Changes in dimension of neurovascular canals in the mandible and maxilla : a radiographic finding in patients diagnosed with MRONJ

The aim of this retrospective study was to compare the morphological features of neurovascular canals and foramina of patients with medication-related osteonecrosis of the jaws (MRONJ) and healthy individuals by using cone beam computed tomography (CBCT). The CBCT images of 58 patients under bisphosphonate therapy diagnosed with MRONJ and age gender- matched controls were retrospectively evaluated. The diameter of mandibular and nasopalatine canal and mandibular, mental and lingual foramina were measured on several sections of CBCT. The value of mental index (MI) and panoramic mandibular index (PMI) were also assessed. The mean value of diametric measurements for all neurovascular canals and foramina in MRONJ patients were narrower than controls. Left mandibular foramen was the most affected area (p<0.001). There were significantly difference in all measurements of mental foramen, lingual foramen and mandibular incisive canal between two groups (p<0.05). PMI of MRONJ subjects were also significantly differences in both sides (p<0.05). In MRONJ patient, neurovascular canals and foramina are affected due to the alterations in bone remodeling. Therefore, the diametric measurement of neurovascular canals and assessment of MI and PMI on CBCT, is a potentially useful method for detection of early changes associated with bisphosphonate therapy and for predict areas where new necrosis may occur

Evaluating the impact of drought stress in Nure and Tremois barleys (Hordeum vulgare) treated with plant growth promoting rhizobacteria (PGPR) at seedling phase

Barley is the fifth cultivated herbaceous crop in the world, and its important is due to its economic and nutritional value. Climate change is posing a new challenge to barley production. While drought stress was traditionally associated with the flowering and caryopsis filling stages in barley plants, a new form of drought is now emerging in seedling stage. To mitigate the impact of environmental stresses, plant growth promoting rhizobacteria (PGPR) have been proposed to promote nutrient absorption and plant growth with the production of a range of beneficial substances, such as phytohormones, organic acids, and enzymes. The aim of this study was to evaluate the genotype response and the impact of PGPR treatment on two cultivars of barley, Nure (Italian feeding barley, winter habitus) and Tremois (French malting barley, spring habitus) in seedling phase under drought stress. At sowing, the soil was treated with PGPR and after two weeks of control condition two different water regimes were applied on seedlings (control at 25% and stressed at 12% of soil moisture). The results showed that both genotypes exhibited analogous stress response, however the PGPR treatment showed different effects on the two cultivars. Specifically, PGPR treatment increased root dry weight in stress conditions in Nure seedlings (by 36.6%) and increased dry weight in control conditions in Tremois seedlings (by 31.1%). Furthermore, the treatment increased the photosynthesis efficiency (PhiPS2) in Tremois seedlings (by 6.2%) and generally in both cultivars (by 7.6%) under drought stress. These findings suggest that the use of PGPR could be a useful tool for protecting barley seedlings against drought stress in early stages of development. However, further research is needed to fully understand the mechanisms of action to determine the optimal conditions for using this approach in the field

Investigation of Polar and Nonpolar Cyclotides Separation from Violet Extract Through Microfluidic Chip

Cyclotides (CTs) as a cyclic peptide obtained from different groups of plants have been very attractable field of research for scientists because of their specific properties like their natural function as host defense agents. CTs are bioactive peptides from plants that characterized by their head-to-tail cyclic backbone and knotted arrangement of their three conserved disulfide bonds. Their natural function is thought to be as host defense agents and a single plant can express dozens to hundreds of CTs. CTs stand out as a family of antimicrobial peptides (AMPs) because of their exceptional stability, structural plasticity, unique biochemical target, and Gram-negative selective antimicrobial action. These features together with recent advancements in the methods of production of CTs make them an intriguing prospect from a drug development perspective. To accomplish this aim, as part of a separation, detection and research of anti-cancer properties CTs study, we investigate the separation of cyclotides in violets into polar and non-polar groups by microfluidic chips

Biologically modified microelectrode sensors provide enhanced sensitivity for detection of nucleic acid sequences from Mycobacterium tuberculosis

This paper describes improved sensitivity when using biosensors based on microfabricated microelectrodes to detect DNA, with the goal of progressing towards a low cost and mass manufacturable assay for antibiotic resistance in tuberculosis (TB). The microelectrodes gave a near 20 times improvement in sensitivity compared to polycrystalline macroelectrodes. In addition, experimental parameters such as redox mediator concentration and experimental technique were investigated and optimised. It was found that lower concentrations of redox mediator gave higher signal changes when measuring hybridisation events and, at these lower concentrations, square wave voltammetry was more sensitive and consistent than differential pulse voltammetry. Together, this paper presents a quantifiable comparison of macroelectrode and microelectrode DNA biosensors. The final assay demonstrates enhanced sensitivity through reduction of sensor size, reduction of redox mediator concentration and judicious choice of detection technique, therefore maintaining manufacturability for incorporation into point of care tests and lab-on-a-chip devices

Investigation of the effect of channel structure and flow rate on on-chip bacterial lysis

Successful lysis of cells/microorganisms is a key step in the sample preparation in fields like molecular biology, bioengineering, and biomedical engineering. This study therefore aims to investigate the lysis of bacteria on-chip and its dependence on both microfluidic channel structure and flow rate. Effects of temperature on lysis on-chip were also investigated. To perform these investigations, three different microfluidic chips were designed and produced (straight, zigzag and circular configurations), while the length of the channels were kept constant. As an exemplary case, Mycobacterium smegmatis was chosen to represent the acid-fast bacteria. Bacterial suspensions of 1.5 McFarland were injected into the chips at various flow rates (0.6-8 ll/min) either at room temperature or 500 C. In order to understand the on-chip lysis performance fully, off-chip experiments were carried out at durations which are equal to those bacteria spent in the channel from inlet to the outlet at different flow rates. We also performed COMSOL multiphysics program simulations to evaluate further the effect of the applied parameters. As a result, we found that the structure and the flow rate do not affect lysis over all in all investigated channel types, however on-chip experiments at room temperature produced more effective lysis compared to the on-chip and the off-chip samples performed at higher temperatures. Interestingly on-chip experiments at higher tempratures do not result in effective lysis

Structure-property relationships of novel phosphonate-functionalized networks and gels of poly(β-amino esters)

pH sensitivity, biodegradability and high biocompatibility make poly(β-amino esters) (PBAEs) important biomaterials with many potential applications including drug and gene delivery and tissue engineering, where their degradation should be tuned to match tissue regeneration rates. Therefore, we synthesize novel phosphonate-functionalized PBAE macromers, and copolymerize them with polyethylene glycol diacrylate (PEGDA) to produce PBAE networks and gels. Degradation and mechanical properties of gels can be tuned by the chemical structure of phosphonate-functionalized macromer precursors. By changing the structure of the PBAE macromers, gels with tunable degradations of 5–97% in 2 days are obtained. Swelling of gels before/after degradation is studied, correlating with the PBAE identity. Uniaxial compression tests reveal that the extent of decrease of the gel cross-link density during degradation is much pronounced with increasing amount and hydrophilicity of the PBAE macromers. Degradation products of the gels have no significant cytotoxicity on NIH 3T3 mouse embryonic fibroblast cells

POLYESTER ESASLI KOMPOZİT MALZEME ÜRETİLMESİNDE KUMAŞ ATIKLARININ DEĞERLENDİRİLMESİ

Termoset esaslı kompozit malzemeler, termoset esaslı bir matris ile bir takviye elemanının birleştirilmesiyle üretilen malzemeler için kullanılan bir terimdir. Termoset polimerler olarak alkidler, amino, epoksi reçine, fenolikler, polyester, poliüretan’lar sayılabilir. Bu çalışmada takviye elemanı olarak atık kumaşlar (pamuklu dokuma ve pamuklu örme)ve dokuma cam elyafı kullanılarak polyester esaslı termoset kompozitler üretilmiştir. Kompozit üretim el yatırma yöntemi kullanılarak gerçekleştirilmiştir. Üretilen kompozitlerin mekanik özellikleri (çekme, eğilme ve darbe direnci) ASTM standartlarına uygun olarak Üniversal test makinesi yardımıyla belirlenmiştir

Impedance testing of porous Si3N4 scaffolds for skeletal implant applications

Si3N4 ceramics show excellent characteristics of mechanical and chemical resistance in combination with good biocompatibility, antibacterial property and radiolucency. Therefore, they are intensively studied as structural materials in skeletal implant applications. Despite their attractive properties, there are limited data in the field about in vitro studies of cellular growth on ceramic implant materials. In this study, the growth of bone cells was investigated on porous Silicon Nitride (Si3N4) ceramic implant by using electrochemical impedance spectroscopy (EIS). Partial sintering was performed at 1700 °C with limited amount of sintering additive for the production of porous Si3N4 scaffolds. All samples were then sterilized by using ethylene oxide followed by culturing MG-63 osteosarcoma cells on the substrates for in vitro assays. At 20 and 36 hours, EIS was performed and results demonstrated that magnitude of the impedance as a result of the changes in the culture media increased after incubation with osteosarcoma cells. The changes are attributed to the cellular uptake of charged molecules from the media. Si3N4 samples appear to show large impedance magnitude changes, especially between 100 Hz and 1 Hz. Impedance changes were also correlated with WST-1 measurements (36 hr) and DAPI results

Novel nanofibre integrated SiN scaffolds for skeletal implant applications

Nowadays, increase in number of orthopedic surgery accelerates global interest in the world orthopedic industry. Apart from the increased number of the surgery, the rapid recovery becomes very important following the initial operations. One of the common problem for the patients is the biocompatibility between the implant and tissue [1-3]. In this study, we aimed to improve attachment of the implant to the tissue in addition to provide high biocompatibility. After preparing a scaffold by using SiN subsequently we have coated with fine gelatine nanofibers. SiN is one of the most commonly used bioactive ceramic class, and also its biocompatibility is good enough

Adsorption challenge in the PDMS-based microfluidic systems for drug screening application

Drug screening is one of the demand areas due to close and direct dependency on human health. On the other hand, recently microfluidic systems have been increasingly used for drug development and screening purposes. However, this system has some challenges such as adsorption issue which can effect pharmacokinetic-pharmacodynamic (PK-PD) of the drugs. Thus, in this research, the issue was characterized and evaluated by UV-Vis spectrophotometry and FTIR spectroscopy devices as a model drug of cisplatin. Despite of strong relationship between logP and adsorption, and the very low value of logP in the drug candidate, the results for both apical and basal planes of the microfluidic chip confirmed the adsorption. In the UV-Vis spectrophotometry, the basal plane show 5%, and 10% higher adsorption compared to apical and control polydimethylsiloxane (PDMS)-based microfluidic. Additionally, the FTIR patterns were a good coincide with UV-Vis results