Tannin-assisted interfacial polymerization towards COF membranes for efficient dye separation

Membrane separation has been shown to have significant potential in addressing the global shortage of clean water. Covalent organic frameworks (COFs) have gained significant attention in the field of membrane separation due to their structural stability and controllable pore size. Here, a modification of polyethersulfone ultrafiltration membranes with TA-assisted COFs is prepared by interfacial polymerization and co-deposition. Intriguingly, in comparison to the conventional COF synthesis method, the interfacial polymerization reaction used n-butanol as the oil-phase monomer to prevent substrate corrosion. More importantly, the TA-assisted co-deposition not only introduces a large number of environmentally friendly hydrophilic groups to enhance the hydrophilicity of the membrane surface, but also the phenolic hydroxyl group contained in TA generates a quinone group upon oxidation. This group can undergo a Michael addition reaction with the amine group, followed by interfacial polymerization to regulate the COFs pore size. Consequently, the optimized membrane exhibited a high permeation flux of 122.03 L m-2 h-1 bar-1 without altering the pore size structure of the original membranes and demonstrated separation performance for various dyes (Mw: 300-1300 g mol-1), with a retention rate of over 98%. Despite multiple filtrations of methyl blue dye, the membrane prepared by simple rinsing still exhibited high retention rates (>98%) with exceptional stability and retention performance. The optimized membrane demonstrated good hydrophilicity and dye separation performance, indicated promising potential for dye separation applications.

The interaction of RELN-DNMT genes involving in neurotrophin signaling pathway contributes to schizophrenia susceptibility

OBJECTIVE

Schizophrenia belongs to a severe mental illness with complicated clinical presentations, an ill-defined pathogenesis, and no known cause. Many genetic studies imply that polygenic interaction is important in the development of schizophrenia. The main mechanism of the RELN-BDNF-CREB-DNMT signaling pathway in neurodevelopment involves RELN, brain-derived neurotrophic factor (BDNF), transcription factor cyclic adenosine monophosphate response element binding protein (CREB), DNA methyltransferase 1 (DNMT1), as well as DNA methyltransferase 3B (DNMT3B). An early case-control research on 15 polymorphisms in the RELN, CREB, BDNF, DNMT1, and DNMT3B genes was done. A single gene variation has little effect on the pathogenesis of schizophrenia, but the combination of intergenic variation loci has a bigger impact because schizophrenia is a complex polygenic disorder. The objective of the current study sought to explore the impact of genetic interactions between RELN, BDNF, CREB, DNMT1, and DNMT3B on schizophrenia in order to further highlight the genetic factors influencing the risk of schizophrenia.

METHODS

Taking the case-control study design, with the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition (DSM-5) to be the evaluation norm, 134 individuals suffering from schizophrenia hospitalized in the Third People's Hospital of Zhongshan City within January 2018 to April 2020 (case group) were selected, and 64 healthy individuals (control group) from the same geographical area had been chosen as well. MassArray identified DNMT1 gene single nucleotide polymorphisms (rs2114724 and rs2228611) and DNMT3B gene SNPs (rs2424932, rs1569686, rs6119954, and rs2424908). Using the generalized multifactor dimensionality reduction (GMDR), the RELN-BDNF-CREB-DNMT pathway's gene interactions were examined for their impact on schizophrenia.

RESULTS

GMDR analysis showed that the three-order interaction model RELN (rs2073559, rs2229864)-DNMT3B (rs2424908) was the optimal model (p = 0.001), with the consistency of cross-validation of 10/10 and the test accuracy of 0.8711.

CONCLUSION

The interaction between the RELN (rs2073559, rs2229864)-DNMT3B (rs2424908) may be related to schizophrenia, and large sample sizes should be verified in different population.

An LQT2-related mutation in the voltage-sensing domain is involved in switching the gating polarity of hERG

BACKGROUND

Cyclic Nucleotide-Binding Domain (CNBD)-family channels display distinct voltage-sensing properties despite sharing sequence and structural similarity. For example, the human Ether-a-go-go Related Gene (hERG) channel and the Hyperpolarization-activated Cyclic Nucleotide-gated (HCN) channel share high amino acid sequence similarity and identical domain structures. hERG conducts outward current and is activated by positive membrane potentials (depolarization), whereas HCN conducts inward current and is activated by negative membrane potentials (hyperpolarization). The structural basis for the "opposite" voltage-sensing properties of hERG and HCN remains unknown.

RESULTS

We found the voltage-sensing domain (VSD) involves in modulating the gating polarity of hERG. We identified that a long-QT syndrome type 2-related mutation within the VSD, K525N, mediated an inwardly rectifying non-deactivating current, perturbing the channel closure, but sparing the open state and inactivated state. K525N rescued the current of a non-functional mutation in the pore helix region (F627Y) of hERG. K525N&F627Y switched hERG into a hyperpolarization-activated channel. The reactivated inward current induced by hyperpolarization mediated by K525N&F627Y can be inhibited by E-4031 and dofetilide quite well. Moreover, we report an extracellular interaction between the S1 helix and the S5-P region is crucial for modulating the gating polarity. The alanine substitution of several residues in this region (F431A, C566A, I607A, and Y611A) impaired the inward current of K525N&F627Y.

CONCLUSIONS

Our data provide evidence that a potential cooperation mechanism in the extracellular vestibule of the VSD and the PD would determine the gating polarity in hERG.

Chromosomal microarray analysis for prenatal diagnosis of uniparental disomy: a retrospective study

BACKGROUND

Chromosomal microarray analysis (CMA) is a valuable tool in prenatal diagnosis for the detection of chromosome uniparental disomy (UPD). This retrospective study examines fetuses undergoing invasive prenatal diagnosis through Affymetrix CytoScan 750 K array analysis. We evaluated both chromosome G-banding karyotyping data and CMA results from 2007 cases subjected to amniocentesis.

RESULTS

The detection rate of regions of homozygosity (ROH) ≥ 10 Mb was 1.8% (33/2007), with chromosome 11 being the most frequently implicated (17.1%, 6/33). There were three cases where UPD predicted an abnormal phenotype based on imprinted gene expression.

CONCLUSION

The integration of UPD detection by CMA offers a more precise approach to prenatal genetic diagnosis. CMA proves effective in identifying ROH and preventing the birth of children affected by imprinting diseases.

Brain tumor image segmentation based on improved FPN

PURPOSE

Automatic segmentation of brain tumors by deep learning algorithm is one of the research hotspots in the field of medical image segmentation. An improved FPN network for brain tumor segmentation is proposed to improve the segmentation effect of brain tumor.

MATERIALS AND METHODS

Aiming at the problem that the traditional full convolutional neural network (FCN) has weak processing ability, which leads to the loss of details in tumor segmentation, this paper proposes a brain tumor image segmentation method based on the improved feature pyramid networks (FPN) convolutional neural network. In order to improve the segmentation effect of brain tumors, we improved the model, introduced the FPN structure into the U-Net structure, captured the context multi-scale information by using the different scale information in the U-Net model and the multi receptive field high-level features in the FPN convolutional neural network, and improved the adaptability of the model to different scale features.

RESULTS

Performance evaluation indicators show that the proposed improved FPN model has 99.1% accuracy, 92% DICE rating and 86% Jaccard index. The performance of the proposed method outperforms other segmentation models in each metric. In addition, the schematic diagram of the segmentation results shows that the segmentation results of our algorithm are closer to the ground truth, showing more brain tumour details, while the segmentation results of other algorithms are smoother.

CONCLUSIONS

The experimental results show that this method can effectively segment brain tumor regions and has certain generalization, and the segmentation effect is better than other networks. It has positive significance for clinical diagnosis of brain tumors.

Ten years' experience in prenatal diagnosis of α-thalassemia in a municipal hospital and retrospective analysis of ultrasonic abnormalities

OBJECTIVE

This study reviewed and analyzed the prenatal diagnosis experience of thalassemia in our center over the past decade and the abnormal ultrasonic characteristics of fetuses with hemoglobin (Hb) Bart's hydrops fetalis.

METHODS

Pregnant women and their partners who tested positive for α0-thalassemia or were diagnosed with thalassemia intermedia (HbH diseases) underwent genetic counseling, and a prenatal diagnostic procedure for α-thalassemia was recommended. Ultrasonography was performed before prenatal diagnosis.

RESULTS

Invasive prenatal α-thalassemia diagnosis and ultrasonography were performed in 1049 patients at risk for Hb Bart's hydrops fetalis syndrome at our hospital from 2012 to 2021. Chorionic villus sampling (CVS) was performed in 58 cases (5.5%), amniocentesis in 902 cases (86%), and cordocentesis in 89 cases (8.5%). Hb Bart's hydrops fetalis syndrome was diagnosed in 280 fetuses. The most common body cavity effusion was pericardial effusion, ascites, and fetal systemic edema.

CONCLUSIONS

The extensive experience at our center shows that carrier screening, molecular diagnostics, genetic counseling, and prenatal diagnosis are effective measures to prevent Hb Bart's hydrops fetalis syndrome. The ultrasonographic abnormalities in fetuses with Hb Bart's hydrops are mainly caused by an increase in cardiac output, which leads to the body cavity effusion from various organs.

Tunable lipid-coated nanoporous silver sheet for characterization of protein-membrane interactions by surface-enhanced Raman scattering (SERS)

Membrane environments affect protein structures and functions through protein-membrane interactions in a wide range of important biological processes. To better study the effects from the lipid's hydrophilic and hydrophobic interaction with protein on different membrane regions, we developed the lipid-coated nanoporous silver sheets to provide tunable supported lipid monolayer/bilayer environments for in situ surface-enhanced Raman vibrational spectroscopy (SERS) characterizations. Under the controllable surface pressure, lipid monolayer/bilayer was coated along the microscopic curved surface of nanoporous silver sheets to serve as a cell membrane mimic as well as a barrier to avoid protein denaturation while empowering the high SERS enhancements from the underlying metallic bases allowing detection sensitivity at low physiological concentrations. Moreover, we fine-tuned the lipid packing density and controlled the orientation of the deposited lipid bilayers and monolayers to directly monitor the protein structures upon interactions with various membrane parts/positions. Our results indicate that lysozyme adopted the α-helical structure in both hydrophilic and hydrophobic interaction with lipid membrane. Interestingly, alpha-synuclein folded into the α-helical structure on the negatively charged lipid heads, whereas the hydrophobic lipid tails induced the β-sheet structural conversion of alpha-synuclein originated from its unstructured monomers. These direct observations on protein hydrophilic and hydrophobic interaction with lipid membrane might provide profound insights into the formation of the β-sheet-containing alpha-synuclein oligomers for further membrane disruptions and amyloid genesis associated with Parkinson's disease. Hence, with the controllability and tunability of lipid environments, our platform holds great promise for more general applications in investigating the influences from membranes and the correlative structures of proteins under both hydrophilic and hydrophobic effects.