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Bioreactors are commonly used apparatuses generally equipped with several built-in specifications for the investigation of biological treatment studies. Each bioreactor test may require different types of specialty such as heating, agitation, re-circulation and some further technologies like online sensoring. Even thought, there are many ready-to-use fabricated bioreactors available in the market with a cost usually over than 1000 €, it is often not possible to access those advanced (but inflexible) systems for many students, young-researchers or small-scale private R&D companies. In this work, a new low cost (≈100€) packed-bed anaerobic bioreactor was developed, and all methodological details including open-source coding and 3D design files are shared with informative descriptions. Some preliminary tests were conducted to verify the developed bioreactor system's credibility in terms of leak-tightness, accurate gas monitoring, temperature controlling, and mass balance (COD-eq) coverage, which all have shown a very promising performance.•A consistent model bioreactor that will be called as "tetrapod" was developed for anaerobic treatment of challenging substrates such as pyrolytic liquids.•Coarse biochar grains were used as an organic packing material to stimulate the microbial bioconversion by increasing the active surface area for the attached-growth anaerobic mixed microbial culture (MMC).•An open-source Arduino based digital gasometer was developed for online monitoring of biogas change in the lab-scale system. Arduino was also used as a digital controller for maintaining pulse-mode liquid recirculation of the bioreactor.

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PURPOSE: To evaluate the choroidal thickness (CT) with enhanced depth-imaging optical coherence tomography (EDI-OCT) in healthcare professionals using surgical masks or FFP2 (N95) masks. METHODS: We included the 120 eyes of 120 healthy volunteers who were using a surgical mask (Group 1) or FFP2 mask (Group 2) in the study. Spectral domain (SD) OCT was used to measure CT. EDI-OCT was used to measure subfoveal and perifoveal CT. Points 1500 µm nasal (CN1500) and temporal (CT1500) to the foveal center were used to measure perifoveal CT. Oxygen saturation and heart rate were measured with a pulse oximeter. All measurements were performed at 8:30, before wearing the mask, and at 12:30, when the mask was removed for the lunch break. RESULTS: Of a total of 120 subjects, Group 1 consisted of 60 subjects (mean age 38.50±8.60 (range 24-44) years) and Group 2 also consisted of 60 subjects (mean age 36.60±6.53 (range 26-45) years). Although not statistically significant, CT was seen to have increased at 3 measurement points in Group 1 after using the mask for 4 h: subfoveal CT (CSF) (p = 0.545), CT1500 (p = 0.080), and CN1500 (p = 0.251)). In Group 2, the increase in CSF (p = 0.001) was statistically significant while the increases in CN1500 and CT1500 were not (p = 0.162 and p = 0.058, respectively) after using the mask for 4 h. CONCLUSION: We found CT to increase after 4 h of mask use, and this increase was more marked in Group 2. The increase in subfoveal CT in particular was statistically significant in Group 2.

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The novel coronavirus disease 2019 (COVID-19) is one of the biggest public health crises globally. Although Africa did not display the worst-case scenario compared to other continents, fears were still at its peak since Africa was already suffering from a heavy load of other life-threatening infectious diseases such as HIV/AIDS and malaria. Other factors that were anticipated to complicate Africa's outcomes include the lack of resources for diagnosis and contact tracing along with the low capacity of specialized management facilities per capita. The current review aims at assessing and generating discussions on the realities, and pros and cons of the WHO COVID-19 interim guidance 2020.5 considering the known peculiarities of the African continent. A comprehensive evaluation was done for COVID-19-related data published across PubMed and Google Scholar (date of the last search: August 17, 2020) with emphasis on clinical management and psychosocial aspects. Predefined filters were then applied in data screening as detailed in the methods. Specifically, we interrogated the WHO 2020.5 guideline viz-a-viz health priority and health financing in Africa, COVID-19 case contact tracing and risk assessment, clinical management of COVID-19 cases as well as strategies for tackling stigmatization and psychosocial challenges encountered by COVID-19 survivors. The outcomes of this work provide links between these vital sub-themes which may impact the containment and management of COVID-19 cases in Africa in the long-term. The chief recommendation of the current study is the necessity of prudent filtration of the global findings along with regional modelling of the global care guidelines for acting properly in response to this health threat on the regional level without exposing our populations to further unnecessary adversities.

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OBJECTIVE: To distinguish between sepsis only vs progressive lymphoma in patients with a history of lymphoma who present to the hospital with lactic acidosis. PATIENTS AND METHODS: We identified patients with non-Hodgkin lymphoma (NHL) or Hodgkin lymphoma from January 2014 to December 2015. Patients were categorized into 2 groups: sepsis only or progressive lymphoma. Two-sided Wilcoxon rank sum test and χ1/Fisher exact test were used to compare the continuous and categorical variables, respectively. Kaplan-Meier analysis was used to estimate overall survival (OS). RESULTS: A total of 51 patients were identified; 33 (65%) patients were categorized into the sepsis only group, and 18 (35%), into the progressive lymphoma group. Values for serum lactate dehydrogenase (LDH) drawn during hospitalization were statistically different between the sepsis only and progressive lymphoma groups (median, 262 vs 665 U/L; P=.005), respectively. The sensitivity and specificity of serum LDH level 2 or more times the upper limit of normal for progressive lymphoma were 56% (95% CI, 33% to 79%) and 85% (95% CI, 73% to 97%), respectively. Serum LDH level was independently predictive of inferior OS (hazard ratio, 27.8; 95% CI, 4.0 to 160.1; P<.001), while serum albumin level (hazard ratio, 0.05; 95% CI, 0.01 to 0.27; P<.001) was independently predictive of improved OS. CONCLUSION: Serum LDH levels used in conjunction with serial serum lactate values may be reliable markers to differentiate patients with progressive lymphomatous disease from patients with lymphoma with sepsis only. The LDH levels should be obtained in all patients with lymphoma who present to the hospital with lactic acidosis.

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Blood oxygen saturation (SaO2) is one of the most important environmental factors in clinical heart protection. This study used human heart samples and human induced pluripotent stem cell-cardiomyocytes (iPSC-CMs) to assess how SaO2 affects human CM cell cycle activities. The results showed that there were significantly more cell cycle markers in the moderate hypoxia group (SaO2: 75% to 85%) than in the other 2 groups (SaO2 <75% or >85%). In iPSC-CMs 15% and 10% oxygen (O2) treatment increased cell cycle markers, whereas 5% and rapid change of O2 decreased the markers. Moderate hypoxia is beneficial to the cell cycle activities of post-natal human CMs.

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QUESTION: Donor liver organs with moderate to high fat content (i.e. steatosis) suffer from an enhanced susceptibility to ischemia/reperfusion injury (IRI) during liver transplantation. Responsible for the cellular injury is an increased level of oxidative stress, however the underlying mechanistic network is still not fully understood. METHOD: We developed a phenomenological mathematical model of key processes of hepatic lipid metabolism linked to pathways of oxidative stress. The model allows the simulation of hypoxia (i.e. ischemia-like conditions) and reoxygenation (i.e. reperfusion-like conditions) for various degrees of steatosis and predicts the level of hepatic lipid peroxidation (LPO) as a marker of cell damage caused by oxidative stress. RESULTS & CONCLUSIONS: Our modeling results show that the underlying feedback loop between the formation of reactive oxygen species (ROS) and LPO leads to bistable systems behavior. Here, the first stable state corresponds to a low basal level of ROS production. The system is directed to this state for healthy, non-steatotic livers. The second stable state corresponds to a high level of oxidative stress with an enhanced formation of ROS and LPO. This state is reached, if steatotic livers with a high fat content undergo a hypoxic phase. Theoretically, our proposed mechanistic network would support the prediction of the maximal tolerable ischemia time for steatotic livers: Exceeding this limit during the transplantation process would lead to severe IRI and a considerable increased risk for liver failure.

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Nitric oxide (•NO) is a biologically important short-lived free radical signaling molecule. Both the enzymatic synthesis and the predominant forms of cellular metabolism of •NO are oxygen-dependent. For these reasons, changes in local oxygen concentrations can have a profound influence on steady-state •NO concentrations. Many proteins are regulated by •NO in a concentration-dependent manner, but their responses are elicited at different thresholds. Using soluble guanylyl cyclase (sGC) and p53 as model •NO-sensitive proteins, we demonstrate that their concentration-dependent responses to •NO are a function of the O2 concentration. p53 requires relatively high steady-state •NO concentrations (>600 nM) to induce its phosphorylation (P-ser-15), whereas sGC responds to low •NO concentrations (<100 nM). At a constant rate of •NO production (liberation from •NO-donors), decreasing the O2 concentration (1%) lowers the rate of •NO metabolism. This raises steady-state •NO concentrations and allows p53 activation at lower doses of the •NO donor. Enzymatic •NO production, however, requires O2 as a substrate such that decreasing the O2 concentration below the K m for O2 for nitric oxide synthase (NOS) will decrease the production of •NO. We demonstrate that the amount of •NO produced by RAW 264.7 macrophages is a function of the O2 concentration. Differences in rates of •NO production and •NO metabolism result in differential sGC activation that is not linear with respect to O2. There is an optimal O2 concentration (≈5-8%) where a balance between the synthesis and metabolism of •NO is established such that both the •NO concentration and sGC activation are maximal.

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