Virus-derived circular RNAs populate hepatitis C virus-infected cells.

It is known that pre-mRNAs in eukaryotic cells can be processed to circular RNAs by a backsplicing mechanism. Circular RNAs have great stability and can sequester proteins or small RNAs to exert functions on cellular pathways. Because viruses often exploit host pathways, we explored whether the RNA genome of the cytoplasmic hepatitis C virus is processed to yield virus-derived circRNAs (vcircRNAs). Computational analyses of RNA-seq experiments predicted that the viral RNA genome is fragmented to generate hundreds of vcircRNAs. More than a dozen of them were experimentally verified by rolling-circle amplification. VcircRNAs that contained the viral internal ribosome entry site were found to be translated into proteins that displayed proviral functions. Furthermore, two highly abundant, nontranslated vcircRNAs were shown to enhance viral RNA abundance. These findings argue that novel vcircRNA molecules modulate viral amplification in cells infected by a cytoplasmic RNA virus.

The genomic landscape of acute lymphoblastic leukemia with intrachromosomal amplification of chromosome 21.

Intrachromosomal amplification of chromosome 21 defines a subtype of high-risk childhood acute lymphoblastic leukemia (iAMP21-ALL) characterized by copy number changes and complex rearrangements of chromosome 21. The genomic basis of iAMP21-ALL and the pathogenic role of the region of amplification of chromosome 21 to leukemogenesis remains incompletely understood. In this study, using integrated whole genome and transcriptome sequencing of 124 patients with iAMP21-ALL, including rare cases arising in the context of constitutional chromosomal aberrations, we identified subgroups of iAMP21-ALL based on the patterns of copy number alteration and structural variation. This large data set enabled formal delineation of a 7.8 Mb common region of amplification harboring 71 genes, 43 of which were differentially expressed compared with non-iAMP21-ALL ones, including multiple genes implicated in the pathogenesis of acute leukemia (CHAF1B, DYRK1A, ERG, HMGN1, and RUNX1). Using multimodal single-cell genomic profiling, including single-cell whole genome sequencing of 2 cases, we documented clonal heterogeneity and genomic evolution, demonstrating that the acquisition of the iAMP21 chromosome is an early event that may undergo progressive amplification during disease ontogeny. We show that UV-mutational signatures and high mutation load are characteristic secondary genetic features. Although the genomic alterations of chromosome 21 are variable, these integrated genomic analyses and demonstration of an extended common minimal region of amplification broaden the definition of iAMP21-ALL for more precise diagnosis using cytogenetic or genomic methods to inform clinical management.

Landsat observations of total suspended solids concentrations in the Pearl River Estuary, China, over the past 36 years.

Information on long-term trends in total suspended solids (TSS) is critical for assessing aquatic ecosystems. However, the long-term patterns of TSS concentration (CTSS) and its latent drivers have not been well investigated. In this study, we developed and validated three semi-analysis algorithms for deriving CTSS using Landsat images. Subsequently, the long-term trends in CTSS in the Pearl River Estuary (PRE) from 1987 to 2022 and the driving factors were clarified. The developed algorithms yielded excellent performance in estimating CTSS, with mean absolute percentage errors <25% and root mean square errors of <13 mg/L. Long-term Landsat observations showed an overall decreasing trend and significant spatiotemporal dynamics of the CTSS in the PRE from 1987 to 2022. The analysis of driving factors suggested that industrial sewage, cropland, forests and grasslands, and built-up land were the four potential driving forces that explained 87.81% of the long-term variation in CTSS. This study not only provides 36-year recorded datasets of CTSS in estuary water, but also offers new insights into the complex mechanisms that regulate CTSS spatiotemporal dynamics for water resource management.

Long-term dynamics and drivers of particulate phosphorus concentration in eutrophic lake Chaohu, China.

Particulate phosphorus (PP) plays an important biological role in the eutrophication process, and is thus an important water quality parameter for assessing climatic change and anthropogenic activity factors that affect aquatic ecosystems. Here, we used 20-year Moderate Resolution Imaging Spectroradiometer (MODIS) data to explore the patterns and trends of PP concentration (CPP) in eutrophic Lake Chaohu based on a new empirical model. The validation results indicated that the developed model performed satisfactorily in estimating CPP, with a mean absolute percentage error of 31.89% and root mean square error of 0.022 mg/L. Long-term MODIS observations (2000-2019) revealed that the CPP of Lake Chaohu has experienced an overall increasing trend and distinct spatiotemporal heterogeneity. The driving factor analysis revealed that the chemical fertilizer consumption, municipal wastewater, industrial sewage, precipitation, and air temperature were the five potential driving factors and collectively explained more than 81% of the long-term variation in CPP. This study provides the long-term datasets of CPP in inland waters and new insights for future water eutrophication control and restoration efforts.

Enhanced GII.4 human norovirus infection in gnotobiotic pigs transplanted with a human gut microbiota.

The role of commensal microbiota in enteric viral infections has been explored extensively, but the interaction between human gut microbiota (HGM) and human norovirus (HuNoV) is poorly understood. In this study, we established an HGM-Transplanted gnotobiotic (Gn) pig model of HuNoV infection and disease, using an infant stool as HGM transplant and a HuNoV GII.4/2006b strain for virus inoculation. Compared to germ-free Gn pigs, HuNoV inoculation in HGMT Gn pigs resulted in increased HuNoV shedding, characterized by significantly higher shedding titres on post inoculation day (PID) 3, 4, 6, 8 and 9, and significantly longer mean duration of virus shedding. In addition, virus titres were significantly higher in duodenum and distal ileum of HGMT Gn pigs on PID10, while comparable and transient HuNoV viremia was detected in both groups. 16S rRNA gene sequencing demonstrated that HuNoV infection dramatically altered intestinal microbiota in HGMT Gn pigs at the phylum (Proteobacteria, Firmicutes and Bacteroidetes) and genus (Enterococcus, Bifidobacterium, Clostridium, Ruminococcus, Anaerococcus, Bacteroides and Lactobacillus) levels. In summary, enhanced GII.4 HuNoV infection was observed in the presence of HGM, and host microbiota was susceptible to disruption upon HuNoV infection.

HMGB1 Promotes Hepatitis C Virus Replication by Interaction with Stem-Loop 4 in the Viral 5' Untranslated Region.

UNLABELLED: High-mobility group box 1 (HMGB1) protein is a highly conserved nuclear protein involved in multiple human diseases, including infectious diseases, immune disorders, metabolic disorders, and cancer. HMGB1 is comprised of two tandem HMG boxes (the A box and the B box) containing DNA-binding domains and an acidic C-terminal peptide. It has been reported that HMGB1 enhances viral replication by binding to viral proteins. However, its role in hepatitis C virus (HCV) replication is unknown. Here, we show that HMGB1 promoted HCV replication but had no effect on HCV translation. RNA immunoprecipitation experiments indicated that the positive strand, not the negative strand, of HCV RNA interacted with HMGB1. HCV infection triggered HMGB1 protein translocation from the nucleus to the cytoplasm, in which it interacted with the HCV genome. Moreover, the A box of HMGB1 is the pivotal domain to interact with stem-loop 4 (SL4) of the HCV 5' untranslated region. Deletion of the HMGB1 A box abrogated the enhancement of HCV replication by HMGB1. Our data suggested that HMGB1 serves as a proviral factor of HCV to facilitate viral replication in hepatocytes by interaction with the HCV genome. IMPORTANCE: Hepatitis C virus (HCV) is a major global health threat, affecting more than 170 million people infection worldwide. These patients are at high risk of developing severe liver diseases such as chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Currently, no vaccine is available. Many host factors may be implicated in the pathogenesis of HCV-related diseases. In this study, we found a novel HCV RNA-binding protein, HMGB1, that promotes HCV RNA replication. Moreover, SL4 in the 5' untranslated region of the HCV genome is the key region for HMGB1 binding, and the A box of HMGB1 protein is the functional domain to interact with HCV RNA and enhance viral replication. HMGB1 appears to play an important role in HCV-related diseases, and further investigation is warranted to elucidate the specific actions of HMGB1 in HCV pathogenesis.

Humification levels of dissolved organic matter in the eastern plain lakes of China based on long-term satellite observations.

Under the influence of intensive human activities and global climate change, the sources and compositions of dissolved organic matter (DOM) in the eastern plain lake (EPL) region in China have fluctuated sharply. It has been successfully proven that the humification index (HIX), which can be derived from three-dimensional excitation-emission matrix fluorescence spectroscopy, can be an effective proxy for the sources and compositions of DOM. Therefore, combined with remote sensing technology, the sources and compositions of DOM can be tracked on a large scale by associating the HIX with optically active components. Here, we proposed a novel HIX remote sensing retrieval (IRHIX) model suitable for Landsat series sensors based on the comprehensive analysis of the covariation mechanism between HIX and optically active components in different water types. The validation results showed that the model runs well on the independent validation dataset and the satellite-ground synchronous sampling dataset, with an uncertainty ranging from 30.85 % to 36.92 % (average ± standard deviation = 33.6 % ± 3.07 %). The image-derived HIX revealed substantial spatiotemporal variations in the sources and compositions of DOM in 474 lakes in the EPL during 1986-2021. Subsequently, we obtained three long-term change modes of the HIX trend, namely, significant decline, gentle change, and significant rise, accounting for 74.68 %, 17.09 %, and 8.23 % of the lake number, respectively. The driving factor analysis showed that human activities had the most extensive influence on the DOM humification level. In addition, we also found that the HIX increased slightly with increasing lake area (R2 = 0.07, P < 0.05) or significantly with decreasing trophic state (R2 = 0.83, P < 0.05). Our results provide a new exploration for the effective acquisition of long-term dynamic information about the sources and compositions of DOM in inland lakes and provide important support for lake water quality management and restoration.

Long-term remote observations of particulate organic phosphorus concentration in eutrophic Lake Taihu based on a novel algorithm.

Monitoring the long-term spatiotemporal variations in particulate organic phosphorus concentration (CPOP) is imperative for clarifying the phosphorus cycle and its biogeochemical behavior in waters. However, little attention has been devoted to this owing to a lack of suitable bio-optical algorithms that allow the application of remote sensing data. In this study, based on Moderate Resolution Imaging Spectroradiometer (MODIS) data, a novel absorption-based algorithm of CPOP was developed for eutrophic Lake Taihu, China. The algorithm yielded a promising performance with a mean absolute percentage error of 27.75% and root mean square error of 21.09 µg/L. The long-term MODIS-derived CPOP demonstrated an overall increasing pattern over the past 19 years (2003-2021) and a significant temporal heterogeneity in Lake Taihu, with higher value in summer (81.97 ± 3.81 µg/L) and autumn (82.07 ± 3.8 µg/L), and lower CPOP in spring (79.52 ± 3.81 µg/L) and winter (78.74 ± 3.8 µg/L). Spatially, relatively higher CPOP was observed in the Zhushan Bay (85.87 ± 7.5 µg/L), whereas the lower value was observed in the Xukou Bay (78.95 ± 3.48 µg/L). In addition, significant correlations (r > 0.6, P < 0.05) were observed between CPOP and air temperature, chlorophyll-a concentration and cyanobacterial blooms areas, demonstrating that CPOP was greatly influenced by air temperature and algal metabolism. This study provides the first record of the spatial-temporal characteristics of CPOP in Lake Taihu over the past 19 years, and the CPOP results and regulatory factors analyses could provide valuable insights for aquatic ecosystem conservation.

A semi-analytical model to estimate Chlorophyll-a spatial-temporal patterns from Orbita Hyperspectral image in inland eutrophic waters.

It can be challenging to accurately estimate the Chlorophyll-a (Chl-a) concentration in inland eutrophic lakes due to lakes' extremely complex optical properties. The Orbita Hyperspectral (OHS) satellite, with its high spatial resolution (10 m), high spectral resolution (2.5 nm), and high temporal resolution (2.5 d), has great potential for estimating the Chl-a concentration in inland eutrophic waters. However, the estimation capability and radiometric performance of OHS have received limited examination. In this study, we developed a new quasi-analytical algorithm (QAA716) for estimating Chl-a using OHS images. Based on the optical properties in Dianchi Lake, the ability of OHS to remotely estimate Chl-a was evaluated by comparing the signal-to-noise ratio (SNR) and the noise equivalent of Chl-a (NEChl-a). The main findings are as follows: (1) QAA716 achieved significantly better results than those of the other three QAA models, and the Chl-a estimation model, using QAA716, produced robust results with a mean absolute percentage difference (MAPD) of 11.54 %, which was better than existing Chl-a estimation models; (2) The FLAASH (Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes) atmospheric correction model (MAPD = 22.22 %) was more suitable for OHS image compared to the other three atmospheric correction models we tested; (3) OHS had relatively moderate SNR and NEChl-a, improving its ability to accurately detect Chl-a concentration and resulting in an average SNR of 59.47 and average NEChl-a of 72.86 µg/L; (4) The increased Chl-a concentration in Dianchi Lake was primarily related to the nutrients input, and this had a significant positive correlation with total nitrogen. These findings expand existing knowledge of the capabilities and limitations of OHS in remotely estimating Chl-a, thereby facilitating effective water quality management in eutrophic lake environments.

Remote sensing identification of urban water pollution source types using hyperspectral data.

Owing to accelerated urbanisation, increased pollutants have degraded urban water quality. Timely identification and control of pollution sources enable relevant departments to effectively perform water treatment and restoration. To achieve this goal, a remote sensing identification method for urban water pollution sources applicable to unmanned aerial vehicle (UAV) hyperspectral images was established. First, seven fluorescent components were obtained through three-dimensional excitation-emission matrix fluorescence spectroscopy of dissolved organic matter (DOM) combined with parallel factor analysis. Based on the hierarchical cluster analysis of the seven fluorescence components and three spectral indices, four pollution source (PS) types were determined, namely, domestic sewage, terrestrial input, agricultural and algal, and industrial wastewater sources. Second, several water colour and optical parameters, including the absorption coefficient of chromophoric DOM at 254 nm, humification index, chlorophyll-a concentration, and hue angle, were utilised to develop an identification method with a recognition accuracy exceeding 70% for the four PSs that is suitable for UAV hyperspectral data. This study demonstrated the potential of identifying PSs by combining the fluorescence characteristics of DOM with the optical properties of water, thus expanding the application of remote sensing technologies and providing more comprehensive and reliable information for urban water quality management.

Hemagglutinin destabilization in H3N2 vaccine reference viruses skews antigenicity and prevents airborne transmission in ferrets.

During influenza virus entry, the hemagglutinin (HA) protein binds receptors and causes membrane fusion after endosomal acid activation. To improve vaccine efficiency and pandemic risk assessment for currently-dominant H3N2 influenza viruses, we investigated HA stability of 6 vaccine reference viruses and 42 circulating viruses. Recent vaccine reference viruses had destabilized HA proteins due to egg-adaptive mutation HA1-L194P. Virus growth in cell culture was independent of HA stability. In ferrets, the vaccine reference viruses and circulating viruses required a relatively stable HA (activation and inactivation pH < 5.5) for airborne transmissibility. The recent vaccine reference viruses with destabilized HA proteins had reduced infectivity, had no airborne transmissibility unless reversion to HA1-P194L occurred, and had skewed antigenicity away from the studied viruses and circulating H3N2 viruses. Other vaccine reference viruses with stabilized HAs retained infectivity, transmissibility, and antigenicity. Therefore, HA stabilization should be prioritized over destabilization in vaccine reference virus selection to reduce mismatches between vaccine and circulating viruses.

An Exosome-Based Therapeutic Strategy Targeting Neuroinflammation in Alzheimer's Disease with Berberine and Palmatine.

Introduction: Neuroinflammation is one of the major pathogeneses in Alzheimer's disease (AD) and mainly involves abnormal inflammatory activation of microglia by multiple pathological stimuli. The treatment of AD remains a major challenge due to the multifactorial characterization of AD and the inefficient ability of therapeutic drugs to permeate through the blood‒brain barrier (BBB). Accordingly, drug combination treatment and drug carrier delivery have become important therapeutic tools for the treatment of multifactorial diseases, especially AD. Methods: Inflammatory cytokine levels in microglia, including NO, TNF-α, IL-1ß, IL-4, and IL-10, were detected. The Morris water maze and object location task were used to investigate the learning and memory functions of APP/PS1 mice in different treatment groups. The number of neurons and plasticity of synapses were evaluated by immunofluorescence double labelling. Additionally, the ratio of ß-amyloid plaques and the number of activated microglia were evaluated by immunofluorescence staining. The concentrations of ß-amyloid plaques and inflammatory factors in the hippocampus were determined by ELISA. Microglia-derived exosomes (Exos) were extracted and purified by size exclusion chromatography. The distribution of exosomes and drugs was investigated in vitro and in vivo. Results: Compared to single drug interventions, the combination of Ber and Pal (Ber/Pal) modulated microglial inflammatory cytokine levels. Ber/Pal promoted the recovery of learning and memory impairment in APP/PS1 mice. Immunofluorescence staining indicated that Ber/Pal restored neurons, inhibited Aß plaque formation and microglial activation, and regulated the secretion of inflammatory factors. Exos promoted the accumulation of drugs in cells and tissues and improved the targeting of drugs across the BBB. Conclusion: Ber/Pal could offer a synergistic and more comprehensive therapeutic effect in AD. Additionally, the microglia-derived Exos-Ber/Pal delivery system promoted the targeting and permeation of drugs into the brain, suggesting a creative strategy for targeting AD therapy by regulating neuroinflammation in microglial cells.

A hybrid remote sensing approach for estimating chemical oxygen demand concentration in optically complex waters: A case study in inland lake waters in eastern China.

Chemical oxygen demand concentration (CCOD) is widely used to indicate the degree of organic pollution of lakes, reservoirs and rivers. Mastering the spatiotemporal distribution of CCOD is imperative for understanding the variation mechanism and controlling of organic pollution in water. In this study, a hybrid approach suitable for Sentinel 3A/Ocean and Land Colour Instrument (OLCI) data was developed to estimate CCOD in inland optically complex waters embedding the interaction between CCOD and the absorption coefficients of optically active constituents (OACs). Based on in-situ sampling in different waters, the independent validations of the proposed model performed satisfactorily in Lake Taihu (MAPE = 23.52 %, RMSE = 0.95 mg/L, and R2 = 0.81), Lake Qiandaohu (MAPE = 21.63 %, RMSE = 0.50 mg/L and R2 = 0.69), and Yangtze River (MAPE = 29.34 %, RMSE = 0.83 mg/L, and R2 = 0.64). In addition, the approach not only showed significant superiority compared with previous algorithms, but also was suitable for other common satellite sensors equipped same or similar bands. The hybrid approach was applied to OLCI images to retrieve CCOD of Lake Taihu from 2016 to 2020 and reveals substantial interannual and seasonal variations. The above results indicate that the proposed approach is effective and stable for studying spatiotemporal dynamic of CCOD in optically complex waters, and that satellite-derived products can provide reliable information for lake water quality management.

Remote monitoring of total dissolved phosphorus in eutrophic Lake Taihu based on a novel algorithm: Implications for contributing factors and lake management.

Understanding the spatiotemporal dynamics of total dissolved phosphorus concentration (CTDP) and its regulatory factors is essential to improving our understanding of its impact on inland water eutrophication, but few studies have assessed this in eutrophic inland lakes due to a lack of suitable bio-optical algorithms allowing the use of remote sensing data. We developed a novel semi-analytical algorithm for this purpose and tested it in the eutrophic Lake Taihu, China. Our algorithm produced robust results with a mean absolute square percentage error of 29.65% and root mean square error of 9.54 µg/L. Meanwhile, the new algorithm demonstrates good portability to other waters with different optical properties and could be applied to various image data, including Moderate Resolution Imaging Spectroradiometer (MODIS), Medium Resolution Imaging Spectrometer (MERIS), and Ocean and Land Color Instrument (OLCI). Further analysis based on Geostationary Ocean Color Imager observations from 2011 to 2020 revealed a significant spatiotemporal heterogeneity of CTDP in Lake Taihu. Correlation analysis of the long-term trend between CTDP and driving factors demonstrated that air temperature is the dominant regulating factor in variations of CTDP. This study provides a novel algorithm allowing remote-sensing monitoring of CTDP in eutrophic lakes and can lead to new insights into the role of dissolved phosphorus in water eutrophication.

Monitoring the particulate phosphorus concentration of inland waters on the Yangtze Plain and understanding its relationship with driving factors based on OLCI data.

Tracking the spatiotemporal dynamics of particulate phosphorus concentration (CPP) and understanding its regulating factors is essential to improve our understanding of its impact on inland water eutrophication. However, few studies have assessed this in eutrophic inland lakes, owing to a lack of suitable bio-optical algorithms allowing the use of remote sensing data. Herein, a novel semi-analytical algorithm of CPP was developed to estimate CPP in lakes on the Yangtze Plain, China. The independent validations of the proposed algorithm showed a satisfying performance with the mean absolute percentage error and root mean square error less than 27% and 27 µg/L, respectively. The Ocean and Land Color Instrument observations revealed a remarkable spatiotemporal heterogeneity of CPP in 23 lakes on the Yangtze Plain from 2016 to 2020, with the lowest value in December (62.91 ± 34.59 µg/L) and the highest CPP in August (114.9 ± 51.69 µg/L). Among the 23 examined lakes, the highest mean CPP was found in Lake Poyang (124.58 ± 44.71 µg/L), while the lowest value was found in Lake Qiandao (33.51 ± 4.71 µg/L). Additionally, 13 lakes demonstrated significant decreasing or increasing trends (P < 0.05) of annual mean CPP during the observation period. The driving factor analysis revealed that four natural factors (wind speed, air temperature, precipitation, and sunshine duration) and two anthropogenic factors (the normalized difference vegetation index and nighttime light) combined explained more than 91% of the variation in CPP, while the impacts of these factors on CPP showed considerable differences among lakes. This study offered a novel and scalable algorithm for the study of the spatiotemporal variation of CPP in inland waters and provided new insights into the regulating factors in water eutrophication.

A New Gnotobiotic Pig Model of P[6] Human Rotavirus Infection and Disease for Preclinical Evaluation of Rotavirus Vaccines.

Human rotavirus (HRV) is a leading cause of gastroenteritis in children under 5 years of age. Licensed vaccines containing G1P[8] and G1-4P[8] strains are less efficacious against newly emerging P[6] strains, indicating an urgent need for better cross protective vaccines. Here, we report our development of a new gnotobiotic (Gn) pig model of P[6] HRV infection and disease as a tool for evaluating potential vaccine candidates. The Arg HRV (G4P[6]) strain was derived from a diarrheic human infant stool sample and determined to be free of other viruses by metagenomic sequencing. Neonatal Gn pigs were orally inoculated with the stool suspension containing 5.6 × 105 fluorescent focus units (FFU) of the virus. Small and large intestinal contents were collected at post inoculation day 2 or 3. The virus was passaged 6 times in neonatal Gn pigs to generate a large inoculum pool. Next, 33-34 day old Gn pigs were orally inoculated with 10-2, 103, 104, and 105 FFU of Arg HRV to determine the optimal challenge dose. All pigs developed clinical signs of infection, regardless of the inoculum dose. The optimal challenge dose was determined to be 105 FFU. This new Gn pig model is ready to be used to assess the protective efficacy of candidate monovalent and multivalent vaccines against P[6] HRV.

CPX-351 induces remission in newly diagnosed pediatric secondary myeloid malignancies.

Secondary myelodysplastic syndromes and acute myeloid leukemia (sMDS/AML) are rare in children and adolescents and have a dismal prognosis. The mainstay therapy is hematopoietic cell transplantation (HCT), but there has been no innovation in cytoreductive regimens. CP X-351, a fixed 5:1 molar ratio of liposomal cytarabine to daunorubicin, has shown favorable safety and efficacy in elderly individuals with secondary AML and children with relapsed de novo AML. We report the outcomes of 7 young patients (6 with newly diagnosed sMDS/AML and 1 with primary MDS/AML) uniformly treated with CP X-351. Five patients had previously received chemotherapy for osteosarcoma, Ewing sarcoma, neuroblastoma, or T-cell acute lymphoblastic leukemia; 1 had predisposing genomic instability disorder (Cornelia de Lange syndrome) and 1 had MDS-related AML and multiorgan failure. The median age at diagnosis of myeloid malignancy was 17 years (range, 13-23 years). Patients received 1 to 3 cycles of CP X-351 (cytarabine 100 mg/m2 plus daunorubicin 44 mg/m2) on days 1, 3, and 5, resulting in complete morphologic remission without overt toxicity or treatment-related mortality. This approach allowed for adding an FLT3 inhibitor as individualized therapy in 1 patient. Six patients were alive and leukemia-free at 0.5 to 3.3 years after HCT. One patient died as a result of disease progression before HCT. To summarize, CP X-351 is an effective and well-tolerated regimen for cytoreduction in pediatric sMDS/AML that warrants prospective studies.

Simultaneous inversion of concentrations of POC and its endmembers in lakes: A novel remote sensing strategy.

Data on the concentration of particulate organic carbon (POC) and its endmembers provide a basis for the characterisation of lake biogeochemical cycles. Here, a novel remote sensing strategy (the SCPOC algorithm) was developed to determine total POC concentrations, as well as terrestrial and endogenous POC concentrations in lakes. This strategy provides a successful example for the combination of isotope tracer and remote sensing technology. First, we obtained the terrestrial and endogenous POC concentration at the sampling point based on isotope tracing technology. Afterwards, we established a relationship between the phytoplankton absorption coefficient and the endogenous POC concentration (Cend), and applied a semi-analytical algorithm to invert the Cend value. Finally, the POC source ratio model and Cend value were combined to obtain the POC concentration (CPOC) and terrestrial POC (Cter). The results of synchronisation verification based on ocean and land colour instrument (OLCI) images show that the SCPOC algorithm has high Cend, Cter, and CPOC inversion accuracy, with MAPE values of 26.07%, 30.43%, and 42.28%, respectively. In fact, the SCPOC algorithm not only improved the accuracy of lake POC mapping, but also fills the gap of optical retrieval of POC endmember concentrations. Additionally, data from the OLCI images indicated that the studied lakes were dominated by external POC. However, because of the greater contribution of algal blooms to POC, this dominant advantage weakens in summer, although the terrestrial organic carbon carried by rainfall runoff also affects lake POC composition. Different POC sources have different ecological roles in lakes, and the superior POC end-element estimation capability of the SCPOC algorithm can not only be used as a supplement to traditional tracing methods, but also provides accurate spatial data for lake management.

A semi-analytical algorithm for deriving the particle size distribution slope of turbid inland water based on OLCI data: A case study in Lake Hongze.

The particle size distribution (PSD) slope (ξ) can indicate the predominant particle size, material composition, and inherent optical properties (IOPs) of inland waters. However, few semi-analytical methods have been proposed for deriving ξ from the surface remote sensing reflectance due to the variable optical state of inland waters. A semi-analytical algorithm was developed for inland waters having a wide range of turbidity and ξ in this study. Application of the proposed model to Ocean and Land Color Instrument (OLCI) imagery of the water body resulted in several important observations: (1) the proposed algorithm (754 nm and 779 nm combination) was capable of retrieving ξ with R2 being 0.72 (p < 0.01, n = 60), and MAPE and RMSE being 4.37% and 0.22 (n = 30) respectively; (2) the ξ in HZL was lower in summer than other seasons during the period considered, this variation was driven by the phenological cycle of algae and the runoff caused by rainfall; (3) the band optimization proposed in this study is important for calculating the particle backscattering slope (η) and deriving ξ because it is feasible for both algae dominant and sediment governed turbid inland lakes. These observations help improve our understanding of the relationship between IOPs and ξ, which are affected by different bio-optic processes and algal phenology in the lake environment.