Preoperative MELD-Na Score Predicts 30-day Post-operative Complications After Colorectal Resection for Malignancy

Introduction:Predicting possible complications in colon surgery is important in terms of reducing postoperative mortality and morbidity rates. Various scoring methods have been used to predict these complications. The MELD score was developed to predict mortality following Transjugular Intrahepatic Portosystemic Shunt (TIPS) placement in cirrhotic patients. This model was revised by adding Na data and used to predict complications in non-cirrhotic patients. We investigated the value of the MELD-Na score in predicting postoperative 30-day complications in patients undergoing colorectal resection for malignancy.Methods:Patients who underwent colorectal resection for malignant diseases were included in the study. Demographics and clinical outcomes were recorded. The MELD-Na scores of the patients were calculated within 48 h before the surgery. Patients were divided into 2 groups according to the status of development of any complication.Results:Age, gender, operative time, and length of stay was not statistically significant for developing complications. The MELD-Na score was significantly higher in patients with any complications. Also, MELD-NA score, stoma creation, and postoperative erythrocyte suspension replacement were found to be independent risk factors for developing complications in patients undergoing surgery for colon cancer.Conclusion:The MELD-Na score may predict the complications that may develop in the first 30 days postoperatively in patients undergoing colorectal resection for malignant diseases

Metal-Enhanced Fluorescence from Silver Nanowires with High Aspect Ratio on Glass Slides for Biosensing Applications

High enhancement of fluorescence emission, improved fluorophore photostability, and significant reduction of fluorescence lifetimes have been obtained from high aspect ratio (>100) silver (Ag) nanowires. These quantities are found to depend on the surface loading of Ag nanowires on glass slides, where the enhancement of fluorescence emission increases with the density of nanowires. The surface loading dependence was attributed to the creation of intense electric fields around the network of Ag nanowires and to the coupling of fluorophore excited states that takes place efficiently at a distance of 10 nm from the surface of nanowires, which was confirmed by theoretical calculations. The enhancement of fluorescence emission of fluorescein isothiocyanate (FITC) was assessed by fluorescence spectroscopy and fluorescence-lifetime imaging microscopy (FLIM) to demonstrate the potential of high aspect ratio Ag nanowires. Fluorescence enhancement factors exceeding 14 were observed on Ag nanowires with high loading by FLIM. The photostability of FITC was the highest on nanowires with medium loading under continuous laser excitation for 10 min because of the significant reduction in the fluorescence lifetime of FITC on these surfaces. These results clearly demonstrate the potential of Ag nanowires in metal-enhanced fluorescence-based applications of biosensing on planar surfaces and cellular imaging

Organik Işik Yayan Diyot Uygulamalari İçin Konjüge Polimerlerin Sentezi

Bu çalışmada kimyasal yöntemle benzotriazol ve selenofen üniteleri içeren yeni polimerler Suziki kenetlenme yöntemi ile sentezlenecektir. Sentezlenecek polimerler, NMR, IR, GPC, TGA ve DSC yöntemleriyle karakterize edilecektir. Sentezlenen polimerlerin temizleme işlemleri gerçekleştirildikten sonra dönüşümlü voltametri tekniği kullanılarak redoks davranışları araştırılacak ve HOMO-LUMO enerji seviyeleri hesaplanacaktır. Spektroskopik teknikler kullanılarak yapısal analizlerine bakılacak, çözeltideki ve filmdeki kopolimerlerin ışığı soğurma ve floresan özellikleri incelenecektir. İnce film morfolojileri AFM ve TEM kullanılarak analiz edilecektir. Termal ve çözelti tavlama yöntemlerinin morfolojiye etkisine bakılacaktır ve son olarak kalınlığın ve morfolojinin optimizasyonu yapıldıktan sonra OLED yapımı gerçekleştirilecektir. ITO ve PEDOT: PSS kaplı substratlar inert(azot dolu) bir atmosfere sahip (O2 < 0.1 ppm H2O < 0.1 ppm) eldivenli kabin sistemi içerisinde polimerlerin kaplanması ve metal kontakların eklenmesi gerçekleştirilerek gerekli hesaplanmalar yapılacaktır. Bunun yanında, polimerler silisyum yüzeyler üzerine kaplanarak elipsometri tekniği kullanılarak optimum kalınlıkları belirlenecektir

Studying the pyroelectric effects of LiNbO3 modified composites

LiNbO3 (LN) crystal has been widely used as a pyroelectric material due to its spontaneous electric polarization, which could be recharged easily and can directly convert heat energy into electricity. LN crystal's heat-resistant, low-cost, and low dielectric loss properties make it possible for its applications in room-temperature pyroelectric devices and thermal sensors. However, LN crystal suffers from fragility, inflexibility, and other mechanical properties, which limit its suitability for many applications in various fields. In this study, the LN modified flexible pyroelectric films, composed of LN micro-particles, polypropylene (PP) matrix, and multiwalled carbon nanotubes (MWCNTs), are successfully fabricated. The pyroelectric effects of LN crystal and LN/PP/MWCNT composite films are characterized by monitoring the patterned self-assembly of nanoparticles and the output pyroelectric currents. The excellent pyroelectric properties of the composites have potential applications in energy harvesters or sensors.Published versio

Size and Carbon Content of Sub-seafloor Microbial Cells at Landsort Deep, Baltic Sea

The discovery of a microbial ecosystem in ocean sediments has evoked interest in life under extreme energy limitation and its role in global element cycling. However, fundamental parameters such as the size and the amount of biomass of sub-seafloor microbial cells are poorly constrained. Here we determined the volume and the carbon content of microbial cells from a marine sediment drill core retrieved by the Integrated Ocean Drilling Program (IODP), Expedition 347, at Landsort Deep, Baltic Sea. To determine their shape and volume, cells were separated from the sediment matrix by multi-layer density centrifugation and visualized via epifluorescence microscopy (FM) and scanning electron microscopy (SEM). Total cell-carbon was calculated from amino acid-carbon, which was analyzed by high-performance liquid chromatography (HPLC) after cells had been purified by fluorescence-activated cell sorting (FACS). The majority of microbial cells in the sediment have coccoid or slightly elongated morphology. From the sediment surface to the deepest investigated sample (similar to 60 m below the seafloor), the cell volume of both coccoid and elongated cells decreased by an order of magnitude from similar to 0.05 to 0.005 mu m(3). The cell-specific carbon content was 19-31 fg C cell(-1), which is at the lower end of previous estimates that were used for global estimates of microbial biomass. The cell specific carbon density increased with sediment depth from about 200 to 1000 fg C mu m(-3), suggesting that cells decrease their water content and grow small cell sizes as adaptation to the long-term subsistence at very low energy availability in the deep biosphere. We present for the first time depth-related data on the cell volume and carbon content of sedimentary microbial cells buried down to 60 m below the seafloor. Our data enable estimates of volume-and biomass-specific cellular rates of energy metabolism in the deep biosphere and will improve global estimates of microbial biomass