A multi-omics approach to unravelling the coupling mechanism of nitrogen metabolism and phenanthrene biodegradation in soil amended with biochar.

The presence of polycyclic aromatic hydrocarbons (PAHs) in soil negatively affects the environment and the degradation of these contaminants is influenced by nitrogen metabolism. However, the mechanisms underlying the interrelationships between the functional genes involved in nitrogen metabolism and phenanthrene (PHE) biodegradation, as well as the effects of biochar on these mechanisms, require further study. Therefore, this study utilised metabolomic and metagenomic analysis to investigate primary nitrogen processes, associated functional soil enzymes and functional genes, and differential soil metabolites in PHE-contaminated soil with and without biochar amendment over a 45-day incubation period. Results showed that dissimilatory nitrate reduction to ammonium (DNRA) and denitrification were the dominant nitrogen metabolism processes in PHE-contaminated soil. The addition of biochar enhanced nitrogen modules, exhibiting discernible temporal fluctuations in denitrification and DNRA proportions. Co-occurrence networks and correlation heatmap analysis revealed potential interactions among functional genes and enzymes responsible for PHE biodegradation and nitrogen metabolism. Notably, enzymes associated with denitrification and DNRA displayed significant positive correlation with enzymes involved in downstream phenanthrene degradation. Of particular interest was stronger correlation observed with the addition of biochar. However, biochar amendment inhibited the 9-phenanthrol degradation pathway, resulting in elevated levels of glutathione (GSH) in response to environmental stress. These findings provide new insights into the interactions between nitrogen metabolism and PHE biodegradation in soil and highlight the dual effects of biochar on these processes.

Effects of a death education based on narrative pedagogy in a palliative care course among Chinese nursing students.

Background: Death education has been confirmed to be an effective method to enhance nursing students' attitudes and coping abilities toward death. However, integrated Narrative Pedagogy into the death education to explore educational effectiveness is still limited. The study aimed to evaluate the effects of a death education based on Narrative Pedagogy in a palliative care course on the attitude toward death, coping with death, and attitude toward caring for the dying among undergraduate nursing students in China. Methods: The study was designed as a pre-post intervention study with a quasi-experimental design. All the participants received 6 class hours of death education which was designed in a palliative care course. The death education includes preparation, presentation, discussion, reflection, and practice of the narrative materials. Death Attitude Profile-Revised (DAP-R), Coping with Death Scale (CDS), and Frommelt Attitude Toward Care of the Dying-Form B (FATCOD-Form B) were used to measure outcomes. Results: Sixty undergraduate nursing students who consented. There were statistically significant increases in the mean score of neutral acceptance and approach acceptance in the DAP-R, CDS, and FATCOD-Form B before and after the intervention. Conclusion: This death education integrated Narrative Pedagogy which indicated to improve attitude toward death, competence to cope with death, and attitude toward the care of dying patients. The findings assist teachers in understanding the importance and urgency of death education, as well as providing a favorable approach to death education. However, the long-term effectiveness still needs to study in further.

Quantifying ecological and human health risks of heavy metals from different sources in farmland soils within a typical mining and smelting industrial area.

The quality of food crops and human health is threatened by heavy metals (HMs) accumulated in farmland soils for a long time. In this study, we selected 148 soil samples randomly from farmlands in a region featuring abandoned lead-zinc (Pb-Zn) mining activities with the aim to quantify the pollution risk and identify potential sources of heavy metals, based on a case in the southwestern of China. The median contents of metals, such as Pb, Zn, Cd, As, Cu and Cr, are above the background values for Chinese soils and prescribed pollution threshold guide values (GB15618-2018), except Hg and Ni. The farmland soils in sites surrounding areas with previous Pb-Zn mining and smelting activities were classified as seriously polluted. Pollution sources were evaluated using GIS-based geostatistical methods, multivariate statistical analyses and positive matrix factorization (PMF) modeling. Four sources were quantitatively apportioned, which were industrial sources such as mining and smelting (53.1%), agricultural practices (11.6%), natural source (21.6%) and other industrial sources such as electroplating (13.7%). The potential risks of contamination associated with the heavy metals were evaluated using several indices including the Nemerow, geoaccumulation (Igeo) and ecological risk (RI) indices. Based on the Igeo index, As and Pb were the most severe pollutants among all of those measured. With the combination of the potential ecological risk index (RI) and human health risk (HHR) assessment models, the ecological risk and HHR from different sources were analyzed quantitatively. Industrial activities such as mining and smelting were the greatest contributors to ecological risk, non-carcinogenic risk and carcinogenic risk, accounting for about 86.9%,73.9% and 81.9%, respectively. Additionally, the health risks of children were more serious relative to those of adults from the perspective of non-carcinogenic and carcinogenic risks.

Evaluation of the local decoupling of livestock and cropland in the Huang-Huai-Hai region.

Decoupling livestock and cropland production at regional scale have poor resource-use efficiency and detrimental effects on environment in China. It is therefore necessary to identify the decoupled livestock and cropland production system and make recommendations to recouple livestock and cropland. This study used the indexes of land carrying capacity (LCC), animal manure absorption capacity (AMAC), and risk warning value (R) to evaluate the coupling between cropland and livestock at the local scale in the Huang-Huai-Hai region. The decoupling of cropland and livestock in the case of Beijing (SY_BJ) was found assessed with lower theoretical value of LCC and higher theoretical value of AMAC compared with local actual situation, categorized as grade IV with a high R value (above 1). Contrary results were found that the livestock and cropland production systems were coupled at the local scale in the cases located in Hebei and Shandong Provinces, categorized as grade I or II. Two measures were used to optimize the decoupled case by adjusting the ratio of manure to fertilization or reducing breeding quantity. The decoupled case of SY_BJ could be optimized by adjusting the ratio of manure to fertilization (95.34% based on nitrogen and 81.97% based on phosphorus, respectively). The breeding quantity in this case should be reduced by at least 46% to recouple the livestock and cropland at the local level to manage nutrient surpluses from livestock and poultry breeding.

Livelihood resilience in pastoral communities: Methodological and field insights from Qinghai-Tibetan Plateau.

Livelihood resilience is crucial for both people and the environment, especially in remote and harsh ecosystems, such as the Qinghai Tibetan Plateau (QTP). This research aimed to fill the gap of assessing herders' livelihood resilience using more inclusive method. Using survey data from 758 pastoralists, complemented with focus group discussions and transect walks in the Three River Headwater Region (TRHR) on the QTP, we first developed a livelihood resilience evaluation index comprising dimensions of buffer capacity, self-organization and learning capacity. The method of entropy-TOPSIS was then applied to assess the livelihood resilience of local herders, and the spatial patterns were analyzed by spatial autocorrelation method. The results showed the overall level of pastoral livelihood resilience resulted weak, with an east to west spatial gradient toward lower livelihood resilience. Self-organization was the most important dimensions of livelihood resilience, with social cohesion being a dominant factor. Buffer capacity resulted the less important, but the natural capital was significantly higher than the other four livelihood capitals. Furthermore, the northeastern region was a hotspot, while the northwestern region was a cold spot of livelihood resilience. While pastoral populations in the TRHR had high self-organization abilities and potentially high learning capacities, the overall low buffer capacity and livelihood capital limited the improvement of their livelihood resilience. The key findings provide support for enabling policies and integrated strategies to enhance social-ecological resilience. Study may help as paradigm shift reference for the livelihood resilience of pastoral communities in high-altitude areas globally.

NOx attenuation in flue gas by •OH/SO4•--based advanced oxidation processes.

The combustion of fossil fuels has resulted in rapidly increasing emissions of nitrogen oxide (NOx), which has caused serious human health and environmental problems. NO capture has become a research focus in gas purification because NO accounts for more than 90% of NOx and is difficult to remove. Advanced oxidation processes (AOPs), features the little secondary pollution and the broad-spectrum strong oxidation of hydroxyl radicals (•OH), are effective and promising strategies for NO removal from coal-fired flue gas. This review provides the state of the art of NO removal by AOPs, highlighting several methods for producing •OH and SO4•-. According to the main radicals responsible for NO removal, these processes are classified into two categories: hydroxyl radical-based AOPs (HR-AOPs) and sulfate radical-based AOPs (SR-AOPs). This paper also reviews the mechanisms of NO capture by reactive oxygen species (ROS) and SO4•- in various AOPs. A HiGee (high-gravity) enhanced AOP process for improving NO removal, characterized by intensified gas-liquid mass transfer and efficient micro-mixing, is then proposed and discussed in brief. We believe that this review will be useful for workers in this field. Graphical abstract.

[Distribution Characteristics and Source Analysis of Polycyclic Aromatic Hydrocarbons in Salinized Farmland Soil from the Oil Mining Area of the Yellow River Delta].

Eighty-nine soil samples were collected from the Binzhou oil mining area of the Yellow River Delta (including 83 farmland soil samples and 6 soil samples from an oil extraction area). A total of 16 US-EPA priority polycyclic aromatic hydrocarbons (PAHs) were measured by gas chromatography-mass spectrometry (GC-MS). Principal component analysis (PCA) and positive matrix factorization (PMF) were employed to investigate potential source apportionment of PAHs in the farmland soil. The total PAH concentrations ranged from 31.5 µg·kg-1 to 1399.4 µg·kg-1 (dry weight) with an arithmetic mean concentration of 119.4 µg·kg-1. The characteristics of PAHs showed that 4- to 6-ring PAHs were slightly dominant in this study area, and most of the PAHs were significantly correlated (P<0.01), which indicates that the sources of the PAHs had some similarities in this sampling area. Source apportionment results derived from two different models were similar, indicating that the sources of PAHs were coal combustion, biomass combustion, fossil fuel combustion, and diesel combustion. The results of the PMF were more detailed, with the following four factors being identified:gasoline combustion (24.05%), diesel combustion (6.17%), low-temperature pyrolysis processes (60.67%), and coal combustion (9.11%).

[Progress of research on Maple syrup disease].

Maple syrup disease (MSUD) is a rare autosomal recessive disorder caused primarily by mutations of branched-chain keto acid dehydrogenase complex (BCKDC). BCKDC includes at least four pathogenic genes of BCKDHA, BCKDHB, DLD and DBT. The clinical manifestations of MSUD are complex, and the main symptoms at the early stage include difficulty in feeding, drowsiness, change in muscle tone and special urine flavor of maple syrup. As the disease progresses, convulsion, hypoglycemia, coma and systemic failure may occur. MSUD is easily missed or misdiagnosed during the neonatal period. This paper provides a review for recent progress made in research on MSUD including etiology, physiopathology, clinical manifestation, auxiliary examination and treatment, with a particular emphasis on genetic testing and treatment.

Nitrogen doped chiral carbonaceous nanotube for ultrasensitive DNA direct electrochemistry, DNA hybridization and damage study.

In the interest of developing novel electrocatalyst for high performance DNA biosensing, with distinctive chiral double helix nanostructure, nitrogen doped chiral carbonaceous nanotube (Chiral-CNT) was employed for ultrasensitive label-free DNA biosensing research. Chiral-CNT can quantitative detection of four DNA bases with high sensitivity and selectivity. Without any prehydrolysis and labeling process, direct electrochemistry of single-stranded DNA and double-stranded DNA, qualitative and quantitative detection of DNA hybridization (low detection limit: 0.0268 g L-1) were realized. Moreover, sensitive detection of DNA damage induced by fenton reagent was also realized with low detection limit of 0.0350 mg mL-1 and high sensitivity of 7.42 µA mg-1 mL. The high biosensing performance attributes to the unique chiral structure of Chiral-CNT, leads to efficient interreaction between Chiral-CNT and DNA molecule.

Design synthesis of a controllable flower-like Pt-graphene oxide architecture through electrostatic self-assembly for DNA damage biomarker 8-hydroxy-2'-deoxyguanosine biosensing research.

A controllable flower-like Pt-graphene oxide (PtNF-GO) architecture was synthesized through layer-by-layer electrostatic self-assembly. Hexadecyltrimethylammonium chloride (CTAC) micelles were employed as the template and Pt nanoflowers with different sizes were selectively synthesized by controlling the dissolved K2PtCl4 precursor and CTAC amounts in the reaction system. The prepared PtNF-GO was applied for DNA damage biomarker 8-hydroxy-2'-deoxyguanosine (8-OHdG) biosensing research. With the distinctive flower-like morphology of PtNFs and high electrical conductivity of GO, the PtNF-GO architecture shows excellent electrochemical biosensing performance towards the oxidation of 8-OHdG. A very low detection limit of 0.025 nM is obtained. Moreover, the fabricated PtNF-GO was used for the detection of 8-OHdG generated from the damaged DNA sample, which can be used to evaluate and confirm the mechanism of DNA damage, and it is of great importance in gene diagnosis, clinical and life sciences.

[Analysis of CLCN1 gene mutations in a family affected with myotonia congenita].

OBJECTIVE: To detect potential mutations of chloride channel l (CLCN1) gene in a family affected with myotonia congenita. METHODS: Clinical data of the proband and her parents and brother was collected. The coding regions of the CLCN1 gene were subjected to PCR and Sanger sequencing. RESULTS: Two missense mutations (c.937G>A and c.1205C>T), which were respectively located within exons 8 and 11 of the CLCN1 gene, were identified in the proband. The mother and father of the proband were found to harbor the c.937G>A and c.1205C>T mutation, respectively, whilst neither mutation was found in her brother. CONCLUSION: The novel missense CLCN1 mutations probably underlie the disease in this family. These have enriched the spectrum of CLCN1 mutations and may facilitate further research on this disorder.

The influence on cell cycle and cell division by various cadmium-containing quantum dots.

Quantum dots (QDs) have attracted great attention because of their favorable optical properties and have been widely applied in biomedical fields. However, in recent years, there have been an increasing number of reports about the cytotoxicity of QDs, especially cadmium-containing QDs, which may release cadmium ions to induce cytotoxicity. Importantly, the chemical composition and surface modifications of cadmium-based QDs determine the amount of Cd(2+) released inside the cell. Thus, there is an urgent need for more systematic work to study the relationship between cytotoxicity and the surface properties of QDs. In this article, the cytotoxicity of seven cadmium-containing QDs with different constituent elements and surface chemistries are compared. The results show that the cytotoxicity of QDs is closely related to their constituent elements and surface properties: First, CdTe@ZnS core-shell QDs show much lower cytotoxicity than naked ones when they have similar surface modifications; second, the positively charged QDs are more toxic than the negatively charged ones. Moreover, both positively and negatively charged QDs without ZnS coatings lead to multipolar spindles, misaligned chromosomes, and G2/M checkpoint failures. Interestingly, although CdSe QDs with a PEG coating cause no apparent cytotoxicity in any of the cell lines studied, they can localize near the contractile ring during cytokinesis and then block contractile ring disassembly. The cellular effect of CdTe QDs comes not only from the release of cadmium ions but also the intracellular distribution of QD nanoparticles in cells and the associated nanoscale effects. It is also found that QD-caused cytokinesis failure is closely related to the decreased expression of Cyclin A and Cyclin B. Taken together, the above findings provide new insight into the dynamic fate of QDs during cell mitosis, and are important for understanding the intracellular effects of QDs on the mitotic spindle and chromosomes during cell division. Furthermore, this kind of cytotoxicity evaluation method should be applicable to studies of the biological effects and health impacts of other nanomaterials.

A general route to efficient functionalization of silicon quantum dots for high-performance fluorescent probes.

A general technique for efficient surface modification of silicon nanocrystals is highly desirable for the development of silicon quantum dots (SiQDs) as fluorescent probes for biological applications. Herein, a facile microwave-assisted hydrosilylation process for the preparation of stable SiQDs in a single step is presented. FTIR spectroscopy indicates that molecules with various terminal functionalities, such as alcohol, alkyl groups, and carboxylic acid, are grafted successfully onto the surface of silicon nanocrystals. The dispersibility of such SiQDs is clearly dependent on the terminal functional groups of the grafted molecules. In addition, the as-prepared SiQDs show excellent cell compatibility, photoluminescence properties, and stability, and their use as long-term intracellular fluorescent probes is also demonstrated. It is envisaged that this facile and effective method for the stabilization and functionalization of SiQDs with tailored wetting and chemical properties will enable wide application of SiQDs in a number of areas.

Efficient delivery of antitumor drug to the nuclei of tumor cells by amphiphilic biodegradable poly(L-aspartic acid-co-lactic acid)/DPPE co-polymer nanoparticles.

The use of biodegradable polymeric nanoparticles (NPs) for controlled drug delivery has shown significant therapeutic potential. Polyaspartic acid and polylactic acid are the most intensively studied biodegradable polymers. In the present study, novel amphiphilic biodegradable co-polymer NPs, poly(L-aspartic acid-co-lactic acid) with 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE) (poly(AA-co-LA)/DPPE) is synthesized and subsequently used to encapsulate an antitumor drug doxorubicin (DOX). The formulation parameters of the NPs are optimized to improve encapsulation efficiency. The resulting drug-loaded NPs possess better size homogeneity (polydispersity) and exhibit pH-responsive drug release profiles. Cellular viability assays indicate that the poly(AA-co-LA)/DPPE NPs did not induce cell death, whereas doxorubicin encapsulated NPs were cytotoxic to various types of tumor cells. In addition, the free NPs could not enter the cell nuclei after internalized in tumor cells. The DOX-loaded NPs exhibit efficient intracellular delivery in tumor cells with co-localization in lysosome and delay entering into the nucleus, which suggests a time- and pH-dependent drug release profile within cells. When applied to deliver chemotherapeutics to a mouse xenograft model of human lung adenocarcinoma, DOX-loaded NPs have a comparable antitumor activity with free DOX, and greatly reduce systemic toxicity and mortality. The delivery of cytotoxic drugs directly to the nucleus specifically within tumor cells is of great interest. These results demonstrate the feasibility of the application of the amphiphilic polyaspartic acid derivative, poly(AA-co-LA)/DPPE, as a nanocarrier for cell nuclear delivery of potent antitumor drugs.

Anti-tumor activity of paclitaxel through dual-targeting carrier of cyclic RGD and transferrin conjugated hyperbranched copolymer nanoparticles.

Targeted delivery strategies are becoming increasingly important. Herein, a novel hyperbranched amphiphilic poly[(amine-ester)-co-(D,L-lactide)]/1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine copolymer (HPAE-co-PLA/DPPE) with RGD peptide (cRGDfK) and transferrin (Tf) on the periphery was synthesized and used to prepare paclitaxel-loaded nanoparticles (NPs) for dual-targeting chemotherapy. These NPs show satisfactory size distribution, high encapsulated efficiency and a pH-dependent release profile. The intrinsic fluorescence of the hyperbranched copolymer renders the detection and tracking of NPs in vitro and in vivo conveniently. In vitro cytotoxicity studies proved that the presence of cRGDfK enhanced the cytotoxic efficiency by 10 folds in α(ν)ß(3) integrin over-expressed human umbilical vein endothelial cells, while Tf improved cytotoxicity by 2 folds in Tf receptor over-expressed human cervical carcinoma cells. The drug-loaded NPs can be efficiently transported into the vascular endothelial cells and the target tumor cells. These results indicate that the cRGDfK and Tf decorated HPAE-co-PLA/DPPE could deliver chemotherapies specifically inside the cell via receptor-mediated endocytosis with greater efficacy. Therefore, such a fluorescent nanocarrier prepared from non-cytotoxic and biodegradable polymers is promising for drug delivery in tumor therapy.

Reactivation of Syk gene by AZA suppresses metastasis but not proliferation of breast cancer cells.

Spleen tyrosine kinase (Syk) is reported to be involved in the suppression of proliferation and invasion of breast cancer. Methylation-mediated Syk gene silencing is found in a subset of breast cancer. In this study, we used a DNA methyltransferase inhibitor, 5-aza-2-deoxycytidine (AZA), to restore Syk expression of breast cancer cells. Surprisingly, we found that AZA treatment could reestablish the expression of Syk, but not affect the proliferation of breast cancer cells. Moreover, tumor formation in situ by MDA-MB-435s treated with (+) or without (-) AZA in a nude mice MFP (Mammary fat pad) model did not show significant difference, too. Interestingly, pulmonary metastasis was still significantly suppressed in MDA-MB-435s(+) group (1/9 vs. 7/9). Our findings suggested Syk may be more correlated to metastasis rather than proliferation. This study implied a potential use of Syk methylation as a valuable biomarker to detect high metastatic potential cancerous lesions and the prospect of AZA to join the arsenal of drug candidates to be developed as a new reagent for management of advanced breast cancer.

Intracellular dynamics of cationic and anionic polystyrene nanoparticles without direct interaction with mitotic spindle and chromosomes.

The fate of nanomaterials with different sizes and charges in mitotic cells is of great importance but seldom explored. Herein we investigate the intracellular fate of negatively charged carboxylated polystyrene (COOH-PS) and positively charged amino-modified polystyrene (NH(2)-PS) nanoparticles of three different diameters (50, 100 and 500 nm) on cancer HeLa cells and normal NIH 3T3 cells during the cell cycles. The results showed that all the fluorescent PS nanoparticles differing in size and/or charge did not interact with chromosome reorganization and cytoskeleton assembly during the mitotic process in live cells. They neither disturbed chromosome reorganization nor affected the cytoskeleton reassembly in both normal and cancer cells. However, NH(2)-PS at the size of 50 nm caused G1 phase delay and a decrease of cyclin (D, E) expression, respectively. Moreover, NH(2)-PS displayed higher cellular toxicity and NH(2)-PS of 50 nm disturbed the integrity of cell membranes. Both cationic and anionic PS nanoparticles had a more pronounced effect on normal NIH 3T3 cells than cancer HeLa cell. Our research provides insight into the dynamic fate, intracellular behavior, and the effects of nanoparticles on spindle and chromosomes during cell division, which will enable the optimization of design and selection of much safer nanoparticles for lower risk to human health and widely medical applications.

Correlation of tumor-positive ratio and number of perigastric lymph nodes with prognosis of patients with surgically-removed gastric carcinoma.

AIM: To evaluate the tumor-positive ratio and number of perigastric lymph nodes as prognostic factors of gastric carcinoma in surgically-treated patients. METHODS: The postoperative survival of 169 patients with gastric cancer who were performed D2 curative gastrectomy was analyzed with regard to its lymph node metastasis ratio and number. Meanwhile correlation of tumor-positive ratio and number of perigastric lymph nodes with pathological parameters of these patients was studied. RESULTS: The overall 5-year survival rate of all the patients studied was 29.6%. The 5-year cumulative survival rate in patients with 1%-20% and more than 20% of tumor-positive lymph nodes was 70.6% and 12.0% respectively, and 46.6% and 17.4% in those with 1-5 and more than 5 of tumor-positive lymph nodes respectively, which were significantly decreased with the increment of involved lymph nodes assessed by either numbers or ratio (P<0.05). Multiple stepwise regression analysis showed that both the positive ratio and number of tumor-involved lymph nodes were sensitive prognostic factors in these surgically-treated patients, which were also significantly correlated with tumor size and depth of submucosal invasion (P<0.05). CONCLUSION: Tumor-positive ratio and number of perigastric lymph nodes are associated with cancer progression and five-year survival rate, and may serve as valuable prognostic factors of gastric cancer in surgically-treated patients.