Evaluation of Residue Distribution of Spraying Nozzles Produced for the Prevention of Spray Drift

The widespread use of pesticides has negative impacts on human health and the environment. This situation increases the severity day by day. Especially spray drift is one of the factors that should be controlled. In addition, pesticide costs have led to new solutions. Conventional spraying nozzles and anti-drift spraying nozzles are discussed in this study. The study carried out in viticulture areas. Pesticide residual amounts were determined by sampling surfaces placed in different parts of the plant. The sampling surfaces were placed on the top and bottom surfaces of the leaves. Pesticide residue rates were determined in different regions of the plant. The average pesticide residual amounts on the leaves with the anti-drift spray nozzles AITX 8002 VK and ITR 8002 were found to 63.5%25 and 49.9%25 higher than the conventional TX VK12 spray nozzle, respectively, also 44.2%25 and 32.2%25 higher than the other conventional spray nozzle TR 8002, respectively. The lowest value of top to bottom pesticide residue ratio for leaves was 2.22 at anti-drift ITR 8002 spray nozzle and the highest value of top to bottom pesticide residue ratio for leaves was 2.95 with the conventional spray nozzle TR 8002. All the type of spray nozzles except anti-drift AITX 8002, produced less residue in the inner parts compared to outer parts. The highest penetration rate was 90%25 with the AITX 8002 VK spray nozzle and the lowest penetration was 55%25 with the conventional TX VK12 spray nozzle type

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

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

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

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

Label-free molecular detection of antibiotic susceptibility for Mycobacterium smegmatis using a low cost electrode format

Today, the emergence of antibiotic resistance in pathogenic bacteria is considered an important problem for society. Excessive consumption of antibiotics, long-term treatments, and inappropriate prescriptions continually increase the severity of the problem. Improving antibiotic stewardship requires improved diagnostic testing, and, therefore, in vitro antibiotic susceptibility testing is becoming increasingly important. This research details the development of an antibiotic susceptibility test for Mycobacterium smegmatis using streptomycin as antibiotics. This strain was selected because it is a member of the slow growing Mycobacterium genus and serves as a useful surrogate organism for M. tuberculosis. A commercially available and low-cost screen-printed gold electrode in combination with a specifically developed nucleic acid probe sequence for the 16SrRNA region of the mycobacterial genome was employed to monitor M. smegmatis nucleic acid sequences using the techniques of square-wave voltammetry and electrochemical impedance spectroscopy. The results show that it was possible to detect M. smegmatis sequences and distinguish antibiotic-treated cells from untreated cells with a label-free molecular detection. As a result, the in vitro antibiotic susceptibility test revealed that M. smegmatis showed sensitivity to streptomycin after a 24-H incubation, with the developed protocol representing a potential approach to determining antibiotic susceptibility more quickly and economically than current methods

Hypoxia parameters, physical variables, and severity of obstructive sleep apnea

Objective: To determine the relation between hypoxia and physical parameters in patients who had different levels of severity of obstructive sleep apnea (OSA). Methods: This was a retrospective, cross-sectional study of 259 men who were evaluated with overnight polysomnography. Severity of OSA was graded based on the apnea-hypopnea index (AHI): normal/simple snoring (n=31); mild OSA (n=70); moderate OSA (n=63); severe OSA (n=95). Patients with different severity were divided into subgroups, based on having the lowest or highest values of the total sleep time with oxygen saturation <90% (ST90) or minimum oxygen saturation (min SaO(2)). Results: Median AHI was 20.4 events/hour. Univariate analysis showed that ST90 was correlated with AHI (r=0.772; p <= 0.001) and Epworth sleepiness scale (ESS) (r=0.344; p <= 0.001), and min SaO(2) was inversely correlated with AHI (r=-0.748; p <= 0.001) and ESS (r=-0.319; p <= 0.001). Multivariate linear regression showed that ST90 was independently associated with AHI, ESS, and neck circumference, and min SaO(2) was independently inversely associated with AHI, ESS, and body mass index (BMI). In patients who had severe OSA, the subgroups which had lowest and highest min SaO(2) differed significantly in BMI, modified Mallampati score, neck and waist circumferences, and ret-roglossal Muller grade. In patients with percentage of sleep time with oxygen saturation below 90% (CT90) <10%, the upper limit of ST90 was 36 minutes and corresponded to 70% lower limit of min SaO(2). Conclusion: Hypoxia parameters show significant variation in OSA severity categories. None of the physical parameters had clinically useful relations with hypoxia parameters in OSA patients except patients who had severe OSA

The relationship between clinical and laboratory findings and duration of sleep where oxygen saturation remains below 90-95% in obstructive sleep apnea

Objective: The aim of the present study was to determine correlations between CT90 and CT95 values and physical examination parameters, chronic metabolic diseases, smoking, mean platelet volume, cerebral magnetic resonance imaging (MRI), presence and number of hyperintense foci in obstructive sleep apnea (OSA). Methods: A total of 1154 patients who underwent polysomnography in our sleep laboratory between 2011 and 2014 were screened retrospectively. Among them, 72 cases who underwent ear, nose and throat examinations, cerebral MR, CBC and biochemical tests were included in the study. All patients underwent a detailed anamnesis together with (1) measurements of BMI (body mass index) (2) circumferences of neck and abdomen, (3) examination of oropharynx, (4) Muller maneuver with the aid of fiberoptic endoscope, (5) estimation of Epworth sleep scale scores, (6) and polysomnographic (PSG) tests. Results: According to the severity of OSA, the patients had simple snoring (22.2%), mild (19.4%) and severe OSA (38.9%). In multivariate regression analysis, body mass index (BMI) (p=0.026) and apnea/hypopnea index (AHI) (p=0.013) were seen as independent variables affecting CT90 (R-2=49%). Multivariate linear regression analysis demonstrated that independent variables of smoking (p=0.001), AHI (p=0.003) and number of hyperintense foci (p=0.013) affected CT95 (R-2=%47.9), while relationships between diabetes, BMI and CT95 were not statistically significant. Conclusion: Since CT95 values are affected by smoking without any statistically significant correlation with retropalatal and retroglossal Muller stages, we think that consideration of CT90 value will be more appropriate in the evaluation of the severity of chronic intermittent hypoxia in patients with obstructive sleep apnea. However, the correlation between CT90 value and AHI is closer to the value indicated in the literature, but not stronger

Electrophoretic comparison of blood-serum proteins of Apathya cappadocica (Sauria, Lacertidae) subspecies from Anatolia

WOS: 000286480300007Blood-serum proteins of the known subspecies of Apathya cappadocica (Werner, 1902) were studied comparatively by polyacrylamide disc gel electrophoresis. In order to obtain useful biochemical data for classification, differences between the electrophoreograms of the samples included in the morphologically different subspecies were distinguished qualitatively and quantitatively. These comparisons indicated that electrophoretic results supported morphological discrimination of the known subspecies of A. cappadocica.TUBITAK (The Scientific and Technical Research Council of Turkey)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TBAG-104T017]This work forms part of a Project (Project No. TBAG-104T017) supported by TUBITAK (The Scientific and Technical Research Council of Turkey)