Longitudinal profiling identifies co-occurring BRCA1/2 reversions, TP53BP1, RIF1 and PAXIP1 mutations in PARP inhibitor-resistant advanced breast cancer

BACKGROUND

Resistance to therapies that target homologous recombination deficiency (HRD) in breast cancer limits their overall effectiveness. Multiple, preclinically validated, mechanisms of resistance have been proposed, but their existence and relative frequency in clinical disease are unclear, as is how to target resistance.

PATIENTS AND METHODS

Longitudinal mutation and methylation profiling of circulating tumour (ct)DNA was carried out in 47 patients with metastatic BRCA1-, BRCA2- or PALB2-mutant breast cancer treated with HRD-targeted therapy who developed progressive disease-18 patients had primary resistance and 29 exhibited response followed by resistance. ctDNA isolated at multiple time points in the patient treatment course (before, on-treatment and at progression) was sequenced using a novel >750-gene intron/exon targeted sequencing panel. Where available, matched tumour biopsies were whole exome and RNA sequenced and also used to assess nuclear RAD51.

RESULTS

BRCA1/2 reversion mutations were present in 60% of patients and were the most prevalent form of resistance. In 10 cases, reversions were detected in ctDNA before clinical progression. Two new reversion-based mechanisms were identified: (i) intragenic BRCA1/2 deletions with intronic breakpoints; and (ii) intragenic BRCA1/2 secondary mutations that formed novel splice acceptor sites, the latter being confirmed by in vitro minigene reporter assays. When seen before commencing subsequent treatment, reversions were associated with significantly shorter time to progression. Tumours with reversions retained HRD mutational signatures but had functional homologous recombination based on RAD51 status. Although less frequent than reversions, nonreversion mechanisms [loss-of-function (LoF) mutations in TP53BP1, RIF1 or PAXIP1] were evident in patients with acquired resistance and occasionally coexisted with reversions, challenging the notion that singular resistance mechanisms emerge in each patient.

CONCLUSIONS

These observations map the prevalence of candidate drivers of resistance across time in a clinical setting, information with implications for clinical management and trial design in HRD breast cancers.

Molecular-level insights into the temperature-dependent formation dynamics and mechanism of water-soluble dissolved organic carbon derived from biomass pyrolysis smoke

Water soluble organic carbon (WSOC) derived from biomass pyrolytic smoke is deposited through atmospheric aerosols, negatively affecting aquatic ecological quality and safety. However, the temperature-dependent molecular diversity and dynamic formation of smoke-derived WSOC remain poorly understood in water. Herein, we explored the molecular-level formation mechanism of pyrolytic smoke-derived WSOC in water to explain the evolution, heterogeneous correlations, and sequential responses of molecules and functional groups to increasing pyrolysis temperature. Two-dimensional correlation spectroscopy was used to innovatively establish the characteristic correlations between spectroscopy and Fourier transform-ion cyclotron resonance mass spectrometry. Temperature-dependent formation of WSOC exhibited diversity in absorbance/fluorescent components, unique/common molecules, and their chemical parameters, showing the simultaneous formation and degradation reactions. The common WSOC molecules with lower and higher degrees of oxidation showed significant positive and negative correlations with the fluorescent components, respectively. The primary sequential response of WSOC molecules to increasing pyrolysis temperature (lignin-like molecules → unsaturated hydrocarbons, condensed aromatic molecules → lipid-like/aliphatic-/peptide-like molecules) corresponded to the temperature response of functional groups (carboxylic/alcoholic → polysaccharides → aromatics/amides/phenolic/aliphatic groups), demonstrating well synergistic relationships between them. These novel findings will contribute to the comprehensive understanding and assessments of potential environmental behavior or risks of WSOC in aquatic ecosystems.

Treatment of auricular pseudocysts using enhanced negative drainage: a prospective study of 21 cases

OBJECTIVE

Auricular pseudocysts are rare, painless, benign intracartilaginous cysts of the auricle that are not lined by epithelium and have no known aetiology.

METHOD

This was a prospective study conducted in an ENT department from January 2020 to June 2022. In 21 patients, complete aspiration of the pseudocyst with enhanced negative drainage was performed. They were followed for a minimum of six months.

RESULTS

All patients completely responded to the negative drainage treatment. No cases of recurrence or obvious deformities were observed.

CONCLUSION

Aspiration with intensified negative drainage was associated with a positive response in patients with auricular pseudocysts. Complete resolution of the swelling can be achieved without any serious complications. Thus, it appears to be a simple and effective method for managing the condition.

Characteristics of solid waste from common generation source in nonferrous smelting industry reveal a new classification method

Solid waste produced by the nonferrous smelting industry has a significant number of notable differences. The lack of recognition of solid waste characteristics is the main factor restricting its disposal and utilization. In this study, we analyzed the main production processes of the nonferrous smelting industry; identified the key production nodes of solid waste; and clarified the characteristics, including the physical, chemical, and pollution characteristics of solid wastes, through a large sample statistical analysis. We found similarities among solid wastes from a common generation source as well as notable differences among the different generation sources: slags and sludges from waste acid treatment and wastewater treatment units had a water content of 27.43-52.71% and 51.14-68.27%, respectively, which were significantly higher than those of other metallurgy and dust collection units; the pH of slags from an electrorefining unit was strongly alkaline; the mineral phase of sludges from wastewater treatment was only calcite; slags from a waste acid treatment unit were mainly in phase of gypsum, claudetite, and anglesite; the chemical composition of slags from pyrometallurgy and hydrometallurgy units was mainly SiO2 and Fe2O3. In this paper, we discuss a new classification method based on a common generation source for the first time. These results are beneficial to guide the disposal, utilization, and management of solid waste.

Molecular-level insights into the heterogeneous variations and dynamic formation mechanism of leached dissolved organic matter during the photoaging of polystyrene microplastics

Microplastics (MPs) and their derivatives have received worldwide attention owing to their adverse effects on ecosystems. However, molecular diversity and dynamic formation of dissolved organic matter (DOM) during the photoaging of MPs remain unclear. Herein, we explored a molecular‒level formation mechanism for polystyrene MP (MPPS)‒derived DOM (PSDOM) during the photoaging of MPs to explain the evolution, heterogeneity, and sequential response of molecules to irradiation. Two‒dimensional correlation spectroscopy was applied to correlate the variations of PSDOM molecules detected by Fourier transform-ion cyclotron resonance mass spectrometry with those of MPPS functional groups detected by Fourier transform infrared spectroscopy. Irradiation‒induced PSDOM contained the most highly unsaturated structures with oxygen, but showed fewer aromatic structures than natural aquatic DOM. Photochemical transformations occurred between saturated‒reduced and oxidized molecules during PSDOM leaching, with the low‒oxidized and high‒oxidized molecules undergoing considerable changes in the normal carbon oxidation state and molecular number, respectively. The primary sequential response of PSDOM molecules to increasing irradiation time [low‒oxidized/high‒weight (450 Collapse

Key Words

• Dynamic formation
• Fluorescence properties
• Heterogeneous correlations
• Leaching responses
• Molecular parameters
• Unique molecules

Collapse

MESH Headings

• Microplastics
• Polystyrenes
• Plastics
• Dissolved Organic Matter
• Ecosystem
• Skin Aging

Collapse

Grants Collapse

Affiliation(s)

Fanhao Song State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
Tingting Li State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; School of Environment, Tsinghua University, Beijing 100084, China
Jin Hur Department of Environment and Energy, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul, 05006, South Korea
Quan Shi State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China
Fengchang Wu State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
Wei He Ministry of Education Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, China
Di Shi State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
Chen He State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China
Lingfeng Zhou State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
Mingqi Ruan State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
Yuhan Cao State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China

Collapse

Integrated assessment of land-to-river Cd fluxes and riverine Cd loads using SWAT-HM to guide management strategies

In 2011, China invested US$9.8 billion to combat the severe heavy metal pollution in the Xiang River basin (XRB), aiming to reduce 50% of the 2008 industrial metal emissions by 2015. However, river pollution mitigation requires a holistic accounting of both point and diffuse sources, yet the detailed land-to-river metal fluxes in the XRB remain unclear. Here, by combining emissions inventories with the SWAT-HM model, we quantified the land-to-river cadmium (Cd) fluxes and riverine Cd loads across the XRB from 2000 to 2015. The model was validated against long-term historical observations of monthly streamflow and sediment load and Cd concentrations at 42, 11, and 10 gauges, respectively. The analysis of the simulation results showed that the soil erosion flux dominated the Cd exports (23.56-80.14 Mg yr^-1). The industrial point flux decreased by 85.5% from 20.84 Mg in 2000 to 3.02 Mg in 2015. Of all the Cd inputs, approximately 54.9% (37.40 Mg yr^-1) was finally drained into Dongting Lake; the remaining 45.1% (30.79 Mg yr^-1) was deposited within the XRB, increasing the Cd concentration in riverbed sediment. Furthermore, in XRB's 5-order river network, the Cd concentrations in small streams (1st order and 2nd order) showed larger variability due to their low dilution capacity and intense Cd inputs. Our findings highlight the need for multi-path transport modeling to guide future management strategies and better monitoring schemes to restore the small polluted streams.

Temperature-Dependent Molecular Evolution of Biochar-Derived Dissolved Black Carbon and Its Interaction Mechanism with Polyvinyl Chloride Microplastics

Biochar-derived dissolved black carbon (DBC) molecules are dependent on the BC formation temperature and affect the fate of emerging contaminants in waters, such as polyvinyl chloride microplastic (MP_PVC). However, the temperature-dependent evolution and MP_PVC-interaction of DBC molecules remain unclear. Herein, we propose a novel DBC-MP_PVC interaction mechanism by systematically interpreting heterogeneous correlations, sequential responses, and synergistic relationships of thousands of molecules and their linking functional groups. Two-dimensional correlation spectroscopy was proposed to combine Fourier transform-ion cyclotron resonance mass spectrometry and spectroscopic datasets. Increased temperature caused diverse DBC molecules and fluorophores, accompanied by molecular transformation from saturation/reduction to unsaturation/oxidation with high carbon oxidation states, especially for molecules with acidic functional groups. The temperature response of DBC molecules detected via negative-/positive-ion electrospray ionization sequentially occurred in unsaturated hydrocarbons → lignin-like → condensed aromatic → lipid-/aliphatic-/peptide-like → tannin-like → carbohydrate-like molecules. DBC molecular changes induced by temperature and MP_PVC interaction were closely coordinated, with lignin-like molecules contributing the most to the interaction. Functional groups in DBC molecules with m/z < 500 showed a sequential MP_PVC-interaction response of phenol/aromatic ether C-O, alkene C═C/amide C═O → polysaccharides C-O → alcohol/ether/carbohydrate C-O groups. These findings help to elucidate the critical role of DBCs in MP environmental behaviors.

[The role of CD4+ CD25+ Treg in the mechanism of autoimmune auditory neuropathy in SD rats]

Objective: To investigate the role of CD4⁺CD25⁺regulatory cell (CD4⁺CD25⁺Treg) in auditory neuropathy (AN) using a rat model of autoimmune auditory neuropathy. Methods: The SD rats were immunized with P0 protein emulsified in complete Freunds adjuvant for 8 weeks. The number of CD4⁺CD25⁺Treg in peripheral blood and cochlea and the expression of Foxp3 gene in cochlea were detected respectively 2, 4, 6 and 8 weeks after the immunization with P0 protein in rats. Then CD4⁺CD25⁺Treg were transferred intravenously to the AN rats at 2, 4, 6 and 8 weeks of the immunization, respectively. The change of auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE) were detected, and the morphological changes in the inner ear were investigated. Results: The number of CD4⁺CD25⁺Treg in the peripheral blood of AN rats decreased gradually after 2, 4, 6 and 8 weeks of P0 protein immunization. The number of CD4⁺CD25⁺Treg in cochlea gradually increased with the prolongation of immunization time, but the expression of Foxp3 gene in cochlea gradually decreased over time. After intravenous transplantation of CD4⁺CD25⁺Treg in AN rats, the threshold of ABR response decreased, and DPOAE had no significant change. The number of spiral ganglion neurons in cochlea increased, and hair cells had no significant change under electron microscope. Conclusions: The decrease in the number and function of CD4⁺CD25⁺Treg reduces its inhibitory effect on autoimmune response and promotes the occurrence of autoimmune auditory neuropathy in AN rats. Adoptive transfer of CD4⁺CD25⁺Treg can reduce the autoimmune response and promote the recovery of autoimmune auditory neuropathy.

Effects of biochar on the phytotoxicity of polyvinyl chloride microplastics

Polyvinyl chloride microplastics (PVC-MPs) are toxic to crops, resulting in economic losses during agricultural production. Owing to its strong adsorption capacity, biochar can effectively remove MPs from water. It is presumed that biochar can alleviate the phytotoxicity of PVC-MPs. To verify this hypothesis, the effects of different concentrations of corncob biochar (CCBC) on the phytotoxicity of PVC-MPs were investigated using hydroponic experiments. The results showed that PVC-MPs attached to lettuce roots substantially inhibited the growth and quality of lettuce. The tested CCBC adsorbed the PVC-MPs. At appropriate concentrations, CCBC alleviated the inhibitory effect of PVC-MPs on lettuce yield; however, it decreased some quality indicators. The single PVC-MPs induced oxidative damage to lettuce, as demonstrated by the increased hydrogen peroxide (H2O2) and malondialdehyde (MDA) content. Addition of CCBC considerably decreased the contents of H2O2 and MDA in the lettuce shoots but increased the H2O2 content in the roots. These findings indicate that CCBC may alleviate the adverse effects caused by PVC-MPs to the lettuce shoots but aggravate the toxic effects on the lettuce roots. This study provides a basis for understanding the removal of the phytotoxicity of MPs.

The association between dietary selenium intake and Hashimoto's thyroiditis among US adults: National Health and Nutrition Examination Survey (NHANES), 2007-2012

BACKGROUND

Selenium has been shown to influence the pathological processes and physiological functions of thyroid. Although growing evidence has shown that selenium can improve the treatment of Hashimoto's thyroiditis (HT), there is a need to evaluate the association between dietary selenium intake and HT in a large cross-sectional study. This study explored the association between dietary selenium intake and HT based on the National Health reand Nutrition Examination Survey (NHANES) database (2007-2012).

METHODS

A total of 8756 of 30,442 participants were included in the study. Dietary selenium intake was the independent variable, while HT was the dependent variable. In addition, the relative importance of the selected variables was determined using the XGBoost model. A smooth curve was constructed based on the fully adjusted model to investigate the potential linear relationship between dietary selenium intake and HT. Smooth curves were also constructed to explore the linear/non-linear relationship between dietary selenium intake and thyroid peroxidase antibody (TPOAb)/ thyroglobulin antibody (TgAb).

RESULTS

The mean age of the enrolled participants was 44.35 years (± 20.92). The risk of HT was significantly reduced by a 35% per-unit increase in dietary selenium intake after fully adjusting for covariates according to the model (log2-transformed data; OR 0.65; 95% CI 0.51, 0.83). The XGBoost model revealed that dietary selenium intake was the most important variable associated with Hashimoto's thyroiditis. Dietary selenium intake (Log2-transformed) was negatively correlated with TPOAb levels [- 16.42 (- 22.18, - 10.65), P < 0.0001], while a non-linear relationship was observed between dietary selenium intake and TgAb with an inflection point of 6.58 (95.67 μg, Log2-transformed).

CONCLUSION

Dietary selenium intake is independently and inversely associated with HT risk. Moreover, dietary selenium intake is negatively correlated with TPOAb levels and non-linearly correlated with TGAb levels. Therefore, dietary selenium intake may be a safe and low-cost alternative for the prevention and treatment of HT.

Heterogeneous Dynamic Behavior and Synergetic Evolution Mechanism of Internal Components and Released Gases during the Pyrolysis of Aquatic Biomass

Evolution of gaseous contaminants from biomass pyrolysis has drawn increasing attention. However, the thermal degradation, dynamics, and synergetic evolution mechanisms during real-time biomass pyrolysis remain unclear. Herein, a novel method using thermogravimetry-Fourier transform infrared spectrometry-gas chromatography/mass spectrometry (TG-FTIR-GC/MS) combined with thermal kinetics and two-dimensional correlation spectroscopy was proposed to explore the chemical properties and temperature response mechanisms of gaseous species released during Phragmites communis (PC) and Typha angustifolia (TA) pyrolysis. The thermal degradation mechanisms of PC/TA pyrolysis were mainly associated with the sigmoidal rate and random nucleation mechanisms. The formation intensities of alcohols/ethers, phenols/esters, acids, aldehydes, and ketones were higher during low-temperature TA pyrolysis and high-temperature PC pyrolysis. The average carbon oxidation state (OS¯C) of gaseous species mainly ranged from -1.5 to -0.5, and the OS¯C slope of most gaseous species was greater than -2.0, which was related to the reduction of aldehyde/ketone groups. Two-dimensional (2D)-TG-FTIR-COS analysis revealed that the sequential temperature response of gaseous species followed: acids → phenols, esters → aldehydes → hydrocarbons → alcohols, ethers → aromatics during PC/TA pyrolysis. The establishment of relationships between the sequential response of gases and degraded components provides an important basis for online monitoring/recovery of gaseous contaminants during biomass pyrolysis.

Identification priority source of soil heavy metals pollution based on source-specific ecological and human health risk analysis in a typical smelting and mining region of South China

An in-depth understanding of the ecological and health risks posed by heavy metals originating from various pollution sources is critical for foresighted soil-quality management. Based on 220 grid samples (2 × 2 km) analyzed for eight heavy metals (Cd, Hg, As, Pb, Cr, Ni, Cu, and Zn) in the Chenshui (CS) watershed of Hunan Province, China, we applied an integrated approach for identifying and apportioning pollution sources of soil heavy metals and exploring their source-specific pollution risks. This approach consists of three sequential steps: (1) source identification by combining the positive matrix factorization model with geostatistical analysis; (2) quantification of ecological, carcinogenic, and non-carcinogenic risks in a source-specific manner; (3) prioritization of sources in a holistic manner, considering both ecological risks and human health risks. Cd (68.0%) and Hg (13.3%) dominated the ecological risk in terms of ecological risk index; As dominated the non-carcinogenic health risk in terms of total hazard index (THI; adults: 84.8%, children: 84.7%) and the carcinogenic health risk in terms of total carcinogenic risk index (TCRI; adults: 69.0%, children: 68.8%). Among three exposure routes, oral ingestion (89.4-95.2%) was the predominant route for both adults and children. Compared with adults (THI = 0.41, TCRI = 7.01E-05), children (THI = 2.81, TCRI = 1.22E-04) had greater non-carcinogenic and carcinogenic risks. Four sources (F1-4) were identified for the CS watershed: atmospheric deposition related to coal-burning and traffic emissions (F1, 18.0%), natural sources from parent materials (F2, 34.3%), non-ferrous mining and smelting industry (F3, 37.9%), and historical arsenic-related activity (F4, 9.8%). The F3 source contributed the largest (45.2%) to the ecological risks, and the F4 source was the predominant contributor to non-carcinogenic (52.4%) and carcinogenic (64.6%) risks. The results highlight the importance of considering legacy As pollution from abandoned industries when developing risk reduction strategies in this region. The proposed methodology for source and risk identification and apportionment formulates the multidimensional concerns of pollution and the various associated risks into a tangible decision-making process to support soil pollution control.

Influence of CaO on the thermal kinetics and formation mechanism of high value-added products during waste tire pyrolysis

There is a lack of detailed research on the production of isoprene and D-limonene by solid base-catalysed thermal depolymerization of waste tires (WTs). This work aimed to investigate the thermal decomposition characteristics, reaction kinetics, high value-added products production and potential mechanisms during WT pyrolysis in the presence of calcium oxide (CaO) via Thermogravimetry-Fourier Transform Infrared spectrometer (TG-FTIR) and Pyrolyzer-Gas Chromatography/Mass spectrometry (Py-GC/MS). The results obtained from TG indicated that CaO accelerated depolymerization in terms of reducing the reaction temperature, which is also reflected in the kinetic parameters. It can be found that the content of D-limonene increased by 13.76% and that of isoprene increased by 37.57%, which were attributed to differences in the depolymerization mechanisms in the presence of CaO. Furthermore, CaO had a profound impact on desulfurization by reducing benzothiazole, sulfoacid, and thiophene. The potential catalytic mechanisms of isoprene and D-limonene production and desulfurization were also proposed. This work deepens the understanding of the catalytic pyrolysis of WT under CaO and unambiguously demonstrates the great potential of CaO in enhancing isoprene and D-limonene production, providing new insight for the cleaner production of high value-added products from WT.

Dynamic Evolution and Covariant Response Mechanism of Volatile Organic Compounds and Residual Functional Groups during the Online Pyrolysis of Coal and Biomass Fuels

Volatile organic compound (VOC) emissions from pyrolysis of widely used biomass are expected to increase significantly under the carbon neutrality target. However, the dynamic emissions and evolution mechanism of biomass-VOCs remain unclear, hindered by complex reactions and offline measurements. Here, we propose a novel covariant evolution mechanism to interpret the emission heterogeneities, sequential temperature responses, and evolved correlations of both VOCs and residual functional groups (RFGs) during corn straw (CS), wood pellet (WP), and semibituminous coal (SBC) pyrolysis. An innovative combination of online thermogravimetric-Fourier transform infrared-gas chromatography/mass spectrometry and two dimensional-correlation spectroscopy was applied. The relative percentages of CS/WP-VOCs were higher than those of SBC-VOCs, and most VOCs tended to have relatively small carbon skeletons as the average carbon oxidation state increased. With the temperature increased from low to high during CS/WP pyrolysis, the primary sequential response of VOCs (acids → phenols/esters → alcohols/ethers/aldehydes/ketones → hydrocarbons/aromatics) corresponded to the RFG response (hydroxyl groups → -CH₃/-CH₂-/-CH groups → aliphatic ethers and conjugated ketones). Compared with the relative regularity for CS/WP responses, the gas-solid products from SBC pyrolysis exhibited complex temperature-dependent responses and high oxidation-induced variability. These insights provide favorable strategies for the online monitoring system to facilitate priority removal of coal and biomass fuels-VOCs.

Pyrogenic dissolved organic matter produced at higher temperature is more photoactive: Insight into molecular changes and reactive oxygen species generation

Pyrogenic dissolved organic matter (pyDOM) is the photolabile fraction in the dissolved organic matter pool. However, the molecular changes and reactive oxygen species generation of pyDOMs under continuous irradiation, and how these vary with feedstock type and pyrolysis temperature, are not well understood. In this study, the soluble fractions of 300 and 450 ºC biochars (pyDOM300 and pyDOM450) were subjected to photo-irradiation. PyDOM450 was of higher aromaticity, molecular variety, but lower unsaturation than pyDOM300. The molecular weight, aromaticity, and double bond equivalents of pyDOMs generally decreased after photo-irradiation. The degradation pattern of pyDOMs can be divided into two stages. In the initial 24 h, pyDOM300 degraded faster than pyDOM450, with the more profound transformation of condensed aromatics and carbohydrate into aliphatic/proteins, lignins, and tannins in pyDOM300. After 720 h irradiation, however, the degradation ratio of pyDOM450 (36.2-43.9%) exceeded that of pyDOM300 (23.7-30.3%), with the initially preserved condensed aromatics in pyDOM450 further transforming into aliphatic/proteins and tannins. This was potentially attributed to the generation of more reactive oxygen species (·OH and ¹O₂) in pyDOM450. This study uncovered the photodegradation mechanisms of pyDOMs at molecular scale and helped to understand their cycling and effects on environment.

The Status of Iodine Nutrition after Removing Iodized Salt in High Water Iodine Regions: a Cross-sectional Study in China

Currently, the removal of iodized salt is carried out in high water iodine regions. The present situation of iodine nutrition and the prevalence of thyroid diseases in such regions have not been clearly elucidated. This study aimed to figure out these problems to help render effective measures for cases of abnormal iodine nutrition status. A cross-sectional study was carried out in four areas of Jining and Heze, Shandong Province, China, with different water iodine concentrations (WIC). In total, 1344 adults were enrolled in this study, and data related to their iodine nutrition, thyroid function, and thyroid ultrasonography were collected. Subjects were grouped according to WIC, urine iodine concentration (UIC), serum iodine concentration (SIC), and combined UIC and SIC for analysis. Iodine levels were in excess in the 100 μg/L ≤ WIC < 300 μg/L and WIC ≥ 300 μg/L areas. Compared with the control WIC group (10-100 μg/L), the WIC ≥ 300 μg/L group had a higher prevalence of thyroid autoimmunity (TAI, 21.25% vs. 13.19%, P <0.05), subclinical hypothyroidism (SH, 20.20% vs. 11.96%, P < 0.05), thyroid nodules (TN, 31.75% vs. 18.71%, P < 0.05), and thyroid dysfunction (23.62% vs. 12.26%, P < 0.05). Compared with the UIC control group (100-300 μg/L), high UIC group (≥ 800 μg/L) had a higher prevalence of TN (33.75% vs. 21.14%, P < 0.05) and thyroid dysfunction (25% vs. 14.47%, P < 0.05). Next, compared with the control SIC group (50-110 μg/L), high SIC group (≥ 110 μg/L) had a higher prevalence of TAI (33.80% vs. 14.47%, P < 0.05), SH (23.94% vs. 14.30%, P < 0.05), and thyroid dysfunction (33.80% vs. 15.29%, P < 0.05). Finally, subjects with the highest UIC and the highest SIC also had a higher prevalence of TAI (25.92% vs. 10.97%, P < 0.05), SH (23.45% vs. 10.97%, P < 0.05), TN (34.56% vs. 15.85%, P < 0.05), and thyroid dysfunction (27.16% vs. 13.41%, P < 0.05) than subjects with middle iodine levels. The iodine nutrition of subjects in the WIC ≥ 300 μg/L areas was still in excess after removing iodized salt from their diets. High levels of iodine also increased the prevalence of TAI, SH, TN, and thyroid dysfunction in those areas. Simply removing iodized salt may not be sufficient for high water iodine regions.

Characterization of CwlC, an autolysin, and its role in mother cell lysis of Bacillus thuringiensis subsp. israelensis

Bacillus thuringiensis subsp. israelensis (Bti) has been proven to efficiently control mosquitoes, of which many species are important vectors of human disease. The larvicidal action is attributed to the parasporal crystals formed in the sporulating cells and released upon cell autolysis. In this study, a sporulation-specific cwlC gene that encodes an N-acetylmuramoyl-_L -alanine amidase was characterized in Bti strain Bt-59. CwlC was the only cell wall hydrolase in Bti found to contain both MurNAc-LAA and Amidase02_C domains. A recombinant CwlC-His protein was able to digest the Bacillus cell wall. Deletion of the cwlC gene delayed Bti mother cell lysis without impacting vegetative growth or insecticidal efficacy. Transcriptional analyses indicated that cwlC was expressed at the late sporulation stage and was controlled by SigK. Two other cell wall hydrolase genes, cwlB and cwlE, with high expression levels at T₁₄ in Bt-59, were also identified. Like cwlC, cwlB expression was controlled by SigK; in contrast, cwlE was found not to be under the control of this sigma factor and unlike the other two, its gene was found to be plasmid encoded.

Novel Insights into the Molecular-Level Mechanism Linking the Chemical Diversity and Copper Binding Heterogeneity of Biochar-Derived Dissolved Black Carbon and Dissolved Organic Matter

Biochar-derived dissolved black carbon (DBC) varies in chemical composition and significantly affects the environmental fate of metal ions. However, the intrinsic molecular composition of DBC fractions and their molecular interaction mechanisms with metal ions remain unclear. We propose a novel, molecular-level covariant binding mechanism to comparatively interpret the heterogeneities, active sites, and sequential responses of copper binding with molecular compounds in DBC and natural dissolved organic matter (DOM). Relatively large proportions of lipid/aliphatic/peptide-like compounds with low mass distributions and lignin-like compounds with oxidized/unsaturated groups existed in acidic- and alkaline-extracted DBC, respectively. A larger percentage of tannin-like/condensed aromatic compounds and higher average conditional stability constants (logK̅_Cu) of visible fluorescent components were found for DOM than for DBC. Overall, 200-320 Da and 320-480 Da molecular components contributed significantly to the logK̅_Cu values of UVA and visible fluorescent components, respectively, in DBC/DOM. Nitrogenous groups likely exhibited stronger binding affinities than phenolic/carboxylic groups. The sequential copper-binding responses of molecular compounds in DBC/DOM generally followed the order lipid/aliphatic/peptide-like compounds → tannin-like compounds → condensed aromatic compounds. These insights will improve the prediction of the potential effects of DBC on various contaminants and the risks of biochar application to ecosystems.

Tumor-stroma ratio is a crucial histological predictor of occult cervical lymph node metastasis and survival in early-stage (cT1/2N0) oral squamous cell carcinoma

Occult cervical lymph node metastasis is a significant prognostic factor in patients with early-stage (cT1/2N0) oral squamous cell carcinoma (OSCC). The aim of this study was to investigate the potential value of the tumor-stroma ratio (TSR) as a histological predictor of occult cervical metastasis and survival in early-stage OSCC. This retrospective study included 151 patients who underwent excision of the primary lesion and elective neck dissection from 2013 to 2017. The clinicopathological features of the tumor, risk factors associated with occult neck metastasis, and prognostic factors for overall survival (OS) and disease-free survival (DFS) were studied. A significant correlation of TSR (P = 0.009) was found with occult neck metastasis in the multivariate logistic regression model. Multivariate Cox proportional hazards regression analysis showed that the TSR (P = 0.002) and perineural invasion (P = 0.011) were associated with OS. Occult neck metastasis (P = 0.032) was associated with DFS. These findings indicate that assessment of the TSR might be useful in prognostication for early-stage OSCC patients. Moreover, the TSR is effective in allowing an accurate evaluation of the risk of occult neck metastasis, and this may be easily applicable in the routine pathological diagnosis and clinical decision-making for elective neck dissection.

Pcsk9 Knockout Aggravated Experimental Apical Periodontitis via LDLR

Apical periodontitis (AP), an inflammatory lesion around the apex of tooth roots, is mostly caused by dental pulp infection. Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a vital role in regulating cholesterol homeostasis by targeting low-density lipoprotein receptor (LDLR) and participates in bacterium-induced chronic periodontitis. However, the roles of PCSK9 in AP are unknown. Here, we investigated its role in AP by using Pcsk9^-/- mice. Micro-computed tomography scanning and histological staining revealed that the periapical bone loss of Pcsk9^-/- mice was greater than that of wild-type (WT) mice, and increased expression of inflammation-related factors tumor necrosis factor α (TNF-α) and interleukin (IL)-6 was also observed. Immunofluorescence staining and quantitative real-time polymerase chain reaction showed PCSK9 expression in bone marrow macrophages (BMMs) was increased after treatment with lipopolysaccharide (LPS). This finding was consistent with the in vivo results that the expression level of PCSK9 in exposed WT mice increased compared with that in unexposed WT mice. After LPS challenge, the expression levels of TNF-α, IL-1β, and IL-6 in BMMs were increased, and Pcsk9 knockout aggravated the expression of these inflammatory factors. The number of osteoclasts positive for tartrate-resistant acid phosphatase staining around the apical lesion in Pcsk9^-/- mice was higher than that in WT mice. Then BMMs underwent the osteoclast differentiation. Pcsk9 knockout BMMs induced increased and larger osteoclasts. While this effect of Pcsk9 knockout was abolished by the addition of Ldlr small interfering RNA, revealing that Pcsk9 knockout increased osteoclastogenesis was dependent on the LDLR. Immunohistochemistry staining showed increased expression level of LDLR in exposed Pcsk9^-/- periapical areas. In vitro experiments showed that LPS promoted the expression level of LDLR in Pcsk9^-/- BMMs and increased osteoclast formation ability, indicating that LPS promoted the elevation of osteoclasteogenesis caused by the Pcsk9 knockout. In conclusion, Pcsk9 deficiency aggravated the inflammatory response and promoted the osteoclastogenesis in an LDLR-dependent manner in AP experimental mice.

The cross-talk of NLRP3 inflammasome activation and necroptotic hepatocyte death in acetaminophen-induced mice acute liver injury

Overdose acetaminophen (APAP) can result in severe liver injury, which is responsible for nearly half of drug-induced liver injury in western countries. Previous studies have found that there existed massive hepatocellular necrosis and severe inflammatory response in APAP-induced liver injury. However, the mechanistic linkage between necroptosis and NLRP3 inflammasome pathway in APAP-induced hepatotoxicity remains poorly understood. In order to investigate the relationship between inflammation and hepatocytes death in APAP hepatotoxicity, a time-course model for APAP hepatotoxicity in C57/BL6 mice was established by intraperitoneal (i.p) injection of 300 mg/kg APAP in this study. The activity of serum enzymes and pathological changes of APAP-treated mice were evaluated, and the critical molecules in necroptosis and NF-κB-NLRP3 inflammasome signaling pathway were determined by immunoblot and immunofluorescence analysis. The results demonstrated that APAP overdose resulted in a severe liver injury. Furthermore, the expression of critical molecules in NLRP3 inflammasome and necroptosis pathways peaked at 12-24 h, and then was decreased gradually, which is consistent with the pattern of pathological injury induced by APAP. Our further investigation found that the level of IL-1β in mouse liver was closely correlated with the level of phosphorylated MLKL following exposure to APAP. Furthermore, inhibition of necroptosis with necrostatin-1 significantly suppressed the activation of NLRP3 inflammasome signaling. Taken together, our results highlighted that the cross-talk between necroptosis and NLRP3 inflammasome played a critical role for promoting APAP-induced liver injury. Inhibition of the interaction of inflammation and necroptosis by pharmaceutical methods may represent a promising therapeutic strategy for APAP-induced liver injury.

The synergistic antifungal activity of resveratrol with azoles against Candida albicans

Candida albicans is one of the most common clinical pathogenic microorganisms and it is becoming a serious health threat, particularly to immunocompromised populations. Drug resistance of Candida species has also frequently emerged, and combination therapy for fungal infections has attracted considerable attention. In this study, we established the Qinling Mountains myxobacterial secondary metabolites library and a synergic assay in combination with ketoconazole against C. albicans was introduced for metabolites screening. Two active compounds with synergic anticandidal activities were obtained, which were identified as trans-resveratrol and cis-resveratrol. According to our study, resveratrol can reduce the dosage to 1/64 of ketoconazole as well as itraconazole. Furthermore, synergistic anticandidal activity of resveratrol combined with azoles was verified against a panel of clinical C. albicans isolates, and the combination strategy enhanced the azoles susceptibility of three fluconazole-resistant isolates. These findings suggest that resveratrol enhances the efficacy of azoles and provides a promising application in therapy of C. albicans infection.

Effects of targeted hydration on risk of major adverse renal and cardiac events: a systematic review and meta-analysis of randomized controlled trials

Background

Inconsistent results have been published that have evaluated the preventive effect of targeted hydration in major adverse renal and cardiac events among patients exposed to contrast agents.

Methods

Online databases were searched up to October, 2019, for randomized controlled trials (RCTs). The primary outcome was the incidence of contrast-induced acute kidney injury (CI-AKI), and the secondary outcomes were all-cause in-hospital mortality, all-cause long-term mortality, requirement for dialysis, acute pulmonary edema and stroke/transient ischemic attack (TIA).

Results

9 high quality trials were identified including 2424 patients. Overall, compared with general hydration, targeted hydration significantly reduced the incidence of CI-AKI by 58% (RR 0.42; 95% CI: 0.33–0.54, p&lt;0.01), the requirement for dialysis by 68% (RR 0.32, 95% CI: 0.17–0.62, p&lt;0.01) and the all-cause long-term mortality by 55% (RR 0.45; 95% CI: 0.26–0.76, p&lt;0.01). The effect on all-cause in-hospital mortality was not statistically significant. The effect on acute pulmonary edema and stroke/TIA also showed no difference between two groups (RR: 0.54, 95% CI: 0.28–1.03, p=0.18; RR: 0.61, 95% CI: 0.14–2.61, p=0.49, respectively). Trial sequential analysis confirmed that an additional 3900 study participants would need to be recruited to demonstrate a statistically significant improvement for all-cause in-hospital mortality.

Conclusions

Targeted hydration likely reduces the incidence of CI-AKI, dialysis and all-cause long-term mortality in patients exposed to contrast agents. However, further independent high-quality RCTs should elucidate the effectiveness and safety of this prophylactic strategy in interventional cardiology.

Funding Acknowledgement

Type of funding source: None

Global risk factors of contrast-induced acute kidney injury: systematic review and meta-analysis

Background

Administration of iodinated contrast is common but may be associated with contrast-induced acute kidney injury (CI-AKI), particularly in at-risk patients. There is no recent systematic review of potentially modifiable risk factors.

Methods

We searched MEDLINE, Embase and the Cochrane Database of Systematic Reviews (to 30 th June 2019) for observational studies assessing risk factors associated with CI-AKI. Twelve potentially modifiable risk factors were finally included in this thematic review and meta-analysis. Random or fixed meta-analysis was performed to derive the adjusted odds ratio (aOR), and the population attributable risk (PAR) was calculated for each risk factor globally and by region.

Findings

We included 157 studies (2,297,863 participants). The global incidence of CI-AKI was 5.4%. The potentially modifiable risk factors included high contrast volume (PAR 33%), eight cardiovascular risk factors (diuretic use, multivessel coronary artery disease, acute coronary syndrome, hypertension, hypotension, heart failure, reduced left ventricular ejection fraction and intra-aortic balloon pump use) (combined PAR 76.2%) and three noncardiovascular risk factors (renal dysfunction, diabetes mellitus and anaemia) (combined PAR 47.4%) with geographical differences.

Bubble chart of the 12 risk factors

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): National Science Foundation of China

Composition characterization and biotransformation of dissolved, particulate and algae organic phosphorus in eutrophic lakes

Characteristics and transformation of organic phosphorus in water are vital to biogeochemical cycling of phosphorus and support of blooms of phytoplankton and cyanobacteria. Using solution ³¹P nuclear magnetic resonance (NMR), combined with field surveys and lab analyses, composition and structural characteristics of dissolved phosphorus (DP), particulate phosphorus (PP) and organic P in algae were studied in two eutrophic lakes in China, Tai Lake and Chao Lake. Factors influencing migration and transformation of these constituents in lake ecosystems were also investigated. A method was developed to extract, flocculate and concentrate DP and PP from lake water samples. Results showed that orthophosphate (Ortho-P) constituted 32.4%-81.3% of DP and 43.7%-54.9% of PP, respectively; while monoester phosphorus (Mono-P) was 13.2%-54.0% of DP and 32.9%-43.7% of PP, respectively. Phosphorus in algae was mostly organic P, especially Mono-P, which was ≥50% of TP. Environmental factors and water quality parameters such as temperature (T), electrical conductivity (EC), pH, secchi depth (SD), dissolved oxygen (DO), chemical oxygen demand (COD_cr), chlorophyll-a (Chl-a), affected the absolute and relative concentrations of various P components in the two lakes. Increased temperature promoted bioavailable P (Ortho-P and Mono-P) release to the lake waters. The results can provide an important theoretical basis for the mutual conversion process of organic P components between various media in the lake water environment.

Polymorphisms of 19 Autosomal STR Loci in Sichuan Han Population and Their Forensic Application

Objective To investigate the allele distribution, population genetics parameters and genetic analysis of neighboring populations of 19 autosomal STR loci in Sichuan Han population, and to evaluate their forensic application value. Methods The Goldeneye?? DNA ID system 20A was used to perform multiplex PCR amplification and allelic gene typing of 19 STR loci in 1 201 unrelated Han individuals from Sichuan Province. Allele frequencies and population genetics parameters were calculated. The Nei's genetic distances between Sichuan Han population and 12 previously reported populations were analyzed. Multidimensional scaling and principal component analysis were carried out and phylogenetic trees were also constructed. Results The heterozygosity of 19 STR loci ranged from 0.617 0 to 0.915 1, their discrimination power ranged from 0.777 4 to 0.986 5, matching probability ranged from 0.013 5 to 0.222 6, polymorphism information content ranged from 0.546 4 to 0.910 5, probability of exclusion ranged from 0.311 8 to 0.826 3 （triplet） and from 0.197 9 to 0.712 1 （biplet）, and no significant deviations from Hardy-Weinberg equilibrium were observed. Based on the results of multidimensional scaling, principal component analysis and phylogenetic trees of the genetic distances between Sichuan Han population and the other 12 populations, Sichuan Han population was closest to Hubei Han population and was farthest to Xinjiang Uygur population. Conclusion The 19 autosomal STR loci showed a high polymorphism and discriminating ability in Sichuan Han population, which can provide a data foundation for personal identification, paternity test and population genetics study.

[Transcriptome profiling of differentiated lenses through RNA sequencing]

Objective: To gain insight into the transcriptional landscape including mRNA, long non-coding RNA (lncRNA), and circular RNA (circRNA) of the differentiated lens. Methods: Experiment research. The total RNAs of the differentiated lenses were extracted and purified. Total RNAs of 16-week, 23-week, and 25-week differentiated lenses were then sequenced using Illumina HiSeq 2500, and analyzed using bioinformatics tools. The top expressed and differentially expressed mRNAs and lncRNAs were screened. The expressions of overlap genes among the 16-week, 23-week, and 25-week lenses were analyzed by Venn diagram. The expression tendency of lens-specific genes was obtained and verified with real-time polymerase chain reaction. Results: A total of 67 518 311 mapped reads were obtained from differentiated lenses at 16 weeks, 99 440 160 at 23 weeks, and 67 262 320 at 25 weeks. The gene overlap expression analysis showed 740 of the top 1 000 highly expressed mRNAs, 170 of the top 300 highly expressed lncRNAs, and 69 of the top 100 highly expressed circRNAs overlapping expressed in lenses at 16, 23, and 25 weeks, respectively. Lens specific gene expression analysis revealed that the expression of crystallin (CRY) AA, CRYGA, CRYGB, CRYGC, CRYGD, CRYGEP, and CRYGS was upregulated, while the expression of gap junction (GJ) A3 and GJA8 was downregulated with the differentiation of lenses. Conclusion: The lens transcriptome profile shows that more than half of the high expressed mRNA, lncRNA and circRNA at different differentiation stages are overlapping expressed, and all of them have high expression of lens specific protein genes, such as CRY, GJ etc. (Chin J Ophthalmol, 2020, 56: 356-363).

Investigation of eluted characteristics of fulvic acids using differential spectroscopy combined with Gaussian deconvolution and spectral indices

The characteristics of subfractions of soil fulvic acid (FA₃, FA₅, FA₇, FA₉, and FA₁₃) using stepwise elution from XAD-8 resin with pyrophosphate buffers were investigated by differential absorption spectroscopy (DAS) and differential fluorescence spectroscopy (DFS) combined with mathematical deconvolution and spectral indices. The log-transformed absorbance spectra (LTAS) exhibited three regions for both acidic-buffer-eluted subfractions (AESF) and neutral-buffer-eluted subfraction (NESF) and four regions for basic-buffer-eluted subfractions (BESF) according to the differences in spectral slopes. The DAS spectra of FA subfractions were closely fitted with seven Gaussian bands with maxima location at 199.66, 216.18 ± 1.50, 246.20 ± 3.85, 285.22 ± 7.26, 345.64 ± 5.30, 389.27, and 307.37 nm, respectively (R² > 0.993). The content of salicylic-like and carboxyl groups in FA subfractions decreased, while the phenolic chromophore increased with elution sequence. From the 11 spectral indices, AESF had greater molecular weight, condensation, polymerization, hydroxyl radical production, humification degree, and terrigenous contribution, as well as contained more conjugated aromatic structures and less N-containing groups than NESF and BESF. The humification degree and humic characters of FA subfractions were closely associated to the aromaticity, molecular condensation, and DOM-metal-bound functional groups. The proper separation of FA into subfractions is beneficial for reducing its complexity and heterogeneity, which helps us to further explore its chemical properties and interactions with various contaminants in soil environments. Graphical abstract.

Simulated photo-degradation of dissolved organic matter in lakes revealed by three-dimensional excitation-emission matrix with regional integration and parallel factor analysis

Simulated photo-degradation of fluorescent dissolved organic matter (FDOM) in Lake Baihua (BH) and Lake Hongfeng (HF) was investigated with three-dimensional excitation-emission matrix (3DEEM) fluorescence combined with the fluorescence regional integration (FRI), parallel factor (PARAFAC) analysis, and multi-order kinetic models. In the FRI analysis, fulvic-like and humic-like materials were the main constituents for both BH-FDOM and HF-FDOM. Four individual components were identified by use of PARAFAC analysis as humic-like components (C1), fulvic-like components (C2), protein-like components (C3) and unidentified components (C4). The maximum 3DEEM fluorescence intensity of PARAFAC components C1-C3 decreased by about 60%, 70% and 90%, respectively after photo-degradation. The multi-order kinetic model was acceptable to represent the photo-degradation of FDOM with correlation coefficient (R_adj²) (0.963-0.998). The photo-degradation rate constants (k_n) showed differences of three orders of magnitude, from 1.09 × 10^-6 to 4.02 × 10^-4 min^-1, and half-life of multi-order model ( T_1/2ⁿ) ranged from 5.26 to 64.01 min. The decreased values of fluorescence index (FI) and biogenic index (BI), the fact that of percent fluorescence response parameter of Region I (P_I,n) showed the greatest change ratio, followed by percent fluorescence response parameter of Region II (P_II,n), while the largest decrease ratio was found for C3 components, and the lowest T_1/2ⁿ was observed for C3, indicated preferential degradation of protein-like materials/components derived from biological sources during photo-degradation. This research on the degradation of FDOM by 3DEEM/FRI-PARAFAC would be beneficial to understanding the photo-degradation of FDOM in natural environments and accurately predicting the environmental behaviors of contaminants in the presence of FDOM.

Pyrolysis characteristics of soil humic substances using TG-FTIR-MS combined with kinetic models

The incorporation and cycling of pyrogenic organic matter in soil is a potential carbon sink, while the pyrolysis behaviors of soil organic matter are still lacking. Pyrolysis characteristics of soil fulvic acid (FA) and humic acid (HA) were investigated using thermogravimetry combined with Fourier transform infrared spectrometer-mass spectrometer (TG-FTIR-MS) and kinetic models. Four reaction stages corresponding to four pseudo-components were distinguished for both FA and HA. FA exhibited greater transformation contributions of hemicellulose-like and cellulose-like pseudo-components, while HA exhibited greater transformation contributions of lignin-like pseudo-components. Compared to HA, higher levels of heat-resistant aromatic compounds, phenolic groups, and carboxylic groups were recognized in FA. Values of both activation energy (Ea, 246.13-661.40 kJ·mol^-1) and pre-exponential factor (lnA, 53.49-107.16 min^-1) of FA were greater than corresponding Ea (241.74-466.70 kJ·mol^-1) and lnA (51.99-74.36 min^-1) values of HA determined by Flynn-Wall-Ozawa method and Distributed Activation Energy Model. The main pyrolysis reaction mechanisms of both FA and HA closely matched with the order-based model corresponding to 2nd and 3rd order random nucleation on an individual particle. The evolved gas species of H₂, CH₄, H₂O, and CO₂ were dominant for FA and HA pyrolysis. Generally, the total H₂/CO₂ and CH₄/H₂O releases were relatively larger for FA and HA pyrolysis, respectively. TG-FTIR-MS is shown to be an effective method to provide valuable and qualitative analysis of the gaseous volatile species evolved during HS pyrolysis. Findings from this systematic study of soil organic matter responding to pyrolysis will be critical for predicting the changes of soil systems or carbon cycle affected by future climate and fire regimes.

Experimental and modeling study of proton and copper binding properties onto fulvic acid fractions using spectroscopic techniques combined with two-dimensional correlation analysis

Fulvic acid (FA) significantly influences the bioavailability and fate of heavy metals in environments, while its acid-base characters and metal binding processes are still unclear. Here, spectroscopic techniques combined with multiple models (e.g., NICA-Donnan model) and two-dimensional correlation spectroscopy (2D COS) were applied to explore the proton and copper binding properties of FA sub-fractions (FA₃-FA₁₃). The charge densities, average contents of carboxylic and phenolic groups, average dissociation constants pKa₁ and pKa₂ of sub-fractions ranged 0-16 meq∙g∙C^-1, 5.03-9.58 meq∙g∙C^-1, 2.52-4.67 meq∙g∙C^-1, 4.15-4.33 and 8.52-9.72, respectively. FA sub-fractions had a relatively narrow distribution of carboxyl group and a broad distribution of phenolic group. FA sub-fractions also exhibited roughly two phenolic hydroxyl groups per every 1-3 phenyl rings. Differential absorbance spectra (DAS) derived Gaussian bands were associated to the inter-chromophore interactions, the changes of molecular conformations and functional groups with copper addition. Differential spectra slopes (DSlope_{275-295&325-375}) were more significant with higher copper concentration and copper amounts bonded to carboxylic groups. UV-Vis and fluorescence spectra with 2D heterospectral COS revealed the copper binding heterogeneities and sequential orders of chromophores and fluorophores, quantitatively confirming by the order of conditional stability constants (log K_Cu: 4.64-5.56). Salicylic-/polyhydroxyphenolic, hydroxyl and amino groups were strongly associated to the basic units for fluorophores. Sequential changes followed the order of humic-like→fulvic-like materials for FA₃/FA₅, humic-like→fulvic-like→tryptophan-like materials for FA₇, and humic-like→tryptophan-like→fulvic-like→tyrosine-like materials for FA₉/FA₁₃. Spectroscopic techniques combined with various models (especially for 2D COS) are beneficial to elucidate the binding heterogeneity and sensitivity for metal-organic matters at the functional group level.

Novel Insights into the Kinetics, Evolved Gases, and Mechanisms for Biomass (Sugar Cane Residue) Pyrolysis

Biomass, a renewable energy source, via available thermo-chemical processes has both engineering and environmental advantages. However, the understanding of the kinetics, evolved gases, and mechanisms for biomass pyrolysis is limited. We first propose a novel temperature response mechanism for the pyrolysis of sugar cane residue using thermogravimetric analysis-Fourier transform infrared spectrometry-mass spectrometry (TG-FTIR-MS) combined with Gaussian model and two-dimensional correlation spectroscopy (2D COS). The existence and contribution of distinct peaks in TG-FTIR spectra were innovatively distinguished and quantified, and the temperature-dependent dynamics of gas amounts were determined using Gaussian deconvolution. The 2D-TG-FTIR/MS-COS results revealed for the first time that the primary sequential temperature responses of gases occurred in the order: H₂O/CH₄ > phenols/alkanes/aromatics/alcohols > carboxylic acids/ketones > CO₂/ethers > aldehyde groups/acetaldehyde. Subtle sequential changes even occurred within the same gases during pyrolysis. The quantity dynamics and sequential responses of gases were fitted to the combined effects of the order-based, diffusion, and chemical reaction mechanisms for the component degradation. The combination of TG-FTIR-MS, Gaussian model, and 2D COS is a promising approach for the online monitoring and real-time management of biomass pyrolysis, providing favorable strategies for pyrolysis optimization, byproduct recovery, energy generation, and gas emission control in engineering and environmental applications.

[Preliminary evaluation and mechanism of adipose-derived stem cell transplantation from allogenic diabetic rats in the treatment of diabetic rat wounds]

Objective: To investigate whether adipose-derived stem cells (ASCs) from allogeneic diabetic rats can promote wound healing in diabetic rats or not and the mechanism. Methods: (1) Fifty-six male Wistar rats aged 12-16 weeks were divided into diabetic group and healthy group according to the random number table (the same grouping method below), with 28 rats in each group. Rats in healthy group were not treated with any treatment. Rats in diabetic group were injected with 10 g/L streptozotocin 60 mg/kg intraperitoneally in one time to establish the diabetic model. Four rats in diabetic group and 4 rats in healthy group were selected according to the random number table, and the adipose tissue in the inguinal region was taken to culture and purify ASCs, so as to obtain healthy rat-derived ASCs (hereinafter referred to as nASCs) and diabetic rat-derived ASCs (hereinafter referred to as dASCs). The third passage of nASCs (n=3) and dASCs (n=3) were taken, and the positive expression rates of cell surface differentiation antigens CD105, CD31, CD34, and CD44 were detected with flow cytometer for defining ASCs purity. (2) The rest 24 rats in healthy group and 24 rats in diabetic group were used to make three round full-thickness skin defect wounds with a diameter of 12 mm on the back of each rat. Immediately after injury, phosphate buffer saline (PBS), nASCs of 2×10(7)/mL, and dASCs of 2×10(7)/mL each in the volume of 0.5 mL were subcutaneously injected into three wounds and their margins of each rat, respectively. On post injury day (PID) 1, 3, 7, and 12, 6 rats in each group were selected according to the random number table to calculate the wound area, and the wound tissue was stained with hematoxylin-eosin to observe the histological morphology of the wound. (3) Human ASCs (hASCs) were subcultured, and the 4th to 7th passage of cells were used for the subsequent experiments. The hASCs were divided into 7 groups, with 12 samples in each group. Cells in blank control group were cultured with mesenchymal stem cell culture medium, and cells in simple advanced glycation end products (AGEs) group, simple protein group, simple high glucose group, simple high osmotic pressure group, AGEs-high glucose combination group, and protein-high osmotic pressure combination group were cultured with mesenchymal stem cell culture medium containing a final mass concentration of 100 mg/L AGEs, 100 mg/L bovine serum albumin (BSA), 28 mmol/L D-glucose, 28 mmol/L mannitol, 100 mg/L AGEs+ 28 mmol/L D-glucose, 100 mg/L BSA+ 28 mmol/L mannitol, respectively. Cell proliferation was detected by cell counting kit 8 at post culture hour (PCH) 2 and on post culture day (PCD) 2, 4 and 6. (4) The hASCs were divided into blank control group, simple AGE group, simple high glucose group, and AGE-high glucose combination group, with 12 samples in each group, which were treated the same as corresponding groups in experiment (3). On PCD 0, 2, 4, and 6, the positive expression rates of cell surface differentiation antigens CD105, CD44, and CD45 were detected by flow cytometer to estimate their homeostasis. (5) The hASCs were divided into AGE-high glucose combination group and protein-high osmotic pressure combination group, with 9 samples in each group, which were treated the same as corresponding groups in experiment (3). On PCD 2, 4, and 6, the expression of intracellular protein was detected by cyanine 3-streptavidin double-antibody sandwich technique. Data were processed with analysis of variance for factorial design, least significant difference test, and Bonferroni correction. Results: (1) The positive expression rates of CD44 in nASCs and dASCs were both higher than 96%, the positive expression rates of CD31 and CD34 were low, and the positive expression rates of CD105 were about 40%, which basically met the purity requirements. (2) The areas of wounds treated by three methods in rats of healthy group and diabetic group were similar on PID 1 (P>0.05). In healthy group, compared with (0.682 1±0.078 9), (0.314 3±0.113 7), and (0.064 3±0.002 1) cm(2) of the PBS-treated wounds in rats, the area of nASCs-treated wounds in rats decreased significantly on PID 3, 7, and 12 [(0.464 1±0.092 6), (0.223 9±0.072 7), and (0.034 3±0.012 5) cm(2), P<0.05], the area of dASCs-treated wounds in rats decreased significantly on PID 3 and 12 [(0.514 1±0.124 1) and (0.043 7±0.032 8) cm(2), P<0.05] but was not obviously changed on PID 7 [(0.274 2±0.062 5) cm(2), P>0.05]. Compared with those of the dASCs-treated wounds of rats within the same group, the area of the nASCs-treated wounds of rats in healthy group decreased significantly on PID 3 and 7 (P<0.05) but was not obviously changed on PID 12 (P>0.05). In diabetic group, compared with (0.853 5±0.204 8), (0.670 5±0.164 8), and (0.131 4±0.074 4) cm(2) of the PBS-treated wounds in rats, the area of nASCs-treated wounds in rats decreased significantly on PID 3, 7, and 12 [(0.633 4±0.132 5), (0.331 8±0.023 5), and (0.074 2±0.003 8) cm(2), P<0.05], the area of dASCs-treated wounds in rats decreased significantly on PID 3 [(0.773 6±0.182 2) cm(2), P<0.05] but was not obviously changed on PID 7 and 12 [(0.510 6±0.192 2) and (0.114 4±0.003 1) cm(2), P>0.05]. Compared with the dASCs-treated wounds of rats within the same group, the area of the nASCs-treated wounds of rats in diabetic group was not obviously changed on PID 3 and 7 (P>0.05) but decreased significantly on PID 12 (P<0.05). There was no obvious difference in histological morphology of the wounds treated with three methods in rats of each group on PID 1. On PID 3, a small amount of microvessels were formed in the wounds treated with nASCs and dASCs of rats in both groups, but microvessel formation was almost undetected in the PBS-treated wounds. On PID 7, more small blood vessels and fibroblasts (Fbs) were observed in the wounds treated with nASCs and dASCs of rats in both groups, but the small blood vessels and Fbs were slightly less in the PBS-treated wounds. On PID 12, the wounds treated with nASCs and dASCs of rats in the two groups were covered by epithelial tissue, the granulation tissue in the PBS-treated wounds of rats in healthy group was not obvious, and the PBS-treated wounds of rats in diabetic group were not completely epithelialized. (3) Compared with those of blank control group, the cell number of hASCs in simple AGEs group decreased significantly on PCD 2, 4, and 6 (P<0.05), which increased significantly on PCD 2 and 4 in simple high glucose group (P<0.05), and that in AGEs-high glucose combination group decreased significantly on PCD 4 and 6 (P<0.05). (4) Compared with that on PCD 4 within the same group, the positive expression rate of CD105 in hASCs decreased significantly in blank control group, simple AGEs group, and AGEs-high glucose combination group on PCD 6 (P<0.05). The positive expression rate of CD44 was higher than 95%, and that of CD45 was less than 2% in hASCs of each group at each time point. (5) Detection values of 7 proteins were located in the confidence interval. The expression levels of basic fibroblast growth factor and tissue inhibitor of metalloproteinase-1 in hASCs of AGEs-high glucose combination group and protein-high osmotic pressure combination group showed increasing trend with the prolongation of culture time. The expression level of human monocyte chemoattractant protein 1 (MCP-1) in hASCs of AGEs-high glucose combination group showed increasing trend with the prolongation of culture time, while the expression level of growth-regulated oncogene (GRO) on PCD 6 was significantly higher than that on PCD 4 within the same group (P<0.05); the expression levels of MCP-1 and GRO in hASCs of protein-high osmotic pressure combination group showed decreasing trend with the prolongation of culture time. The expression level of follistatin in hASCs of protein-high osmotic pressure combination group decreased obviously on PCD 4, while that in hASCs of AGEs-high glucose combination group was significantly lower on PCD 6 than that on PCD 4 (P<0.05). The expression level of vascular endothelial growth factor (VEGF) in hASCs of protein-high osmotic pressure combination group decreased gradually with the prolongation of culture time, while that in hASCs of AGEs-high glucose combination group on PCD 4 decreased significantly as compared with that on PCD 2 (P<0.05). The expression level of urokinase-type plasminogen activator receptor in hASCs of protein-high osmotic pressure combination group on PCD 6 was significantly higher than that on PCD 4 within the same group (P<0.05) and that of AGEs-high glucose combination group on PCD 6 (P<0.05). Conclusions: Both nASCs and dASCs can promote wound healing in rats with simple defect injury, but dASCs have no significant effect on wound healing in rats with diabetes mellitus, which may be related to the inhibition of ASCs proliferation and the influence of high glucose and AGEs intervention on their homeostasis and secretory function.

Correlations between slow pyrolysis characteristics and organic carbon structure of aquatic plant biomass

Thermal analysis techniques have been widely used to characterize natural organic matter; in particular, thermal oxidation has been used to examine soil and sediment organic matter. However, few studies have characterized natural organic matter (NOM) by using slow thermal degradation under a N₂ atmosphere. ¹³C nuclear magnetic resonance (NMR) spectroscopy, UV-Vis spectroscopy, and three-dimensional excitation and emission matrix (EEM) fluorescence spectroscopy were used to characterize aquatic plant biomass for the detailed interpretation of the structures of organic carbon during slow pyrolysis. There was a significant linear correlation between the absorption of heat (99-110 °C) and the loss of mass (110-160 °C) (r² = 0.507, p = 0.01), which indicates that the initial slight loss in mass of the plant materials was due to the loss of less thermally stable components. The release of heat (277-311 °C) and the ratio of the specific absorbances at 253 and 203 nm (A_253/203) were also correlated (r² = 0.388, p = 0.008), which suggests that the release of plant biomass upon heating was associated with the proportion of substituent groups on aromatic rings and that the release of heat increased with the amount of substitution. The coefficient of determination (r²) between fulvic acid-like fluorescence peaks and the loss of mass (230-340 °C) was 0.236 (p = 0.048). This result indicates that the loss of mass in the plant material samples was related to fulvic acid-like substances. More specifically, the reason for this result was the splitting of some aromatic functional groups, such as ether bonds, carbonyl groups, and oxygen heterocycles. In conclusion, these results suggest that the developed correlations between slow pyrolysis characteristics and organic carbon structures contribute to the investigation of the inner chemical structures of natural organic matter.

Depth-dependent variations of dissolved organic matter composition and humification in a plateau lake using fluorescence spectroscopy

In aquatic systems, dissolved organic matter (DOM) plays an important role in regulating the reactivity and transport of environmental pollutants. Fluorescence excitation-emission matrix (EEM) analysis combined with fluorescence regional integration (FRI) and parallel factorial analysis (PARAFAC) were applied to investigate the composition, humification degree and depth-dependent variation of DOM in Lake Baihua, China. The results showed that humic-like materials with more than 60% of percentage fluorescence response (P_i,n) were dominant in DOM. The molecular complexity and structural condensation of PARAFAC components showed the order of C1 (humic-like components) > C3 (protein-like components) > C4 (fulvic-like components) > C2 (fulvic-like components). The lower maximum fluorescence intensities (F_max) of components in surface layers were attributed to photo-oxidation of DOM by radiation. With depths less than 16 m, the F_max increases and decreases were attributed to accumulation of recalcitrant humic substances and microbial/abiotic degradation of particulate DOM, respectively. A combination of biological and humification indices could be used as indicators for distinguishing different degrees of humification and sources of DOM. DOM from Lake Baihua mainly originated from an aquatic bacterial source that consisted of an important/intermediate autochthonous component with a weak humic character. The fluorescence indices of P_I,n/P_II,n, P_I+II+IV,n/P_III+V,n, C2, C1/C2 and C2/(C3+C4) were more suitable to determine the humification degree. Stronger humic characters and higher humification degree for DOM were present at depths of 10-13 m. The fluorescence spectroscopy combined with fluorescence indices is convenient to investigate depth-dependent DOM characteristics and to assess water quality or pollution risk in lake systems.

[Preliminary study on the relationship between OSA and renal function]

Objective:To explore the relationship between obstructive sleep apnea(OSA) and renal function. Method:We collected the clinical data of 487 patients who underwent sleep monitoring in our hospital from January 2013 to December 2017 and excluded history of chronic heart disease, acute and chronic glomerulonephritis, and pyelonephritis. Among the 487 patients, 54 were in nonOSA control group and 433 were in OSA group, including 64 patients with mild OSA, 77 patients with moderate OSA, 108 patients with severe OSA, and 188 patients with extremly severe OSA. The eGFR was calculated using an equation combined serum creatinine and cystatin C. Then propensity score matching(PSM) was used to reduce differences in confounders among groups. The differences of creatinine, cystatin and eGFR between the control group and different degrees of OSA were compared, and the relationship between OSA severity and renal dysfunction was analyzed.Result:There was no statistically significant difference in creatinine between the OSA group and the control group. Serum cystatin C levels in the moderate OSA group and the extremly severe OSA group were higher compared with the control group(0.90±0.18)mg/L, (0.82±0.21) mg/L,P=0.026;(0.92±0.22) mg/L,(0.82±0.21) mg/L,P=0.006,there was no statistically significant difference in cystatin C level of mild OSA group or severe OSA group compared with the control group.The eGFR levels in the moderate OSA group and extremly severe OSA group were lower than that in the control group, 100.64±16.09, 108.57±19.31,P=0.012; 102.03±18.39, 108.57±19.31, P=0.024.After matching with the PSM, the serum cystatin C levels in the moderate OSA group and in the extremely severe OSA group were higher compared with the control group, (0.91±0.19) mg/L,P=0.028;(0.91±0.23) mg/L,P=0.031;(0.82±0.21) mg/L, but only in moderate OSA group, eGFR was lower than the control group,100.86±17.31,108.57±19.31,P<0.05. Conclusion: The renal function of OSA patients has different degrees of impairment. Renal function impairment and the severity of OSA do not show a single linear relationship.

[Thoughts and principles of diagnosis and treatment of chronic refractory wounds in China]

The correct thoughts and principles of diagnosis and treatment of chronic refractory wounds need to be formulated. Through the relevant domestic and international consensus and based on clinical experience, the Thoughts and principles of diagnosis and treatment of chronic refractory wounds in China is proposed. It is considered that in the diagnosis and treatment of chronic refractory wounds, in the case of fully understanding the patient's medical history, the following thoughts and principles should be complied in order. (1) Pay attention to the cleanliness of the wound after being cleaned. (2) Reasonably perform debridement to avoid being " excessive" or " not thorough". (3) Reasonably perform examination, diagnosis, and differential diagnosis of pathogenic factors. (4) Treat according to etiology. (5) Find comorbidities and prevent adverse outcomes. (6) Select the correct wound treatment method reasonably and timely. When the conservative wound care treatment is considered, pay attention to embodying the concept of etiological treatment, treat the wound according to the principles of safety, phase, selectivity, and effectiveness, and make a reasonable choice of continuing conservative treatment or surgical treatment in time after completing the preparation of the wound bed. When surgical treatment is considered, pay attention to the selection of reasonable surgical method and donor site, pay attention to the healing rate of surgical wound site and the outcome of donor site, and give reasonable protection to the wound site after surgery. (7) Carry out rehabilitation treatment after wound healing and related health education.

Three decades of changes in water environment of a large freshwater Lake and its relationship with socio-economic indicators

Tai Lake (Ch: Taihu) has attracted international attention forcyanobacteria blooms. However, the drivers of cultural eutrophication, especially long-term socio-economic indicators have been little researched. The results of research demonstrate how socio-economic development affected quality of water and how it has been improved by anthropogenic activities. This study described variability in indicators of water quality in Tai Lakeand investigated thedrivers. Significant relationships existed between concentrations of annual mean total nitrogen (TN), total phosphorous (TP), chemical oxygen demand (COD) and biological oxygen demand (BOD), and population, per capital gross domestic production (GDP) and sewage discharge (p < 0.05). However, mechanisms causing change varied among TN, TP, COD and BOD. Before 2000, the main contributors to increases in concentrations of TN were human population, GDP and volumes of domestic sewage discharges. After 2000, discharges of industrial sewage become the primary contributor. After 1998, the regressions of annual mean TN, TP and COD on per capital GDP, population and domestic sewage discharge were reversed compared to the former period. Since 1999, an apparent inverted U-shaped relationship between environmental pollution and economic development has developed, which indicated that actions taken by governments have markedly improved quality of water in Tai Lake. The statistical relationship between BOD and per capital GDP didn't conform to the Kuznet curve. The U-shaped Kuznet curve may offer hope for the future that with significant environmental investments a high GDP can be reached and maintained without degradation of the environment, especially through appropriate management of industrial sewage discharge.

Dissolved organic matter characterization of biochars produced from different feedstock materials

Fluorescence excitation-emission matrix (EEM) spectroscopy coupled with parallel factor analysis (PARAFAC) enables better understanding of the nature of dissolved organic matter (DOM). In the current study, we characterized 10 biochar samples produced from different feedstocks using EEM/PARAFAC analysis. The composition and distribution of DOM substances present in biochar varied significantly according to feedstock, activation, and pyrolysis temperature. The integration of proximate and ultimate analyses of the solid phase together with water extractable organic matter (WEOM) phase of biochar provided new insights into the characterization of biochars, including nature and functionality. Characterization of both WEOM and solid phases is recommended for biochar research before large-scale production for various environmental and industrial applications.

[Clinical manifestations and genetics analysis of collagen type Ⅵ-related myopathy caused by variants in COL6A3 gene]

Objective: To summarize the clinical manifestations and determine the molecular etiology for two collagen type Ⅵ-related myopathy pedigrees. Methods: Two spontaneous collagen type Ⅵ-related myopathy patients were admitted to Department of Neurology, Children's Hospital, Capital Institute of Pediatrics in October 2017. Clinical data of probands and their family members were collected and their genomic DNA was obtained for genetic testing. Next generation sequencing was performed and the variants were verified by the Sanger sequencing in the family members. Results: Target region sequencing indicated that the proband of family 1 has carried a heterozygous variant of COL6A3 gene, c.6229G>C(p.Gly2077Arg), and it was de novo variant confirmed by Sanger-sequencing in the family.The patient 1, a 2-year-three-month old boy, was admitted due to motor retardation at birth. He was defined as early severe Ullrich congenital muscular dystrophy. He never achieved independent ambulation, he had onset of symptoms was found at birth, including diffuse muscle weakness, striking distal joint hyperlaxity, proximal contractures, calcaneal protrusion, kyphosis, and hip dislocation. Serum CK level was elevated slightly and EMG showed neurogenic changes. The patient 2, a 7-year-old girl with a limp for 4 years, carried one de novo variant of COL6A3 gene,c.5169_5177del (p.Glu1724_Leu1726del). This variant results in the deletion of amino acids (1724 to 1726) in α3 chain of collagen Ⅵ, which may disturb the function of this protein.She was diagnosed as Bethlem myopathy with a mild phenotype. She had delayed motor milestones and presented with walking on tiptoe, hypotonia, and ithylordosis. The contracture of proximal joints was not very obvious. Serum CK level was normal and EMG showed myogenic changes.Muscle biopsy revealed muscular dystrophy and muscle magnetic resonance imaging of patient 2 showed vastus lateral is a "sandwich" sign. Immunofluorescence staining for COL6A3 chain in the cultured skin fibroblasts from patients 2 showed decreased deposition compared with control. Conclusions: These two patients were diagnosed as spontaneous collagen type Ⅵ-related myopathy and carried different variants of COL6A3 gene. Different in pathogenetic variants could cause different genetic features and different phenotypes. Collagen type Ⅵ- related myopathy patients have various clinical manifestations. Typical phenotypes include muscular dystrophies, proximal contractures, and distal hyperlaxity. Muscle MRI shows diffuse fatty infiltration of gluteus maximus and thigh muscle. The histological staining showed the low level expression of COL6A3 chain. The seventy of phenotype was related to the genotype.