Acidification state and interannual variability in marginal sea: A case study of the Bohai and the Yellow Seas surface waters in April 2023.

The acidification of the marginal seawater was a more intricate process than the ocean. Although some studies have been done on seasonal acidification in the bottom water of Chinese marginal seas, research on surface water acidification has still been insufficient. We analyzed the acidification properties and controlling factors in the Bohai Sea (BS) and Yellow Sea (YS) surface water during April 2023. The observation showed that the average surface water pH of the BS, North Yellow Sea (NYS), and South Yellow Sea (SYS) were 8.09 ± 0.06, 8.13 ± 0.05, and 8.15 ± 0.05. Phytoplankton significantly impacted pH and Ωarag, while riverine inputs and biological activity played a vital role in controlling DIC and TA. The Yellow River significantly impacted the BS. The North Yellow Sea Cold Water Mass had a limited impact on acidification, while the South Yellow Sea Cold Water Mass significantly affected the SYS. Regarding seasonal fluctuations, Ωarag was significantly higher in summer than in other seasons. DIC and TA showed different patterns in both the BS and YS, with a minimal fluctuation in pH. Over the last two decades, the pH in the BS showed a slight annual decline, and the rate of change was (-1.45 ± 2.19) × 10-5 yr-1. In contrast, the NYS and SYS have slightly risen, with rates of change of (2.39 ± 1.24) × 10-5 and (1.23 ± 0.76) × 10-5 yr-1. We believed that surface water acidification in the BS and YS did not follow the expected trend of significant acidification observed in open oceanic regions. Instead, the acidification process in these marginal seas was dominated by local factors such as riverine inputs, biological activity, and cold water masses, resulting in minimal pH changes over the last two decades.

Enhanced nitrogen removal performance of nitrogen-rich saline wastewater by marine anammox bacteria: Based on different influent loading strengths.

In an anaerobic sequential batch reactor (SBR), marine anammox bacteria (MAB) were able to enhance microbial activity in nitrogen-rich saline wastewater and it was significantly affected by influent substrate composition and loading strength. This study therefore enhanced nitrogen removal efficiency by adjusting the influent nitrogen loading strength of MAB-inoculated anaerobic SBRs and assessed the correlation with the bacterial community. The results displayed that the system obtained optimal nitrogen removal efficiency (TN = 83.52%, NH4-N = 90.14%, and NO2-N = 83.57%) as the strength of influent nitrogen loading was increased to 201.35 mg L-1 for NH4-N and 266.42 mg L-1 for NO2-N. Moreover, the increase in the strength of influent nitrogen loading also enhanced the anammox 16S rRNA abundance (4.09 × 108 copies g-1) and ladderanes content (22.49 ng g-1dw). Analysis of 15N isotope further illustrated that all systems were dominated by anammox (average ra = 95.22%). In conclusion, these findings provide scientific guidance for the management of eutrophic seawater and contribute to the realization of industrial applications for the treatment of nitrogen-rich saline wastewater.

Achieving Efficient Dark Blue Room-Temperature Phosphorescence with Ultra-Wide Range Tunable-Lifetime.

Tunable-lifetime room-temperature phosphorescence (RTP) materials have been widely studied due to their broad applications. However, only few reports have achieved wide-range lifetime modulation. In this work, ultra-wide range tunable-lifetime efficient dark blue RTP materials were realized by doping methyl benzoate derivatives into polyvinyl alcohol (PVA) matrix. The phosphorescence lifetimes of the doped films can be increased from 32.8 ms to 1925.8 ms. Such wide range of phosphorescence lifetime modulation is extremely rare in current reports. Moreover, the phosphorescence emission of the methyl 4-hydroxybenzoate-doped film is located in the dark blue region and the phosphorescence quantum yield reaches as high as 15.4 %, which broadens their applications in organic optoelectronic information. Further studies demonstrated that the reason for the tunable lifetime was that the magnitude of the electron-donating ability of the substituent group modulates the HOMO-LUMO and singlet-triplet energy gap of methyl benzoate derivatives, as well as the ability to non-covalent interactions with PVA. Moreover, the potential applications of luminescent displays and optical anti-counterfeiting of these high-performance dark blue RTP materials have been conducted.

Phage resistance mutation triggered by OmpC deficiency in Klebsiella pneumoniae induced limited fitness costs.

Outer membrane proteins (OMPs) play an important role in bacterial fitness costs. Derived from the interaction between Klebsiella pneumoniae K7 and phage GH-K3, K7RB is an outer membrane porin-deficient phage-resistant mutant strain triggered by ompC712 deletion, exhibits expression inhibition of OmpC, OmpN, KPN_02430 and OmpF, but its fitness costs and regulatory mechanism remains unknown. In this study, compared with K7, K7RB showed almost unaffected growth rate, slightly decreased virulence, and increased resistance to some antibiotics. Transcriptome analysis showed that the pathways of glycerolipid metabolism and nitrogen metabolism in K7RB were significantly inhibited, while the transcription of permeases belonging to ABC transporters tended to be active, nutrient uptakes such as citrate and phenylalanine were also enhanced. However, transcriptional up-regulation in K7RB was inhibited by overexpression of OmpC, OmpN, KPN_02430 and OmpF in general. Overexpression of OmpN, KPN_02430 and OmpF, respectively, restoring the sensitivity of strains to antibiotics to varying degrees, while OmpC overexpression aggravated the bacterial drug-resistance especially to ß-lactam antibiotics. Besides, unlike OmpC and OmpF, overexpression of OmpN and KPN_02430 reduced bacterial virulence. In brief, by revealing the limited fitness costs of phage-resistant mutant K. pneumoniae with porin-deficiency, our study providing a reference for the design and development of drugs to inhibit the ways of bacterial metabolic rewiring and to increase fitness costs.

Reversible Multilevel Stimuli-Responsiveness and Multicolor Room-Temperature Phosphorescence Emission Based on a Single-Component System.

There are limited reports about the transformation of pure organic room-temperature phosphorescence (RTP) materials with multilevel stimuli-responsiveness at different RTP emission wavelengths under external stimuli. It is difficult to ensure efficient intersystem crossing (ISC) in different states of a single-component system. This research reports the conversion of the organic single-component small molecule 1,2-bis(4-alkoxyphenyl)ethane-1,2-dione (N-BOX) with multilevel stimuli-responsiveness between high-efficiency blue and yellow RTP by grinding or thermal annealing N-BOX crystals. The RTP emission of N-BOX in the crystalline state was easy to adjust by external stimuli (grinding or thermal annealing) due to its non-compact packing, which led to a phase transition and generated unique multilevel stimuli-responsiveness. In particular, the RTP quantum yield of 7-BOX with multilevel stimuli-responsiveness reached 68.4 %, which provides an opportunity for regulation of smart optical materials based on pure organic RTP.

Three dimensionally printed nitrocellulose-based microfluidic platform for investigating the effect of oxygen gradient on cells.

In this article, we present a novel nitrocellulose-based microfluidic chip with 3-dimensional (3D) printing technology to study the effect of oxygen gradient on cells. Compared with conventional polydimethylsiloxane (PDMS) chips of oxygen gradient for cell cultures that can only rely on fluorescence microscope analysis, this hybrid nitrocellulose-based microfluidic platform can provide a variety of analysis methods for cells, including flow cytometry, western blot and RT-PCR, because the nitrocellulose-based chips with cells can be taken out from the growth chambers of 3D printed microfluidic chip and then used for cell collection or lysis. These advantages allow researchers to acquire more information and data on the basic biochemical and physiological processes of cell life. The effect of oxygen gradient on the zebrafish cells (ZF4) was used as a model to show the performance and application of our platform. Hypoxia caused the increase of intercellular reactive oxygen species (ROS) and accumulation of hypoxia-inducible factor 1α (HIF-1α). Hypoxia stimulated the transcription of hypoxia-responsive genes vascular endothelial growth factor (VEGF) and induced cell cycle arrest of ZF4 cells. The established platform is able to obtain more information from cells in response to different oxygen concentration, which has potential for analyzing the cells under a variety of pathological conditions.

Privacy protection of medical data in social network.

BACKGROUND: Protection of privacy data published in the health care field is an important research field. The Health Insurance Portability and Accountability Act (HIPAA) in the USA is the current legislation for privacy protection. However, the Institute of Medicine Committee on Health Research and the Privacy of Health Information recently concluded that HIPAA cannot adequately safeguard the privacy, while at the same time researchers cannot use the medical data for effective researches. Therefore, more effective privacy protection methods are urgently needed to ensure the security of released medical data. METHODS: Privacy protection methods based on clustering are the methods and algorithms to ensure that the published data remains useful and protected. In this paper, we first analyzed the importance of the key attributes of medical data in the social network. According to the attribute function and the main objective of privacy protection, the attribute information was divided into three categories. We then proposed an algorithm based on greedy clustering to group the data points according to the attributes and the connective information of the nodes in the published social network. Finally, we analyzed the loss of information during the procedure of clustering, and evaluated the proposed approach with respect to classification accuracy and information loss rates on a medical dataset. RESULTS: The associated social network of a medical dataset was analyzed for privacy preservation. We evaluated the values of generalization loss and structure loss for different values of k and a, i.e. [Formula: see text] = {3, 6, 9, 12, 15, 18, 21, 24, 27, 30}, a = {0, 0.2, 0.4, 0.6, 0.8, 1}. The experimental results in our proposed approach showed that the generalization loss approached optimal when a = 1 and k = 21, and structure loss approached optimal when a = 0.4 and k = 3. CONCLUSION: We showed the importance of the attributes and the structure of the released health data in privacy preservation. Our method achieved better results of privacy preservation in social network by optimizing generalization loss and structure loss. The proposed method to evaluate loss obtained a balance between the data availability and the risk of privacy leakage.

A Cost-Effective In Situ Zooplankton Monitoring System Based on Novel Illumination Optimization.

A cost-effective and low-power-consumption underwater microscopic imaging system was developed to capture high-resolution zooplankton images in real-time. In this work, dark-field imaging was adopted to reduce backscattering and background noise. To produce an accurate illumination, a novel illumination optimization scheme for the light-emitting diode (LED) array was proposed and applied to design a lighting system for the underwater optical imaging of zooplankton. A multiple objective genetic algorithm was utilized to find the best location of the LED array, which resulted in the specific illumination level and most homogeneous irradiance in the target area. The zooplankton imaging system developed with the optimal configuration of LEDs was tested with Daphnia magna under laboratory conditions. The maximal field of view was 16 mm × 13 mm and the optical resolution was 15 µm. The experimental results showed that the imaging system developed could capture high-resolution and high-definition images of Daphnia. Subsequently, Daphnia individuals were accurately segmented and their geometrical characters were measured by using a classical image processing algorithm. This work provides a cost-effective zooplankton measuring system based on an optimization illumination configuration of an LED array, which has a great potential for minimizing the investment and operating costs associated with long-term in situ monitoring of the physiological state and population conditions of zooplankton.

Occurrence and origins of biomarker aliphatic hydrocarbons and their indications in surface sediments of the East China Sea.

The composition, distribution, indexes and budget of saturated lipid biomarker aliphatic hydrocarbons (AHs) in sediments of the East China Sea (ESC) were analyzed to identify their indications and sources. The resolved n-alkane (R) contents were 0.70-2.89 µg/g, with long-chain n-alkanes as the dominant composition in the ECS. The high R values mainly appeared at south inner shelf and north outer upwelling area, corresponding to the high mud, total organic carbon (TOC) and Chl a contents there. The composition, distribution pattern, combined with indexes of AHs, suggested no petroleum contamination and predominant biogenic sources in the ECS. The biogenic sources mainly were the mixed terrestrial higher plant, marine plankton and bacteria and aquatic macrophyte origins. Biotic source apportionment suggested that terrestrial higher plants were the dominant source of AHs, followed by marine planktons, with the lowest of submerged/floating macrophytes. Quantitative evaluation of R sources suggested that the Changjiang River input was the primary terrestrial contributor, accounting for 67.9% of total terrestrial input. The burial flux of R was 1.11 × 103 t/yr, with inner shelf and estuary as main accumulation areas. Although there was a huge amount of R influx from terrestrial and marine sources, only 9.8% could be preserved in sediments.

Atmospheric wet deposition of dissolved organic carbon to a typical anthropogenic-influenced semi-enclosed bay in the western Yellow Sea, China: Flux, sources and potential ecological environmental effects.

Dissolved Organic Carbon (DOC) is a key organic compound in wet precipitation, but few data are available in China marginal seas. To probe the concentration, deposition flux, seasonality, source and potential ecological environmental effects of precipitation DOC, in this study, one-year precipitation samples were collected at Jiaozhou Bay (JZB), a typical anthropogenic-influenced semi-enclosed bay in the western Yellow Sea for the first time from June 2015 to May 2016. The concentrations of DOC in precipitation were highly variable with a volume-weighted mean (VWM) concentration of 3.63 mg C L-1, which was mostly higher than those in other areas. DOC concentrations were lower in wet season than that in dry season due to the dilution from more amount of rainfall. The wet deposition flux of DOC was calculated to be 3.15 g C m-2 yr-1 with 68.7% of which occurred in wet season mainly owing to the promoting of more rainfall amount. Besides, local emissions together with the long-range transport of pollutants were other factors controlling precipitation DOC. Fossil fuel combustion particularly coal burning was considered to be the leading source of precipitation DOC based on correlation analysis with some generally accepted indicators. Wet deposition dominates the external input of DOC at JZB by comparison with riverine input with a percentage of 54%. Heavy storm may exert enrichment effect on DOC levels in the surface water of JZB, and then promote the secondary productivity. This study emphasizes that wet deposition is an important process that should be seriously considered in the models of global/regional carbon biogeochemical cycling.

Continuous Fluorescence Depletion Anisotropy Measurement of Protein Rotation.

Protein rotation in viscous environments can be measured by fluorescence depletion anisotropy (FDA) which combines long lifetimes of chromophore triplet states with the sensitivity of fluorescence excitation and detection. FDA achieves sensitivity well beyond that attainable by the more common technique of time-resolved phosphorescence anisotropy (TPA). We have now combined benefits of both time-domain and frequency-domain FDA into a single continuous technique (CFDA). Intensity and polarization of a single laser beam are modulated continuously according to a complex, repeating waveform. Fluorescence signals excited from triplet-forming fluorescent probes are digitized over recurring waveform periods by a high-speed signal averager. CFDA experiments typically involve substantial ground state depletion. Thus signals, unlike those of TPA, are not linear in the exciting light intensity and simple data analysis based on such linearity is not appropriate. An exact solution of the coupled diffusion and triplet production/decay equation describing CFDA within individual data points has been combined with simulated annealing optimization to extract triplet and anisotropy decay kinetics from experimental data. Related calculations compare possible excitation waveforms with respect to rotational information provided per fluorescence photon. We present CFDA results for the model system of eosin conjugates of carbonic anhydrase, BSA and immunoglobulin G in 90% glycerol at various temperatures and initial cellular results on eosin-IgE bound to 2H3 cell Type I Fcε receptors. We explore how CFDA reflects rotational parameters of heterogeneous systems and discuss challenges of extending this method to single cell microscopic measurements.

Speciation of heavy metals in different grain sizes of Jiaozhou Bay sediments: Bioavailability, ecological risk assessment and source analysis on a centennial timescale.

Heavy metal contamination is an essential indicator of environmental health. In this work, one sediment core was used for the analysis of the speciation of heavy metals (Cr, Mn, Ni, Cu, Zn, As, Cd, and Pb) in Jiaozhou Bay sediments with different grain sizes. The bioavailability, sources and ecological risk of heavy metals were also assessed on a centennial timescale. Heavy metals were enriched in grain sizes of < 63µm and were predominantly present in residual phases. Moreover, the mobility sequence based on the sum of the first three phases (for grain sizes of < 63µm) was Mn > Pb > Cd > Zn > Cu >Ni > Cr > As. Enrichment factors (EF) indicated that heavy metals in Jiaozhou Bay presented from no enrichment to minor enrichment. The potential ecological risk index (RI) indicated that Jiaozhou Bay had been suffering from a low ecological risk and presented an increasing trend since 1940s owing to the increase of anthropogenic activities. The source analysis indicated that natural sources were primary sources of heavy metals in Jiaozhou Bay and anthropogenic sources of heavy metals presented an increasing trend since 1940s. The principal component analysis (PCA) indicated that Cr, Mn, Ni, Cu and Pb were primarily derived from natural sources and that Zn and Cd were influenced by shipbuilding industry. Mn, Cu, Zn and Pb may originate from both natural and anthropogenic sources. As may be influenced by agricultural activities. Moreover, heavy metals in sediments of Jiaozhou Bay were clearly influenced by atmospheric deposition and river input.

CDC-NET: a cell detection and confirmation network of bone marrow aspirate images for the aided diagnosis of AML.

Standardized morphological evaluation in pathology is usually qualitative. Classifying and qualitatively analyzing the nucleated cells in the bone marrow aspirate images based on morphology is crucial for the diagnosis of acute myoid leukemia (AML), acute lymphoblastic leukemia (ALL), and Myelodysplastic syndrome (MDS), etc. However, it is time-consuming and difficult to accurately identify nucleated cells and calculate the percentage of the cells because of the complexity of bone marrow aspirate images. This paper proposed a deep learning analysis model of bone marrow aspirate images, termed Cell Detection and Confirmation Network (CDC-NET), for the aided diagnosis of AML by improving the accuracy of cell detection and recognition. Specifically, we take the nucleated cells in the bone marrow aspirate images as the detection objects to establish the model. Since some cells from different categories have similar morphology, classification error is inevitable. We design a confirmation network in which multiple trained classifiers work as pathologists to confirm the cell category by a voting method. To demonstrate the effectiveness of the proposed approach, experiments on clinical microscopic datasets are conducted. The Recall and Precision of CDC-NET are 78.54% and 91.74% respectively, and the missed rate of our method is lower than those of the other popular methods. The experimental results demonstrated that the proposed model has the potential for the pathological analysis of aspirate smears and the aided diagnosis of AML.

Unraveling seasonal shifts in microbial and geochemical mediated arsenic mobilization at the estuarine sediment-water interface under redox changes.

The mobilization of arsenic (As) at the sediment-water interface (SWI) is crucial for determining the accumulation of dissolved As to potentially toxic levels. However, the specific impacts of redox processes involving iron (Fe) and sulfur (S), as well as microbial activities occurring in sediments, on As mobilization at the marine SWI remain poorly understood. In this study, we investigated As mobilization at the SWI in the Changjiang Estuary during three different seasons with different benthic redox conditions. The preferential reduction of arsenate (As(V)) to arsenite (As(III)) and subsequent re-adsorption onto newly formed crystalline Fe oxides restricted As release in the As(V) reduction layer. Enhanced Fe(III) reduction in the Fe(III) reduction layer contributed to As release, while the presence of low As-high Fe-high SO42- levels resulted in As removal through adsorption onto pyrite in the sulfate reduction layer. Analysis of functional genes indicated that As(V) in sediments was released into porewater through the reductive dissolution of As(V)-bearing Fe(III) oxides by Geobacter species, followed by microbial reduction of the liberated As(V) to As(III) by microbes carrying the arrA gene. The dominant pathway governing As mobilization at the SWI in the Changjiang Estuary shifted from microbial reduction control during the hypoxic summer to Fe redox control during the aerobic autumn and winter. These findings provide valuable insights into the complex mechanisms driving As mobilization and highlight the importance of considering seasonal variations in understanding As dynamics at the marine SWI.

Organic carbon in wet deposition of an urbanized coastal bay, North China: Flux, sources and biogeochemical implications.

The process of atmospheric organic carbon (OC) entering the ocean through wet deposition plays a crucial role in the global carbon cycle. To gain insights into the biogeochemical dynamics of OC at the land-sea margin, we conducted an extensive four-year investigation on precipitation OC in Jiaozhou Bay (JZB). The results showed that the volume-weighted mean concentration of particulate OC (POC) and dissolved OC (DOC) in precipitation were 0.38 and 2.06 mg C L-1 with an average wet deposition flux of OC for 2666.5 mg C m-2 yr-1. The source of POC in precipitation is predominantly by the C3 plant emission and burning and fossil fuel combustion. Wet deposition contributed 986.6 t yr-1 of OC of which 506.3 t yr-1 of bioavailable DOC, which could have significant implications for carbon cycle in the JZB. This study could enhance the understanding of the marine atmospheric OC in coastal areas.

Nutrient characteristics driven by multiple factors in large estuaries during summer: A case study of the Yangtze River Estuary.

Nutrients directly control the level of primary productivity and are crucial for the stability of marine ecosystems. Focusing on the survey results in August 2020 of the Yangtze River Estuary, this study elucidated the distribution characteristics and controlling factors of three nutrients: NO3-N, PO4-P, SiO3-Si. The results showed that the concentrations of NO3-N, PO4-P, SiO3-Si in the study area were generally higher near the shore than far shore, with average concentrations of 11.40, 0.70, and 23.73 µmol/L, respectively. The ocean currents drove the distribution of nutrients, and the transport of CDW and YSCC increased the nutrient levels. The resuspension of sediment caused by factors such as terrain and weather may lead to an abnormal increase in nutrients in the bottom waters. The main controlling factors of the three nutrients were different. NO3-N was significantly affected by human activities, PO4-P and SiO3-Si were mainly affected by natural factors.

Tailoring raloxifene into single-component molecular crystals possessing multilevel stimuli-responsive room-temperature phosphorescence.

Simultaneously achieving room-temperature phosphorescence (RTP) and multiple-stimuli responsiveness in a single-component system is of significance but remains challenging. Crystallization has been recognized to be a workable strategy to fulfill the above task. However, how the molecular packing mode affects the intersystem crossing and RTP lifetime concurrently remains unclear so far. Herein, four economic small-molecular compounds, analogues of the famous drug raloxifene (RALO), are facilely synthesized and further explored as neat single-component and stimuli-responsive RTP emitters via crystallization engineering. Thanks to their simple structures and high ease to crystallize, these raloxifene analogues function as models to clarify the important role of molecular packing in the RTP and stimuli-responsiveness properties. Thorough combination of the single-crystal structure analysis and theoretical calculations clearly manifests that the tight antiparallel molecular packing mode is the key point to their RTP behaviors. Interestingly, harnessing the controllable and reversible phase transitions of the two polymorphs of RALO-OAc driven by mechanical force, solvent vapor, and heat, a single-component multilevel stimuli-responsive platform with tunable emission color is established and further exploited for optical information encryption. This work would shed light on the rational design of multi-stimuli responsive RTP systems based on single-component organics.