Enzymatic hydrolysis of low temperature alkali pretreated wheat straw using immobilized β-xylanase nanoparticles

A low temperature alkali (LTA) pretreatment method was used to treat wheat straw. In order to obtain good results, different factors like temperature, incubation time, NaOH concentration and solid to liquid ratio for the pretreatment process were optimized. Wheat straw is a potential biomass for the production of monomeric sugars. The objective of the current study was to observe the saccharification (%) of wheat straw with immobilized magnetic nanoparticles (MNPs). For this purpose, immobilized MNPs of purified β-xylanase enzyme was used for hydrolysis of pretreated wheat straw. Wheat straw was pretreated using the LTA method and analyzed by SEM analysis. After completion of the saccharification process, saccharification% was calculated by using a DNS method. Scanning electron micrographs revealed that the hemicellulose, cellulose and lignin were partially removed and changes in the cell wall structure of the wheat straw had caused it to become deformed, increasing the specific surface area, so more fibers of the wheat straw were exposed to the immobilized β-xylanase enzyme after alkali pretreatment. The maximum saccharification potential of wheat straw was about 20.61% obtained after pretreatment with optimized conditions of 6% NaOH, 1/10 S/L, 30 °C and 72 hours. Our results indicate the reusability of the β-xylanase enzyme immobilized magnetic nanoparticles and showed a 15% residual activity after the 11th cycle. HPLC analysis of the enzyme-hydrolyzed filtrate also revealed the presence of sugars like xylose, arabinose, xylobiose, xylotriose and xylotetrose. The time duration of the pretreatment has an important effect on thermal energy consumption for the low-temperature alkali method.

A low temperature alkali (LTA) pretreatment method was used to treat wheat straw.     

Cardiovascular mortality patterns in Turkey: What is the evidence?

In Turkey, reliable cause-specific mortality data are not available. It is thus unknown whether ischaemic heart disease (as in western Europe and the US) or stroke (as in the Far East) is the prevailing cause of cardiovascular death. This information, however, is required for planning cardiovascular prevention programmes. We analyse available Turkish national cause-of-death data as well as patterns of cardiovascular mortality in a hospital in Ankara and among Turkish migrants in Germany. According to national statistics, the ischaemic heart disease-to-stroke ratio would be 0.3 among men aged 45–64 years, lower than that in Japan. Hospital and migrant data show this ratio to be 2–4. We demonstrate the implausibility of the national data by assessing the precision of cause-of-death assignment. We then discuss to what degree mortality experience among migrants is representative for their country of origin. Our findings suggest that the pattern of cardiovascular mortality in Turkey is closer to that in western Europe and the US than to that in the Far East. Finally, we discuss options for improving cardiovascular surveillance in Turkey.     

Assessment of right and left ventricular perfusion in patients with right bundle branch block

BACKGROUND: Patients with conduction abnormalities may have abnormal images on perfusion scintigraphy without evidence of coronary artery disease (CAD). Based on the presence of left ventricular perfusion abnormalities in left bundle branch block and taking advantage of the Tc-99m sestamibi for the assessment of myocardial perfusion of both ventricles, we aimed to evaluate right (RV) and left (LV) myocardial perfusion in patients with right bundle branch block (RBBB). METHODS: This study included 21 patients with RBBB and 21 control subjects without conduction abnormality. None had previous myocardial infarction, known CAD, left ventricular hypertrophy, LVEF <55%, congenital, pulmonary or valvular heart disease. Rest and stress SPECT images were obtained using 1-d Tc-99m sestamibi SPECT protocol. Regional perfusion of LV and RV myocardium was semiquantitatively evaluated. Also, RV/LV uptake ratio was calculated in two different ways. RESULTS: In patients with RBBB, the normality ratios of RV and LV myocardial perfusion were very high (both 90.5%) and not different from those of patients with normal intraventricular conduction. In the comparison of RV/LV uptake ratios, no significant difference was found between the RBBB and control groups. CONCLUSIONS: LV perfusion, RV perfusion or R-to-L perfusion ratio were not significantly influenced by the conduction abnormality in this selected patient population with RBBB. Tc-99m sestamibi myocardial scintigraphy could help in the exclusion of myocardial ischemia in patients with RBBB.     

F-18 FDG PET/CT findings of primary sinonasal hemangiopericytoma: rare location in a young adult patient

Hemangiopericytoma is an unusual tumor that arises from vascular smooth muscle cells. It is mainly experienced in 4th to 5th decades of life and soft-tissue masses are frequently located in lower extremity, pelvis, and retroperitoneum. A 29-year-old man presented with a mass lesion in the right nasal cavity associated with shortness of breath as a result of nasal obstruction. An incisional biopsy was reported as sinonasal type hemangiopericytoma. The initial staging F-18 flourodeoxyglucose PET/CT successfully demonstrated severe hypermetabolism in the primary tumor location and mild-to-moderate hypermetabolism in the right upper jugular lymph node.