclusion: This study suggested that anti-gyrA-PPNAs could be introduced as a novel candidate for developing antisense antibiotic to treat all S. aureus infections.
Subject(s)
Anti-Bacterial Agents/pharmacology , DNA Gyrase/metabolism , Gene Expression Regulation, Bacterial/drug effects , Peptide Nucleic Acids/pharmacology , Staphylococcus aureus/drug effects , Staphylococcus aureus/growth & development , Ciprofloxacin/pharmacology , DNA Gyrase/genetics , Drug Synergism , Microbial Sensitivity Tests , Staphylococcus aureus/geneticsABSTRACT
PURPOSE: Uropathogenic Escherichia coli (UPEC) strains are a common cause of transplant rejection, morbidity, and mortality among kidney transplant recipients. The virulence of UPEC strains differs based on their pathogenicity islands (PAIs) and susceptibility to antibiotics. The present study evaluates the clonal relationship and antibiotic susceptibility of UPEC PAI-genotypes among Escherichia coli (E. coli) isolates from kidney transplant patients. PATIENTS AND METHODS: A total of 115 Escherichia coli (E. coli) isolates were collected from kidney transplant recipients with acute urinary tract infections (UTIs). Isolates were typed based on the presence of PAI-markers, and random amplified polymorphic DNA (RAPD). The disk diffusion method was performed for the antibiotic susceptibility pattern of isolates. RESULTS: According to the PAI-specific virulence markers, 69 (60%), 21 (18.3%), and 25 (21.7%) isolates were identified as genotypes related to UPEC 536, UPEC J96, and UPEC CFT073 strains, respectively. PAI III536 genotypes were the most prevalent genotype in this study. The findings showed a high-sensitivity to imipenem (93.9%) and nitrofurantoin (91.3%) and a low-sensitivity to trimethoprim/sulfamethoxazole (36.5%). Clonal association and similar antibiotic susceptibility pattern were seen in the PAI-related genotypes. CONCLUSION: Due to a similar pattern of antibiotic susceptibility of these clonal groups and increased resistance to some important antibiotics such as trimethoprim/sulfamethoxazole in the treatment of urinary tract infections, especially in kidney transplant patients, the spread of these clones should be considered as a serious concern.