Unveiling the underestimated direct emissions of nitrous acid (HONO).

Gaseous nitrous acid (HONO) is a critical source of hydroxyl radicals (OH) in the troposphere. While both direct and secondary sources contribute to atmospheric HONO, direct emissions have traditionally been considered minor contributors. In this study, we developed δ15N and δ18O isotopic fingerprints to identify six direct HONO emission sources and conducted a 1-y case study on the isotopic composition of atmospheric HONO at rural and urban sites. Interestingly, we identified that livestock farming is a previously overlooked direct source of HONO and determined its HONO to ammonia (NH3) emission ratio. Additionally, our results revealed that spatial and temporal variations in atmospheric HONO isotopic composition can be partially attributed to direct emissions. Through a detailed HONO budget analysis incorporating agricultural sources, we found that direct HONO emissions accounted for 39~45% of HONO production in rural areas across different seasons. The findings were further confirmed by chemistry transport model simulations, highlighting the significance of direct HONO emissions and their impact on air quality in the North China Plain. These findings provide compelling evidence that direct HONO emissions play a more substantial role in contributing to atmospheric HONO than previously believed. Moreover, the δ15N and δ18O isotopic fingerprints developed in this study may serve as a valuable tool for further research on the atmospheric chemistry of reactive nitrogen gases.

Genetic and clinical characteristics of primary hemophagocytic lymphohistiocytosis in children.

To analyze the genetic variation and prognosis of primary hemophagocytic lymphohistiocytosis (pHLH) in children and the clinical features of isolated central nervous system HLH (CNS-HLH). We retrospectively analyzed the clinical and genetic data of 480 HLH children admitted to our hospital from September 2017 to September 2022. There were 66 patients (13.75%) with pHLH, and the median age was 3.21 years (0.17-12.92 years). Variants in UNC13D (22/66, 33.33%), PRF1 (20/66, 30.30%) and XIAP (11/66, 16.67%) were the most common. More CNS involvement was observed in pHLH patients than in secondary hemophagocytic lymphohistiocytosis (sHLH) patients (50% vs. 25.3%, P = 0.001). Eight pHLH patients had isolated CNS-HLH at onset, which progressed to systemic HLH within 10-30 days to several years. Among them, five patients who underwent hematopoietic stem cell transplantation (HSCT) survived without CNS sequelae, and the three patients who did not undergo HSCT died of disease progression or recurrence. Determination of natural killer (NK) cell cytotoxicity and CD107a levels had low sensitivity and specificity in the diagnosis of pHLH, especially in patients with PRF1 and XIAP mutations. The 3-year overall survival (OS) was significantly lower in pHLH patients than in sHLH patients (74.5% ± 14.7% vs. 89.2% ± 3.53%, P = 0.021) and in patients with CNS involvement than in those without (53.8% ± 26.07% vs. 94.4% ± 10.58%, P = 0.012). There was a significant difference in OS among pHLH patients with different gene variants (P = 0.032); patients with PRF1 variants had poor 3-year OS, and patients with XIAP variants had good 3-year OS (50% ± 28.22% and 100%, respectively). pHLH patients with distinct variants have different prognoses. Isolated CNS-HLH patients are easily misdiagnosed, and HSCT may be beneficial for these patients. Determination of NK cell cytotoxicity and CD107a levels cannot precisely distinguish pHLH from sHLH.

Reducing Soil-Emitted Nitrous Acid as a Feasible Strategy for Tackling Ozone Pollution.

Severe ozone (O3) pollution has been a major air quality issue and affects environmental sustainability in China. Conventional mitigation strategies focusing on reducing volatile organic compounds and nitrogen oxides (NOx) remain complex and challenging. Here, through field flux measurements and laboratory simulations, we observe substantial nitrous acid (HONO) emissions (FHONO) enhanced by nitrogen fertilizer application at an agricultural site. The observed FHONO significantly improves model performance in predicting atmospheric HONO and leads to regional O3 increases by 37%. We also demonstrate the significant potential of nitrification inhibitors in reducing emissions of reactive nitrogen, including HONO and NOx, by as much as 90%, as well as greenhouse gases like nitrous oxide by up to 60%. Our findings introduce a feasible concept for mitigating O3 pollution: reducing soil HONO emissions. Hence, this study has important implications for policy decisions related to the control of O3 pollution and climate change.

Optical Genome Mapping Reveals Novel Structural Variants in Lymphoblastic Lymphoma.

BACKGROUND: Accurate histologic and molecular genetic diagnosis is critical for the pathogenesis study of pediatric patients with lymphoblastic lymphoma (LBL). Optical genome mapping (OGM) as all-in-one process allows the detection of most major genomic risk markers, which addresses some of the limitations associated with conventional cytogenomic testing, such as low resolution and throughput, difficulty in ascertaining genomic localization, and orientation of segments in duplication, inversions, and insertions. Here, for the first time, we examined the cytogenetics of 5 children with LBL using OGM. METHODS: OGM was used to analyze 5 samples of pediatric LBL patients treated according to the modified NHL-BFM95 backbone regimen. Whole-exon Sequencing (WES) was used to confirm the existence of structural variants (SVs) identified by OGM with potentially clinical significance on MGI Tech (DNBSEQ-T7) platform. According to the fusion exon sequences revealed by WES, the HBS1L :: AHI1 fusion mRNA in case 4 was amplified by cDNA-based PCR. RESULTS: In total, OGM identified 251 rare variants (67 insertions, 129 deletions, 3 inversion, 25 duplications, 15 intrachromosomal translocations, and 12 interchromosomal translocations) and 229 copy number variants calls (203 gains and 26 losses). Besides all of the reproducible and pathologically significant genomic SVs detected by conventional cytogenetic techniques, OGM identified more SVs with definite or potential pathologic significance that were not detected by traditional methods, including 2 new fusion genes, HBS1L :: AHI1 and GRIK1::NSDHL , which were confirmed by WES and/or Reverse Transcription-Polymerase Chain Reaction. CONCLUSIONS: Our results demonstrate the feasibility of OGM to detect genomic aberrations, which may play an important role in the occurrence and development of lymphomagenesis as an important driving factor.

Correlation between telomere shortening in maternal peripheral blood and fetal aneuploidy.

BACKGROUND: This study aimed to assess whether maternal telomere length is a more accurate predictor of trisomy 21 than maternal age while also exploring the factors influencing maternal and fetal telomere length. METHODS: Forty mothers with fetuses carrying extra maternal copies of chromosome 21 were defined as trisomy 21 cases, and 18 mothers with normal karyotype fetuses were defined as controls. Telomere lengths of maternal blood lymphocytes and amniotic fluid cells were determined using real-time polymerase chain reaction. Fetal and maternal telomere lengths were compared between the two groups. Moreover, we analyzed the factors influencing maternal and fetal telomere length in the trisomy 21 pedigree. A logistic regression model was used to analyze the correlation between maternal telomere length and trisomy 21 risk. In addition, receiver operating characteristic (ROC) curve analysis was used to determine the accuracy of using maternal telomere length as an indicator of trisomy 21 risk. RESULTS: The study revealed that both maternal and fetal telomere lengths were significantly shorter in trisomy 21 cases than in the controls. In the trisomy 21 group, the maternal age, occupation, and nationality showed no significant correlation with their telomere length; fetal telomere length exhibited a positive correlation with maternal telomere length. Furthermore, maternal telomere length shortening is associated with trisomy 21 (OR = 0.311; 95% CI, 0.109-0.885, P < 0.05). The results of ROC curve analysis indicated that a combined assessment of maternal age and maternal telomere length predicted fetal chromosome trisomy more effectively than a single assessment (area under the curve 0.808, 95% CI, 0.674-0.941, P < 0.001). CONCLUSION: Maternal age combined with maternal telomere length proved to be a superior predictor of trisomy risk. Additionally, maternal telomere length was found to influence fetal telomere length.

Clinical characteristics of peripheral lymphocyte subtypes in chronic active Epstein-Barr virus infection.

PURPOSE: To analyze the clinical characteristics of peripheral Epstein-Barr virus(EBV)-infected lymphocyte subtypes in children with chronic active EBV infection(CAEBV). METHODS: The levels of peripheral EBV infection of CD4 + T cells, CD8 + T cells, and CD56 + NK cells were determined by flow cytometry and qPCR in patients with CAEBV from July 2017 to July 2022. RESULTS: A total of 112 children with CAEBV were evaluated in the study. Of them, CD4 + type, CD8 + type, and CD56 + type were defined in 44, 21, and 47 patients, respectively. Patients with CD8 + T-cell type had a significantly higher frequency of rash, while hepatomegaly was more common in patients with CD4 + T-cell type. Generally, patients with CD8 + T-cell type had the lowest overall survival(OS) rate(P = 0.017). As for treatment, patients treated with chemotherapy and hematopoietic stem cell transplantation had a better prognosis(P = 0.001). In multivariate analysis, rash, HLH, CD8 + T-cell type, and no decrease of plasma EBV-DNA after treatment were indicated as independent factors of poor prognosis(P = 0.002, 0.024, 0.022, and 0.012, respectively). CONCLUSION: In children with CAEBV, the rash was more frequent in patients with CD8 + T-cell type, whereas patients with CD4 + T-cell type were more likely to develop hepatomegaly. Patients with CD8 + T-cell type had a poor prognosis despite receiving chemotherapy or further HSCT.

Reconstructing the immunosenescence core pathway reveals global characteristics in pan-cancer.

Immunosenescence has been demonstrated to play an important role in tumor progression. However, there is lacking comprehensive analyses of immunosenescence-related pathways. Meanwhile, the sex disparities of immunosenescence in cancer are still poorly understood. In this study, we analyzed the multi-omics data of 12,836 tumor samples, including genomics, transcriptomics, epigenomics, proteomics, and metabolomics. We systematically identified immunosenescence pathways that were disordered across cancer types. The mutations and copy number variations of immunosenescence pathways were found to be more active in pan-cancer. We reconstructed the immunosenescence core pathways (ISC-pathways) to improve the ability of prognostic stratification in 33 cancer types. We also found the head and neck squamous carcinoma (HNSC) contained abundant sex-specific immunosenescence features and showed sex differences in survival. We found that OSI-027 was a potential sex-specific drug in HNSC tumors, which tended to be more effective in male HNSC by targeting the MTOR gene in the PI3K-Akt signaling pathway. In conclusion, our study provided a systematic understanding of immunosenescence pathways and revealed the global characteristics of immunosenescence in pan-cancer. We highlighted MTOR gene could be a powerful immunosenescence biomarker of HNSC that helps to develop sex-specific immunosenescence drugs.

BPTF in bone marrow provides a potential progression biomarker regulated by TFAP4 through the PI3K/AKT pathway in neuroblastoma.

BACKGROUND: Neuroblastoma (NB) is the most common extracranial malignant solid tumor in children, which is highly prone to bone marrow (BM) metastasis. BM can monitor early signs of mild disease and metastasis. Existing biomarkers are insufficient for the diagnosis and treatment of NB. Bromodomain PHD finger transcription factor (BPTF) is an important subunit of the chromatin-remodeling complex that is closely associated with tumors. Here, we evaluated whether BPTF in BM plays an important role in predicting NB progression, and explore the molecular mechanism of BPTF in NB. METHODS: The clinical relevance of the BPTF was predicted in the GEO (GSE62564) and TARGET database. The biological function of BPTF in NB was investigated by constructing cell lines and employing BPTF inhibitor AU1. Western blot was used to determine the changes of BPTF, TFAP4, PI3K/AKT signaling and Epithelial-mesenchymal transition (EMT) related markers. A total of 109 children with newly diagnosed NB in Beijing Children's Hospital from January 2018 to March 2021 were included in this study. RT-PCR was used to measure the BPTF and TFAP4 expression in BM. The cut-off level was set at the median value of BPTF expression levels. RESULTS: Databases suggested that BPTF expression was higher in NB and was significantly associated with stage and grade. Proliferation and migration of NB cells were slowed down when BPTF was silenced. Mechanistically, TFAP4 could positively regulate BPTF and promotes EMT process through activating the PI3K/AKT signaling pathway. Moreover, detection of the newly diagnosed BM specimens showed that BPTF expression was significantly higher in high-risk group, stage IV group and BM metastasis group. Children with high BPTF at initial diagnosis were considered to have high risk for disease progression and recurrence. BPTF is an independent risk factor for predicting NB progression. CONCLUSIONS: A novel and convenient BPTF-targeted humoral detection that can prompt minimal residual and predict NB progression in the early stages of the disease were identified. BPTF inhibitor AU1 is expected to become a new targeted drug for NB therapy. It's also reveal previously unknown mechanisms of BPTF in NB cell proliferation and metastasis through TFAP4 and PI3K/AKT pathways.

DNMT3A low-expression is correlated to poor prognosis in childhood B-ALL and confers resistance to daunorubicin on leukemic cells.

BACKGROUND: Little is known about DNMT3A expression and its prognostic significance in childhood B cell acute lymphoblastic leukemia (B-ALL). METHODS: We determined DNMT3A mRNA expression in 102 children with B-ALL. Correlations with relapse-free survival (RFS) and common clinical characteristics were analyzed. DNMT3A was stably knocked out by CRISPR/Cas9 gene editing technology in Reh and 697 B-ALL cell lines. Cell proliferation activity after treated with daunorubicin (DNR) was determined by CCK8 assay in DNMT3A KO Reh and 697 cell lines. RESULTS: DNMT3A expression in B-ALL patients who were in continuous complete remission (CCR) was higher than in those who got relapse (P = 0.0111). Receiver operating characteristic curve showed prognostic significance of DNMT3A expression (P = 0.003). Low expression of DNMT3A (≤ 0.197) was significantly correlated with poor RFS (P < 0.001) in children with B-ALL. Knock-out of DNMT3A in Reh and 697 cell lines significantly increased IC50 of DNR (P = 0.0201 and 0.0022 respectively), indicating elevated resistance to DNR. CONCLUSION: Low expression of DNMT3A associates with poor prognosis in children with B-ALL. Knock-out of DNMT3A confers resistance to DNR on leukemic cells.

Transport Pathways of Nitrate Formed from Nocturnal N2O5 Hydrolysis Aloft to the Ground Level in Winter North China Plain.

Particulate nitrate (NO3-) has currently become the major component of fine particles in the North China Plain (NCP) during winter haze episodes. However, the contributions of formation pathways to ground NO3- in the NCP are not fully understood. Herein, the NO3- formation pathways were comprehensively investigated based on model simulations combined with two-month field measurements at a rural site in the winter NCP. The results indicated that the nocturnal chemistry of N2O5 hydrolysis aloft could contribute evidently to ground NO3- at the rural site during the pollution episodes with high aerosol water contents, achieving the contribution percentages of 25.2-30.4% of the total. In addition to the commonly proposed vertical mixing of breaking nocturnal boundary layer in the early morning, two additional transport pathways (frontal downdrafts and downslope mountain breezes) in the nighttime were found to make higher contributions to ground NO3-. Considering the dominant role (69.6-74.8%) of diurnal chemistry in NO3- formation, reduction of NOx emissions in the daytime may be an effective control measure for reducing regional NO3- in the NCP.

Clinical Significance of Plasma Soluble MICB in Children With EBV-associated Hemophagocytic Lymphohistiocytosis.

BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is a potentially fatal systemic inflammation disease in children. The most common cause is Epstein-Barr virus (EBV) infection. MHC class I polypeptide-related sequence B (MICB) is a membrane protein inducibly expressed upon cellular stress, viral infection, or malignant transformation, thus marking these cells for clearance through natural killer group 2 member D-positive lymphocytes. MICB can be released into plasma through several mechanisms, reducing NK cell cytotoxicity. METHODS: We conducted clinical research on HLH patients and cell research in vitro. In the retrospective clinical part, 112 HLH patients (including EBV-HLH group and non-EBV-HLH group), 7 infectious mononucleosis patients, and 7 chronic active EBV infection patients were treated in Beijing Children's Hospital, affiliated with Capital Medical University, from January 2014 to December 2020, were enrolled in this study. Real-time quantitative polymerase chain reaction, standard enzyme-linked immunosorbent assay methods, and lactate dehydrogenase release tests were used to examine the expression of MICB mRNA, the soluble MICB (sMICB) levels, and the activity of NK cells in those patients. In vitro research, MICB overexpression-vector virus, MICB knockdown-vector virus, and empty-vector virus were transfected into two kinds of target cells, such as K562 and MCF7. The level of sMICB and NK cell killing activity between other groups was compared. Finally, we compared NK92 cell killing activity in different concentrations of sMICB. RESULTS: In clinical studies, compared with the non-EBV-HLH group, the EBV-HLH group had lower NK cell killing activity ( P < 0.05). The level of sMICB in the EBV-HLH group was significantly higher than in non-EBV-HLH, infectious mononucleosis, and chronic active EBV infection patients ( P ＜0.05). A high level of sMICB was associated with poor treatment response and poor prognosis ( P ＜0. 05). Cellular studies showed that an increased level of membrane MICB could positively correlate with the killing activity of NK92 cells ( P ＜0. 05), and a high level of sMICB (1250 to 5000pg/ml) could reduce the killing activity of NK92 cells ( P < 0.05). A high level of sMICB (2500pg/ml) could increase the release of cytokines from NK92 cells. CONCLUSION: The expression level of sMICB in EBV-HLH patients increased, and a high level of sMICB at the initial onset indicated a poor treatment response. The killing activity of NK cells in EBV-HLH patients decreased more significantly. The high level of sMICB may inhibit the killing activity but increase the release of cytokines of NK92 cells.

The effects of alcohol tax policies on alcohol consumption and alcohol use disorders in Mainland of China: an interrupted time series analysis from 1961-2019.

Background: Overwhelming evidence suggests that increasing alcohol taxes is an effective strategy for curbing alcohol consumption. However, research on the effects of such strategies in low- and middle-income nations is limited.Objective: The aim is to explore the temporal effect of alcohol tax policy in China.Methods: We employ interrupted time series analysis to investigate the temporal effects of tax policy changes on alcohol consumption and related consequences in Mainland China from 1961 to 2019. The study population, the total population of mainland region of China, aged more than 15 years.Results: The results show that the volume tax policy, which was announced in 2000 and implemented in 2001, led to an immediate reduction in the alcohol consumption (coefficient = -0.429, p < .001). Following the implementation of higher alcohol taxes in 1998 and 2001, the prevalence of alcohol use disorders (AUDs) and related years lived with disability (YLDs) gradually decreased. The relaxation of tax policy in 2006 led to a significant increase in alcohol consumption, both immediately (coefficient = 0.406, p < .001) and in the middle term (coefficient = 0.495, p < .001), as well as contribute to an immediate or medium term significant increase in the prevalence of AUDs (coefficient = 0.038, p = .010; coefficient = 0.032, p < .001) and YLDs (coefficient = 4.363, p = .001; coefficient = 4.226, p < .001).Conclusion: This study demonstrates that changes in alcohol consumption and related consequences (increase or decrease) have followed corresponding changes in alcohol tax policies (easing or tightening), indicating that increasing alcohol taxes can be an effective strategy in China for controlling alcohol consumption and related harms.

Nano-Hydroxyapatite Composite Scaffolds Loaded with Bioactive Factors and Drugs for Bone Tissue Engineering.

Nano-hydroxyapatite (n-HAp) is similar to human bone mineral in structure and biochemistry and is, therefore, widely used as bone biomaterial and a drug carrier. Further, n-HAp composite scaffolds have a great potential role in bone regeneration. Loading bioactive factors and drugs onto n-HAp composites has emerged as a promising strategy for bone defect repair in bone tissue engineering. With local delivery of bioactive agents and drugs, biological materials may be provided with the biological activity they lack to improve bone regeneration. This review summarizes classification of n-HAp composites, application of n-HAp composite scaffolds loaded with bioactive factors and drugs in bone tissue engineering and the drug loading methods of n-HAp composite scaffolds, and the research direction of n-HAp composite scaffolds in the future is prospected.

Significance of serum Th1/Th2 cytokine levels in underlying disease classification of childhood HLH.

OBJECT: Goal of this research was to investigate values of serum cytokines in childhood HLH with different triggers, with the expectation to find secretion spectrum of 5 main types of underlying diseases. METHOD: 118 newly diagnosed HLH were included, and serum concentrations of 6 cytokines were tested before treatment began. Absolute cytokine levels and ratios between them were then studied in the HLH groups collectively and separately RESULTS: In general, IFN-γ, IL-10 and IL-6 showed differences among 5 HLH groups. Specifically, relative levels of these three cytokines to each other were meaningful in distinguishing 4 types of HLH. Level of IL-6 was higher than those of IFN-γ or IL-10 in HLH driven by Systemic auto-inflammatory disorders (SAIDs) or Langerhans Cell Histiocytosis (LCH), while primary HLH and EBV-HLH shared elevated ratio of IL-10 to IL-6. Although more than one distinctive ratios were found in 3 HLH groups, combination of these parameters didn't offer optimal balance between sensitivity and specificity. CONCLUSION: As a group of easily gained laboratory findings, cytokine levels were reliable in the procedure of roughly classifying HLH cases with the help of patients' clinical phenotype. However, adequate data is still needed to explore the significance of these indicators in identifying one particular underlying disease accurately.

Effect of Different Combustion Processes on Atmospheric Nitrous Acid Formation Mechanisms: A Winter Comparative Observation in Urban, Suburban and Rural Areas of the North China Plain.

Atmospheric nitrous acid (HONO) is a dominant precursor of hydroxyl (OH) radicals, and its formation mechanisms are still controversial. Few studies have simultaneously explored effects of different combustion processes on HONO sources. Hereby, synchronous HONO measurement in urban (BJ), suburban (XH) and rural (DBT) areas with different combustion processes is performed in the North China Plain in winter. A box model is utilized to analyze HONO formation mechanisms. HONO concentration is the highest at the DBT site (2.51 ± 1.90 ppb), followed by the XH (2.18 ± 1.95 ppb) and BJ (1.17 ± 1.20 ppb) sites. Vehicle exhaust and coal combustion significantly contribute to nocturnal HONO at urban and rural sites, respectively. During a stagnant pollution period, the NO+OH reaction and combustion emissions are more crucial to HONO in urban and rural areas; meanwhile, the heterogeneous reaction of NO2 is more significant in suburban areas. Moreover, the production rate of OH from HONO photolysis is about 2 orders of magnitude higher than that from ozone photolysis. Consequently, vehicle exhaust and coal combustion can effectively emit HONO, further causing environmental pollution and health risks. It is necessary to expand the implementation of the clean energy transition policy in China, especially in areas with substantial coal combustion.

Second-line regimen for CNS-involved pediatric Langerhans cell histiocytosis.

PURPOSE: Langerhans cell histiocytosis (LCH) can affect any organ. Central nervous system (CNS) involvement is rare, and its management is poorly understood. This study aimed to analyze the clinical response and prognosis of pediatric LCH with central diabetes insipidus (CDI) treated with second-line therapy with cytarabine (Ara-c), cladribine (2-cdA), dexamethasone, and vindesine. METHODS: This retrospective case series study included pediatric LCH with CDI treated at Beijing Children's Hospital affiliated with Capital Medical University (11/2012-01/2018). After the first-line 2009-LCH regimen, patients with active disease/worse response, relapse, or no significant improvement in risk organs, pituitary, or lung were given the second-line therapy. Baseline characteristics, clinical response and adverse reactions were observed. RESULTS: Twenty-six children with CDI and disappearance of hyperintensity in the posterior pituitary were included. They received "Regimen A" Ara-c + dexamethasone + vindesine (n = 7) or "Regimen B" Ara-c + dexamethasone + vindesine + 2-cdA (n = 19) as second-line therapy. There were 14 patients with CDI but without pituitary stalk thickening (PST) and 12 with CDI and PST. In patients with CDI alone, 4/4 patients receiving Regimen A and 3/10 receiving Regimen B improved. All patients with CDI and PST showed improvement for PST. The reappearance of hyperintensity at the posterior pituitary was observed in 10 patients with CDI. All 26 children were alive after a median follow-up of 40.5 months. There were no chemotherapy-related deaths. CONCLUSION: A combined therapy with Ara-c, 2-cdA, dexamethasone, and vindesine could partially alleviate pituitary disease conditions in pediatric LCH with CNS involvement, with good tolerance.

Mendel's controlled pollination experiments in Mirabilis jalapa confirmed his discovery of the gamete theory of inheritance in Pisum.

The historian studies revealed during Mendel's later research period when mainly focusing on the constant hybrid in Hieracium, he had to be intervened to conduct the controlled pollination experiments in Mirabilis jalapa. Two letters to Nageli recorded the experimental aim was to disprove Darwin's opinion regarding three pollen grains required for one fertilization (note: that could completely destroy his previous discovery of segregation inheritance in variable hybrid in Pisum, for it was expressed in a mathematical equation). The experimental results of single pollen grain pollination confirmed the referenced view of one pollen cell uniting one egg cell in plant fertilization; the further pedigree introduction of the single and of the designed two pollen grain experiment succeeded in exemplifying that one hereditary factor carried by one gamete (pollen cell or egg cell) can independently transmit a trait to offspring. Here we coined the observation as the Gamete Theory of Inheritance. Remarkably, in contrast with the bulked pollination experiment, in this system, Mendel could easily manipulate a hereditary factor by merely taking a gamete as a carrier. Then, Mendel's work in M. jalapa together with the previous Pisum study was able to jointly suppport his second lecture content that regarded "gamete formation, fertilization, and seed development" and also regarded hereditary factors in the processes. All in all, the 1866 paper was published during a rapid burst of interest in hybrid species likely induced by Darwin, and Mendel's attempts at accommodation of the two incompatible inheritances of segregation in variable hybrids versus of nonsegregation in constant hybrids might be responsible for some historical controversies when understanding his discovery of inheritance.

Particle-Phase Photoreactions of HULIS and TMIs Establish a Strong Source of H2O2 and Particulate Sulfate in the Winter North China Plain.

During haze periods in the North China Plain, extremely high NO concentrations have been observed, commonly exceeding 1 ppbv, preventing the classical gas-phase H2O2 formation through HO2 recombination. Surprisingly, H2O2 mixing ratios of about 1 ppbv were observed repeatedly in winter 2017. Combined field observations and chamber experiments reveal a photochemical in-particle formation of H2O2, driven by transition metal ions (TMIs) and humic-like substances (HULIS). In chamber experiments, steady-state H2O2 mixing ratios of 116 ± 83 pptv were observed upon the irradiation of TMI- and HULIS-containing particles. Correspondingly, H2O2 formation rates of about 0.2 ppbv h-1 during the initial irradiation periods are consistent with the H2O2 rates observed in the field. A novel chemical mechanism was developed explaining the in-particle H2O2 formation through a sequence of elementary photochemical reactions involving HULIS and TMIs. Dedicated box model studies of measurement periods with relative humidity >50% and PM2.5 ≥ 75 µg m-3 agree with the observed H2O2 concentrations and time courses. The modeling results suggest about 90% of the particulate sulfate to be produced from the SO2 reaction with OH and HSO3- oxidation by H2O2. Overall, under high pollution, the H2O2-caused sulfate formation rate is above 250 ng m-3 h-1, contributing to the sulfate formation by more than 70%.

L-DEP regimen salvage therapy for paediatric patients with refractory Epstein-Barr virus-associated haemophagocytic lymphohistiocytosis.

Epstein-Barr virus-associated haemophagocytic lymphohistiocytosis (EBV-HLH) is one of the most common subtypes of secondary HLH. However, more than 30% of patients do not respond to traditional treatment. Here, we investigated the efficacy and safety of the L-DEP regimen as a salvage therapy for paediatric refractory EBV-HLH. We retrospectively analysed 26 paediatric patients with refractory EBV-HLH who received the L-DEP regimen at Beijing Children's Hospital from 1 January 2016 to 31 March 2019. Five of the patients achieved complete response (CR) and 11 achieved partial response (PR), indicating an overall response rate of 61·5% (CR + PR). Ten of the 16 patients who achieved CR or PR received allogenic haematopoietic stem cell transplantation (allo-HSCT), and seven were still alive at the last follow-up on 30 April 2020. Two of the 10 patients who did not respond were alive after allo-HSCT. Major side effects included increased amylase, bone marrow suppression and coagulation disorders, though these could be controlled by supportive therapy in most cases. Thus, we conclude that the L-DEP regimen is an effective and relatively safe salvage therapy for children with refractory EBV-HLH. This regimen also provides a bridge to allo-HSCT.

ß-catenin promotes MTX resistance of leukemia cells by down-regulating FPGS expression via NF-κB.

BACKGROUND: Aberrant activation of ß-catenin has been shown to play important roles in the chemoresistance of acute lymphoblastic leukemia (ALL), but the involvement and mechanism of ß-catenin in methotrexate (MTX) resistance is poorly understood. In the present study, we demonstrate a critical role of ß-catenin-NF-κB-FPGS pathway in MTX resistance in the human T-lineage ALL cell lines. METHODS: Lentivirus sh-ß-catenin was used to silence the expression of ß-catenin. Flow cytometry was performed to detect apoptosis after MTX treatment. Western blot, real-time PCR, Co-immunoprecipitation (Co-IP), Chromatin immunoprecipitation (ChIP), Re-ChIP, and Luciferase assay were utilized to investigate the relationship among ß-catenin, nuclear factor (NF)-κB, and folypoly-γ-glutamate synthetase (FPGS). RESULTS: Depletion of ß-catenin significantly increased the cytotoxicity of MTX. At the molecular level, knockdown of ß-catenin caused the increase of the protein level of FPGS and NF-κB p65. Furthermore, ß-catenin complexed with NF-κB p65 and directly bound to the FPGS promoter to regulate its expression. In addition, ß-catenin repression prolonged the protein turnover of FPGS. CONCLUSIONS: Taken together, our results demonstrate that ß-catenin may contribute to MTX resistance in leukemia cells via the ß-catenin-NF-κB-FPGS pathway, posing ß-catenin as a potential target for combination treatments during ALL therapy.