Efficient and selective capture of Au(III) from PCBs by pentaethylenehexamine-modified chloromethylated polystyrene beads.

Recycling of gold promotes solving the problems of resource waste and environmental pollution. In this work, pentaethylenehexamine (PEHA)-modified chloromethylated polystyrene beads (PEHA-CMPS) was synthesized for the recovery of Au(III) from actual printed circuits boards (PCBs) leaching solution. PEHA-CMPS exhibited excellent adsorption efficiency at a wide pH range. It was discovered that the pseudo-second-order and Langmuir model provided a superior match for the Au(III) adsorption process. The maximum adsorption capacity for Au(III) was 1186 mg/g. Furthermore, PEHA-CMPS was able to selectively capture trace Au(III) with recovery efficiencies of above 80% from the actual PCBs leaching solution. In addition, the column separation approach was utilized to better assess the practical applications for PEHA-CMPS, proving that the prepared adsorbent exhibited great prospects in industrial applications. The adsorption efficiency still maintained 95% after five adsorption-desorption cycles. The FTIR, XRD, and XPS analyses demonstrated that Au(III) uptake on PEHA-CMPS was a collaborative process involving electrostatic interaction, chelation, and oxidation-reduction. The PEHA-CMPS provided a promising strategy in Au(III) recovery and environmental remediation.

Pact-Net: Parallel CNNs and Transformers for medical image segmentation.

BACKGROUND AND OBJECTIVE: The image segmentation of diseases can help clinical diagnosis and treatment in medical image analysis. Because medical images usually have low contrast and large changes in the size and shape of some structures, this will lead to over-segmentation and under-segmentation. These problems are particularly evident in the segmentation of skin damage. The blurring of the boundary in skin images and the specificity of patients will further increase the difficulty of skin lesion segmentation. Currently, most researchers use deep learning networks to solve these skin segmentation problems. However, traditional convolution methods often fail to obtain satisfactory segmentation performance due to their shortcomings in obtaining global features. Recently, Transformers with good global information extraction ability has achieved satisfactory results in computer vision, which brings new solutions to optimize the model of medical image segmentation further. METHODS: To extract more features related to medical image segmentation and effectively use features to further optimize the skin image segmentation model, we designed a network that combines CNNs and Transformers to improve local and global features, called Parallel CNNs and Transformers for Medical Image Segmentation (Pact-Net). Specifically, due to the advantages of Transformers in extracting global information, we create a novel fusion module CSMF, which uses channel and spatial attention mechanism and multi-scale mechanism to effectively fuse the global information extracted by Transformers into the local features extracted by CNNs. Therefore, our Pact-Net dual-branch runs in parallel to effectively capture global and local information. RESULTS: Our Pact-Net exceeds the models submitted on the three datasets ISIC 2016, ISIC 2017 and ISIC 2018, and the indicators required for the datasets reach 86.95%, 79.31% and 84.14%, respectively. We also conducted medical image segmentation experiments on cell and polyp datasets to evaluate the robustness, learning and generalization ability of the network. The ablation study of each part of Pact-Net proves the validity of each component, and the comparison with state-of-the-art methods on different indicators proves the predominance of the network. CONCLUSIONS: This paper uses the advantages of CNNs and Transformers in extracting local and global features, and further integrates features for skin lesion segmentation. Compared with the state-of-the-art methods, Pact-Net can achieve the most advanced segmentation ability on the skin lesion segmentation dataset, which can help doctors diagnose and treat diseases.

Lactate modulates microglial inflammatory responses after oxygen-glucose deprivation through HIF-1α-mediated inhibition of NF-κB.

Metabolic adaption drives microglial inflammatory responses, and lactate shapes immunological and inflammatory states. However, whether lactate was involved in the regulation of microglial inflammatory responses after cerebral ischemia remains unclear. In this study, the expression of iNOS, arginase-1, phosphorylated NF-κB p65 and IκB-α, and HIF-1α in BV2 cells after oxygen-glucose deprivation (OGD) were detected by western blotting and immunofluorescence. The mRNA levels of microglial responsive markers and inflammatory factors were assessed by real-time-qPCR. The effect of lactate-treated BV2 cells on the survival of primary neurons was observed using transwell co-culture. The results showed that the protein levels of iNOS and arginase-1, the ratio of mRNA levels of iNOS/CD206, CD86/Ym1, IL-6/IL-10, TNF-α/IL-10 and the mRNA levels of IL-6 and TNF-α, as well as the protein levels of phosphorylated NF-κB p65 and IκB-α, were increased after OGD. Lactate treatment inhibited the OGD-induced increase in the protein levels of iNOS, phosphorylated NF-κB p65 and IκB-α, as well as iNOS/CD206, CD86/Ym1, IL-6/IL-10, TNF-α/IL-10, IL-6 and TNF-α mRNA levels in BV2 cells, while promoted arginase-1 protein expression as well as IL-10 and TGF-ß mRNA level. Interestingly, lactate activated HIF-1α and the HIF-1α inhibitor YC-1 reversed the effect of lactate on levels of microglial responsive markers and phosphorylated NF-κB p65 and IκB-α in BV2 cells. Moreover, knockdown of HIF-1α by lentivirus-delivered shRNA also reversed the effect of lactate on phosphorylated NF-κB p65 and IκB-α in BV2 cells after OGD. Finally, and importantly, lactate-treated BV2 microglia increased the viability and decreased the apoptosis of neurons after OGD. These findings revealed that lactate inhibited NF-κB pathway and skewed BV2 microglia toward the protective response through activation of HIF-1α after OGD, thereby improving neuronal survival.

Neuroprotective effects of metformin on cerebral ischemia-reperfusion injury by regulating PI3K/Akt pathway.

Metformin (Met) is a commonly used drug in the treatment of type 2 diabetes. Currently, it has been found that Met can effectively reduce the incidence of stroke and exert anti-inflammatory effects. However, its role in ischemia-reperfusion (I/R)-induced nerve injury remains unclear. This study aims to investigate the neuroprotective effects of Met in I/R-induced neuron injury as well as the underlying mechanism. A middle cerebral artery occlusion (MCAO) model was established in Sprague Dawley (SD) rats, which were then treated with different doses of Met. Neurological deficits of rats were measured at different times post-surgery. TTC staining was done to observe the volume of cerebral infarction. HE staining was performed to observe pathological changes of brain tissues. Immunohistochemistry was performed to observe the expression of inflammatory factors in the cerebral tissues. qRT-PCR method was used to detect the relative expression of PI3K, Akt mRNA in cells after 24 h of drug action. Western blot method was used to detect the expression of PI3K, p-PI3K, Akt, and p-Akt in hippocampus. What is more, in vitro experiments were performed on BV2 microglia to verify the role of Met against oxygen-glucose deprivation (OGD). As a result, Met dose-dependently attenuated neurological deficits and neuronal apoptosis. Besides, Met administration also significantly reduced BV2 cells apoptosis and inflammatory response. Mechanistically, Met inactivated PI3K/Akt pathway induced by I/R and OGD, while it upregulated PI3K. In conclusion, Met protected rats from cerebral I/R injury via reducing neuronal apoptosis and microglial inflammation through PI3K/Akt pathway.

Neural Stem Cell-Laden Self-Healing Polysaccharide Hydrogel Transplantation Promotes Neurogenesis and Functional Recovery after Cerebral Ischemia in Rats.

Exploring a strategy to effectively repair cerebral ischemic injury is a critical requirement for neuroregeneration. Herein, we transplanted a neural stem cell (NSC)-laden self-healing and injectable hydrogel into the brains of ischemic rats and evaluated its therapeutic effects. We observed an improvement in neurological functions in rats transplanted with the NSC-laden hydrogel. This strategy is sufficiently efficient to support neuroregeneration evidenced by NSC proliferation, differentiation, and athletic movement recovery of rats. This therapeutic effect relates to the inhibition of the astrocyte reaction and the increased expression of vascular endothelial growth factor. This work provides a novel approach to repair cerebral ischemic injury.

Dexmedetomidine Alleviates Neurogenesis Damage Following Neonatal Midazolam Exposure in Rats through JNK and P38 MAPK Pathways.

Midazolam, a widely used anesthetic, inhibits proliferation of neural stem cells (NSCs) and induces neuroapoptosis in neonates. Dexmedetomidine, an effective auxiliary medicine in clinical anesthesia, protects the developing brain against volatile anesthetic-induced neuroapoptosis. Whether dexmedetomidine protects against neurogenesis damage induced by midazolam remains unknown. This study aims to clarify the protective effect of dexmedetomidine on midazolam-induced neurogenesis damage and explore its potential mechanism. Postnatal 7-day-old Sprague-Dawley (SD) rats and cultured NSCs were treated with either normal saline, midazolam, or dexmedetomidine combined with midazolam. The rats were sacrificed at 1, 3, and 7 days after treatment. Cell proliferation was assessed by 5-bromodeoxyurdine (BrdU) incorporation. Cell viability was determined using MTT assay. Cell differentiation and apoptosis were detected by immunofluorescent staining and terminal dUTP nick-end labeling (TUNEL), respectively. The protein levels of p-JNK, p-P38, and cleaved caspase-3 were quantified using Western blotting. Midazolam decreased cell proliferation and increased cell apoptosis in the subventricular zone (SVZ), the subgranular zone (SGZ) of the hippocampus, and cultured NSCs. Moreover, midazolam decreased cell viability and increased the expression of p-JNK and p-P38 in cultured NSCs. Co-treatment with dexmedetomidine attenuated midazolam-induced changes in cell proliferation, viability, apoptosis, and protein expression of p-JNK and p-P38 in cultured NSCs. Midazolam and dexmedetomidine did not affect the differentiation of the cultured NSCs. These results indicate that dexmedetomidine alleviated midazolam-induced neurogenesis damage via JNK and P38 MAPK pathways.

Fluorometric determination of ssDNA based on functionalized magnetic microparticles and DNA supersandwich self-assemblies.

A method is described for the determination of DNA via nucleic acid amplification by using nucleic acid concatemers that result from DNA supersandwich self-assemblies (SSAs). The method employs two auxiliary probes to form self-assembled biotin SSAs. These exhibit strong fluorescence if labeled with intercalator SYBR Green I. In the presence of the target (as exemplified for a 30-mer), streptavidin is released from the surface of the functionalized magnetic microparticles (FMMPs) by competitive hybridization on the surface. However, the SSA products do not conjugate to the FMMPs. This leads to a large amount of SYBR Green I intercalated into the concatemers and eventually results in amplified fluorescence in the supernate. The SSA products can be prepared beforehand, and amplification therefore can be completed within 50 min. The method is more efficient than any other conventional amplification. The detection limit for the 30-mer is 26.4 fM which is better by a factor of 10 compared to other amplification methods. Conceivably, the method can be further extended to the determination of a wide variety of targets simply by replacing the sequences of the probes. Finally, this rapid and highly sensitive method was employed for detection of Ebola virus gene (≈30-mer) and ATP in spiked serum with satisfactory results. Graphical abstract A high sensitivity and efficiency bioassay is described based on functionalized magnetic microparticles and DNA supersandwich self-assemblies.

Effect of Urinary Kallidinogenase on Transforming Growth Factor-ß1 and High-Sensitivity C-Reactive Protein Expression in Rat Focal Cerebral Ischemic Injury.

BACKGROUND In this study we investigated the effect of urinary kallidinogenase (UK) on transforming growth factor beta 1 (TGF-ß1) expression in brain tissue. We also explored the neuroprotective mechanism of UK against ischemic injury by measuring serum high-sensitivity C-reactive protein (hs-CRP) level changes after rat cerebral ischemic injury. MATERIAL AND METHODS The rat middle cerebral artery ischemia/reperfusion model was established using the suture method. Sprague-Dawley rats were randomly divided into 3 groups: treatment, Gegen control, and blank control. Each group was subsequently divided into 5 subgroups according to time (6, 12, 24, 48, and 72 h). Rats in the treatment group were administered UK as treatment. TGF-ß1 expression was observed at each time point using SABC and immunohistochemical staining methods to estimate cerebral infarct volume percentage. Serum hs-CRP levels were also measured. RESULTS TGF-ß1 protein expression in ischemic brain tissues of the treatment group significantly increased at each time point (P<0.01) compared with both control groups. Treatment group serum hs-CRP levels significantly decreased at each time point (P<0.05) compared with both control groups. CONCLUSIONS UK exerts a neuroprotective effect by upregulating TGF-ß1 expression and inhibiting excessive inflammatory responses.

Effect of ischemic postconditioning on cerebral edema and the AQP4 expression following hypoxic-eschemic brain damage in neonatal rats.

BACKGROUND: A rat model for neonatal hypoxic-ischemic brain damage (HIBD) was established to observe the effect of ischemic postconditioning (IPostC) on cerebral edema and the AQP4 expression following HIBD and to verify the neuroprotection of IPostC and the relationship between changes of AQP4 expression and cerebral edema. METHODS: Water content was measured with dry-wet method, and AQP4 transcription and the protein expression of the lesions were detected with real-time PCR and immunohistochemistry staining, respectively. RESULTS: Within 6-48 hours, the degree of ipsilateral cerebral edema was significantly lower in IPostC-15 s/15 s group than in HIBD group. Similar to the HIBD group, the AQP4 transcription and expression in the IPostC group showed a downward and then upward trend. But the expression was still more evident in the HIBD group than in the IPostC-15 s/15 s group. From 24 to 48 hours, IPostC-15 s/15 s decreased the slowing down expression of AQP4. CONCLUSION: IPostC has neuroprotective effect on neonatal rats with HIBD and it may relieve cerebral edema by regulating the expression of AQP4.

Improvement of the suture-occluded method in rat models of focal cerebral ischemia-reperfusion.

The aim of the present study was to provide a simple method of establishing a rat model for focal cerebral ischemia-reperfusion (FCIR). The suture-occluded method was used to establish FCIR in male Sprague-Dawley rats. An incision was made over the bifurcation of the common carotid artery (CCA), through which a suture was inserted up to the internal carotid artery (ICA). The suture remained in the skin subsequent to model establishment and was withdrawn to the CCA to enable reperfusion. The reliability of the rat model was assessed via analysis of nerve function, tetrazolium (TTC) staining and pathological examination. Following FCIR in rats, the resulting neurological impairments were observed. TTC staining revealed infarcts and pathological examination revealed typical pathological changes. This modified method was simple, reliable and, therefore, may be used to investigate FCIR.

Transplantation with retinal progenitor cells repairs visual function in rats with retinal ischemia-reperfusion injury.

The retinal ischemia-reperfusion injury (RIR) is a common pathological process that leads to progressive visual loss and blindness in many retinal diseases such as retinal vascular occlusion disease, diabetic retinopathy, and acute glaucoma. Currently, there has been no effective therapy. The purpose of this study was to investigate the effects of transplantation of retinal progenitor cells (RPCs) into the subretinal space (SRS) and the superior colliculus (SC) in a rat model of RIR injury. We used cultured postnatal day 1 rat RPCs transfected with adeno-associated virus containing the cDNA encoding enhanced green fluorescence protein (EGFP) for transplantation. RIR injury was induced by increases in the intraocular pressure to 110 mmHg for 60 min. The effects of transplantation were evaluated by immunohistochemistry, electroretinography (ERG), and visual evoked potentials (VEP). We found that in rats with RIR injury, RPCs transplanted into the SRS and the SC survived for at least 8 weeks, migrated into surrounding tissues, and improved the ERG and VEP responses. Cells transplanted into the SC improved the VEP response more than those transplanted into the SRS. Our data suggest that transplantation of RPCs into the SRS and the SC may be a possible method for cell replacement therapy for retinal diseases.

Characterization of the sesame (Sesamum indicum L.) global transcriptome using Illumina paired-end sequencing and development of EST-SSR markers.

BACKGROUND: Sesame is an important oil crop, but limited transcriptomic and genomic data are currently available. This information is essential to clarify the fatty acid and lignan biosynthesis molecular mechanism. In addition, a shortage of sesame molecular markers limits the efficiency and accuracy of genetic breeding. High-throughput transcriptomic sequencing is essential to generate a large transcriptome sequence dataset for gene discovery and molecular marker development. RESULTS: Sesame transcriptomes from five tissues were sequenced using Illumina paired-end sequencing technology. The cleaned raw reads were assembled into a total of 86,222 unigenes with an average length of 629 bp. Of the unigenes, 46,584 (54.03%) had significant similarity with proteins in the NCBI nonredundant protein database and Swiss-Prot database (E-value < 10-5). Of these annotated unigenes, 10,805 and 27,588 unigenes were assigned to gene ontology categories and clusters of orthologous groups, respectively. In total, 22,003 (25.52%) unigenes were mapped onto 119 pathways using the Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG). Furthermore, 44,750 unigenes showed homology to 15,460 Arabidopsis genes based on BLASTx analysis against The Arabidopsis Information Resource (TAIR, Version 10) and revealed relatively high gene coverage. In total, 7,702 unigenes were converted into SSR markers (EST-SSR). Dinucleotide SSRs were the dominant repeat motif (67.07%, 5,166), followed by trinucleotide (24.89%, 1,917), tetranucleotide (4.31%, 332), hexanucleotide (2.62%, 202), and pentanucleotide (1.10%, 85) SSRs. AG/CT (46.29%) was the dominant repeat motif, followed by AC/GT (16.07%), AT/AT (10.53%), AAG/CTT (6.23%), and AGG/CCT (3.39%). Fifty EST-SSRs were randomly selected to validate amplification and to determine the degree of polymorphism in the genomic DNA pools. Forty primer pairs successfully amplified DNA fragments and detected significant amounts of polymorphism among 24 sesame accessions. CONCLUSIONS: This study demonstrates that Illumina paired-end sequencing is a fast and cost-effective approach to gene discovery and molecular marker development in non-model organisms. Our results provide a comprehensive sequence resource for sesame research.

[Organotypic slice culture of neonatal rat cortex and induced neural stem cell differentiation].

OBJECTIVE: To establish a method for organotypic slice culture of neonatal rat cortex in a modified condition and investigate the effect of spatial signals on neural stem cell (NSC) differentiation. METHODS: The brain slices (200 µm in thickness) of neonatal SD rats (3 to 5 days old) were prepared and cultured in modified serum-free DMEM/F12 medium at 37 degrees celsius; with 95% O(2) and 5% CO(2). The organotypic slice cultures were observed regularly. NSCs isolated from the cortex of rat embryos (14-15 embryonic days) were cultured in serum-free DMEM/F12 supplemented with B27 and N2, and the passage 3 NSCs were labeled by CM-DiI before transplanted onto the organotypic slices cultured for 2 weeks. The survival of transplanted NSCs was assessed, and the cell differentiation was identified by immunofluorescence staining. RESULTS: The organotypic slice cultures were well maintained for at least 4 weeks in the modified medium. The thickness of the organotypic slices reduced from 200 µm to 130 µm after 2-week culture in vitro due to the migration of the cells on the edge of the slices. CM-DiI-labeled NSCs survived well and differentiated into GFAP(+) glia and ß-tubullin III(+) neurons. CONCLUSION: Neonatal rat organotypic brain slice can be successfully cultured in a modified condition to serve as a model for studying NSC differentiation induced by spatial signals.

[Culture and identification of neural stem cells from mouse embryos].

OBJECTIVE: The purpose of this study was to culture and identify neural stem cells from mouse embryos in vitro using a modified method and provide a basis for further study of the biology of neural stem cells under hypoxia. METHODS: The cells were isolated mechanically from the front cortex of fetal Institute of Cancer Research (ICR) mice on embryonic day 14. They were passaged by mechanical dissociation and enzymatic digestion. The neurospheres were identified by immunofluorescent staining of nestin. Cell differentiation was induced by 1% fetal bovine serum and then the cells were identified by immunohistochemistry of ß-tubulin III and GFAP. RESULTS: The cells obtained from the front cortex of fetal ICR mice had the capacity of forming neurospheres which showed nestin immunoreactive positivity. After being induced by 1% fetal bovine serum, the cells were differentiated into ß-tubulin III-positive cells and GFAP-positive cells. CONCLUSIONS: Using mechanical dissociation of primary cells and mechanical dissociation with enzymatic digestion of primary cells, the NSCs from the front cortex of mouse embryos can be obtained.