Extensive application of clustering and classification algorithms shows the potential of a CNT-based sensor array in breathomics.
Ongoing rapid arctic warming leads to extensive permafrost thaw, which in turn increases the hydrologic connectivity of the landscape by opening up subsurface flow paths. Suspended particulate organic matter (POM) has proven useful to trace permafrost thaw signals in arctic rivers, which may experience higher organic matter loads in the future due to expansion and increasing intensity of thaw processes such as thermokarst and river bank erosion. Here we focus on the Kolyma River watershed in Northeast Siberia, the world's largest watershed entirely underlain by continuous permafrost. To evaluate and characterize the present\uffe2\uff80\uff90day fluvial release of POM from permafrost thaw, we collected water samples every 4\uffe2\uff80\uff937 days during the 4\uffe2\uff80\uff90month open water season in 2013 and 2015 from the lower Kolyma River mainstem and from a small nearby headwater stream (Y3) draining an area completely underlain by Yedoma permafrost (Pleistocene ice\uffe2\uff80\uff90 and organic\uffe2\uff80\uff90rich deposits). Concentrations of particulate organic carbon generally followed the hydrograph with the highest concentrations during the spring flood in late May/early June. For the Kolyma River, concentrations of dissolved organic carbon showed a similar behavior, in contrast to the headwater stream, where dissolved organic carbon values were generally higher and particulate organic carbon concentrations lower than for Kolyma. Carbon isotope analysis (\uffce\uffb413C, \uffce\uff9414C) suggested Kolyma\uffe2\uff80\uff90POM to stem from both contemporary and older permafrost sources, while Y3\uffe2\uff80\uff90POM was more strongly influenced by in\uffe2\uff80\uff90stream production and recent vegetation. Lipid biomarker concentrations (high\uffe2\uff80\uff90molecular\uffe2\uff80\uff90weight n\uffe2\uff80\uff90alkanoic acids and n\uffe2\uff80\uff90alkanes) did not display clear seasonal patterns, yet implied Y3\uffe2\uff80\uff90POM to be more degraded than Kolyma\uffe2\uff80\uff90POM.Arctic climate warming is causing permafrost thaw and erosion, which may lead to enhanced inputs of terrestrial organic matter into Arctic Ocean shelf sediments. Degradation of terrestrial organic matter in sediments might contribute to carbon dioxide production and bottom water acidification. Yet, the degradability of organic matter in shallow Arctic Ocean sediments, as well as the contribution of terrestrial input, is poorly quantified. Here, potential organic matter degradation rates were investigated for 16 surface sediments from the Kara Sea, Laptev Sea, and the western East Siberian Sea and compared with physicochemical sediment properties including molecular biomarkers, stable and radioactive carbon isotopes, and grain size. Aerobic oxygen and carbon dioxide fluxes, measured in laboratory incubations of sediment slurry, showed high spatial variability and correlated significantly with organic carbon content as well as with the amount and degradation state of terrestrial organic matter. The dependency on terrestrial organic matter declined with increasing distance from land, indicating that the presence of terrestrial organic matter is likely a constraining factor for organic matter degradation in shallow shelf seas. However, sediment oxygen consumption rates, measured in incubations of intact sediment cores, also exhibited substantial spatial variability but were not related to organic carbon content or terrestrial influence. Oxygen consumption of intact sediments may be more strongly influenced by in situ redox conditions. Together with previous observations, our findings support that terrestrial organic matter is easily degradable in shelf sea sediments and might substantially contribute to aerobic carbon dioxide production and oxygen consumption.Erosion of permafrost coasts due to climate warming releases large quantities of organic carbon (OC) into the Arctic Ocean. While burial of permafrost OC in marine sediments potentially limits degradation, resuspension of sediments in the nearshore zone potentially enhances degradation and greenhouse gas production, adding to the \uffe2\uff80\uff9cpermafrost carbon feedback.\uffe2\uff80\uff9d Recent studies, focusing on bulk sediments, suggest that permafrost OC derived from coastal erosion is predominantly deposited close to shore. However, bulk approaches disregard sorting processes in the coastal zone, which strongly influence the OC distribution and fate. We studied soils and sediments along a transect from the fast\uffe2\uff80\uff90eroding shoreline of Herschel Island\uffe2\uff80\uff94Qikiqtaruk (Yukon, Canada) to a depositional basin offshore. Sample material was fractionated by density (1.8\uffc2\uffa0g\uffc2\uffa0cm\uffe2\uff88\uff923) and size (63\uffc2\uffa0\uffce\uffbcm), separating loose OC from mineral\uffe2\uff80\uff90associated OC. Each fraction was analyzed for element content (TOC, TN), carbon isotopes (\uffce\uffb413C, \uffce\uff9414C), molecular biomarkers (n\uffe2\uff80\uff90alkanes, n\uffe2\uff80\uff90alkanoic acids, lignin phenols, cutin acids), and mineral surface area. The OC partitioning between fractions changes considerably along the transect, highlighting the importance of hydrodynamic sorting in the nearshore zone. Additionally, OC and biomarker loadings decrease along the land\uffe2\uff80\uff90ocean transect, indicating significant loss of OC during transport. However, molecular proxies for degradation show contrasting trends, suggesting that OC losses are not always well reflected in its degradation state. This study, using fraction partitioning that crosses land\uffe2\uff80\uff90ocean boundaries in a way not done before, aids to disentangle sorting processes from degradation patterns, and provides quantitative insight into losses of thawed and eroded permafrost OC.Arctic climate warming is causing permafrost thaw and erosion, which may lead to enhanced inputs of terrestrial organic matter into Arctic Ocean shelf sediments. Degradation of terrestrial organic matter in sediments might contribute to carbon dioxide production and bottom water acidification. Yet, the degradability of organic matter in shallow Arctic Ocean sediments, as well as the contribution of terrestrial input, is poorly quantified. Here, potential organic matter degradation rates were investigated for 16 surface sediments from the Kara Sea, Laptev Sea, and the western East Siberian Sea and compared with physicochemical sediment properties including molecular biomarkers, stable and radioactive carbon isotopes, and grain size. Aerobic oxygen and carbon dioxide fluxes, measured in laboratory incubations of sediment slurry, showed high spatial variability and correlated significantly with organic carbon content as well as with the amount and degradation state of terrestrial organic matter. The dependency on terrestrial organic matter declined with increasing distance from land, indicating that the presence of terrestrial organic matter is likely a constraining factor for organic matter degradation in shallow shelf seas. However, sediment oxygen consumption rates, measured in incubations of intact sediment cores, also exhibited substantial spatial variability but were not related to organic carbon content or terrestrial influence. Oxygen consumption of intact sediments may be more strongly influenced by in situ redox conditions. Together with previous observations, our findings support that terrestrial organic matter is easily degradable in shelf sea sediments and might substantially contribute to aerobic carbon dioxide production and oxygen consumption.Subsea permafrost represents a large carbon pool that might be or become a significant greenhouse gas source. Scarcity of observational data causes large uncertainties. We here use five 21-56\uffe2\uff80\uff89m long subsea permafrost cores from the Laptev Sea to constrain organic carbon (OC) storage and sources, degradation state and potential greenhouse gas production upon thaw. Grain sizes, optically-stimulated luminescence and biomarkers suggest deposition of aeolian silt and fluvial sand over 160 000 years, with dominant fluvial/alluvial deposition of forest- and tundra-derived organic matter. We estimate an annual thaw rate of 1.3\uffe2\uff80\uff89\uffc2\uffb1\uffe2\uff80\uff890.6\uffe2\uff80\uff89kg OC m\uffe2\uff88\uff922 in subsea permafrost in the area, nine-fold exceeding organic carbon thaw rates for terrestrial permafrost. During 20-month incubations, CH4 and CO2 production averaged 1.7 nmol and 2.4 \uffc2\uffb5mol g\uffe2\uff88\uff921 OC d\uffe2\uff88\uff921, providing a baseline to assess the contribution of subsea permafrost to the high CH4 fluxes and strong ocean acidification observed in the region.Chronic inflammation, which can be modulated by diet, is linked to high white blood cell counts and correlates with higher cardiometabolic risk and risk of more severe infections, as in the case of COVID-19.
MethodsHere, we assessed the association between white blood cell profile (lymphocytes, basophils, eosinophils, neutrophils, monocytes and total white blood cells) as markers of chronic inflammation, habitual diet and gut microbiome composition (determined by sequencing of the 16S RNA) in 986 healthy individuals from the PREDICT-1 nutritional intervention study. We then investigated whether the gut microbiome mediates part of the benefits of vegetable intake on lymphocyte counts.
ResultsHigher levels of white blood cells, lymphocytes and basophils were all significantly correlated with lower habitual intake of vegetables, with vegetable intake explaining between 3.59 and 6.58% of variation in white blood cells after adjusting for covariates and multiple testing using false discovery rate (q\uffe2\uff80\uff89<\uffe2\uff80\uff890.1). No such association was seen with fruit intake. A mediation analysis found that 20.00% of the effect of vegetable intake on lymphocyte counts was mediated by one bacterial genus, Collinsella, known to increase with the intake of processed foods and previously associated with fatty liver disease. We further correlated white blood cells to other inflammatory markers including IL6 and GlycA, fasting and post-prandial glucose levels and found a significant relationship between inflammation and diet.
ConclusionA habitual diet high in vegetables, but not fruits, is linked to a lower inflammatory profile for white blood cells, and a fifth of the effect is mediated by the genus Collinsella.
Trial registrationThe ClinicalTrials.gov registration identifier is NCT03479866.
", "keywords": ["Adult", "Male", "0301 basic medicine", "610", "Leukocyte Count", "03 medical and health sciences", "RNA", " Ribosomal", " 16S", "Leukocytes", "Humans", "Lymphocyte Count", "White blood cell", " Gut microbiome", " Diet", " Vegetable intake", " Chronic inflammation", "White blood cell", "Clostridium", "2. Zero hunger", "Gut microbiome", "Clostridiales", "0303 health sciences", "Mediation Analysis", "Interleukin-6", "R", "COVID-19", "Chronic inflammation; Diet; Gut microbiome; Vegetable intake; White blood cell", "Chronic inflammation", "General Medicine", "Fasting", "Middle Aged", "Diet", "Gastrointestinal Microbiome", "3. Good health", "Actinobacteria", "Vegetable intake", "Fruit", "Medicine", "Female", "Biomarkers", "Research Article"]}, "links": [{"href": "https://air.unimi.it/bitstream/2434/1101012/2/s12916-021-01913-w.pdf"}, {"href": "https://iris.unitn.it/bitstream/11572/329112/1/s12916-021-01913-w.pdf"}, {"href": "http://link.springer.com/content/pdf/10.1186/s12916-021-01913-w.pdf"}, {"href": "https://doi.org/10.1186/s12916-021-01913-w"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/BMC%20Medicine", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1186/s12916-021-01913-w", "name": "item", "description": "10.1186/s12916-021-01913-w", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1186/s12916-021-01913-w"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2021-02-11T00:00:00Z"}}, {"id": "10.1039/d1ra03337a", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-28T16:17:51Z", "type": "Journal Article", "created": "2021-09-10", "title": "Exploring the performance of a functionalized CNT-based sensor array for breathomics through clustering and classification algorithms: from gas sensing of selective biomarkers to discrimination of chronic obstructive pulmonary disease", "description": "Extensive application of clustering and classification algorithms shows the potential of a CNT-based sensor array in breathomics.
Fungal metabolic carbon acquisition and its subsequent partitioning between biomass production and respiration, i.e. the carbon-use efficiency (CUE), are central parameters in biogeochemical modeling. However, current available techniques for estimating these parameters are all associated with practical and theoretical shortcomings, making assessments unreliable. Gene expression analyses hold the prospect of phenotype prediction by indirect means, providing new opportunities to obtain information about metabolic priorities. We cultured four different fungal isolates (Chalara longipes, Laccaria bicolor, Serpula lacrymans and Trichoderma harzianum) in liquid media with contrasting nitrogen availability and measured growth rates and respiration to calculate CUE. By relating gene expression markers to measured carbon fluxes, we identified genes coding for 1,3-\uffce\uffb2-glucan synthase and 2-oxoglutarate dehydrogenase as suitable markers for growth and respiration, respectively, capturing both intraspecific variation as well as within-strain variation dependent on growth medium. A transcript index based on these markers correlated significantly with differences in CUE between the fungal isolates. Our study paves the way for the use of these markers to assess differences in growth, respiration and CUE in natural fungal communities, using metatranscriptomic or the RT-qPCR approach. Diagnosis of neurodegenerative disorders (NDDs) including Parkinson\u2019s disease and Alzheimer\u2019s disease is challenging owing to the lack of tools to detect preclinical biomarkers. The misfolding of proteins into oligomeric and fibrillar aggregates plays an important role in the development and progression of NDDs, thus underscoring the need for structural biomarker\u2013based diagnostics. We developed an immunoassay-coupled nanoplasmonic infrared metasurface sensor that detects proteins linked to NDDs, such as alpha-synuclein, with specificity and differentiates the distinct structural species using their unique absorption signatures. We augmented the sensor with an artificial neural network enabling unprecedented quantitative prediction of oligomeric and fibrillar protein aggregates in their mixture. The microfluidic integrated sensor can retrieve time-resolved absorbance fingerprints in the presence of a complex biomatrix and is capable of multiplexing for the simultaneous monitoring of multiple pathology-associated biomarkers. Thus, our sensor is a promising candidate for the clinical diagnosis of NDDs, disease monitoring, and evaluation of novel therapies.
Warming air and sea temperatures, longer open-water seasons and sea-level rise collectively promote the erosion of permafrost coasts in the Arctic, which profoundly impacts organic matter pathways. Although estimates on organic carbon (OC) fluxes from erosion exist for some parts of the Arctic, little is known about how much OC is transformed into greenhouse gases (GHGs). In this study we investigated two different coastal erosion scenarios on Qikiqtaruk \uffe2\uff80\uff93 Herschel Island (Canada) and estimate the potential for GHG formation. We distinguished between adelayedrelease represented bymud debrisdraining a coastal thermoerosional feature and adirectrelease represented bycliff debrisat a low collapsing bluff. Carbon dioxide (CO2) production was measured during incubations at 4\uffc2\uffb0C under aerobic conditions for two months and were modeled for four months and a full year. Our incubation results show thatmud debrisandcliff debrislost a considerable amount of OC as CO2(2.5 \uffc2\uffb1 0.2 and 1.6 \uffc2\uffb1 0.3% of OC, respectively). Although relative OC losses were highest in mineralmud debris, higher initial OC content and fresh organic matter incliff debrisresulted in a \uffe2\uff88\uffbcthree times higher cumulative CO2release (4.0 \uffc2\uffb1 0.9 compared to 1.4 \uffc2\uffb1 0.1 mg CO2gdw\uffe2\uff80\uff931), which was further increased by the addition of seawater. After four months, modeled OC losses were 4.9 \uffc2\uffb1 0.1 and 3.2 \uffc2\uffb1 0.3% in set-ups without seawater and 14.3 \uffc2\uffb1 0.1 and 7.3 \uffc2\uffb1 0.8% in set-ups with seawater. The results indicate that adelayedrelease may support substantial cycling of OC at relatively low CO2production rates during long transit timesonshoreduring the Arctic warm season. By contrast,directerosion may result in a single CO2pulse and less substantial OC cyclingonshoreas transfer times are short. Once eroded sediments are deposited in thenearshore, highest OC losses can be expected. We conclude that the release of CO2from eroding permafrost coasts varies considerably between erosion types and residence timeonshore. We emphasize the importance of a more comprehensive understanding of OC degradation during the coastal erosion process to improve thawed carbon trajectories and models. Permafrost soils, which store almost half of the global belowground organic carbon (OC), are susceptible to thaw upon climate warming. On the Peel Plateau of northwestern Canada, the number and size of retrogressive thaw slumps (RTS) has increased in recent decades due to rising temperatures and higher precipitation. These RTS features caused by the rapid thaw of ice-rich permafrost release organic matter dominantly as particulate organic carbon (POC) to the stream network. In this study, we sampled POC and streambank sediments along a fluvial transect (\u223c12 km) downstream from two RTS features and assessed the composition and degradation status of the mobilized permafrost OC. We found that RTS features add old, Pleistocene-aged permafrost POC to the stream system that is traceable kilometers downstream. The POC released consists mainly of recalcitrant compounds that persists within stream networks, whereas labile compounds originate from the active layer and appear to largely degrade within the scar zone of the RTS feature. Thermokarst on the Peel Plateau is likely to intensify in the future, but our data suggest that most of the permafrost OC released is not readily degradable within the stream system and thus may have little potential for atmospheric evasion. Possibilities for the recalcitrant OC to degrade over decadal to millennial time scales while being transported via larger river networks, and within the marine environment, do however, still exist. These findings add to our understanding of the vulnerable Arctic landscapes and how they may interact with the global climate. A novel photochemical technological route for one-step functionalization of a graphene surface with an azide-modified DNA aptamer for biomarkers is developed. The methodology is demonstrated for the functionalization of a DNA aptamer for an N-terminal B-type natriuretic peptide (NT-proBNP) heart failure biomarker on the surface of a graphene channel within a system based on a liquid-gated graphene field effect transistor (GFET). The limit of detection (LOD) of the aptamer-functionalized sensor is 0.01 pg/mL with short response time (75 s) for clinically relevant concentrations of the cardiac biomarker, which could be of relevance for point-of-care (POC) applications. The novel methodology could be applicable for the development of different graphene-based biosensors for fast, stable, real-time, and highly sensitive detection of disease markers. Graphene-based materials are actively being investigated as sensing elements for the detection of different analytes. Both graphene grown by chemical vapor deposition (CVD) and graphene oxide (GO) produced by the modified Hummers\u2019 method are actively used in the development of biosensors. The production costs of CVD graphene- and GO-based sensors are similar; however, the question remains regarding the most efficient graphene-based material for the construction of point-of-care diagnostic devices. To this end, in this work, we compare CVD graphene aptasensors with the aptasensors based on reduced GO (rGO) for their capabilities in the detection of NT-proBNP, which serves as the gold standard biomarker for heart failure. Both types of aptasensors were developed using commercial gold interdigitated electrodes (IDEs) with either CVD graphene or GO formed on top as a channel of liquid-gated field-effect transistor (FET), yielding GFET and rGO-FET sensors, respectively. The functional properties of the two types of aptasensors were compared. Both demonstrate good dynamic range from 10 fg/mL to 100 pg/mL. The limit of detection for NT-proBNP in artificial saliva was 100 fg/mL and 1 pg/mL for rGO-FET- and GFET-based aptasensors, respectively. While CVD GFET demonstrates less variations in parameters, higher sensitivity was demonstrated by the rGO-FET due to its higher roughness and larger bandgap. The demonstrated low cost and scalability of technology for both types of graphene-based aptasensors may be applicable for the development of different graphene-based biosensors for rapid, stable, on-site, and highly sensitive detection of diverse biochemical markers. Mesoporous silica nanoparticles (MSNs) exhibit highly beneficial characteristics for devising efficient biosensors for different analytes. Their unique properties, such as capabilities for stable covalent binding to recognition groups (e.g., antibodies or aptamers) and sensing surfaces, open a plethora of opportunities for biosensor construction. In addition, their structured porosity offers capabilities for entrapping signaling molecules (dyes or electroactive species), which could be released efficiently in response to a desired analyte for effective optical or electrochemical detection. This work offers an overview of recent research studies (in the last five years) that contain MSNs in their optical and electrochemical sensing platforms for the detection of cancer biomarkers, classified by cancer type. In addition, this study provides an overview of cancer biomarkers, as well as electrochemical and optical detection methods in general.
Ongoing rapid arctic warming leads to extensive permafrost thaw, which in turn increases the hydrologic connectivity of the landscape by opening up subsurface flow paths. Suspended particulate organic matter (POM) has proven useful to trace permafrost thaw signals in arctic rivers, which may experience higher organic matter loads in the future due to expansion and increasing intensity of thaw processes such as thermokarst and river bank erosion. Here we focus on the Kolyma River watershed in Northeast Siberia, the world's largest watershed entirely underlain by continuous permafrost. To evaluate and characterize the present\uffe2\uff80\uff90day fluvial release of POM from permafrost thaw, we collected water samples every 4\uffe2\uff80\uff937 days during the 4\uffe2\uff80\uff90month open water season in 2013 and 2015 from the lower Kolyma River mainstem and from a small nearby headwater stream (Y3) draining an area completely underlain by Yedoma permafrost (Pleistocene ice\uffe2\uff80\uff90 and organic\uffe2\uff80\uff90rich deposits). Concentrations of particulate organic carbon generally followed the hydrograph with the highest concentrations during the spring flood in late May/early June. For the Kolyma River, concentrations of dissolved organic carbon showed a similar behavior, in contrast to the headwater stream, where dissolved organic carbon values were generally higher and particulate organic carbon concentrations lower than for Kolyma. Carbon isotope analysis (\uffce\uffb413C, \uffce\uff9414C) suggested Kolyma\uffe2\uff80\uff90POM to stem from both contemporary and older permafrost sources, while Y3\uffe2\uff80\uff90POM was more strongly influenced by in\uffe2\uff80\uff90stream production and recent vegetation. Lipid biomarker concentrations (high\uffe2\uff80\uff90molecular\uffe2\uff80\uff90weight n\uffe2\uff80\uff90alkanoic acids and n\uffe2\uff80\uff90alkanes) did not display clear seasonal patterns, yet implied Y3\uffe2\uff80\uff90POM to be more degraded than Kolyma\uffe2\uff80\uff90POM. Extensive application of clustering and classification algorithms shows the potential of a CNT-based sensor array in breathomics.
Warming air and sea temperatures, longer open-water seasons and sea-level rise collectively promote the erosion of permafrost coasts in the Arctic, which profoundly impacts organic matter pathways. Although estimates on organic carbon (OC) fluxes from erosion exist for some parts of the Arctic, little is known about how much OC is transformed into greenhouse gases (GHGs). In this study we investigated two different coastal erosion scenarios on Qikiqtaruk \uffe2\uff80\uff93 Herschel Island (Canada) and estimate the potential for GHG formation. We distinguished between adelayedrelease represented bymud debrisdraining a coastal thermoerosional feature and adirectrelease represented bycliff debrisat a low collapsing bluff. Carbon dioxide (CO2) production was measured during incubations at 4\uffc2\uffb0C under aerobic conditions for two months and were modeled for four months and a full year. Our incubation results show thatmud debrisandcliff debrislost a considerable amount of OC as CO2(2.5 \uffc2\uffb1 0.2 and 1.6 \uffc2\uffb1 0.3% of OC, respectively). Although relative OC losses were highest in mineralmud debris, higher initial OC content and fresh organic matter incliff debrisresulted in a \uffe2\uff88\uffbcthree times higher cumulative CO2release (4.0 \uffc2\uffb1 0.9 compared to 1.4 \uffc2\uffb1 0.1 mg CO2gdw\uffe2\uff80\uff931), which was further increased by the addition of seawater. After four months, modeled OC losses were 4.9 \uffc2\uffb1 0.1 and 3.2 \uffc2\uffb1 0.3% in set-ups without seawater and 14.3 \uffc2\uffb1 0.1 and 7.3 \uffc2\uffb1 0.8% in set-ups with seawater. The results indicate that adelayedrelease may support substantial cycling of OC at relatively low CO2production rates during long transit timesonshoreduring the Arctic warm season. By contrast,directerosion may result in a single CO2pulse and less substantial OC cyclingonshoreas transfer times are short. Once eroded sediments are deposited in thenearshore, highest OC losses can be expected. We conclude that the release of CO2from eroding permafrost coasts varies considerably between erosion types and residence timeonshore. We emphasize the importance of a more comprehensive understanding of OC degradation during the coastal erosion process to improve thawed carbon trajectories and models. Permafrost soils, which store almost half of the global belowground organic carbon (OC), are susceptible to thaw upon climate warming. On the Peel Plateau of northwestern Canada, the number and size of retrogressive thaw slumps (RTS) has increased in recent decades due to rising temperatures and higher precipitation. These RTS features caused by the rapid thaw of ice-rich permafrost release organic matter dominantly as particulate organic carbon (POC) to the stream network. In this study, we sampled POC and streambank sediments along a fluvial transect (\u223c12 km) downstream from two RTS features and assessed the composition and degradation status of the mobilized permafrost OC. We found that RTS features add old, Pleistocene-aged permafrost POC to the stream system that is traceable kilometers downstream. The POC released consists mainly of recalcitrant compounds that persists within stream networks, whereas labile compounds originate from the active layer and appear to largely degrade within the scar zone of the RTS feature. Thermokarst on the Peel Plateau is likely to intensify in the future, but our data suggest that most of the permafrost OC released is not readily degradable within the stream system and thus may have little potential for atmospheric evasion. Possibilities for the recalcitrant OC to degrade over decadal to millennial time scales while being transported via larger river networks, and within the marine environment, do however, still exist. These findings add to our understanding of the vulnerable Arctic landscapes and how they may interact with the global climate.
Erosion of permafrost coasts due to climate warming releases large quantities of organic carbon (OC) into the Arctic Ocean. While burial of permafrost OC in marine sediments potentially limits degradation, resuspension of sediments in the nearshore zone potentially enhances degradation and greenhouse gas production, adding to the \uffe2\uff80\uff9cpermafrost carbon feedback.\uffe2\uff80\uff9d Recent studies, focusing on bulk sediments, suggest that permafrost OC derived from coastal erosion is predominantly deposited close to shore. However, bulk approaches disregard sorting processes in the coastal zone, which strongly influence the OC distribution and fate. We studied soils and sediments along a transect from the fast\uffe2\uff80\uff90eroding shoreline of Herschel Island\uffe2\uff80\uff94Qikiqtaruk (Yukon, Canada) to a depositional basin offshore. Sample material was fractionated by density (1.8\uffc2\uffa0g\uffc2\uffa0cm\uffe2\uff88\uff923) and size (63\uffc2\uffa0\uffce\uffbcm), separating loose OC from mineral\uffe2\uff80\uff90associated OC. Each fraction was analyzed for element content (TOC, TN), carbon isotopes (\uffce\uffb413C, \uffce\uff9414C), molecular biomarkers (n\uffe2\uff80\uff90alkanes, n\uffe2\uff80\uff90alkanoic acids, lignin phenols, cutin acids), and mineral surface area. The OC partitioning between fractions changes considerably along the transect, highlighting the importance of hydrodynamic sorting in the nearshore zone. Additionally, OC and biomarker loadings decrease along the land\uffe2\uff80\uff90ocean transect, indicating significant loss of OC during transport. However, molecular proxies for degradation show contrasting trends, suggesting that OC losses are not always well reflected in its degradation state. This study, using fraction partitioning that crosses land\uffe2\uff80\uff90ocean boundaries in a way not done before, aids to disentangle sorting processes from degradation patterns, and provides quantitative insight into losses of thawed and eroded permafrost OC.Subsea permafrost represents a large carbon pool that might be or become a significant greenhouse gas source. Scarcity of observational data causes large uncertainties. We here use five 21-56\uffe2\uff80\uff89m long subsea permafrost cores from the Laptev Sea to constrain organic carbon (OC) storage and sources, degradation state and potential greenhouse gas production upon thaw. Grain sizes, optically-stimulated luminescence and biomarkers suggest deposition of aeolian silt and fluvial sand over 160 000 years, with dominant fluvial/alluvial deposition of forest- and tundra-derived organic matter. We estimate an annual thaw rate of 1.3\uffe2\uff80\uff89\uffc2\uffb1\uffe2\uff80\uff890.6\uffe2\uff80\uff89kg OC m\uffe2\uff88\uff922 in subsea permafrost in the area, nine-fold exceeding organic carbon thaw rates for terrestrial permafrost. During 20-month incubations, CH4 and CO2 production averaged 1.7 nmol and 2.4 \uffc2\uffb5mol g\uffe2\uff88\uff921 OC d\uffe2\uff88\uff921, providing a baseline to assess the contribution of subsea permafrost to the high CH4 fluxes and strong ocean acidification observed in the region.Fungal metabolic carbon acquisition and its subsequent partitioning between biomass production and respiration, i.e. the carbon-use efficiency (CUE), are central parameters in biogeochemical modeling. However, current available techniques for estimating these parameters are all associated with practical and theoretical shortcomings, making assessments unreliable. Gene expression analyses hold the prospect of phenotype prediction by indirect means, providing new opportunities to obtain information about metabolic priorities. We cultured four different fungal isolates (Chalara longipes, Laccaria bicolor, Serpula lacrymans and Trichoderma harzianum) in liquid media with contrasting nitrogen availability and measured growth rates and respiration to calculate CUE. By relating gene expression markers to measured carbon fluxes, we identified genes coding for 1,3-\uffce\uffb2-glucan synthase and 2-oxoglutarate dehydrogenase as suitable markers for growth and respiration, respectively, capturing both intraspecific variation as well as within-strain variation dependent on growth medium. A transcript index based on these markers correlated significantly with differences in CUE between the fungal isolates. Our study paves the way for the use of these markers to assess differences in growth, respiration and CUE in natural fungal communities, using metatranscriptomic or the RT-qPCR approach. Diagnosis of neurodegenerative disorders (NDDs) including Parkinson\u2019s disease and Alzheimer\u2019s disease is challenging owing to the lack of tools to detect preclinical biomarkers. The misfolding of proteins into oligomeric and fibrillar aggregates plays an important role in the development and progression of NDDs, thus underscoring the need for structural biomarker\u2013based diagnostics. We developed an immunoassay-coupled nanoplasmonic infrared metasurface sensor that detects proteins linked to NDDs, such as alpha-synuclein, with specificity and differentiates the distinct structural species using their unique absorption signatures. We augmented the sensor with an artificial neural network enabling unprecedented quantitative prediction of oligomeric and fibrillar protein aggregates in their mixture. The microfluidic integrated sensor can retrieve time-resolved absorbance fingerprints in the presence of a complex biomatrix and is capable of multiplexing for the simultaneous monitoring of multiple pathology-associated biomarkers. Thus, our sensor is a promising candidate for the clinical diagnosis of NDDs, disease monitoring, and evaluation of novel therapies. Graphene-based materials are actively being investigated as sensing elements for the detection of different analytes. Both graphene grown by chemical vapor deposition (CVD) and graphene oxide (GO) produced by the modified Hummers\u2019 method are actively used in the development of biosensors. The production costs of CVD graphene- and GO-based sensors are similar; however, the question remains regarding the most efficient graphene-based material for the construction of point-of-care diagnostic devices. To this end, in this work, we compare CVD graphene aptasensors with the aptasensors based on reduced GO (rGO) for their capabilities in the detection of NT-proBNP, which serves as the gold standard biomarker for heart failure. Both types of aptasensors were developed using commercial gold interdigitated electrodes (IDEs) with either CVD graphene or GO formed on top as a channel of liquid-gated field-effect transistor (FET), yielding GFET and rGO-FET sensors, respectively. The functional properties of the two types of aptasensors were compared. Both demonstrate good dynamic range from 10 fg/mL to 100 pg/mL. The limit of detection for NT-proBNP in artificial saliva was 100 fg/mL and 1 pg/mL for rGO-FET- and GFET-based aptasensors, respectively. While CVD GFET demonstrates less variations in parameters, higher sensitivity was demonstrated by the rGO-FET due to its higher roughness and larger bandgap. The demonstrated low cost and scalability of technology for both types of graphene-based aptasensors may be applicable for the development of different graphene-based biosensors for rapid, stable, on-site, and highly sensitive detection of diverse biochemical markers. Mesoporous silica nanoparticles (MSNs) exhibit highly beneficial characteristics for devising efficient biosensors for different analytes. Their unique properties, such as capabilities for stable covalent binding to recognition groups (e.g., antibodies or aptamers) and sensing surfaces, open a plethora of opportunities for biosensor construction. In addition, their structured porosity offers capabilities for entrapping signaling molecules (dyes or electroactive species), which could be released efficiently in response to a desired analyte for effective optical or electrochemical detection. This work offers an overview of recent research studies (in the last five years) that contain MSNs in their optical and electrochemical sensing platforms for the detection of cancer biomarkers, classified by cancer type. In addition, this study provides an overview of cancer biomarkers, as well as electrochemical and optical detection methods in general.
Abstract.\uffe2\uff80\uff82 Objectives: Previously, we characterized human islet\uffe2\uff80\uff90derived precursor cells (hIPCs) as mesenchymal stem cells that migrate out from islets in vitro and can differentiate into functional islet\uffe2\uff80\uff90like structures following proliferative expansion. Here, we investigate the role of \uffce\uffb2\uffe2\uff80\uff90catenin signalling in derivation and proliferation of hIPCs. Materials and methods: Localization of \uffce\uffb2\uffe2\uff80\uff90catenin was performed using confocal microscopy. Expression levels of \uffce\uffb2\uffe2\uff80\uff90catenin target genes were measured by quantitative real\uffe2\uff80\uff90time polymerase chain reaction. Loss\uffe2\uff80\uff90of\uffe2\uff80\uff90function studies were performed using specific short interfering RNAs. Results: Immunostaining of islet outgrowths revealed translocation of \uffce\uffb2\uffe2\uff80\uff90catenin from plasma membranes in intact islets to the nucleus in cells migrating out. There were no nuclear \uffce\uffb2\uffe2\uff80\uff90catenin\uffe2\uff80\uff90positive cells in intact islets whereas between 35% and 70% of cells in established hIPC cultures exhibited nuclear \uffce\uffb2\uffe2\uff80\uff90catenin. Transcripts for \uffce\uffb2\uffe2\uff80\uff90catenin target genes were increased in hIPCs compared to those in islets. \uffce\uffb2\uffe2\uff80\uff90Catenin translocated to the cell membrane when hIPCs formed epithelial cell clusters. In proliferating hIPCs, there was a strong correlation between markers of proliferation and nuclear \uffce\uffb2\uffe2\uff80\uff90catenin. Treatment of hIPCs with the glycogen synthase kinase\uffe2\uff80\uff903\uffce\uffb2 inhibitor (2\uffe2\uff80\uffb2Z,3\uffe2\uff80\uffb2E)\uffe2\uff80\uff906\uffe2\uff80\uff90Bromoindirubin\uffe2\uff80\uff903\uffe2\uff80\uffb2\uffe2\uff80\uff90oxime increased intracellular \uffce\uffb2\uffe2\uff80\uff90catenin but reduced nuclear \uffce\uffb2\uffe2\uff80\uff90catenin, and was associated with reduced cell proliferation. Finally, knockdown of \uffce\uffb2\uffe2\uff80\uff90catenin decreased \uffce\uffb2\uffe2\uff80\uff90catenin target gene expression and hIPC proliferation. Conclusions: These results support a functional role for \uffce\uffb2\uffe2\uff80\uff90catenin during proliferation of hIPCs and suggest that activated \uffce\uffb2\uffe2\uff80\uff90catenin signalling may also be important during hIPC derivation from islets.Fungal metabolic carbon acquisition and its subsequent partitioning between biomass production and respiration, i.e. the carbon-use efficiency (CUE), are central parameters in biogeochemical modeling. However, current available techniques for estimating these parameters are all associated with practical and theoretical shortcomings, making assessments unreliable. Gene expression analyses hold the prospect of phenotype prediction by indirect means, providing new opportunities to obtain information about metabolic priorities. We cultured four different fungal isolates (Chalara longipes, Laccaria bicolor, Serpula lacrymans and Trichoderma harzianum) in liquid media with contrasting nitrogen availability and measured growth rates and respiration to calculate CUE. By relating gene expression markers to measured carbon fluxes, we identified genes coding for 1,3-\uffce\uffb2-glucan synthase and 2-oxoglutarate dehydrogenase as suitable markers for growth and respiration, respectively, capturing both intraspecific variation as well as within-strain variation dependent on growth medium. A transcript index based on these markers correlated significantly with differences in CUE between the fungal isolates. Our study paves the way for the use of these markers to assess differences in growth, respiration and CUE in natural fungal communities, using metatranscriptomic or the RT-qPCR approach. A novel photochemical technological route for one-step functionalization of a graphene surface with an azide-modified DNA aptamer for biomarkers is developed. The methodology is demonstrated for the functionalization of a DNA aptamer for an N-terminal B-type natriuretic peptide (NT-proBNP) heart failure biomarker on the surface of a graphene channel within a system based on a liquid-gated graphene field effect transistor (GFET). The limit of detection (LOD) of the aptamer-functionalized sensor is 0.01 pg/mL with short response time (75 s) for clinically relevant concentrations of the cardiac biomarker, which could be of relevance for point-of-care (POC) applications. The novel methodology could be applicable for the development of different graphene-based biosensors for fast, stable, real-time, and highly sensitive detection of disease markers.