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In this study, the kinetics of hydrazodicarbonamide (HDCA) synthesis reaction was investigated. Hydrazodicarbonamide is prepared by reaction of urea and hydrazine in acidic medium. Synthesis of HDCA from urea and hydrazine is a two steps reaction. In the first step, semicarbazide is synthesized from the reaction of one mole of urea and one mole of hydrazine and in the second step, semicarbazide reacts with urea to produce hydrazodicarbonamide. By controlling the temperature and pH in the reaction, hydrazine concentration and the amount of produced hydrazodicarbonamide were measured and using these data, reaction rate constants were calculated. Based on this study, it was found that the semicarbazide formation reaction from hydrazine is the rate limiting step. Rate of semicarbazide synthesis is -r1 = 0.1396 [NH2NH2]0.5810 and the rate of hydrazodicarbonamide synthesis is -r2 = 0.7715 [NH2NHCONH2]0.8430.

Among various wastewater treatment technologies, biological wastewater treatment appears to be the most promising method. A pilot scale of hybrid anaerobic bioreactor was fabricated and used for the whey wastewater treatment. The top and bottom of the hybrid bioreactor known as up flow anaerobic sludge fixed film (UASFF); was a combination of up flow anaerobic sludge blanket (UASB) and up flow anaerobic fixed film reactor (UAFF), respectively. The effects of operating parameters such as temperature and hydraulic retention time (HRT) on chemical oxygen demand (COD) removal and biogas production in the hybrid bioreactor were investigated. Treatability of the samples at various HRTs of 12, 24, 36 and 48 hours was evaluated in the fabricated bioreactor. The desired conditions for COD removal such as HRT of 48 hours and operation temperature of 40 °C were obtained. The maximum COD removal and biogas production were 80% and 2.40 (L/d), respectively. Kinetic models of Riccati, Monod and Verhalst were also evaluated for the living microorganisms in the treatment process. Among the above models, Riccati model was the best growth model fitted with the experimental data with R2 of about 0.99.

The reconstruction of craniomaxillofacial bone defects remains clinically challenging. To date, autogenous grafts are considered the gold standard but present critical drawbacks. These shortcomings have driven recent research on craniomaxillofacial bone reconstruction to focus on synthetic grafts with distinct materials and fabrication techniques. Among the various fabrication methods, additive manufacturing (AM) has shown significant clinical potential. AM technologies build three-dimensional (3D) objects with personalized geometry customizable from a computer-aided design. These layer-by-layer 3D biomaterial structures can support bone formation by guiding cell migration/proliferation, osteogenesis, and angiogenesis. Additionally, these structures can be engineered to degrade concomitantly with the new bone tissue formation, making them ideal as synthetic grafts. This review delves into the key advances of bioceramic grafts/scaffolds obtained by 3D printing for personalized craniomaxillofacial bone reconstruction. In this regard, clinically relevant topics such as ceramic-based biomaterials, graft/scaffold characteristics (macro/micro-features), material extrusion-based 3D printing, and the step-by-step workflow to engineer personalized bioceramic grafts are discussed. Importantly, in vitro models are highlighted in conjunction with a thorough examination of the signaling pathways reported when investigating these bioceramics and their effect on cellular response/behavior. Lastly, we summarize the clinical potential and translation opportunities of personalized bioceramics for craniomaxillofacial bone regeneration., (© 2024. The Author(s).)

This study investigated gelatin methacryloyl (GelMA) and polycaprolactone (PCL) blend scaffolds incorporating cerium oxide (CeO) nanoparticles at concentrations of 0%, 5%, and 10% w/w via electrospinning for periodontal tissue engineering. The impact of photocrosslinking on these scaffolds was evaluated by comparing crosslinked (C) and non-crosslinked (NC) versions. Methods included Fourier transform infrared spectroscopy (FTIR) for chemical analysis, scanning electron microscopy (SEM) for fiber morphology/diameters, and assessments of swelling capacity, degradation profile, and biomechanical properties. Biological evaluations with alveolar bone-derived mesenchymal stem cells (aBMSCs) and human gingival fibroblasts (HGFs) encompassed tests for cell viability, mineralized nodule deposition (MND), and collagen production (CP). Statistical analysis was performed using Kruskal-Wallis or ANOVA/post-hoc tests (α = 5%). Results indicate that C scaffolds had larger fiber diameters (~250 nm) compared with NC scaffolds (~150 nm). NC scaffolds exhibited higher swelling capacities than C scaffolds, while both types demonstrated significant mass loss (~50%) after 60 days ( p < 0.05). C scaffolds containing CeO showed increased Young's modulus and tensile strength than NC scaffolds. Cells cultured on C scaffolds with 10% CeO exhibited significantly higher metabolic activity (>400%, p < 0.05) after 7 days among all groups. Furthermore, CeO-containing scaffolds promoted enhanced MND by aBMSCs (>120%, p < 0.05) and increased CP in 5% CeO scaffolds for both variants (>180%, p < 0.05). These findings underscore the promising biomechanical properties, biodegradability, cytocompatibility, and enhanced tissue regenerative potential of CeO-loaded GelMA/PCL scaffolds for periodontal applications.

This study aimed to develop gelatin methacryloyl (GelMA)-injectable hydrogels incorporated with 58S bioactive glass/BG-doped with strontium for vital pulp therapy applications. GelMA hydrogels containing 0% (control), 5%, 10%, and 20% BG ( w / v ) were prepared. Their morphological and chemical properties were evaluated by scanning electron microscopy/SEM, energy dispersive spectroscopy/EDS, and Fourier transform infrared spectroscopy/FTIR (n = 3). Their swelling capacity and degradation ratio were also measured (n = 4). Cell viability (n = 8), mineralized matrix formation, cell adhesion, and spreading (n = 6) on DPSCs were evaluated. Data were analyzed using ANOVA/post hoc tests (α = 5%). SEM and EDS characterization confirmed the incorporation of BG particles into the hydrogel matrix, showing GelMA's (C, O) and BG's (Si, Cl, Na, Sr) chemical elements. FTIR revealed the main chemical groups of GelMA and BG, as ~1000 cm -1 corresponds to Si-O and ~1440 cm -1 to C-H. All the formulations were degraded by day 12, with a lower degradation ratio observed for GelMA+BG20%. Increasing the concentration of BG resulted in a lower mass swelling ratio. Biologically, all the groups were compatible with cells ( p > 0.6196), and cell adhesion increased over time, irrespective of BG concentration, indicating great biocompatibility. GelMA+BG5% demonstrated a higher deposition of mineral nodules over 21 days ( p < 0.0001), evidencing the osteogenic potential of hydrogels. GelMA hydrogels incorporated with BG present great cytocompatibility, support cell adhesion, and have a clinically relevant degradation profile and suitable mineralization potential, supporting their therapeutic potential as promising biomaterials for pulp capping.

Pulp capping is a necessary procedure for preserving the vitality and health of the dental pulp, playing a crucial role in preventing the need for root canal treatment or tooth extraction. Here, we developed an electrospun gelatin methacryloyl (GelMA) fibrous scaffold incorporating beta-tricalcium phosphate (TCP) particles for pulp capping. A comprehensive morphological, physical-chemical, and mechanical characterization of the engineered fibrous scaffolds was performed. In vitro bioactivity, cell compatibility, and odontogenic differentiation potential of the scaffolds in dental pulp stem cells (DPSCs) were also evaluated. A pre-clinical in vivo model was used to determine the therapeutic role of the GelMA/TCP scaffolds in promoting hard tissue formation. Morphological, chemical, and thermal analyses confirmed effective TCP incorporation in the GelMA nanofibers. The GelMA+20%TCP nanofibrous scaffold exhibited bead-free morphology and suitable mechanical and degradation properties. In vitro, GelMA+20%TCP scaffolds supported apatite-like formation, improved cell spreading, and increased deposition of mineralization nodules. Gene expression analysis revealed upregulation of ALPL, RUNX2, COL1A1, and DMP1 in the presence of TCP-laden scaffolds. In vivo, analyses showed mild inflammatory reaction upon scaffolds' contact while supporting mineralized tissue formation. Although the levels of Nestin and DMP1 proteins did not exceed those associated with the clinical reference treatment (i.e., mineral trioxide aggregate), the GelMA+20%TCP scaffold exhibited comparable levels, thus suggesting the emergence of differentiated odontoblast-like cells capable of dentin matrix secretion. Our innovative GelMA/TCP scaffold represents a simplified and efficient alternative to conventional pulp-capping biomaterials. STATEMENT OF SIGNIFICANCE: Vital pulp therapy (VPT) aims to preserve dental pulp vitality and avoid root canal treatment. Biomaterials that bolster mineralized tissue regeneration with ease of use are still lacking. We successfully engineered gelatin methacryloyl (GelMA) electrospun scaffolds incorporated with beta-tricalcium phosphate (TCP) for VPT. Notably, electrospun GelMA-based scaffolds containing 20% (w/v) of TCP exhibited favorable mechanical properties and degradation, cytocompatibility, and mineralization potential indicated by apatite-like structures in vitro and mineralized tissue deposition in vivo, although not surpassing those associated with the standard of care. Collectively, our innovative GelMA/TCP scaffold represents a simplified alternative to conventional pulp capping materials such as MTA and Biodentine™ since it is a ready-to-use biomaterial, requires no setting time, and is therapeutically effective., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Microbial fuel cells (MFCs) are a self-sustaining and environmentally friendly system for the simultaneous was tewater treatment and bioelectricity generation. The type and material of the electrode are critical factors that can influence the efficiency of this treatment process. In this study, graphite plates and carbon felt were modified through the electrodeposition of nickel followed by the formation of a biofilm, resulting in conductive bio-anode thin film electrodes with enhanced power generation capacity. The structural and morphological properties of the electrode surfaces were characterized using X-ray diffraction, energy-dispersive X-ray spectroscopy, elemental mapping, and field-emission scanning electron microscopy techniques. Maximum voltage, current density, and power generation were investigated using a dual-chamber MFC equipped with a Nafion 117 membrane and bio-nickel-doped carbon felt (bio-Ni@CF) and bio-nickel-doped graphite plate (bio-Ni@GP) electrodes under constant temperature conditions. The polarization and power curves obtained using different anode electrodes revealed that the maximum voltage, power and current density achieved with the bio-Ni@CF electrode were 468.0 mV, 130.72 mW/m 2 and 760.0 mA/m 2 respectively. Moreover, the modified electrodes demonstrated appropriate stability and resistance during successful runs. These results suggest that nickel-doped carbon-based electrodes can serve as suitable and stable supported catalysts and conductors for improving efficiency and increasing power generation in MFCs., (© 2023. The Author(s).)

A novel and first electrochemical biosensor based on Deoxyribonucleic acid (DNA) as a biological component to measure an antimigraine drug, rizatriptan benzoate (RZB) for patients under treatment in biological samples was developed. A carbon paste electrode (CPE) was modified by calf thymus (CT) double-stranded (ds)-DNA, nickel ferrite magnetic nanoparticles (NiFe 2 O 4 NPs), and gold nanoparticles (AuNPs). The morphology of the CT-DNA/NiFe 2 O 4 NPs/AuNPs/CPE was characterized by Field emission scanning electron microscope (FESEM). The presence of NiFe 2 O 4 NPs and AuNPs was confirmed by energy-dispersive X-ray spectroscopy (EDS) image of the NiFe 2 O 4 NPs/AuNPs/CPE surface. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used to determine the structure and electrochemical characteristics of the CT-DNA/NiFe 2 O 4 NPs/AuNPs/CPE. Differential pulse voltammetry (DPV) was used to investigate the electrochemical behavior of RZB. Chronoamperometry (CA) was applied to study the effect of CT-DNA immobilization time on the peak oxidation current of RZB accumulated on the surface of the CT-DNA/NiFe 2 O 4 NPs/AuNPs/CPE. The results showed that, under optimum conditions, the prepared electrode responded linearly to RZB concentrations between 0.01 and 2.0 μM, with a 0.0033 μM detection limit (LOD) and 0.01 μM limit of quantification (LOQ). The parameters influencing the biosensor performance (temperature, CT-DNA immobilization time, and RZB/CT-DNA accumulation time) were optimized. DPV showed the displacement of the peak potential towards positive values and the reduction of its current, indicating that the drug could intercalate between the guanine base pairs of CT-DNA. Our biosensor was successfully applied for RZB measurement in human urine, blood serum, plasma samples, and tablets. The presented biosensor was fast response, sensitive, selective, cost-effective, and easy-to-use for RZB determination in pharmaceutical formulations and biological samples., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Inc.)

The spread of antibiotic resistant genes has become a serious global concern. Thus, the development of efficient antibiotic monitoring systems to reduce their environmental risks is of great importance. Here, a potent electrochemical sensor was fabricated to detect metronidazole (MNZ) on the basis of green synthesis of Fe 3 O 4 nanoparticles (NPs) using Sambucus ebulus L. leaves alcoholic plant extract as a safe and impressive reducing and stabilizing agent. Several analyses such as X-ray diffraction (XRD), Fourier transform infrared spectrophotometer (FTIR), thermogravimetric analysis (TGA), field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDX), and dynamic light scattering (DLS) confirmed the production of homogeneous, monodisperse, regular, and stable magnetite NPs with a spherical morphology. The as-prepared Fe 3 O 4 NPs were afterwards applied to evaluate the electrochemical activity of MNZ by merging them with graphene nanosheets (GR NSs) on the glassy carbon electrode (GCE). The GR/Fe 3 O 4 NPs/GCE represented extraordinary catalytic activity toward MNZ with two dynamic ranges of 0.05-5 μM and 5-120 μM, limit of detection (LOD) of 0.23 nM, limit of quantification (LOQ) of 0.76 nM, and sensitivity of 7.34 μA μM -1 cm -2 . The fabricated sensor was further employed as a practical tool for electrochemical detection of MNZ in real aqueous samples., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier Inc.)

This study reports for the first-time the possibility of deploying gas production by thiosulfate utilizing denitrifying bacteria (TUDB) as a proxy to evaluate water toxicity. The test relies on gas production by TUDB due to inhibited metabolic activity in the presence of toxicants. Gas production was measured using a bubble-type respirometer. Optimization studies indicated that 300 mg NO 3 - -N/L, 0.5 mL acclimated culture, and 2100 mg S 2 O 3 2- /L were the ideal conditions facilitating the necessary volume of gas production for sensitive data generation. Determined EC 50 values of the selected heavy metals were: Cr 6+ , 0.51 mg/L; Ag + , 2.90 mg/L; Cu 2+ , 2.90 mg/L; Ni 2+ , 3.60 mg/L; As 3+ , 4.10 mg/L; Cd 2+ , 5.56 mg/L; Hg 2+ , 8.06 mg/L; and Pb 2+ , 19.3 mg/L. The advantages of this method include operational simplicity through the elimination of cumbersome preprocessing procedures which are used to eliminate interferences caused by turbidity when the toxicity of turbid samples is determined via spectrophotometry., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Bio-electro-Fenton (BEF) systems have been potentially studied as a promising technology to achieve environmental organic pollutants degradation and bioelectricity generation. The BEF systems are interesting and constantly expanding fields of science and technology. These emerging technologies, coupled with anodic microbial metabolisms and electrochemical Fenton's reactions, are considered suitable alternatives. Recently, great attention has been paid to BEFs due to special features such as hydrogen peroxide generation, energy saving, high efficiency and energy production, that these features make BEFs outstanding compared with the existing technologies. Despite the advantages of this technology, there are still problems to consider including low production of current density, chemical requirement for pH adjustment, iron sludge formation due to the addition of iron catalysts and costly materials used. This review has described the general features of BEF system, and introduced some operational parameters affecting the performance of BEF system. In addition, the results of published researches about the degradation of persistent organic pollutants and real wastewaters treatment in BEF system are presented. Some challenges and possible future prospects such as suitable methods for improving current generation, selection of electrode materials, and methods for reducing iron residues and application over a wide pH range are also given. Thus, the present review mainly revealed that BEF system is an environmental friendly technology for integrated wastewater treatment and clean energy production., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Efficient strategies to promote microvascularization in vascular tissue engineering, a central priority in regenerative medicine, are still scarce; nano- and micro-sized aggregates and spheres or beads harboring primitive microvascular beds are promising methods in vascular tissue engineering. Capillaries are the smallest type and in numerous blood vessels, which are distributed densely in cardiovascular system. To mimic this microvascular network, specific cell components and proangiogenic factors are required. Herein, advanced biofabrication methods in microvascular engineering, including extrusion-based and droplet-based bioprinting, Kenzan, and biogripper approaches, are deliberated with emphasis on the newest works in prevascular nano- and micro-sized aggregates and microspheres/microbeads., (© 2021. The Author(s).)

In this new insight, the potential application of the eco-friendly Bio-Electro-Fenton (BEF) system was surveyed with the aim of simultaneous degradation of tetracycline and in situ generation of renewable bioenergy without the need for an external electricity source. To shed light on this issue, catalytic degradation of tetracycline was directly accrued via in situ generated hydroxyl free radicals from Fenton's reaction in the cathode chamber. Simultaneously, the in situ electricity generation as renewable bioenergy was carried out through microbial activities. The effects of operating parameters, such as electrical circuit conditions (in the absence and presence of external resistor load), substrate concentration (1000, 2000, 5000, and 10 000 mg L -1 ), catholyte pH (3, 5, and 7), and FeSO 4 concentration (2, 5, and 10 mg L -1 ) were investigated in detail. The obtained results indicated that the tetracycline degradation was up to 99.04 ± 0.91% after 24 h under the optimal conditions (short-circuit, pH 3, FeSO 4 concentration of 5 mg L -1 , and substrate concentration of 2000 mg L -1 ). Also, the maximum removal efficiency of anodic COD (85.71 ± 1.81%) was achieved by increasing the substrate concentration up to 2000 mg L -1 . However, the removal efficiencies decreased to 78.29 ± 2.68% with increasing substrate concentration up to 10 000 mg L -1 . Meanwhile, the obtained maximum voltage, current density, and power density were 322 mV, 1195 mA m -2 , and 141.60 mW m -2 , respectively, at the substrate concentration of 10 000 mg L -1 . Present results suggested that the BEF system could be employed as an energy-saving and promising technology for antibiotic-containing wastewater treatment and simultaneous sustainable bioelectricity generation., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Environmental xenoestrogen, Bisphenol A (BPA), is a vitally important industrial raw chemical which can bring about a wide variety of adverse impacts on our health and environment. Therefore, it is imperative to develop efficacious systems to measure BPA and improve the life quality. Herein, a mixture of titanium dioxide nanoparticles (TiO 2 NPs) and glutaraldehyde cross-linked chitosan (GA-CS) loaded into a carbon nanotubes paste matrix to construct a novel electrochemical sensor (TiO 2 NPs/GA-CS/CNTPE) with a synergetic intensified current signal for the quantitative analysis of BPA. The surface morphology of the modified sensor was assessed by field emission scanning electron microscope (FESEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). The prepared TiO2NPs/GA-CS/CNTPE displayed increased electrocatalytic activity toward BPA. The calibration curve of BPA shows linear response in the BPA concentration range of 0.01-6 μM with the lowest limit of detection of 9.58 nM (S/N = 3). The sensor exhibited high sensitivity and selectivity, good reproducibility, desirable stability and excellent performance in detection of BPA in real samples, which prove that TiO2NPs/GA-CS/CNTPE is quite applicable for food, medical and environmental analyses., (Copyright © 2019. Published by Elsevier Inc.)

In aquatic ecosystems, real-time water-quality (WQ) biomonitoring has become the most effective technology for monitoring toxic events by using living organisms as a biosensor. In this study, an online WQ monitoring system using sulfur oxidizing bacteria (SOB) was tested to monitor WQ changes in real-time in natural stream water. The WQ monitoring system consisted of three SOB reactors (one continuous and two semi-continuous mode reactors). The SOB system did not detect any toxicity in relatively-unpolluted, natural stream water when operated for more than six months. When diluted swine wastewater (50:1) was added to the influent of the reactors, the system detected toxic conditions in both the continuous and semi-continuous operational modes, showing 90% inhibition of SOB activity within 1 h of operation. The addition of 30 mg/L NO 2 - -N or 2 mg/L of Cr 6+ to the influents of SOB reactors resulted in the complete inhibition of the SOB activity within 1-2 h. The results demonstrated the successful application of an SOB bioassay as an online toxicity monitoring system for detecting pollutants from stream or river waters., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Large numbers of population suffer from burn annually. The promising treatment of burn has not been identified yet. Albizia julibressin ( A. julibressin ) in Fabaceae family is popular for its antiseptic activity. This prospective study was designed to compare the wound healing effects of A. julibressin gel (AG) with silver sulfadiazine (SSD)., Methods: This single blind clinical trial was performed on 40 patients with second and third degree burns. 20 patients treated with SSD and 20 other patients received A. julibressin . The percentage of the wound healing was evaluated with pain, irritation, edema, itching, erythema, purulent discharges and skin discoloration symptoms. Also, the patients' satisfaction and adverse drug reactions were determined., Results: The severity of pain ( p =0.03), inflammation ( p =0.02) and purulent secretions ( p =0.03) were significantly relieved in A. julibressin group. The healing time significantly reduced in second degree burns ( p =0.03) and third degree burns ( p =0.04) with treating by A. julibressin . No significant adverse drug reactions were detected with A. julibressin ., Conclusion: It seems that A. julibressin improves the different therapeutic aspects of burn injuries and could be considered as a new herbal remedy in wound healings., Competing Interests: The authors declare no conflict of interest.

Scars are a natural and unavoidable result from most wound repair procedures and the body's physiological healing response. However, they scars can cause considerable functional impairment and emotional and social distress. There are different forms of treatments that have been adopted to manage or eliminate scar formation. This review covers the latest research in the past decade on using either natural agents or synthetic biomaterials in treatments for scar reduction.

In the present study, the potential application of the bio-electro-Fenton (BEF) process for the treatment of medicinal herbs wastewater in a mediator-less microbial fuel cell (MFC) system is investigated. This process is operated in a dual-chamber MFC with anaerobic seed sludge as biocatalyst in an anode chamber under conditions of neutral pH, an aerobic cathode chamber equipped with a Fe@Fe2O3/graphite composite cathode and a Nafion membrane as a separator. The performance of the MFC is determined in three different mixed liquor suspended solids (MLSS) loadings, Nafions (112, 115) and a salt bridge in an air-cathode BEF process, in terms of power generation, chemical oxygen demand (COD) removal efficiency, columbic and energy efficiencies. Under optimal conditions, the batch experiment results show that the cathode chamber of the BEF reactor, equipped with Nafion 112 and inoculated with seed sludge at 3000 mg L(-1) MLSS concentration, produces the maximum power density of 49.76 mW m(-2), 0.56 mg L(-1) and 29 mol L(-1) of H2O2 and Fe(2+), respectively. Under these conditions, the MFC achieves COD removal 78.05% in the anaerobic anode chamber and 84.02% as a result of aerobic processes from the air-cathode BEF chamber, whilst the maximum voltage εcb and εE values are 600 mV, 4.09% and 1.37%, respectively., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

In this work, a novel self-powered, sensitive, low-cost, and label-free DNA biosensor is reported by applying a two-chambered microbial fuel cell (MFC) as a power supply. A graphite electrode and an Au nanoparticles modified graphite electrode (AuNP/graphite electrode) were used as anode and cathode in the MFC system, respectively. The active biocatalyst in the anodic chamber was a mixed culture of microorganisms. The sensing element of the biosensor was fabricated by the well-known Au-thiol binding the ssDNA probe on the surface of an AuNP/graphite cathode. Electrons produced by microorganisms were transported from the anode to the cathode through an external circuit, which could be detected by the terminal multi-meter detector. The difference between power densities of the ssDNA probe modified cathode in the absence and presence of complementary sequence served as the detection signal of the DNA hybridization with detection limit of 3.1nM. Thereafter, this biosensor was employed for diagnosis and determination of complementary sequence in a human serum sample. The hybridization specificity studies further revealed that the developed DNA biosensor could distinguish fully complementary sequences from one-base mismatched and non-complementary sequences., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: In order to meet the International Maritime Organization (IMO) objectives, the main purpose of this study was using the cheap and practical wastewater treatment system for low-strength bilge water of Caspian Sea ships; therefore, the low-strength bilge water of the Caspian Sea ships has been treated by up-flow anaerobic sludge fixed film (UASFF) reactor at the ambient temperature., Results: The reactor operated at two hydraulic retention times (HRTs) of 10 h and 8 h. The organic loading rates (OLR) ranged (0.12-0.6) g chemical oxygen demand (COD)/l.day. At the beginning of the experimental procedure, the sludge was immobilized on the surface of the support materials. After 10 days of batch feeding of the reactor with the wastewater as an acclimation period (with COD removal of 59%), the reactor operated continuously. At the end of the experiment, with the HRT of 8 h and OLR of 0.6 g COD/l.day, the COD and total suspended solid (TSS) removal efficiencies reached the amounts of 75% and 99%, respectively. In addition to the good features of the reactor in removing COD and TSS, the effluent oil concentration was significantly lower than the standard value (15 ppm) which has been laid down for the discharge of the bilge water from ships by the IMO., Conclusions: The obtained data demonstrated that UASFF reactor is an appropriate system for treatment of a low-strength bilge water.