128 research outputs found

    Procjena uzgoja Aspergillus niger u geometrijski različitim bioreaktorima na osnovi morfoloških analiza

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    The growth of Aspergillus niger, citric acid production and mycelia morphology changes were compared under different mixing conditions in bioreactors with two types of stirrers: Rushton turbine stirrers (RTS1 or RTS2) and axial counterflow stirrers (ACS1 or ACS2). The characteristics of growth, productivity and morphology varied with the mixing system and the applied agitation regime. In the first series of experiments, the flow characteristics of Aspergillus niger broth under different mixing conditions were analysed in a model bioreactor using RTS1 and ACS1. The kinetic energy E of flow fluctuations was measured in gassed and ungassed water and fermentation broth systems using a stirring intensity measuring device (SIMD-f1). The difference of energy E values at different points was more pronounced in the bioreactor with RTS1 than in the case of ACS1. High viscous A. niger broths provided higher energy E values in comparison with water. It was observed that the Aspergillus niger growth rate and citric acid synthesis rate decreased at very high energy E values, the behaviour obviously being connected with the influence of the irreversible shear stress on the mycelial morphology. In the second series of experiments, a higher citric acid yield was achieved in the case of ACS2 at a power input approximately twice lower than in the case of RTS2. Morphological characterization of A. niger pellets was carried out by the image analysis method. ACS2 provided the development of morphology, where pellets and cores had larger area, perimeter and diameter, and the annular region of pellets was looser and more »hairy« in comparison with the case of RTS2. The pellets from the fermentation with RTS2 were smaller, denser, with shorter hyphae in the annular region of pellets, and the broth was characterized by a higher percentage of diffuse mycelia. Power input studies of RTS2 and ACS2 were made at different agitator rotation speeds and gas flow rates using water and Aspergillus niger broths. RTS2 was a high power number mixing system (PO = 6.8), whose PO was practically invariable in different media under study. For ACS2, PO increased approximately 3 times from 0.68 in water to 2.11 in high viscous Aspergillus niger broth. The effect of the agitation and aeration rates on the power input of RTS2 and ACS2 was analysed. ACS2 proved to be more effective, since it lost much less power due to aeration.Ispitivani su rast Aspergillus niger, proizvodnja limunske kiseline i promjene u morfologiji micelija pod različitim uvjetima miješanja u bioreaktorima s dva tipa miješalica: Rushton turbinske miješalice (RTS1 ili RTS2) i aksijalno protustrujne miješalice (ACS1 i ACS2). Značajke rasta, proizvodnosti i morfologija mijenjali su se s vrstom miješalica i načinom miješanja. U prvoj seriji pokusa analizirane su značajke protoka komine s A. niger pod različitim uvjetima miješanja u modelnom bioreaktoru s miješalicama RTS1 i ACS1. Kinetička energija E fluktuacije protoka mjerena je u vodi s aeracijom i bez nje, te u fermentacijskim kominama koristeći uređaj za mjerenje intenziteta miješanja (SIMD-f1). Razlika u količini energije E na različitim mjestima u bioreaktoru bila je izrazitija u bioreaktoru s RTS1 nego s ACS1. Jako viskozna A. niger komina zahtijevala je veće vrijednosti E u usporedbi s vodom. Opaženo je da brzina rasta A. niger i sinteza limunske kiseline opadaju pri visokim vrijednostima energije E, što je očito povezano s utjecajem ireverzibilnog naprezanja na posmik na morfologiju micelija. U drugoj seriji pokusa postignuti su veliki prinosi limunske kiseline primjenom ACS2, pri približno dvostruko manjem utrošku energije u usporedbi s primjenom RTS2. Morfološka karakterizacija peleta A. niger provedena je postupkom analize fotografija. Primjenom ACS2 peleti i jezgre bili su veći po opsegu i promjeru, a anularno područje peleta bilo je labavije i »dlakavije« u usporedbi s pokusima s RTS2. Peleti od fermentacije s RTS2 bili su manji, gušći, s kraćim hifama u anularnom području peleta, a komina je sadržavala veći postotak difuznih micelija. Studije utroška snage primjenom RTS2 i ACS2 provedene su pri različitim brzinama okretaja miješalica i protoka zraka u vodi i u komini s A. niger. RTS2 ima sustav miješanja s velikim utroškom snage (P0 = 6,8) koji se praktički ne mijenja ako se promijeni medij. Za ACS2 se P0 povećava približno tri puta, od 0,68 u vodi do 2,11 u viskoznoj komini s A. niger. Analiziran je utjecaj miješanja i jačine aeracije na utrošak energije primjenom RTS2 i ACS2. ACS2 bio je djelotvorniji jer se aeracijom gubilo puno manje energije

    Impact of storage conditions on preparation of activated carbon from sheep wool fibres

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    Received: January 31st, 2023 ; Accepted: June 16th, 2023 ; Published: July 6th, 2023 ; Correspondence: [email protected] the European Union, up to 200 thousand tons (Zoccola et al., 2015) of sheep wool fibres, that are not used for textile fabrication, are a secondary by-product with wide field of application possibilities, including preparation of activated carbon. Taking into account, that wool fibres can be stored for long time, under impact of the local climate conditions (including low temperatures) before their application, for example, under variety of temperature, presence of air and light, different moisture conditions, it is necessary to estimate the impact of wool’s storage conditions on the preparation of activated carbon. In the present work, various parameters, such as, temperature, presence of air and daylight as well as humidity, were selected for comparison. After storage of wool fibres under selected various conditions, thermogravimetry/differential thermal analysis (TG/DTA) followed by with Fourier transform infrared (FTIR) spectrometry were used in order to estimate the impact of each parameter on the thermal decomposition processes: release of moisture, sulphur and nitrogen containing compounds and oxidative degradation followed by release of carbon dioxide. It was estimated, that one year of storage under varying conditions does not significantly affect the thermal decomposition properties of the wool fibres. However, minor impact of humidity absorbed from air on wool is observed. Wool samples that were stored at elevated humidity gave higher residual carbon yield (R) in comparison to the fibres stored in dry conditions. The obtained results are used to develop recommendations for preparation of activated carbon from wool fibres and for its application in air filtrating systems

    The regulation of miRNAs by reconstituted high-density lipoproteins in diabetes-impaired angiogenesis

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    Diabetic vascular complications are associated with impaired ischaemia-driven angiogenesis. We recently found that reconstituted high-density lipoproteins (rHDL) rescue diabetes-impaired angiogenesis. microRNAs (miRNAs) regulate angiogenesis and are transported within HDL to sites of injury/repair. The role of miRNAs in the rescue of diabetes-impaired angiogenesis by rHDL is unknown. Using a miRNA array, we found that rHDL inhibits hsa-miR-181c-5p expression in vitro and using a hsa-miR-181c-5p mimic and antimiR identify a novel anti-angiogenic role for miR-181c-5p. miRNA expression was tracked over time post-hindlimb ischaemic induction in diabetic mice. Early post-ischaemia when angiogenesis is important, rHDL suppressed hindlimb mmu-miR-181c-5p. mmu-miR-181c-5p was not detected in the plasma or within HDL, suggesting rHDL specifically targets mmu-miR-181c-5p at the ischaemic site. Three known angiogenic miRNAs (mmu-miR-223-3p, mmu-miR-27b-3p, mmu-miR-92a-3p) were elevated in the HDL fraction of diabetic rHDL-infused mice early post-ischaemia. This was accompanied by a decrease in plasma levels. Only mmu-miR-223-3p levels were elevated in the hindlimb 3 days post-ischaemia, indicating that rHDL regulates mmu-miR-223-3p in a time-dependent and site-specific manner. The early regulation of miRNAs, particularly miR-181c-5p, may underpin the rescue of diabetes-impaired angiogenesis by rHDL and has implications for the treatment of diabetes-related vascular complications

    A Forum for Business Growth and Workforce Development: Findings and Recommendations

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    In the fall of 2008, Illinois State University – Extended University (EU) and the Economic Development Council of the Bloomington-Normal Area (EDC) initiated discussions about a community partnership project to identify workforce opportunities and challenges related to economic stabilization and growth in order to gain a better understanding of the state of workforce preparedness in the area. Rapidly changing dynamics in the economy made previous assessments obsolete. Organizations who work toward the promotion of a strong workforce were approached to participate in the project. EU and the EDC were joined in sponsoring a community event by Heartland Community College, Illinois Wesleyan University, Lincoln College – Normal, Regional Office of Education 17, McLean County Chamber of Commerce, CareerLink 16, and the Small Business Development Center at Illinois State University. Project partners designed and developed a series of discussion forums for eight sectors: Agriculture and Energy, Manufacturing, Small Business Retail, Service, Financial Services, Information Technology, Healthcare, and Construction. The Forum for Business Growth and Workforce Development was held from June 8 – 12, 2009 at Illinois State University. Each sector panel discussion was moderated over a ninety minute period and included two to seven panelists from area businesses

    PAI-1 and t-PA/PAI-1 complex potential markers of fibrinolytic bleeding after cardiac surgery employing cardiopulmonary bypass

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    Background: Enhanced bleeding remains a serious problem after cardiac surgery, and fibrinolysis is often involved. We speculate that lower plasma concentrations of plasminogen activator inhibitor - 1 (PAI-1) preoperatively and tissue plasminogen activator/PAI-1 (t-PA/PAI-1) complex postoperatively might predispose for enhanced fibrinolysis and increased postoperative bleeding.Methods: Totally 88 adult patients (mean age 66 ± 10 years) scheduled for cardiac surgery, were enrolled into a prospective study. Blood samples were collected pre-operatively, on admission to the recovery and at 6 and 24 hours postoperatively. Patients with a surgical bleeding that was diagnosed during reoperation were discarded from the study. The patients were allocated to two groups depending on the 24-hour postoperative chest tube drainage (CTD): Group I > 500ml, Group II ≤ 500ml. Associations between CTD, PAI-1, t-PA/PAI-1 complex and D-dimer were analyzed with SPSS.Results: Nine patients were excluded because of surgical bleeding. Of the 79 remaining patients, 38 were allocated to Group I and 41 to Group II. The CTD volumes correlated with the preoperative plasma levels of PAI-1 (r = - 0.3, P = 0.009). Plasma concentrations of preoperative PAI-1 and postoperative t-PA/PAI-1 complex differed significantly between the groups (P < 0.001 and P = 0.012, respectively). Group I displayed significantly lower plasma concentrations of fibrinogen and higher levels of D-dimer from immediately after the operation and throughout the first 24 hours postoperatively.Conclusions: Lower plasma concentrations of PAI-1 preoperatively and t-PA/PAI-1 complex postoperatively leads to higher plasma levels of D-dimer in association with more postoperative bleeding after cardiac surgery.publishersversionPeer reviewe

    Polymorphisms on PAI-1 and ACE genes in association with fibrinolytic bleeding after on-pump cardiac surgery

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    Publisher Copyright: © 2015 Ozolina et al.Background: Carriers of plasminogen activator inhibitor -1 (PAI-1) -675 genotype 5G/5G may be associated with lower preoperative PAI-1 plasma levels and higher blood loss after heart surgery using cardiopulmonary bypass (CPB). We speculate if polymorphisms of PAI-1 -844 A/G and angiotensin converting enzyme (ACE) intron 16 I/D also might promote fibrinolysis and increase postoperative bleeding. Methods: We assessed PAI-1 -844 A/G, and ACE intron 16 I/D polymorphisms by polymerase chain reaction technique and direct sequencing of genomic DNA from 83 open heart surgery patients that we have presented earlier. As primary outcome, accumulated chest tube drainage (CTD) at 4 and 24 h were analyzed for association with genetic polymorphisms. As secondary outcome, differences in plasma levels of PAI-1, t-PA/PAI-1 complex and D-dimer were determined for each polymorphism. SPSS® was used for statistical evaluation. Results: The lowest preoperative PAI-1 plasma levels were associated with PAI-1 -844 genotype G/G, and higher CTD, as compared with genotype A/A at 4 and 24 h after surgery. Correspondingly, 4 h after the surgery CTD was higher in carriers of ACE intron 16 genotype I/I, as compared with genotype D/D. PAI-1 plasma levels and t-PA/PAI-1 complex reached nadir in carriers of ACE intron 16 genotype I/I, in whom we also noticed the highest D-dimer levels immediately after surgery. Notably, carriers of PAI-1 -844 genotype G/G displayed higher D-dimer levels at 24 h after surgery as compared with those of genotype A/G. Conclusions: Increased postoperative blood loss secondary to enhanced fibrinolysis was associated with carriers of PAI-1 -844 G/G and ACE Intron 16 I/I, suggesting that these genotypes might predict increased postoperative blood loss after cardiac surgery using CPB.publishersversionPeer reviewe

    Aspirin induces cell death and caspase-dependent phosphatidylserine externalization in HT-29 human colon adenocarcinoma cells

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    The induction of cell death by aspirin was analysed in HT-29 colon carcinoma cells. Aspirin induced two hallmarks of apoptosis: nuclear chromatin condensation and increase in phosphatidylserine externalization. However, aspirin did not induce either oligonucleosomal fragmentation of DNA, decrease in DNA content or nuclear fragmentation. The effect of aspirin on Annexin V binding was inhibited by the caspase inhibitor Z-VAD.fmk, indicating the involvement of caspases in the apoptotic action of aspirin. However, aspirin did not induce proteolysis of PARP, suggesting that aspirin does not increase nuclear caspase 3-like activity in HT-29 cells. This finding may be related with the ‘atypical’ features of aspirin-induced apoptosis in HT-29 cells. © 1999 Cancer Research Campaig

    Role of ER Stress Response in Photodynamic Therapy: ROS Generated in Different Subcellular Compartments Trigger Diverse Cell Death Pathways

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    We have analyzed the molecular mechanisms of photoinduced cell death using porphyrins with similar structure differing only in the position of the ethylene glycol (EG) chain on the phenyl ring. Meta- and para-positioned EG chains targeted porphyrins to different subcellular compartments. After photoactivation, both types of derivatives induced death of tumor cells via reactive oxygen species (ROS). Para derivatives pTPP(EG)4 and pTPPF(EG)4 primarily accumulated in lysosomes activated the p38 MAP kinase cascade, which in turn induced the mitochondrial apoptotic pathway. In contrast, meta porphyrin derivative mTPP(EG)4 localized in the endoplasmic reticulum (ER) induced dramatic changes in Ca2+ homeostasis manifested by Ca2+ rise in the cytoplasm, activation of calpains and stress caspase-12 or caspase-4. ER stress developed into unfolded protein response. Immediately after irradiation the PERK pathway was activated through phosphorylation of PERK, eIF2α and induction of transcription factors ATF4 and CHOP, which regulate stress response genes. PERK knockdown and PERK deficiency protected cells against mTPP(EG)4-mediated apoptosis, confirming the causative role of the PERK pathway

    Predicting attitudinal and behavioral responses to COVID-19 pandemic using machine learning

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    At the beginning of 2020, COVID-19 became a global problem. Despite all the efforts to emphasize the relevance of preventive measures, not everyone adhered to them. Thus, learning more about the characteristics determining attitudinal and behavioral responses to the pandemic is crucial to improving future interventions. In this study, we applied machine learning on the multi-national data collected by the International Collaboration on the Social and Moral Psychology of COVID-19 (N = 51,404) to test the predictive efficacy of constructs from social, moral, cognitive, and personality psychology, as well as socio-demographic factors, in the attitudinal and behavioral responses to the pandemic. The results point to several valuable insights. Internalized moral identity provided the most consistent predictive contribution—individuals perceiving moral traits as central to their self-concept reported higher adherence to preventive measures. Similar was found for morality as cooperation, symbolized moral identity, self-control, open-mindedness, collective narcissism, while the inverse relationship was evident for the endorsement of conspiracy theories. However, we also found a non-negligible variability in the explained variance and predictive contributions with respect to macro-level factors such as the pandemic stage or cultural region. Overall, the results underscore the importance of morality-related and contextual factors in understanding adherence to public health recommendations during the pandemic
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