Biohydrogen and Biomethane (Biogas) Production in the Consecutive Stages of Anaerobic Digestion of Molasses

Anaerobic digestion, whose final products are methane and carbon dioxide, has been used to produce biogas from waste biomass as an alternative energy source. For the purpose of innovative, modern technologies based on microbial processes, it is desirable to separate the hydrogen- (hydrolysis and acidogenesis) and methane-yielding (acetogenesis and methanogenesis) stages of anaerobic digestion to respectively favor the production of hydrogen and methane under controlled conditions. Previously, we developed a benchscale (3- and 3.5-litre bioreactors) two-stage anaerobic digestion system producing hydrogen (in stage 1)and methane (in stage 2) from sucrose-rich by-products of the sugar beet refining industry as the primary energy substrates under mesophilic conditions. Recently, the two-stage system for hydrogen and methane production has been successfully scaled up 10-fold (a pilot scale) and currently operates in one of the Polish sugar factories. The efficiency of hydrogen and methane production were directly proportional to the scale of installation. The obtained results led to the development objectives of further research that the end result will be an innovative solution for the sugar factory as a producer of gaseous biofuels

Dynamics and Complexity of Dark Fermentation Microbial Communities Producing Hydrogen From Sugar Beet Molasses in Continuously Operating Packed Bed Reactors

This study describes the dynamics and complexity of microbial communities producing hydrogen-rich fermentation gas from sugar-beet molasses in five packed-bed reactors (PBRs). The bioreactors constitute a part of a system producing hydrogen from the by-products of the sugar-beet industry that has been operating continuously in one of the Polish sugar factories. PBRs with different working volumes, packing materials, construction and inocula were tested. This study focused on analysis (based on 16S rRNA profiling and shotgun metagenomics sequencing) of the microbial communities selected in the PBRs under the conditions of high (>100 cm3/g COD of molasses) and low (<50 cm3/g COD of molasses) efficiencies of hydrogen production. The stability and efficiency of the hydrogen production are determined by the composition of dark fermentation microbial communities. The most striking difference between the tested samples is the ratio of hydrogen producers to lactic acid bacteria. The highest efficiency of hydrogen production (130-160 cm3/g COD of molasses) was achieved at the ratios of HPB to LAB ≈ 4:2.5 or 2.5:1 as determined by 16S rRNA sequencing or shotgun metagenomics sequencing, respectively. The most abundant Clostridium species were C. pasteurianum and C. tyrobutyricum. A multiple predominance of LAB over HPB (3:1-4:1) or clostridia over LAB (5:1-60:1) results in decreased hydrogen production. Inhibition of hydrogen production was illustrated by overproduction of short chain fatty acids and ethanol. Furthermore, concentration of ethanol might be a relevant marker or factor promoting a metabolic shift in the DF bioreactors processing carbohydrates from hydrogen-yielding toward lactic acid fermentation or solventogenic pathways. The novelty of this study is identifying a community balance between hydrogen producers and lactic acid bacteria for stable hydrogen producing systems. The balance stems from long-term selection of hydrogen-producing microbial community, operating conditions such as bioreactor construction, packing material, hydraulic retention time and substrate concentration. This finding is confirmed by additional analysis of the proportions between HPB and LAB in dark fermentation bioreactors from other studies. The results contribute to the advance of knowledge in the area of relationships and nutritional interactions especially the cross-feeding of lactate between bacteria in dark fermentation microbial communities

Treatment of patients with acute coronary syndrome: Recommendations for medical emergency teams: Focus on antiplatelet therapies. Updated experts’ standpoint

A group of Polish experts in cardiology and emergency medicine, encouraged by the European Society of Cardiology (ESC) guidelines, have recently published common recommendations for medical emergency teams regarding the pre-hospital management of patients with acute coronary syndrome. Due to the recent publication of the 2017 ESC guidelines for the management of acute myocardial infarction in patients presenting with ST-segment elevation and 2017 focused update on dual antiplatelet therapy in coronary artery disease the current panel of experts decided to update the previous standpoint. Moreover, new data coming from studies presented after the previous document was issued were also taken into consideration

Original articleCardiac troponin I after external electrical cardioversion for atrial fibrillation as a marker of myocardial injury &#8211; a preliminary report

Background: It is uncertain whether external electrical cardioversion (CV) of atrial fibrillation (AF) can cause myocardial injury identifiable by troponin I (cTnI). Aim: To examine whether external CV of AF can cause cTnI rise as measured with high-sensitivity assay, and to identify factors determining this elevation. Methods: Patients with non-valvular AF selected for CV were included. Exclusion criteria were myocardial ischaemia, elevated D-dimer, heart and renal failure. Patients underwent monophasic or biphasic CV. Troponin I was measured before, and 6 and 12 hours after the procedure with TNI-ADV assay; NT-proBNP was measured before CV. Echocardiography was performed in all patients. Results: Twenty-two patients were examined. Troponin I 6 and 12 hours after CV [0.04 ng/ml (0.00-0.30), 0.04 ng/ml (0.00-0.13)] was significantly higher than before [0.017 pg/ml (0.00-0.08)] (p=0.01, p=0.02). Only in one patient did cTnI exceed the cut-off for myocardial infarction after 6 hours (>0.16 ng/ml) with subsequent normalisation after 12 hours. Left ventricular end-diastolic dimension (LVEDD) was significantly higher and ejection fraction lower in the group with cTnI rise in comparison with the group with no cTnI elevation (54,2&#177;6,3 vs. 47,6&#177;5,7 mm, p=0,02; 56,2&#177;8,9 vs. 63,2&#177;7,1%, p=0,05). LVEDD=53 mm had 75% sensitivity and 72% specificity for predicting cTnI elevation after CV. Age, gender, AF duration, type of CV, energy, left atrial dimension, baseline cTnI and NT-proBNP were not predictive of cTnI increase. Conclusions: Cardioversion can lead to mild but significant cTnI rise as measured with a high-sensitivity assay. The influence of CV on cTnI elevation appears to be more pronounced in patients with relatively large LVEDD.Wstęp: Wiele dotychczas opublikowanych danych wskazuje na brak wzrostu stężenia troponin po zewnętrznej kardiowersji elektrycznej migotania przedsionków (AF). Niektórzy autorzy donoszą jednak o możliwości nieznacznego wzrostu stężenia tych markerów w odpowiedzi na zewnętrzną kardiowersję elektryczną u chorych z AF. W ostatnim czasie pojawiają się nowe komercyjne zestawy do oznaczeń troponin o coraz wyższej czułości, których dynamika po zabiegach potencjalnie nieuszkadzających miokardium, w tym po zewnętrznej kardiowersji, nie jest znana. Nie wiadomo też, czy istnieje związek między stężeniami troponiny po kardiowersji i stężeniami peptydów natriuretycznych. Cel: Ocena dynamiki stężenia sercowej troponiny I (cTnI) o wysokiej czułości (ang. advanced troponin I, cTnI ADV) po zewnętrznej kardiowersji elektrycznej AF. Ustalenie klinicznych, demograficznych, echokardiograficznych i biochemicznych predykatorów ewentualnego wzrostu cTnI po kardiowersji elektrycznej. Metodyka: Do badania włączono kolejnych chorych kwalifikowanych do kardiowersji elektrycznej z powodu przetrwałego AF. Kryteriami wykluczenia były stany predysponujące do wzrostu stężenia troponin: podmiotowe lub elektrokardiograficzne cechy niedokrwienia mięśnia serca, objawowa niewydolność serca, podejrzenie zatorowości płucnej (D-dimer >0,5 ng/ml), niewydolność nerek (stężenie kreatyniny >1,5 mg/dl). U wszystkich chorych oznaczono cTnI (AxSYM TnI ADV, Abbott Lab.) i N-końcowy propeptyd natriuretyczny typu B (NT-proBNP) (Elecsys, Roche Diag.) przed kardiowersją. Oznaczenia cTnI powtarzano 6 i 12 godz. po zabiegu. U wszystkich chorych wykonywano badanie echokardiograficzne, w którym oceniano wymiar końcoworozkurczowy lewej komory (LVEDD), wymiar lewego przedsionka (LA) i frakcję wyrzutową lewej komory (LVEF). Kardiowersję zewnętrzną wykonywano kardiowerterem jedno- lub dwufazowym, zależnie od dostępności określonego typu sprzętu. Wyniki: W badaniu wzięło udział 23 chorych (12 mężczyzn i 11 kobiet) w średnim wieku 67,4&#177;13,22 lat. Kardiowersję elektryczną wykonano kardiowerterem jedno- (n=14) lub dwufazowym (n=9). Migotanie przedsionków trwało >48 godz. u 14 chorych, a 0,4 ng/ml) i tylko w jednym stwierdzono wzrost stężenia cTnI >0,16 ng/ml (stężenie oznaczone z nieprecyzyjnością Ł10%, punkt odcięcia zalecany przez producenta do rozpoznania zawału wg definicji z roku 2000). Po 12 godz. u tego chorego doszło do normalizacji stężenia cTnI. Wymiar końcoworozkurczowy lewej komory był istotnie większy, a LVEF mniejsza w grupie ze wzrostem stężenia cTnI po kardiowersji elektrycznej w porównaniu z grupą bez wzrostu stężenia cTnI po zabiegu (odpowiednio: 54,2&#177;6,3 vs 47,6&#177;5,7 mm, p=0,02; 56,2&#177;8,9 vs 63,2&#177;7,1%, p=0,05). Wymiar końcoworozkurczowy lewej komory był jedynym niezależnym predykatorem wzrostu stężenia cTnI po kardiowersji elektrycznej. Wartość LVEDD=53 mm przewidywała wzrost stężenia TnI z czułością 75% i swoistością 72%. Płeć, wiek, czas trwania AF (powyżej lub poniżej 48 godz.), typ kardiowersji, zastosowana energia, wymiar LA, wyjściowe stężenie NT-proBNP i cTnI nie wiązały się ze wzrostem stężenia cTnI po kardiowersji elektrycznej. Wnioski: Zewnętrzna kardiowersja elektryczna AF prowadzi do istotnego wzrostu stężenia cTnI oznaczanej czułym testem. Wpływ kardiowersji zewnętrznej na wzrost stężenia cTnI może być bardziej wyrażony u chorych z względnie większym LVEDD

The use of hydrogen-rich gas obtained from dark fermentation of molasses from sugar industry for fueling a fuel cell

Polymer electrolyte membrane fuel cell was supplied with air and a H2-rich gas obtained by microbial fermentation of molasses from the sugar industry. The energy conversion performance in the fuel cell was examd. under various conditions, including minimum energy input necessary for the prepn. of the gaseous reagents (without pre-cleaning of the fermentation gas, at low airflow, without pressurizing the reagents, and at low fuel cell temp.). The H2 conversion degree was near 100% but decreased even down to 40% during the fuel cell operation time because of flooding of the anode

Textural, surface, thermal and sorption properties of the functionalized activated carbons and carbon nanotubes

Two series of functionalised carbonaceous adsorbents were prepared by means of oxidation and nitrogenation of commercially available activated carbon and multi-walled carbon nanotubes. The effect of nitrogen and oxygen incorporation on the textural, surface, thermal and sorption properties of the adsorbents prepared was tested. The materials were characterized by elemental analysis, low-temperature nitrogen sorption, thermogravimetric study and determination of the surface oxygen groups content. Sorptive properties of the materials obtained were characterized by the adsorption of methylene and alkali blue 6B as well as copper(II) ions. The final products were nitrogen- and oxygen-enriched mesoporous adsorbents of medium-developed surface area, showing highly diverse N and O-heteroatom contents and acidic-basic character of the surface. The results obtained in our study have proved that through a suitable choice of the modification procedure of commercial adsorbents it is possible to produce materials with high sorption capacity towards organic dyes as well as copper(II) ions