Aerobic fitness as a moderator of acute aerobic exercise effects on executive function.

This study aimed to investigate the moderating role of aerobic fitness on the effect of acute exercise on improving executive function from both behavioral and cerebral aspects. Thirty-four young individuals with motor skills were divided into high- and low-fitness groups based on their maximal oxygen uptake. Both groups completed 30 min of moderate-intensity aerobic exercise on a power bike. Executive function tests (Flanker, N-back, More-odd-shifting) were performed before and after exercise and functional near-infrared spectroscopy was used to monitor prefrontal cerebral blood flow changes during the tasks. The results indicated significant differences between the two groups regarding executive function. Participants with lower aerobic fitness performed better than their higher fitness counterparts in inhibitory control and working memory, but not in cognitive flexibility. This finding suggests that the aerobic fitness may moderate the extent of cognitive benefits gained from acute aerobic exercise. Furthermore, the neuroimaging data indicated negative activation in the frontopolar area and dorsolateral prefrontal cortex in response to three complex tasks. These findings underscore the importance of considering individual aerobic fitness when assessing the cognitive benefits of exercise and could have significant implications for tailoring fitness programs to enhance cognitive performance.

Legacy and emerging persistent organic pollutants in the marginal seas of China: Occurrence and phase partitioning.

Emerging per-and polyfluoroalkyl substances (PFASs) and traditional organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs) in the marginal seas of China were analyzed to study the occurrence, transport and phase partitioning. The influence of organic carbon (OC) and element carbon (EC) on particulate emerging pollutants in seawater was studied for the first time. The concentrations of PFASs, OCPs and PAHs in the seawater (dissolved phase plus particulate phase) ranged from 1.4 to 8.6, 0.76 to 4.3 and 8.4 to 130 ng L-1, respectively. Pollutants in the northern East China Sea were generally higher than that in the southern East China Sea and South China Sea, which may be attribute to river discharges and land sources in the Yangtze River Delta. The Yellow Sea Coastal Current and Yangtze River Dilute Water drove the transport of contaminants from north to south marginal seas. Positive correlations between EC and PAHs were found, which can be explained by co-emission of them during combustion. Moreover, positive correlations between OC, EC and Log Kd for BkF, BeP, HCB, 6:2 FTSA were found, which demonstrated that OC and EC promoted the partitioning of these high oleophilic compounds to suspended particle.

Compound-specific radiocarbon reveals sources and land-sea transport of polycyclic aromatic hydrocarbons in an urban estuary.

As typical chemical indicators of the Anthropocene, polycyclic aromatic hydrocarbons (PAHs) and their environmental behavior in urban estuaries can reveal the influence of anthropogenic activities on coastal zones worldwide. In contrast to conventional approaches based on concentration datasets, we provide a compound-specific radiocarbon (14C) perspective to quantitatively evaluate the sources and land‒sea transport of PAHs in an estuarine‒coastal surficial sedimentary system impacted by anthropogenic activities and coastal currents. Compound-specific 14C of PAHs and their 14C end-member mixing models showed that 67-73% of fluoranthene and pyrene and 76-80% of five- and six-ring PAHs in the Jiulong River Estuary (JRE, China) originated from fossil fuels (e.g., coal, oil spill, and petroleum-related emissions). In the adjacent Western Taiwan Strait (WTS), the contributions of fossil fuel to these PAH groups were higher at 74-79% and 84-87%, respectively. Furthermore, as a significant biomarker for source allocation of terrigenous organic matter, perylene, a typical five-ring PAH, and its land‒sea transport from the basin through the JRE and finally to the WTS was quantitatively evaluated based on the 14C transport models. In the JRE, fluvial erosions and anthropogenic emissions affected the 14C signature of perylene (Δ14Cperylene, -535 ± 5‰) with contributions of > 38% and < 62%, respectively. From the JRE to the WTS, the decreased Δ14Cperylene (-735 ± 4‰) could be attributed to the long‒range transport of "ocean current-driven" perylene (-919 ± 53‰) with a contribution of 53 ± 8%. This compound-specific 14C approach and PAH transport model help provide a valuable reference for accurately quantifying land‒sea transport and burial of organic pollutants in estuarine‒coastal sedimentary systems.

Genetic labeling of extracellular vesicles for studying biogenesis and uptake in living mammalian cells.

Molecular imaging methods are powerful tools for gaining insight into the cellular organization of living cells. To understand the biogenesis and uptake of extracellular vesicles (EVs) as well as to engineer cell-derived vesicles for targeted drug delivery and therapy, genetic labeling with fluorescent proteins has increasingly been used to determine the structures, locations, and dynamics of EVs in vitro and in vivo. Here, we report a genetic method for the stable labeling of EVs to study their biogenesis and uptake in living human cells. Fusing a green fluorescent protein (GFP) with either the endogenous CD63 (CD63-GFP) or a vesicular stomatitis virus envelope glycoprotein, VSVG (VSVG-GFP), we successfully obtained distinct fluorescence signals in the cytoplasm, revealing the biogenesis of EVs in post-transfected cells. We describe experimental procedures in detail for EV isolation, imaging, and cellular uptake using both confocal microscopy and flow cytometry. We also provide a perspective on how genetic labeling methods can be used to study EV biology, characterization of engineered EVs, and development of EV-based nano-medicine.

Spatial-temporal distribution and transport flux of polycyclic aromatic hydrocarbons in a large hydropower reservoir of Southeast China: Implication for impoundment impacts.

In order to investigate the impacts of dam-related water impoundment on the spatial-temporal variations and transport of anthropogenic organic pollutants, 15 priority polycyclic aromatic hydrocarbons (PAHs) were analyzed in water samples from the Shuikou Reservoir (SKR) of the Minjiang River. The SKR was formed after the construction of the Shuikou Dam, which is the largest hydropower station in Southeast China. The water samples were collected from the backwater zone of the SKR, in both the wet and dry seasons, corresponding to the drainage and impoundment periods of water flow, respectively. The concentrations of the dissolved PAHs in surface water from the wet season (average of 161 ±â€¯97 ng L-1) were significantly higher (ANOVA, p < 0.01) than those from the dry season (average of 43 ±â€¯21 ng L-1). PAH concentrations in the SKR decreased from upstream (industrialized cities) to downstream (rural towns or counties), indicating high PAH loads caused by intensive urbanization effects. The high proportions of 3-ring PAHs in the wet season were from local sources via surface runoff; while the elevated proportions of 4- to 6- ring PAHs in the dry season reflected atmospheric deposition emerged of these PAHs and/or volatilization of 3-ring PAHs enhanced. Molecular diagnostic ratios of PAH isomers in multimedium and principal component analysis indicated that PAH presence in the SKR was mainly attributed to pyrogenic origin. The isomeric ratios of fluoranthene to fluoranthene plus pyrene in the wet season were homogeneous, implying that there were continuous new inputs along the riverine runoff. However, these ratios showed spatial downward trend in the dry season, indicating continued degradation of PAHs occurred along the transport path during the impoundment period. The input and output fluxes of PAHs in the SKR were 5330 kg yr-1 and 2991 kg yr-1, revealing that the reservoir retained contaminants after impoundment of the hydropower dam.

Finite-element analysis of the proximal tibial sclerotic bone and different alignment in total knee arthroplasty.

BACKGROUND: Despite potential for improving patient outcomes, studies using three-dimensional measurements to quantify proximal tibial sclerotic bone and its effects on prosthesis stability after total knee arthroplasty (TKA) are lacking. Therefore, this study aimed to determine: (1) the distribution range of tibial sclerotic bone in patients with severe genu varum using three-dimensional measurements, (2) the effect of the proximal tibial sclerotic bone thickness on prosthesis stability according to finite-element modelling of TKA with kinematic alignment (KA), mechanical alignment (MA), and 3° valgus alignment, and (3) the effect of short extension stem augment utilization on prosthesis stability. METHODS: The sclerotic bone in the medial tibial plateau of 116 patients with severe genu varum was measured and classified according to its position and thickness. Based on these cases, finite-element models were established to simulate 3 different tibial cut alignments with 4 different thicknesses of the sclerotic bone to measure the stress distribution of the tibia and tibial prosthesis, the relative micromotion beneath the stem, and the influence of the short extension stem on stability. RESULTS: The distribution range of proximal tibial sclerotic bone was at the anteromedial tibial plateau. The models were divided into four types according to the thickness of the sclerotic bone: 15 mm, 10 mm, 5 mm, and 0 mm. The relative micromotion under maximum stress was smallest after MA with no sclerotic bone (3241 µm) and largest after KA with 15 mm sclerotic bone (4467 µm). Relative micromotion was largest with KA and smallest with MA in sclerotic models with the same thickness. Relative micromotion increased as thickness of the sclerotic bone increased with KA and MA (R = 0.937, P = 0.03 and R = 0.756, P = 0.07, respectively). Relative micromotion decreased with short extension stem augment in the KA model when there was proximal tibial sclerotic bone. CONCLUSIONS: The influence of proximal tibial sclerotic bone on prosthesis's stability is significant, especially with KA tibial cut. Tibial component's short extension stem augment can improve stability.

Distribution and isotopic composition of sedimentary black carbon in a subtropical estuarine-coastal region of the western Taiwan Strait: Implications for tracing anthropogenic inputs.

Estuarine and coastal margins are strongly influenced by anthropogenic inputs. To trace anthropogenic inputs to the subtropical Jiulong River Estuary (JRE) and the adjacent western Taiwan Strait (WTS), black carbon (BC) and its stable carbon isotope composition (δ13СBC) in surface sediments were investigated as an indicator of human activities. The concentrations of sedimentary BC were measured by an emerging method of thermal/optical reflectance with wet-chemical treatment (BCTOR, including char and soot), and the conventional method of chemothermal oxidation (BCCTO, related to the soot fraction) was also used to determine BCCTO concentrations and δ13СBC compositions. In the JRE and adjacent WTS, the concentrations of BCTOR (0.77 to 3.79 mg g-1) were higher than those of BCCTO (0.55 to 2.46 mg g-1), and both were similar to the moderate ranges obtained in other coastal sediments around the world. The small offsets between δ13СTOC and δ13СBC and the relatively low char/soot ratios revealed that fossil fuel combustion-derived contributions were likely more significant compared with inputs from biomass burning. The decreasing BC concentrations and increasing δ13СBC values with increasing distance from the JRE towards the adjacent WTS, indicates the decline of land-based anthropogenic inputs through fluvial transport. Furthermore, the differences in BC/TOC and char/soot values between the southern and northern WTS, indicated an effective preferential dispersal of the fluvial BC to the southern coast. The estimation for mass inventories of sedimentary BC in the coastal WTS showed that direct riverine discharge from the JRE was nearly equivalent to atmospheric deposition, and both of them contributed half of the sedimentary BC sink. To balance the sedimentary BC budget in the coastal WTS, long-range alongshore sediment transport driven by the Fujian-Zhejiang coastal current containing Yangtze River derived materials (indirect riverine discharge) could be another significant input pathway to contribute sedimentary BC.

HuMiTar: a sequence-based method for prediction of human microRNA targets.

BACKGROUND: MicroRNAs (miRs) are small noncoding RNAs that bind to complementary/partially complementary sites in the 3' untranslated regions of target genes to regulate protein production of the target transcript and to induce mRNA degradation or mRNA cleavage. The ability to perform accurate, high-throughput identification of physiologically active miR targets would enable functional characterization of individual miRs. Current target prediction methods include traditional approaches that are based on specific base-pairing rules in the miR's seed region and implementation of cross-species conservation of the target site, and machine learning (ML) methods that explore patterns that contrast true and false miR-mRNA duplexes. However, in the case of the traditional methods research shows that some seed region matches that are conserved are false positives and that some of the experimentally validated target sites are not conserved. RESULTS: We present HuMiTar, a computational method for identifying common targets of miRs, which is based on a scoring function that considers base-pairing for both seed and non-seed positions for human miR-mRNA duplexes. Our design shows that certain non-seed miR nucleotides, such as 14, 18, 13, 11, and 17, are characterized by a strong bias towards formation of Watson-Crick pairing. We contrasted HuMiTar with several representative competing methods on two sets of human miR targets and a set of ten glioblastoma oncogenes. Comparison with the two best performing traditional methods, PicTar and TargetScanS, and a representative ML method that considers the non-seed positions, NBmiRTar, shows that HuMiTar predictions include majority of the predictions of the other three methods. At the same time, the proposed method is also capable of finding more true positive targets as a trade-off for an increased number of predictions. Genome-wide predictions show that the proposed method is characterized by 1.99 signal-to-noise ratio and linear, with respect to the length of the mRNA sequence, computational complexity. The ROC analysis shows that HuMiTar obtains results comparable with PicTar, which are characterized by high true positive rates that are coupled with moderate values of false positive rates. CONCLUSION: The proposed HuMiTar method constitutes a step towards providing an efficient model for studying translational gene regulation by miRs.