Enhanced Atlantic Meridional Mode predictability in a high-resolution prediction system.

Accurate prediction of sea surface temperatures (SSTs) in the tropical North Atlantic on multiyear timescales is of paramount importance due to its notable impact on tropical cyclone activity. Recent advances in high-resolution climate predictions have demonstrated substantial improvements in the skill of multiyear SST prediction. This study reveals a notable enhancement in high-resolution tropical North Atlantic SST prediction that stems from a more realistic representation of the Atlantic Meridional Mode and the associated wind-evaporation-SST feedback. The key to this improvement lies in the enhanced surface wind response to changes in cross-equatorial SST gradients, resulting from Intertropical Convergence Zone bias reduction when atmospheric model resolution is increased, which, in turn, amplifies the positive feedback between latent and sensible surface heat fluxes and SST anomalies. These advances in high-resolution climate prediction hold promise for extending tropical cyclone forecasts at multiyear timescales.

COVID-19 antibody responses in individuals with natural immunity and with vaccination-induced immunity: a systematic review and meta-analysis.

BACKGROUND: The COVID-19 pandemic has caused a large mortality and morbidity burden globally. For individuals, a strong immune response is the most effective means to block SARS-CoV-2 infection. To inform clinical case management of COVID-19, development of improved vaccines, and public health policy, a better understanding of antibody response dynamics and duration following SARS-CoV-2 infection and after vaccination is imperatively needed. METHODS: We systematically analyzed antibody response rates in naturally infected COVID-19 patients and vaccinated individuals. Specifically, we searched all published and pre-published literature between 1 December 2019 and 31 July 2023 using MeSH terms and "all field" terms comprising "COVID-19" or "SARS-CoV-2," and "antibody response" or "immunity response" or "humoral immune." We included experimental and observational studies that provided antibody positivity rates following natural COVID-19 infection or vaccination. A total of 44 studies reporting antibody positivity rate changes over time were included. RESULTS: The meta-analysis showed that within the first week after COVID-19 symptom onset/diagnosis or vaccination, antibody response rates in vaccinated individuals were lower than those in infected patients (p < 0.01), but no significant difference was observed from the second week to the sixth month. IgG, IgA, and IgM positivity rates increased during the first 3 weeks; thereafter, IgG positivity rates were maintained at a relatively high level, while the IgM seroconversion rate dropped. CONCLUSIONS: Antibody production following vaccination might not occur as quickly or strongly as after natural infection, and the IgM antibody response was less persistent than the IgG response.

Contralateral C7 nerve transfer in the treatment of central hemiplegia after stroke under general anesthesia: A case report.

Similar reports in the past pay less attention to the anesthetic management of these patients. We reported a 46-year-old man who suffered from hypertensive cerebral apoplexy 5 months ago and accepted C7 nerve transfer to improve the central spastic paralysis in the right upper limb. After careful evaluation and anesthesia management before anesthesia, the operation was successfully completed under general anesthesia. The patient was cured and discharged without complications. The anesthesia management of C7 nerve transfer should choose appropriate operation opportunities for patients according to the type of stroke, improve the preoperative preparation, and form a multidisciplinary diagnosis and treatment.

Influences of shallow groundwater depth on N2O diffusion along the soil profile of summer maize fields in North China Plain.

The emissions of nitrous oxide (N2O) from agricultural fields are a significant contribution to global warming. Understanding the mechanisms of N2O emissions from agricultural fields is essential for the development of N2O emission mitigation strategies. Currently, there are extensive studies on N2O emissions on the surface of agricultural soils, while studies on N2O fluxes at the interface between the saturated and unsaturated zones (ISU) are limited. Uncertainties exist regarding N2O emissions from the soil-shallow groundwater systems in agricultural fields. In this study, a three-year lysimeter experiment (2019-2020, 2022) was conducted to simulate the soil-shallow groundwater systems under four controlled shallow groundwater depth (SGD) (i.e., SGD = 40, 70, 110, and 150 cm) conditions in North China Plain (NCP). Weekly continuous monitoring of N2O emissions from soil surface, N2O concentration in the shallow groundwater and the upper 10 cm of pores at the ISU, and nitrogen cycling-related parameters in the soil and groundwater was conducted. The results showed that soil surface N2O emissions increased with decreased shallow groundwater depth, and the highest emissions of 96.44 kg ha-1 and 104.32 kg ha-1 were observed at G2 (SGD = 40 cm) in 2020 and 2022. During the observation period of one maize growing season, shallow groundwater acted as a sink for the unsaturated zone when the groundwater depth was 40 cm, 70 cm, and 110 cm. However, when SGD was 150 cm, shallow groundwater became a source for the unsaturated zone. After fertilization, the groundwater in all treatment plots behaved as a sink for the unsaturated zone, and the diffusion intensity decreased with increasing SGD. The results would provide a theoretical basis for cropland water management to reduce N2O emissions.

Non-negligible N2O emission hotspots: Rivers impacted by ion-adsorption rare earth mining.

Rare earth mining causes severe riverine nitrogen pollution, but its effect on nitrous oxide (N2O) emissions and the associated nitrogen transformation processes remain unclear. Here, we characterized N2O fluxes from China's largest ion-adsorption rare earth mining watershed and elucidated the mechanisms that drove N2O production and consumption using advanced isotope mapping and molecular biology techniques. Compared to the undisturbed river, the mining-affected river exhibited higher N2O fluxes (7.96 ± 10.18 mmol m-2d-1 vs. 2.88 ± 8.27 mmol m-2d-1, P = 0.002), confirming that mining-affected rivers are N2O emission hotspots. Flux variations scaled with high nitrogen supply (resulting from mining activities), and were mainly attributed to changes in water chemistry (i.e., pH, and metal concentrations), sediment property (i.e., particle size), and hydrogeomorphic factors (e.g., river order and slope). Coupled nitrification-denitrification and N2O reduction were the dominant processes controlling the N2O dynamics. Of these, the contribution of incomplete denitrification to N2O production was greater than that of nitrification, especially in the heavily mining-affected reaches. Co-occurrence network analysis identified Thiomonas and Rhodanobacter as the key genus closely associated with N2O production, suggesting their potential roles for denitrification. This is the first study to elucidate N2O emission and influential mechanisms in mining-affected rivers using combined isotopic and molecular techniques. The discovery of this study enhances our understanding of the distinctive processes driving N2O production and consumption in highly anthropogenically disturbed aquatic systems, and also provides the foundation for accurate assessment of N2O emissions from mining-affected rivers on regional and global scales.

Performance of anammox enchanced by pulsed electric fields under added organic carbon sources using integrated network and metagenomics analyses.

This paper aims to investigate the function of a pulsed electric field (PEF) in the anaerobic ammonia oxidation (anammox) process after adding certain chemical oxygen demand (COD) through integrated network and metagenomics analyses. The findings showed that the presence of COD was detrimental to anammox, but PEF could significantly reduce the adverse effect. The total nitrogen removal in the reactor for applying PEF was 16.99% higher on average than the reactor for only dosing COD. Additionally, PEF upgraded the abundance of anammox bacteria subordinate to the phylum Planctomycetes by 9.64%. The analysis of molecular ecological networks promulgated that PEF resulted in an increase in network scale and topology complexity, thereby boosting the potential collaboration of the communities. Metagenomics analyses demonstrated that PEF dramatically promoted anammox central metabolism in the presence of COD, specifically enhancing pivotal N functional genes (hzs, hdh, amo, hao, nas, nor and nos).

Association of volatile anesthesia exposure and depth with emergence agitation and delirium in children: Prospective observational cohort study.

Background: Sevoflurane anesthesia is widely used in pediatric ambulatory surgery. However, emergency agitation (EA) and emergency delirium (ED), as major complications following sevoflurane anesthesia in children, pose risks to surgery and prognosis. Identifying the high risk of EA/ED, especially anesthesia exposure and the depth of anesthesia, may allow preemptive treatment. Methods: A total of 137 patients were prospectively enrolled in this single-center observational cohort study to assess the incidence of EA or ED. Multivariable logistic regression analyses were used to test the association between volatile anesthesia exposure and depth with EA or ED. The Richmond Agitation and Sedation Scale (RASS), Pediatric Anesthesia Emergence Delirium Scale (PAED) and Face, Legs, Activity, Cry, and Consolability (FLACC) behavioural pain scale was used to assess the severity of EA or ED severity and pain. Bispectral index (BIS) to monitor the depth of anesthesia, as well as TimeLOW-BIS/TimeANES %, EtSevo (%) and EtSevo-time AUC were included in the multivariate logistic regression model as independent variables to analyze their association with EA or ED. Results: The overall prevalence of EA and ED was 73/137 (53.3%) and 75/137 (54.7%) respectively, where 48/137 (35.0%), 19/137 (13.9%), and 6/137 (4.4%) had mild, moderate, and severe EA. When the recovery period was lengthened, the prevalence of ED and extent of FLACC decreased and finally normalized within 30 min in recovered period. Multivariable logistic regression demonstrated that intraoperative agitation [2.84 (1.08, 7.47) p = 0.034], peak FLACC [2.56 (1.70, 3.85) p < 0.001] and adverse event (respiratory complications) [0.03 (0.00, 0.29) p = 0.003] were independently associated with higher odds of EA. Taking EtSevo-time AUC ≤ 2,000 as a reference, the incidence of EA were [15.84 (2.15, 116.98) p = 0.002] times and 16.59 (2.42, 113.83) p = 0.009] times for EtSevo-time AUC 2,500-3,000 and EtSevo-time AUC > 3,000, respectively. Peak FLACC [3.46 (2.13, 5.62) p < 0.001] and intraoperative agitation [5.61 (1.99, 15.86) p = 0.001] were independently associated with higher odds of developing ED. EtSevo (%), intraoperative BIS value and the percentage of the duration of anesthesia at different depths of anesthesia (BIS ≤ 40, BIS ≤ 30, BIS ≤ 20) were not associated with EA and ED. Conclusions: For pediatrics undergoing ambulatory surgery where sevoflurane anesthesia was administered, EA was associated with surgical time, peak FLACC, respiratory complications, and "EtSevo-time AUC" with a dose-response relationship; ED was associated with peak FLACC and intraoperative agitation.

m6A Methyltransferase, WTAP, Promotes Cancer Progression in Laryngeal Squamous Cell Carcinoma by Regulating PLAU Stability.

OBJECTIVE: Laryngeal squamous cell carcinoma (LSCC) is a malignancy originating from laryngeal squamous cell lesions. Wilm's tumor 1-associated protein (WTAP)-mediated N6-methyladenosine (m6A) modification has been verified to stimulate the progression of numerous cancers, except for LSCC. This study was aimed at exploring the role of WTAP and its mechanism of action in LSCC. METHODS: The expression of WTAP and plasminogen activator urokinase (PLAU) mRNAs in LSCC tissues and cells was quantified using qRT-PCR. Western blotting was performed to estimate PLAU levels in LSCC cells. The relationship between WTAP and PLAU was ascertained using luciferase reporter and methylated-RNA immunoprecipitation (Me-RIP) assays. Functionally, the interaction of WTAP with PLAU in LSCC cells was investigated using CCK-8, EdU, and Transwell assays. RESULTS: The expression of WTAP and PLAU was increased in LSCC, and was positively correlated. WTAP regulated PLAU stability in an m6A-dependent manner. WTAP deficiency suppressed the migration, invasion, and proliferation of LSCC cells. Overexpression of PLAU rescued the phenotype induced by WTAP knockdown in vitro. CONCLUSIONS: These results indicate that WTAP mediates the m6A modification of PLAU to accelerate the growth, migration, and invasion of cells in LSCC. To our knowledge, this is the first report to clarify the functions of WTAP in LSCC and the underlying mechanisms in detail. Based on these findings, we suggest that WTAP may serve as a therapeutic target for LSCC.

Pollution caused by mining reshaped the structure and function of bacterial communities in China's largest ion-adsorption rare earth mine watershed.

Ion-adsorption rare earth mining results in the production of high levels of nitrogen, multiple metals, and strong acidic mine drainage (AMD), the impacts of which on microbial assembly and ecological functions remain unclear. To address this knowledge gap, we collected river sediments from the watershed of China's largest ion-adsorption rare earth mine and analyzed the bacterial community's structure, function, and assembly mechanisms. Results showed that bacterial community assembly was weakly affected by spatial dispersion, and dispersal limitation and homogeneous selection were the dominant ecological processes, with the latter increasing with pollution gradients. Bacterial alpha diversity decreased with pollution, which was mainly influenced by lead (Pb), pH, rare earth elements (REEs), and electrical conductivity (EC). However, bacteria developed survival strategies (i.e., enhanced acid tolerance and interspecific competition) to adapt to extreme environments, sustaining species diversity and community stability. Community structure and function showed a consistent response to the polluted environment (r = 0.662, P = 0.001). Enhanced environmental selection reshaped key microbial-mediated biogeochemical processes in the mining area, in particular weakening the potential for microbial denitrification. These findings provide new insights into the ecological response of microbes to compound pollution and offer theoretical support for proposing effective remediation and management strategies for polluted areas.

Developmental dynamic transcriptome and systematic analysis reveal the major genes underlying isoflavone accumulation in soybean.

Introduction: Soy isoflavone, a class of polyphenolic compounds exclusively occurred in legumes, is an important bioactive compound for both plants and human beings. The outline of isoflavones biosynthesis pathway has been drawn up basically in the previous research. However, research on the subject has been mostly restricted to investigate the static regulation of isoflavone content in soybean, rather than characterize its dynamic variation and modulation network in developing seeds. Methods: In this study, by using eight recombinant inbred lines (RIL), the contents of six isoflavone components in the different stages of developing soybean seeds were determined to characterize the dynamic variation of isoflavones, and the isoflavones accumulation pattern at physiological level was investigated. Meanwhile, we integrated and analyzed the whole genome expression profile of four lines and 42 meta-transcriptome data, based on the multiple algorithms. Results: This study: 1) obtained 4 molecular modules strongly correlated with isoflavone accumulation; 2) identified 28 novel major genes that could affect the accumulation of isoflavones in developing seeds free from the limitation of environments; 3) discussed the dynamic molecular patterns regulating isoflavones accumulation in developing seed; 4) expanded the isoflavone biosynthesis pathway. Discussion: The results not only promote the understandings on the biosynthesis and regulation of isoflavones at physiological and molecular level, but also facilitate to breed elite soybean cultivars with high isoflavone contents.

Irradiation with carbon ion beams affects soybean nutritional quality in early generations.

As people's demand for healthy diet increases, improving soybean seed nutritional quality is becoming as important as yield. Carbon ion beam radiation (CIBR) is an effective method to create soybean mutants, and thus breeding cultivars with better seed nutritional quality. In this study, the high-yield soybean line 'Dongsheng 28' was used, and three CIBR doses (100, 120, and 140 Gy) were used to explore the characteristics of quality separation and variation in the offspring of early mutant populations. Eleven quality traits, including protein, oil, sucrose, soluble sugar, iron (Fe), manganese (Mn), zinc (Zn), cupper (Cu), daidzin, glycitin, and genistin concentrations were analyzed in the M2 and M3 generations. The results revealed that the range of protein and oil concentration of all three CIBR doses changed by 38.5-42.9% and 18.8-23.8% in the M2 and M3 generations, respectively, while soluble sugar and sucrose concentrations changed by 48.1-123.4 and 22.7-74.7 mg/g, with significant effects by 140 Gy across the two generations. Therefore, around the optimum range, a higher CIBR dose is better for high protein, oil, and sugar varieties selection. In general, irradiation raised isoflavone concentrations, but 140 Gy had an inhibitory effect on isoflavone concentrations in the M3 generation. Although a variety could not be released in the M2 or M3 generation, the results of this study have important guiding significance for the targeted cultivation of specific nutritional quality materials. For instance, a lower irradiation dose is preferable when breeding targets are higher isoflavones and Mn concentrations. It is essential to increase the irradiation dose if the breeding targets contain high levels of protein, oil, sucrose, soluble sugars, Fe, Zn, and Cu.

Effects of straw mulching and nitrogen application rates on crop yields, fertilizer use efficiency, and greenhouse gas emissions of summer maize.

Although straw mulching and nitrogen applications are extensively practiced in the agriculture sector, large uncertainties remain about their impacts on crop yields and especially the environment. The responses of summer maize yields, fertilizer use efficiency, and greenhouse gas (GHG) emissions including carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in the North China Plain (NCP) to two straw management practices (S0: no straw and S1: straw mulching) and two nitrogen application rates (N1: 180 and N2: 210 kg N ha-1) were investigated in field tests in 2018, 2019, and 2020. The highest yields and partial factor productivity (PFP) were obtained by S1N1, followed by S1N2, S0N1, and S0N2. S1N2 had the highest CO2 emissions and greatest CH4 uptake, S0N1 had the lowest CO2 emissions, and S0N2 had the smallest CH4 uptake. The highest and lowest N2O emissions were found in S0N1 and S1N1, respectively. The S1N2 treatment, an extensively applied practice, had the greatest global warming potential (GWP), which was 70.3 % larger than S1N1 and two times more than S0N1 and S0N2. The largest GHG emission intensity (GHGI) of 19.4 was found in the S1N2 treatment, while the other three treatments, S0N1, S0N2, and S1N1, had a GHGI of 10.1, 10.7, and 10.7, respectively according to three tested results. In conclusion, S1N1 treatment achieved a better trade-off between crop yields and GHG emissions of summer maize in NCP.

The Use of Deep Learning-Based Intelligent Music Signal Identification and Generation Technology in National Music Teaching.

The research expects to explore the application of intelligent music recognition technology in music teaching. Based on the Long Short-Term Memory network knowledge, an algorithm model which can distinguish various music signals and generate various genres of music is designed and implemented. First, by analyzing the application of machine learning and deep learning in the field of music, the algorithm model is designed to realize the function of intelligent music generation, which provides a theoretical basis for relevant research. Then, by selecting massive music data, the music style discrimination and generation model is tested. The experimental results show that when the number of hidden layers of the designed model is 4 and the number of neurons in each layer is 1,024, 512, 256, and 128, the training result difference of the model is the smallest. The classification accuracy of jazz, classical, rock, country, and disco music types can be more than 60% using the designed algorithm model. Among them, the classification effect of jazz schools is the best, which is 77.5%. Moreover, compared with the traditional algorithm, the frequency distribution of the music score generated by the designed algorithm is almost consistent with the spectrum of the original music. Therefore, the methods and models proposed can distinguish music signals and generate different music, and the discrimination accuracy of different music signals is higher, which is superior to the traditional restricted Boltzmann machine method.

Effects of no-tillage on greenhouse gas emissions in maize fields in a semi-humid temperate climate region.

Agricultural tillage practices have a significant impact on the generation and consumption of greenhouse gases (GHGs), the primary causes of global warming. Two tillage systems, conventional tillage (CT) and no-tillage (NT), were compared to evaluate their effects on GHG emissions in this study. Averaged from 2018 to 2020, significant decreases of CO2 and N2O emissions by 7.4% and 51.1% were observed in NT as compared to those of CT. NT was also found to inhibit the soil CH4 uptake. In this study, soil was a source of CO2 and N2O but a sink for CH4. The effect of soil temperature on the fluxes of CO2 was more pronounced than that of soil moisture. However, soil temperature and soil moisture had a weak correlation with CH4 and N2O flux variations. As compared to CT, NT did not affect maize yields but significantly reduced global warming potential (GWP) by 8.07%. For yield-scaled GWP, no significant difference was observed in NT (9.63) and CT (10.71). Taken together, NT was an environment-friendly tillage practice to mitigate GHG emissions in the soil under the tested conditions.

The Impact of Horizontal Resolution on Projected Sea-Level Rise Along US East Continental Shelf With the Community Earth System Model.

The Intergovernmental Panel on Climate Change Fifth Assessment Report lists sea-level rise as one of the major future climate challenges. Based on pre-industrial and historical-and-future climate simulations with the Community Earth System Model, we analyze the projected sea-level rise in the Northwest Atlantic Ocean with two sets of simulations at different horizontal resolutions. Compared with observations, the low resolution (LR) model simulated Gulf Stream does not separate from the shore but flows northward along the entire coast, causing large biases in regional dynamic sea level (DSL). The high resolution (HR) model improves the Gulf Stream representation and reduces biases in regional DSL. Under the RCP8.5 future climate scenario, LR projects a DSL trend of 1.5-2 mm/yr along the northeast continental shelf (north of 40° N), which is 2-3 times the trend projected by HR. Along the southeast shelf (south of 35° N), HR projects a DSL trend of 0.5-1 mm/yr while the DSL trend in LR is statistically insignificant. The different spatial patterns of DSL changes are attributable to the different Gulf Stream reductions in response to a weakening Atlantic Meridional Overturning Circulation. Due to its poor representation of the Gulf Stream, LR projects larger (smaller) current decreases along the north (south) east continental slope compared to HR. This leads to larger (smaller) trends of DSL rise along the north (south) east shelf in LR than in HR. The results of this study suggest that the better resolved ocean circulations in HR can have significant impacts on regional DSL simulations and projections.

Methysticin Acts as a Mechanism-Based Inactivator of Cytochrome P450 2C9.

Methysticin is one of the naturally occurring bioactive constituents extracted from Piper methysticum Forst. In the present study, we intended to investigate the inhibitory effect of methysticin on cytochrome P450 (P450) enzymes. Methysticin exhibited time-, concentration-, and NADPH-dependent inhibition on CYP2C9 using diclofenac as a probe substrate. Approximately 85% of CYP2C9 activity was inhibited by methysticin at 50 µM after a 30 min preincubation with human liver microsomes in the presence of NADPH. The kinetic parameters KI, kinact, and t1/2,inact were 13.32 ± 1.35 µM, 0.054 ± 0.005 min-1, and 12.83 ± 3.23 min, respectively. Sulfaphenazole (competitive inhibitor of CYP2C9) displayed a significant protective effect on methysticin-induced CYP2C9 inactivation. However, the inclusion of catalase/superoxide dismutase or glutathione (GSH) showed no such protection. A carbene intermediate was postulated to be involved in methysticin-induced CYP2C9 inactivation as K3Fe(CN)6 recovered 14.96% of CYP2C9 activity. A methysticin-derived ortho-quinone intermediate dependent on NADPH was trapped by GSH, and this intermediate was believed to be involved in CYP2C9 inactivation. CYP1A2, 2C9, and 3A4 were the major enzymes responsible for methysticin bioactivation. Taken together, the present work demonstrated that methysticin was a mechanism-based inactivator of CYP2C9. Both ortho-quinone and carbene intermediates appeared to be involved in the inactivation of CYP2C9 induced by methysticin.

Virtual water transfers in Africa: Assessing topical condition of water scarcity, water savings, and policy implications.

Africa is facing an increasing challenge with respect to water scarcity (WS), which is driven by climate change, population growth, and socioeconomic growth combined with inadequate water resources management. In particular, there is significant concern of virtual water (VW) trade, which plays the key role in water resource management and food security sustainability. Using bilateral trade data, this study consistently evaluated the change and balanced trade of major grains, the VW flows, WS status, water dependency (WD), water self-sufficiency (WSS), and water savings/losses within5 African sub-regions and their partners from 2000 to 2020. The ratio of water use to water availability was used to estimate the WS. The WD was quantified by the ratio of the net VW import to the regional water appropriation and the regional water savings/losses were also quantified by multiplying the inter-regional trade by the virtual water content of the imported/exported grains. The overall average trade deficit of African regions was found to increase to -1364.22 × 106 tons and Africa imported 41,359.07 Bm3 of VW from grain products. Green water contributed 79.33% of the total VWI. The WS values for East African countries were >100, indicating overexploitation. Besides, the overall WD in Africa was 465.5% for the studied period. The trade of main grains between Africa and the rest of the planet corresponded to a global water loss of 2820.7 Bm3·yr-1. However, the inter-continental cereal VW trade pattern and high trend will continue in the future. In view of the rising tension of WS, some African countries need to revise international crop trade and water resources conservation policies to promote a more balanced ecosystem. This study exemplifies that decision makers would consider VW flows and water savings/losses for enhancing water use efficiency and fair trading, thus increasing food production in Africa.

AK4P1 is a cancer-promoting pseudogene in pancreatic adenocarcinoma cells whose transcripts can be transmitted by exosomes.

Adenylate kinase 4 pseudogene 1 (AK4P1) is a processed pseudogene whose function in cancer biology remains largely underexplored. Bioinformatics analysis suggested an association between the expression levels of adenylate kinase 4 (AK4) gene and AK4P1, as well as a clinical significance in relation to the increased transcription levels of AK4P1 in pancreatic adenocarcinoma (PAAD). In the present study, the expression levels of AK4P1 and AK4 were compared by RT-qPCR and western blotting between PAAD tissue and paired adjacent tissue. The level of AK4P1 transcript was compared between the circulating exosomes derived from patients with PAAD and those derived from healthy donors. Overall survival of the patients with PAAD with high or low expression levels of AK4P1 or AK4 was compared. AK4 gene expression level, in vitro cell viability and gemcitabine-induced apoptosis in PAAD cells with or without AK4P1 overexpression were also assessed using Cell Counting Kit-8 and TUNEL assays. It was identified that the transcription level of AK4P1 and the expression level of AK4 in PAAD tissue were significantly higher compared with those in paired non-cancerous tissue specimens. Transcription levels of AK4P1 and AK4 showed a significant relationship in PAAD. Circulating exosomes derived from patients with PAAD showed significantly higher level of AK4P1 transcript compared with that from circulating exosomes derived from blood samples of healthy donors. Patients with high expression of AK4P1 or AK4 exhibited significantly reduced overall survival compared with those with low expression. AK4P1 overexpression significantly upregulated the expression levels of AK4 in PAAD cells and rescued the viability and survival under gemcitabine challenge decreased by AK4 knockdown but not that by AK4 knockout. Treatment with exosomes secreted by AK4P1-overexpressing PAAD cells but not with those secreted by wild-type PAAD cells significantly increased the viability and survival under gemcitabine challenge of the recipient cells. These results suggested that AK4P1 affects the cellular biological functions of PAAD cells in vitro by upregulating the expression level of AK4. AK4P1 transcripts with elevated expression levels can be transmitted between PAAD cells through exosomes and exert pro-oncogenic effects in recipient cells.

Mechanically reinforced biotubes for arterial replacement and arteriovenous grafting inspired by architectural engineering.

There is a lack in clinically-suitable vascular grafts. Biotubes, prepared using in vivo tissue engineering, show potential for vascular regeneration. However, their mechanical strength is typically poor. Inspired by architectural design of steel fiber reinforcement of concrete for tunnel construction, poly(ε-caprolactone) (PCL) fiber skeletons (PSs) were fabricated by melt-spinning and heat treatment. The PSs were subcutaneously embedded to induce the assembly of host cells and extracellular matrix to obtain PS-reinforced biotubes (PBs). Heat-treated medium-fiber-angle PB (hMPB) demonstrated superior performance when evaluated by in vitro mechanical testing and following implantation in rat abdominal artery replacement models. hMPBs were further evaluated in canine peripheral arterial replacement and sheep arteriovenous graft models. Overall, hMPB demonstrated appropriate mechanics, puncture resistance, rapid hemostasis, vascular regeneration, and long-term patency, without incidence of luminal expansion or intimal hyperplasia. These optimized hMPB properties show promise as an alternatives to autologous vessels in clinical applications.

Nitrate source apportionment and risk assessment: A study in the largest ion-adsorption rare earth mine in China.

Nitrate (NO3-) pollution in water bodies has received widespread attention, but studies on nitrogen transformation and pollution risk assessment are still limited, especially in rare earth mining areas. In this study, surface and groundwater samples were collected from the largest rare earth mining site in southern China, and analyzed for the hydrochemical and stable isotopic characteristics. The results showed that the NO3- concentrations ranged from 1.61 to 453.11 mg/L, with 35% of surface water and 53.3% of groundwater samples exceeding the WHO standard (i.e., 50 mg/L). Health risk assessment showed that 31.4% of the water samples had a moderate to high non-carcinogenic risk, and the high-risk areas were concentrated in rare earth mining regions. Additionally, adults were more vulnerable to the non-carcinogenic health risks than children. The high variability of δ15N-NO3- (from -6.43 to 17.09‰) and δ18O-NO3- (from -7.91 to 22.79‰) showed that NO3- was influenced by multiple nitrogen sources and transformation processes. Hydrochemistry and isotopic evidence further indicated that NO3- was primarily influenced by nitrification and hydraulic connection between surface and groundwater. The results of the Bayesian mixing model showed that about 70% of NO3- originated from mine drainage and soil N in the rare earth mining area, while more than 90% of NO3- originated from fertilizer, soil N, and manure and sewage in rural and urban areas in the middle and downstream. This study suggests reducing anthropogenic nitrogen discharge (e.g., leaching agents and fertilizer inputs) as the primary means of NO3- pollution control with biogeochemical processes (e.g., denitrification) to further reduce its pollution.