Climate-related naturally occurring epimutation and their roles in plant adaptation in A. thaliana.

DNA methylation has been proposed to be an important mechanism that allows plants to respond to their environments sometimes entirely uncoupled from genetic variation. To understand the genetic basis, biological functions and climatic relationships of DNA methylation at a population scale in Arabidopsis thaliana, we performed a genome-wide association analysis with high-quality single nucleotide polymorphisms (SNPs), and found that ~56% on average, especially in the CHH sequence context (71%), of the differentially methylated regions (DMRs) are not tagged by SNPs. Among them, a total of 3235 DMRs are significantly associated with gene expressions and potentially heritable. 655 of the 3235 DMRs are associated with climatic variables, and we experimentally verified one of them, HEI10 (HUMAN ENHANCER OF CELL INVASION NO.10). Such epigenetic loci could be subjected to natural selection thereby affecting plant adaptation, and would be expected to be an indicator of accessions at risk. We therefore incorporated these climate-related DMRs into a gradient forest model, and found that the natural A. thaliana accessions in Southern Europe that may be most at risk under future climate change. Our findings highlight the importance of integrating DNA methylation that is independent of genetic variations, and climatic data to predict plants' vulnerability to future climate change.

Magnetoresistance properties in nickel-catalyzed, air-stable, uniform, and transfer-free graphene.

A transfer-free graphene with high magnetoresistance (MR) and air stability has been synthesized using nickel-catalyzed atmospheric pressure chemical vapor deposition. The Raman spectrum and Raman mapping reveal the monolayer structure of the transfer-free graphene, which has low defect density, high uniformity, and high coverage (>90%). The temperature-dependent (from 5 to 300 K) current-voltage (I-V) and resistance measurements are performed, showing the semiconductor properties of the transfer-free graphene. Moreover, the MR of the transfer-free graphene has been measured over a wide temperature range (5-300 K) under a magnetic field of 0 to 1 T. As a result of the Lorentz force dominating above 30 K, the transfer-free graphene exhibits positive MR values, reaching ∼8.7% at 300 K under a magnetic field (1 Tesla). On the other hand, MR values are negative below 30 K due to the predominance of the weak localization effect. Furthermore, the temperature-dependent MR values of transfer-free graphene are almost identical with and without a vacuum annealing process, indicating that there are low density of defects and impurities after graphene fabrication processes so as to apply in air-stable sensor applications. This study opens avenues to develop 2D nanomaterial-based sensors for commercial applications in future devices.

High-resolution Cs-Rb two-photon spectrometer for directly stabilizing a Ti:sapphire comb laser.

In this paper, we present a simple scheme for efficiently removing the residual Doppler background of a comb laser based two-photon spectrometer to be better than 10-3 background-to-signal ratio. We applied this scheme to stabilize the frequencies of a mode-locked Ti:sapphire laser directly referring to the cesium 6S-8S transition and rubidium 5S-5D transition. We suggest a standard operation procedure (SOP) for the fully direct comb laser stabilization and evaluate the frequency of two spectral lines at a certain temperature, by which we demonstrate an all-atomic-transition-based Ti:sapphire comb laser merely via a 6-cm glass cell.

Measurement of the 5S1/2 to 5D5/2 two-photon clock transition frequency of rubidium-85 in high vacuum.

We present a scheme to precisely resolve the unperturbed line shape of an optical rubidium clock transition in a high vacuum, by which we avoided the systematic errors of "collision shift" and "modulation shift." The spectral resolution resolved by this scheme is significantly improved such that we can use "Zeeman broadening" to inspect the stray magnetic field, through which we were able to compensate the magnetic field inside the Rb cells to be below 10-3 Gauss. We thus update the absolute frequency of the clock transition and propose a standard operation procedure (SOP) for the clock self-calibration.

Convolutional neural network for detecting rib fractures on chest radiographs: a feasibility study.

BACKGROUND: Chest radiography is the standard investigation for identifying rib fractures. The application of artificial intelligence (AI) for detecting rib fractures on chest radiographs is limited by image quality control and multilesion screening. To our knowledge, few studies have developed and verified the performance of an AI model for detecting rib fractures by using multi-center radiographs. And existing studies using chest radiographs for multiple rib fracture detection have used more complex and slower detection algorithms, so we aimed to create a multiple rib fracture detection model by using a convolutional neural network (CNN), based on multi-center and quality-normalised chest radiographs. METHODS: A total of 1080 radiographs with rib fractures were obtained and randomly divided into the training set (918 radiographs, 85%) and the testing set (162 radiographs, 15%). An object detection CNN, You Only Look Once v3 (YOLOv3), was adopted to build the detection model. Receiver operating characteristic (ROC) and free-response ROC (FROC) were used to evaluate the model's performance. A joint testing group of 162 radiographs with rib fractures and 233 radiographs without rib fractures was used as the internal testing set. Furthermore, an additional 201 radiographs, 121 with rib fractures and 80 without rib fractures, were independently validated to compare the CNN model performance with the diagnostic efficiency of radiologists. RESULTS: The sensitivity of the model in the training and testing sets was 92.0% and 91.1%, respectively, and the precision was 68.0% and 81.6%, respectively. FROC in the testing set showed that the sensitivity for whole-lesion detection reached 91.3% when the false-positive of each case was 0.56. In the joint testing group, the case-level accuracy, sensitivity, specificity, and area under the curve were 85.1%, 93.2%, 79.4%, and 0.92, respectively. At the fracture level and the case level in the independent validation set, the accuracy and sensitivity of the CNN model were always higher or close to radiologists' readings. CONCLUSIONS: The CNN model, based on YOLOv3, was sensitive for detecting rib fractures on chest radiographs and showed great potential in the preliminary screening of rib fractures, which indicated that CNN can help reduce missed diagnoses and relieve radiologists' workload. In this study, we developed and verified the performance of a novel CNN model for rib fracture detection by using radiography.

Chromosome segregation in Archaea: SegA- and SegB-DNA complex structures provide insights into segrosome assembly.

Genome segregation is a vital process in all organisms. Chromosome partitioning remains obscure in Archaea, the third domain of life. Here, we investigated the SegAB system from Sulfolobus solfataricus. SegA is a ParA Walker-type ATPase and SegB is a site-specific DNA-binding protein. We determined the structures of both proteins and those of SegA-DNA and SegB-DNA complexes. The SegA structure revealed an atypical, novel non-sandwich dimer that binds DNA either in the presence or in the absence of ATP. The SegB structure disclosed a ribbon-helix-helix motif through which the protein binds DNA site specifically. The association of multiple interacting SegB dimers with the DNA results in a higher order chromatin-like structure. The unstructured SegB N-terminus plays an essential catalytic role in stimulating SegA ATPase activity and an architectural regulatory role in segrosome (SegA-SegB-DNA) formation. Electron microscopy results also provide a compact ring-like segrosome structure related to chromosome organization. These findings contribute a novel mechanistic perspective on archaeal chromosome segregation.

In vitro and in vivo development of interspecies Asian elephant embryos reconstructed with pig enucleated oocytes.

Interspecies somatic cell nuclear transfer (iSCNT) has an immense potential to rescue endangered animals and extinct species like mammoths. In this study, we successfully established an Asian elephant's fibroblast cell lines from ear tissues, performed iSCNT with porcine oocytes and evaluated the in vitro and in vivo development of reconstructed embryos. A total of 7780 elephant-pig iSCNT embryos were successfully reconstructed and showed in vitro development with cleavage rate, 4-cell, 8-cell and blastocyst rate of 73.01, 30.48, 5.64, and 4.73%, respectively. The total number of elephant-pig blastocyte cells and diameter of hatched blastocyte was 38.67 and 252.75 µm, respectively. Next, we designed species-specific markers targeting EDNRB, AGRP and TYR genes to verify the genome of reconstructed embryos with donor nucleus/species. The results indicated that 53.2, 60.8, and 60.8% of reconstructed embryos (n = 235) contained elephant genome at 1-cell, 2-cell and 4-cell stages, respectively. However, the percentages decreased to 32.3 and 32.7% at 8-cell and blastocyst stages, respectively. Furthermore, we also evaluated the in vivo development of elephant-pig iSCNT cloned embryos and transferred 2260 reconstructed embryos into two surrogate gilts that successfully became pregnant and a total of 11 (1 and 10) fetuses were surgically recovered after 17 and 19 days of gestation, respectively. The crown-rump length and width of elephant-pig cloned fetuses were smaller than the control group. Unfortunately, none of these fetuses contained elephant genomes, which suggested that elephant embryos failed to develop in vivo. In conclusion, we successfully obtained elephant-pig reconstructed embryos for the first time and these embryos are able to develop to blastocyst, but the in vivo developmental failure needs further investigated.

Construction and function of a high-efficient synthetic bacterial consortium to degrade aromatic VOCs.

Aromatic volatile organic compounds (VOCs) are a type of common pollution form in chemical contaminated sites. In this study, seven aromatic VOCs such as benzene, toluene, ethylbenzene, chlorobenzene, m-xylene, p-chlorotoluene and p-chlorotrifluorotoluene were used as the only carbon source, and four strains of highly efficient degrading bacteria were screened from the soil of chemical contaminated sites, then the synthetic bacterial consortium was constructed after mixing with an existing functional strain (Bacillus benzoevorans) preserved in the laboratory. After that, the synthetic bacterial consortium was used to explore the degradation effect of simulated aromatic VOCs polluted wastewater. The results showed that the functional bacterium could metabolize with aromatic VOCs as the only carbon source and energy. Meanwhile, the growth of the synthetic bacterial consortium increased with the additional carbon resources and the alternative of organic nitrogen source. Ultimately, the applicability of the synthetic bacterial consortium in organic contaminated sites was explored through the study of broad-spectrum activity.

Mitotically heritable epigenetic modifications of CmMYB6 control anthocyanin biosynthesis in chrysanthemum.

Flower color, which is determined by various chemical pigments, is a vital trait for ornamental plants, in which anthocyanin is a major component. However, the epigenetic regulation of anthocyanin biosynthesis remains poorly understood. During chrysanthemum cultivation, we found a heterochromatic chrysanthemum accession (YP) whose progeny generated by asexual reproduction contained both yellow-flowered (YP-Y) and pink-flowered (YP-P) plants. In this study, we aimed to elucidate the epigenetic mechanisms of different flower colors in the YP plant progeny. Metabolome and transcriptome analyses revealed that the difference in flower color between YP-Y and YP-P was caused by expression variation of the anthocyanin biosynthesis gene CmMYB6. Bisulfite sequencing revealed that methylation at the CmMYB6 promoter, especially in the CHH context, was higher in YP-Y than YP-P. After demethylation of the CmMYB6 promoter using the dCas9-TET1cd system, the flower color returned from yellow to pink. Furthermore, the methylation status of the CmMYB6 promoter was higher in YP-Y over three consecutive generations, indicating that this methylation status was heritable mitotically. Finally, investigation of other chrysanthemum cultivars showed that the methylation of CmMYB6 decreased gradually with the increase in anthocyanin content. These results lay an epigenetic foundation for the improvement of flower color in horticultural plants.

A dual-function transcription factor, SlJAF13, promotes anthocyanin biosynthesis in tomato.

Unlike modern tomato (Solanum lycopersicum) cultivars, cv. LA1996 harbors the dominant Aft allele, which is associated with anthocyanin synthesis in tomato fruit peel. However, the control of Aft anthocyanin biosynthesis remains unclear. Here, we used ethyl methanesulfonate-induced and CRISPR/Cas9-mediated mutation of LA1996 to show, respectively, that two class IIIf basic helix-loop-helix (bHLH) transcription factors, SlJAF13 and SlAN1, are involved in the control of anthocyanin synthesis. These transcription factors are key components of the MYB-bHLH-WD40 (MBW) complex, which positively regulates anthocyanin synthesis. Molecular and genetic analyses showed that SlJAF13 functions as an upstream activation factor of SlAN1 by binding directly to the G-Box motif of its promoter region. On the other hand, SlJAZ2, a JA signaling repressor, interferes with formation of the MBW complex to suppress anthocyanin synthesis by directly binding these two bHLH components. Unexpectedly, the transcript level of SlJAZ2 was in turn repressed in a SlJAF13-dependent manner. Mechanistically, SlJAF13 interacts with SlMYC2, inhibiting SlMYC2 activation of SlJAZ2 transcription, thus constituting a negative feedback loop governing anthocyanin accumulation. Taken together, our findings support a sophisticated regulatory network, in which SlJAF13 acts as an upstream dual-function regulator that fine tunes anthocyanin biosynthesis in tomato.

Carbohydrate mouth rinsing decreases fatigue index of taekwondo frequency speed of kick test.

Carbohydrate mouth rinsing (CMR) potentially affects the interval training performance of taekwondo athletes. This study explored the effect of CMR on vertical jump, kicking speed, and fatigue index before and after simulated taekwondo competition. In a crossover experimental design, 13 trained taekwondo athletes were randomly divided into the CMR and control trials. After warming up, the participants used 6.6% maltodextrin (CMR trial) or mineral water (control trial) to rinse their mouth. Next, the participants underwent tests of vertical jump, kicking speed, and maximum number of kicks. After the tests, the participants rinsed their mouth again, followed by using Wingate testing bikes for 5-s sprint and 25-s rest to simulate taekwondo competitions. Four repetitions were performed in each round for 2 min for a total of three rounds. The results revealed that the fatigue index of the participants in the CMR trial before and after the simulated competition was significantly lower than that of the control trial. However, the two trials differed nonsignificantly in their performance in vertical jump, kicking speed, and the simulated competition. Overall, the study results indicated that CMR reduces the fatigue index but no change was observed in performance for vertical jump, kicking speed, and the simulated competition of trained taekwondo athletes.

A Data-Driven Model with Feedback Calibration Embedded Blood Pressure Estimator Using Reflective Photoplethysmography.

Ambulatory blood pressure (BP) monitoring (ABPM) is vital for screening cardiovascular activity. The American College of Cardiology/American Heart Association guideline for the prevention, detection, evaluation, and management of BP in adults recommends measuring BP outside the office setting using daytime ABPM. The recommendation to use night-day BP measurements to confirm hypertension is consistent with the recommendation of several other guidelines. In recent studies, ABPM was used to measure BP at regular intervals, and it reduces the effect of the environment on BP. Out-of-office measurements are highly recommended by almost all hypertension organizations. However, traditional ABPM devices based on the oscillometric technique usually interrupt sleep. For all-day ABPM purposes, a photoplethysmography (PPG)-based wrist-type device has been developed as a convenient tool. This optical, noninvasive device estimates BP using morphological characteristics from PPG waveforms. As measurement can be affected by multiple variables, calibration is necessary to ensure that the calculated BP values are accurate. However, few studies focused on adaptive calibration. A novel adaptive calibration model, which is data-driven and embedded in a wearable device, was proposed. The features from a 15 s PPG waveform and personal information were input for estimation of BP values and our data-driven calibration model. The model had a feedback calibration process using the exponential Gaussian process regression method to calibrate BP values and avoid inter- and intra-subject variability, ensuring accuracy in long-term ABPM. The estimation error of BP (ΔBP = actual BP-estimated BP) of systolic BP was -0.1776 ± 4.7361 mmHg; ≤15 mmHg, 99.225%, and of diastolic BP was -0.3846 ± 6.3688 mmHg; ≤15 mmHg, 98.191%. The success rate was improved, and the results corresponded to the Association for the Advancement of Medical Instrumentation standard and British Hypertension Society Grading criteria for medical regulation. Using machine learning with a feedback calibration model could be used to assess ABPM for clinical purposes.

Transgenerationally Transmitted DNA Demethylation of a Spontaneous Epialleles Using CRISPR/dCas9-TET1cd Targeted Epigenetic Editing in Arabidopsis.

CRISPR/dCas9 is an important DNA modification tool in which a disarmed Cas9 protein with no nuclease activity is fused with a specific DNA modifying enzyme. A previous study reported that overexpression of the TET1 catalytic domain (TET1cd) reduces genome-wide methylation in Arabidopsis. A spontaneous naturally occurring methylation region (NMR19-4) was identified in the promoter region of the PPH (Pheophytin Pheophorbide Hydrolase) gene, which encodes an enzyme that can degrade chlorophyll and accelerate leaf senescence. The methylation status of NMR19-4 is associated with PPH expression and leaf senescence in Arabidopsis natural accessions. In this study, we show that the CRISPR/dCas9-TET1cd system can be used to target the methylation of hypermethylated NMR19-4 region to reduce the level of methylation, thereby increasing the expression of PPH and accelerating leaf senescence. Furthermore, hybridization between transgenic demethylated plants and hypermethylated ecotypes showed that the demethylation status of edited NMR19-4, along with the enhanced PPH expression and accelerated leaf senescence, showed Mendelian inheritance in F1 and F2 progeny, indicating that spontaneous epialleles are stably transmitted trans-generationally after demethylation editing. Our results provide a rational approach for future editing of spontaneously mutated epialleles and provide insights into the epigenetic mechanisms that control plant leaf senescence.

Genome-wide identification, classification, and expression analysis of the JmjC domain-containing histone demethylase gene family in birch.

BACKGROUND: Histone methylation occurs primarily on lysine residues and requires a set of enzymes capable of reading, writing, and erasing to control its establishment and deletion, which is essential for maintaining chromatin structure and gene expression. Histone methylation and demethylation are contributed to plant growth and development, and are involved in adapting to environmental stresses. The JmjC domain-containing proteins are extensively studied for their function in histone lysine demethylation in plants, and play a critical role in sustaining histone methylation homeostasis. RESULTS: In this study, a total of 21 JmjC domain-containing histone demethylase proteins (JHDMs) in birch were identified and classified into five subfamilies based on structural characteristics and phylogenetic relationships among Arabidopsis, rice, maize, and birch. Although the BpJMJ genes displayed significant schematic variation, their distribution on the chromosomes is relatively uniform. Additionally, the BpJMJ genes in birch have never experienced a tandem-duplication event proved by WGD analysis and were remaining underwent purifying selection (Ka/Ks < < 1). A typical JmjC domain was found in all BpJMJ genes, some of which have other essential domains for their functions. In the promoter regions of BpJMJ genes, cis-acting elements associated with hormone and abiotic stress responses were overrepresented. Under abiotic stresses, the transcriptome profile reveals two contrasting expression patterns within 21 BpJMJ genes. Furthermore, it was established that most BpJMJ genes had higher expression in young tissues under normal conditions, with BpJMJ06/16 having the highest expression in germinating seeds and participating in the regulation of BpGA3ox1/2 gene expression. Eventually, BpJMJ genes were found to directly interact with genes involved in the "intracellular membrane" in respond to cold stress. CONCLUSIONS: The present study will provide a foundation for future experiments on histone demethylases in birch and a theoretical basis for epigenetic research on growth and development in response to abiotic stresses.

Genome-wide identification and expression analysis of the AT-hook Motif Nuclear Localized gene family in soybean.

BACKGROUND: Soybean is an important legume crop and has significant agricultural and economic value. Previous research has shown that the AT-Hook Motif Nuclear Localized (AHL) gene family is highly conserved in land plants, playing crucial roles in plant growth and development. To date, however, the AHL gene family has not been studied in soybean. RESULTS: To investigate the roles played by the AHL gene family in soybean, genome-wide identification, expression patterns and gene structures were performed to analyze. We identified a total of 63 AT-hook motif genes, which were characterized by the presence of the AT-hook motif and PPC domain in soybean. The AT-hook motif genes were distributed on 18 chromosomes and formed two distinct clades (A and B), as shown by phylogenetic analysis. All the AHL proteins were further classified into three types (I, II and III) based on the AT-hook motif. Type-I was belonged to Clade-A, while Type-II and Type-III were belonged to Clade-B. Our results also showed that the main type of duplication in the soybean AHL gene family was segmented duplication event. To discern whether the AHL gene family was involved in stress response in soybean, we performed cis-acting elements analysis and found that AHL genes were associated with light responsiveness, anaerobic induction, MYB and gibberellin-responsiveness elements. This suggest that AHL genes may participate in plant development and mediate stress response. Moreover, a co-expression network analysis showed that the AHL genes were also involved in energy transduction, and the associated with the gibberellin pathway and nuclear entry signal pathways in soybean. Transcription analysis revealed that AHL genes in Jack and Williams82 have a common expression pattern and are mostly expressed in roots, showing greater sensitivity under drought and submergence stress. Hence, the AHL gene family mainly reacts on mediating stress responses in the roots and provide comprehensive information for further understanding of the AT-hook motif gene family-mediated stress response in soybean. CONCLUSION: Sixty-three AT-hook motif genes were identified in the soybean genome. These genes formed into two distinct phylogenetic clades and belonged to three different types. Cis-acting elements and co-expression network analyses suggested that AHL genes participated in significant biological processes. This work provides important theoretical basis for the understanding of AHLs biological functions in soybean.

Screening of silicon-activating bacteria and the activation mechanism of silicon in electrolytic manganese residue.

Electrolytic manganese residue (EMR) is a kind of solid waste with a high silicon content. Most of the silicon in EMR, however, exist in the state of SiO2, which cannot be directly absorbed by plants. Currently, it is very challenge to recover the silicon from EMR. In this study, a preliminary screening of strains with silicon-activating ability was conducted, and four strains were screened out and isolated from the soil around the tailings pond of EMR. Then, single factor experiments were conducted to obtain the optimal growth conditions of the four strains, and the results indicated that the Ochrobactrum sp. T-07 had the best silicon-activating ability from EMR after nitrosoguanidine mutagenesis (Ochrobactrum sp. T-07-B). The available silicon (in terms of SiO2) in the leaching solution was up to 123.88 mg L-1, which was significantly higher than that produced by Bacillus circulans and Paenibacillus mucilaginosus, the two commercial available pure culture strains. Results of direct/indirect contact experiments between Ochrobactrum sp. T-07-B and EMR revealed that bioleaching was promoted under the synergistic effect of bacteria growth on the surface of and metabolism within EMR. The newly isolated strains with silicon-activating effect are different from the existing-known silicate bacteria and may be used for more efficient silicon activation in silicate minerals.

Crystal structures of HpSoj-DNA complexes and the nucleoid-adaptor complex formation in chromosome segregation.

ParABS, an important DNA partitioning process in chromosome segregation, includes ParA (an ATPase), ParB (a parS binding protein) and parS (a centromere-like DNA). The homologous proteins of ParA and ParB in Helicobacter pylori are HpSoj and HpSpo0J, respectively. We analyzed the ATPase activity of HpSoj and found that it is enhanced by both DNA and HpSpo0J. Crystal structures of HpSoj and its DNA complexes revealed a typical ATPase fold and that it is dimeric. DNA binding by HpSoj is promoted by ATP. The HpSoj-ATP-DNA complex non-specifically binds DNA through a continuous basic binding patch formed by lysine residues, with a single DNA-binding site. This complex exhibits a DNA-binding adept state with an active ATP-bound conformation, whereas the HpSoj-ADP-DNA complex may represent a transient DNA-bound state. Based on structural comparisons, HpSoj exhibits a similar DNA binding surface to the bacterial ParA superfamily, but the archaeal ParA superfamily exhibits distinct non-specific DNA-binding via two DNA-binding sites. We detected the HpSpo0J-HpSoj-DNA complex by electron microscopy and show that this nucleoid-adaptor complex (NAC) is formed through HpSoj and HpSpo0J interaction and parS DNA binding. NAC formation is promoted by HpSoj participation and specific parS DNA facilitation.

BrLETM2 Protein Modulates Anthocyanin Accumulation by Promoting ROS Production in Turnip (Brassica rapa subsp. rapa).

In 'Tsuda' turnip, the swollen root peel accumulates anthocyanin pigments in a light-dependent manner, but the mechanism is unclear. Here, mutant g120w which accumulated extremely low levels of anthocyanin after light exposure was identified. Segregation analysis showed that the anthocyanin-deficient phenotype was controlled by a single recessive gene. By using bulked-segregant analysis sequencing and CAPS marker-based genetic mapping analyses, a 21.6-kb region on chromosome A07 was mapped, in which a calcium-binding EF hand family protein named BrLETM2 was identified as the causal gene. RNA sequencing analysis showed that differentially expressed genes (DEGs) between wild type and g120w in light-exposed swollen root peels were enriched in anthocyanin biosynthetic process and reactive oxygen species (ROS) biosynthetic process GO term. Furthermore, nitroblue tetrazolium (NBT) staining showed that the ROS level decreased in g120w mutant. Anthocyanins induced by UV-A were abolished by the pre-treatment of seedlings with DPI (an inhibitor of nicotinamide adenine nucleoside phosphorylase (NADPH) oxidase) and decreased in g120w mutant. These results indicate that BrLETM2 modulates ROS signaling to promote anthocyanin accumulation in turnip under UV-A and provides new insight into the mechanism of how ROS and light regulate anthocyanin production.

Synthesis and characterization of magnetic nanoparticles coated with polystyrene sulfonic acid for biomedical applications.

The development of novel magnetic nanoparticles (MNPs) with satisfactory biocompatibility for biomedical applications has been the subject of extensive exploration over the past two decades. In this work, we synthesized superparamagnetic iron oxide MNPs coated with polystyrene sulfonic acid (PSS-MNPs) and with a conventional co-precipitation method. The core size and hydrodynamic diameter of the PSS-MNPs were determined as 8-18 nm and 50-200 nm with a transmission electron microscopy and dynamic light scattering, respectively. The saturation magnetization of the particles was measured as 60 emu g-1 with a superconducting quantum-interference-device magnetometer. The PSS content in the PSS-MNPs was 17% of the entire PSS-MNPs according to thermogravimetric analysis. Fourier-transform infrared spectra were recorded to detect the presence of SO3 - groups, which confirmed a successful PSS coating. The structural properties of the PSS-MNPs, including the crystalline lattice, composition and phases, were characterized with an X-ray powder diffractometer and 3D nanometer-scale Raman microspectrometer. MTT assay and Prussian-blue staining showed that, although PSS-MNPs caused no cytotoxicity in both NIH-3T3 mouse fibroblasts and SK-HEP1 human liver-cancer cells up to 1000 µg mL-1, SK-HEP1 cells exhibited significantly greater uptake of PSS-MNPs than NIH-3T3 cells. The low cytotoxicity and high biocompatibility of PSS-MNPs in human cancer cells demonstrated in the present work might have prospective applications for drug delivery.

[Effect of Naoshuming decoction on expression of NF-κB, TNF-α, and IL-1ß in focal cerebral ischemia rats].

OBJECTIVE: To explore the effect of Naoshuming decoction on cerebral ischemic rats.
 Methods: The model of cerebral ischemia in rats was established via middle cerebral artery occlusion (MCAO). The MCAO model rats were randomly divided into a model group (n=36), a Naoshuming decoction at high dose group (n=36), a Naoshuming decoction at middle dose group (n=36) and a Naoshuming decoction at low dose group (n=36). In addition, a normal group (n=12) and a sham operation group (n=12) were included. Rats in each group were killed on the 3rd, 7th, and 14th day to detect relevant indicators. The Ayelet Levy 14 method was used to score the neurological function. Immunohistochemical method was used to detect the protein expression of nuclear factor kappa-B (NF-κB)/p50, NF-κB/p65, tumor necrosis factor-α (TNF-α), and IL-1ß. The quantitative real-time PCR were used to detect the mRNA expression of NF-κB, TNF-α and IL-1ß. 
 Results: Compared with the sham group, at each time point, the inflammation indexes in the model group and different dose of Naoshuming decoction groups were significantly enhanced, and all of them showed neurological dysfunction. But the inflammatory indexes and neurological function scores would were gradually improved with the pass of time. Compared with the model group, the neurological dysfunction, the protein levels of NF-κB/p50, NF-κB/p65, TNF-α and IL-1ß, and the mRNA of NF-κB, TNF-α and IL-1ß in the high, middle and low dose of Naoshuming decoction groups were reduced at 3, 7 and 14 d, with statistical difference (all P<0.05 or P<0.01). 
 Conclusion: Naoshuming decoction can alleviate the cerebral ischemic injury in rats.