Efficient electrochemical oxidation of antibiotic wastewater using a graphene-loaded PbO2 membrane anode: Mechanisms and applications.

This paper aims to develop a flow-through electrochemical system with a series of graphene nanoparticles loaded PbO2 reactive electrochemical membrane electrodes (GNPs-PbO2 REMs) on porous Ti substrates with pore sizes of 100, 150, 300 and 600 µm, and apply them to treat antibiotic wastewater. Among them, the GNPs-PbO2 with Ti substrate of 150 µm (Ti-150/GNPs-PbO2) had superior electrochemical degradation performance over the REMs with other pore sizes due to its smaller crystal size, larger electrochemical active specific area, lower charge-transfer impedance and larger oxygen evolution potential. Under the relatively optimized conditions of initial pH of 5, current density of 15 mA cm-2, and membrane flux of 4.20 m3 (m2·h)-1, the Ti-150/GNPs-PbO2 REM realized 99.34% of benzylpenicillin sodium (PNG) removal with an EE/O of 6.52 kWh m-3. Its excellent performance could be explained as the increased mass transfer. Then three plausible PNG degradation pathways in the flow-through electrochemical system were proposed, and great stability and safety of Ti-150/GNPs-PbO2 REM were demonstrated. Moreover, a single-pass Ti-150/GNPs-PbO2 REM system with five-modules in series was designed, which could consistently treat real antibiotic wastewater in compliance with disposal requirements of China. Thus, this study evidenced that the flow-through electrochemical system with the Ti-150/GNPs-PbO2 REM is an efficient alternative for treating antibiotic wastewater.

Experimental research and application of drilling and blasting with directional damage-reduction shaped charge.

In this research, a directional reduction charging structure was proposed to solve the problems caused by drilling and blasting method such as serious damage to surrounding rocks, working face low contour flatness and serious over-under break of root base c. Drilling and blasting tests, numerical calculations and field applications were designed and performed for the verification of the blasting advantages of charge structure. Test results showed that the peak positive strain along the protection direction of directional protection shaped charge was significantly smaller than that of ordinary charge, where PVC material presented the strongest effect such that the peak positive strain of specimen 1 at measuring point 4 (protection direction) was only 0.27 times that at measuring point 9 (non-protected direction). Numerical simulations indicated shaped jet formation, damage-reduction and charge penetration process and obtained the force law of cement target plate. Experimental results revealed that application of charge in tunnel controlled blasting achieved a clear controlling effect on contour line excavation. Compared with ordinary smooth blasting method, all technical indicators of the developed method were improved such that half hole mark rate was increased by about 33% and the amount of over-under break was decreased by about two times. Research results are of certain significance for the stability of surrounding reserved rocks and formation of roadway in blasting engineering and the developed method was found to be applicable to mining, shaft excavation and other projects.

Protein-Loaded Cellular Nanosponges for Dual-Biomimicry Neurotoxin Countermeasure.

Neurotoxins present a substantial threat to human health and security as they disrupt and damage the nervous system. Their potent and structurally diverse nature poses challenges in developing effective countermeasures. In this study, a unique nanoparticle design that combines dual-biomimicry mechanisms to enhance the detoxification efficacy of neurotoxins is introduced. Using saxitoxin (STX), one of the deadliest neurotoxins, and its natural binding protein saxiphilin (Sxph) as a model system, human neuronal membrane-coated and Sxph-loaded metal-organic framework (MOF) nanosponges (denoted "Neuron-MOF/Sxph-NS") are successfully developed. The resulting Neuron-MOF/Sxph-NS exhibit a biomimetic design that not only emulates host neurons for function-based detoxification through the neuronal membrane coating, but also mimics toxin-resistant organisms by encapsulating the Sxph protein within the nanoparticle core. The comprehensive in vitro assays, including cell osmotic swelling, calcium flux, and cytotoxicity assays, demonstrate the improved detoxification efficacy of Neuron-MOF/Sxph-NS. Furthermore, in mouse models of STX intoxication, the application of Neuron-MOF/Sxph-NS shows significant survival benefits in both therapeutic and prophylactic regimens, without any apparent acute toxicity. Overall, the development of Neuron-MOF/Sxph-NS represents an important advancement in neurotoxin detoxification, offering promising potential for treating injuries and diseases caused by neurotoxins and addressing the current limitations in neurotoxin countermeasures.

Platelet Membrane-Derived Nanodiscs for Neutralization of Endogenous Autoantibodies and Exogenous Virulence Factors.

The multifaceted functions of platelets in various physiological processes have long inspired the development of therapeutic nanoparticles that mimic specific platelet features for disease treatment. Here, the development and characterization of platelet membrane-derived nanodiscs (PLT-NDs) as platelet decoys for biological neutralization is reported. In one application, PLT-NDs effectively bind with anti-platelet autoantibodies, thus blocking them from interacting with platelets. In a mouse model of thrombocytopenia, PLT-NDs successfully neutralize pathological anti-platelet antibodies, preventing platelet depletion and maintaining hemostasis. In another application, PLT-NDs effectively neutralize the cytotoxicity of bacterial virulence factors secreted by methicillin-resistant Staphylococcus aureus (MRSA). In a mouse model of MRSA infection, treatment with PLT-NDs leads to significant survival benefits for the infected mice. Additionally, PLT-NDs show good biocompatibility and biosafety, as demonstrated in acute toxicity studies conducted in mice. These findings underscore the potential of PLT-NDs as a promising platelet mimicry for neutralizing various biological agents that target platelets. Overall, this work expands the repertoire of platelet-mimicking nanomedicine by creating a unique disc-like nanostructure made of natural platelet membranes.

Metabolomics integrated with machine learning to discriminate the geographic origin of Rougui Wuyi rock tea.

The geographic origin of agri-food products contributes greatly to their quality and market value. Here, we developed a robust method combining metabolomics and machine learning (ML) to authenticate the geographic origin of Wuyi rock tea, a premium oolong tea. The volatiles of 333 tea samples (174 from the core region and 159 from the non-core region) were profiled using gas chromatography time-of-flight mass spectrometry and a series of ML algorithms were tested. Wuyi rock tea from the two regions featured distinct aroma profiles. Multilayer Perceptron achieved the best performance with an average accuracy of 92.7% on the training data using 176 volatile features. The model was benchmarked with two independent test sets, showing over 90% accuracy. Gradient Boosting algorithm yielded the best accuracy (89.6%) when using only 30 volatile features. The proposed methodology holds great promise for its broader applications in identifying the geographic origins of other valuable agri-food products.

Emerging nanoparticle designs against bacterial infections.

The rise of antibiotic resistance has caused the prevention and treatment of bacterial infections to be less effective. Therefore, researchers turn to nanomedicine for novel and effective antibacterial therapeutics. The effort resulted in the first-generation antibacterial nanoparticles featuring the ability to improve drug tolerability, circulation half-life, and efficacy. Toward developing the next-generation antibacterial nanoparticles, researchers have integrated design elements that emphasize physical, broad-spectrum, biomimetic, and antivirulence mechanisms. This review highlights four emerging antibacterial nanoparticle designs: inorganic antibacterial nanoparticles, responsive antibacterial nanocarriers, virulence nanoscavengers, and antivirulence nanovaccines. Examples in each design category are selected and reviewed, and their structure-function relationships are discussed. These emerging designs open the door to nontraditional antibacterial nanomedicines that rely on mechano-bactericidal, function-driven, nature-inspired, or virulence-targeting mechanisms to overcome antibiotic resistance for more effective antibacterial therapy. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease.

Electronic Source Data Transcription for Electronic Case Report Forms in China: Validation of the Electronic Source Record Tool in a Real-world Ophthalmology Study.

BACKGROUND: As researchers are increasingly interested in real-world studies (RWSs), improving data collection efficiency and data quality has become an important challenge. An electronic source (eSource) generally includes direct capture, collection, and storage of electronic data to simplify clinical research. It can improve data quality and patient safety and reduce clinical trial costs. Although there are already large projects on eSource technology, there is a lack of experience in using eSource technology to implement RWSs. Our team designed and developed an eSource record (ESR) system in China. In a preliminary prospective study, we selected a cosmetic medical device project to evaluate ESR software's effect on data collection and transcription. As the previous case verification was simple, we plan to choose more complicated ophthalmology projects to further evaluate the ESR. OBJECTIVE: We aimed to evaluate the data transcription efficiency and quality of ESR software in retrospective studies to verify the feasibility of using eSource as an alternative to traditional manual transcription of data in RWS projects. METHODS: The approved ophthalmic femtosecond laser project was used for ESR case validation. This study compared the efficiency and quality of data transcription between the eSource method using ESR software and the traditional clinical research model of manually transcribing the data. Usability refers to the quality of a user's experience when interacting with products or systems including websites, software, devices, or applications. To evaluate the system availability of ESR, we used the System Usability Scale (SUS). The questionnaire consisted of the following 2 parts: participant information and SUS evaluation of the electronic medical record (EMR), electronic data capture (EDC), and ESR systems. By accessing log data from the EDC system previously used by the research project, all the time spent from the beginning to the end of the study could be counted. RESULTS: In terms of transcription time cost per field, the eSource method can reduce the time cost by 81.8% (11.2/13.7). Compared with traditional manual data transcription, the eSource method has higher data transcription quality (correct entry rate of 2356/2400, 98.17% vs 47,991/51,424, 93.32%). A total of 15 questionnaires were received with a response rate of 100%. In terms of usability, the average overall SUS scores of the EMR, EDC, and ESR systems were 50.3 (SD 21.9), 51.5 (SD 14.2), and 63.0 (SD 11.3; contract research organization experts: 69.5, SD 11.5; clinicians: 59.8, SD 10.2), respectively. The Cronbach α for the SUS items of the EMR, EDC, and ESR systems were 0.591 (95% CI -0.012 to 0.903), 0.588 (95% CI -0.288 to 0.951), and 0.785 (95% CI 0.576-0.916), respectively. CONCLUSIONS: In real-world ophthalmology studies, the eSource approach based on the ESR system can replace the traditional clinical research model that relies on the manual transcription of data.

Designing MOF Nanoarchitectures for Electrochemical Water Splitting.

Electrochemical water splitting has attracted significant attention as a key pathway for the development of renewable energy systems. Fabricating efficient electrocatalysts for these processes is intensely desired to reduce their overpotentials and facilitate practical applications. Recently, metal-organic framework (MOF) nanoarchitectures featuring ultrahigh surface areas, tunable nanostructures, and excellent porosities have emerged as promising materials for the development of highly active catalysts for electrochemical water splitting. Herein, the most pivotal advances in recent research on engineering MOF nanoarchitectures for efficient electrochemical water splitting are presented. First, the design of catalytic centers for MOF-based/derived electrocatalysts is summarized and compared from the aspects of chemical composition optimization and structural functionalization at the atomic and molecular levels. Subsequently, the fast-growing breakthroughs in catalytic activities, identification of highly active sites, and fundamental mechanisms are thoroughly discussed. Finally, a comprehensive commentary on the current primary challenges and future perspectives in water splitting and its commercialization for hydrogen production is provided. Hereby, new insights into the synthetic principles and electrocatalysis for designing MOF nanoarchitectures for the practical utilization of water splitting are offered, thus further promoting their future prosperity for a wide range of applications.

[Construction of eukaryotic expression vector of F-box protein 6 gene and its expression in HEK293T cells].

OBJECTIVE: To construct eukaryotic expression vector of F-box protein 6 (FBXO6) gene. METHODS: The full-length FBXO6 cDNA containing two restriction sites (BglII and EcoRI) was synthesized by PCR. The pEGFP-C1-FBXO6 and pEGFP-C1-anti-FBXO6 vectors were constructed respectively. The size and sequence of cDNA fragments were confirmed by bacterial colony PCR and BglII and EcoRI digestion and sequencing. HEK293T cells were transfected with the pEGFP-C1-FBXO6 and pEGFP-C1-anti-FBXO6 vectors respectively, and then the expression of FBXO6 protein was detected using Western blotting. RESULTS: The pEGFP-C1-FBXO6 and pEGFP-C1-anti-FBXO6 contained FBXO6 fragments of proper size and sequence. FBXO6 protein was expressed efficiently in pEGFP-C1-FBXO6 transfected HEK293T cells, but it was down-regulated in pEGFP-C1-anti-FBXO6 transfected 293T cells. CONCLUSION: Both pEGFP-C1-FBXO6 and pEGFP-C1-anti-FBXO6 were successfully constructed.

Meta-analysis: therapeutic effect of transcatheter arterial chemoembolization combined with compound kushen injection in hepatocellular carcinoma.

Compound Kushen Injection (CKI) is Sophora Flavescens and Heterosmilacis Japonicae extract. Meta-analysis confirmed that CKI plus transcatheter arterial chemoembolization (TACE) is more superior to TACE alone for unresectable hepatocellular carcinoma (UHCC) patients.

[Exogenous antizyme 1 gene transfection inhibits proliferation and promotes apoptosis of human neuroblastoma SH-SY5Y cells in vitro].

OBJECTIVE: To study the effect of antizyme 1 (ZA1) gene transfection on the cell proliferation, cell cycle and apoptosis of human neuroblastoma SH-SY5Y cells in vitro. METHODS: The recombinant eukaryotic expression vector pAZ1m was constructed by cloning mutant AZ1 gene into the vector pEGFP-N1, and subsequently transfected in SH-SY5Y cells. The transfected cell proliferation was examined using MTT assay, and the changes in cell cycle and apoptosis were assayed using flow cytometry analysis. RT-PCR was performed to measure cyclin D1 and caspase-3 mRNA expressions, Western blotting carried out to examine cyclin D1 protein expression, and the changes in caspase-3 activity were detected using a caspase-3 detection kit. RESULTS: AZ1 gene transfection significantly inhibited the proliferation of SH-SY5Y cells, causing cell cycle arrest at G0/G1 stage and down-regulated cyclin D1 and up-regulated caspase-3 expressions. Obviously increased caspase-3 activity was also observed in the transfected cells. CONCLUSION: Exogenous AZ1 gene transfection can inhibit the proliferation and cause cell cycle arrest of SH-SY5Y cells by down-regulating cyclin D1 expression. Up-regulated caspase-3 expression resulting from AZ1 gene transfection may induce apoptosis of the neuroblastoma cells.

[Research of restriction display technique in cDNA microarrays preparation for detecting of HCV].

The cDNA microarrays for HCV detection was prepared. With the restriction display technique (RD), restriction enzyme Sau3A I was chosen to digest the full-length HCV cDNAs. The products were classified and amplified by RD-PCR. We separated the differential genes through polyacrylamide gel electrophoresis and sliver staining. Single bands were isolated which were cut out from the polyacrylamide gel. The third-round PCR could be performed by using the single bands as PCR template. The RD-PCR fragments were purified and cloned into the pMD18-T vectors. The recombinant plasmids were extracted from positive clones and the target gene fragments were sequenced. The cDNA microarray was prepared by spotting PCR products to the surface of amido modified glass slides by the robotics. We validated the detection of microarray by the hybridization and the results of sequence analysis. A total of 24 different cDNA fragments ranging from 200 to 800 bp were isolated and sequenced, which were the specific gene fragments of HCV. These fragments could be further used as probes in the microarray preparations. From the results of hybridization and sequence date analysis, the specificity, sensitivity, accuracy, reproducibility and linearity in detecting HCV RNA were satisfactory. RD technique is of great value in obtaining a large number of size-comparable gene probes, which provide a swift protocol in generating probes for the preparation of microarrays, and the optimized microarray is sensitive and effective in clinical diagnosis of HCV.

Functional and structural characterization of recombinant dermcidin-1L, a human antimicrobial peptide.

Antimicrobial peptides from human skin are an important component of the innate immune response and play a key role as a first line of defense against infections. One such peptide is the recently discovered dermcidin-1L. To better understand its mechanism and to further investigate its antimicrobial spectrum, recombinant dermcidin-1L was expressed in Escherichia coli as a fusion protein and purified by affinity chromatography. The fusion protein was cleaved by factor Xa protease to produce recombinant dermcidin-1L. Antimicrobial and hemolytic assays demonstrated that dermcidin-1L displayed microbicidal activity against several opportunistic nosocomial pathogens, but no hemolytic activity against human erythrocytes even at concentrations up to 100 microM. Structural studies performed by circular dichroism spectroscopy indicated that the secondary structure of dermcidin-1L was very flexible, and both alpha-helix and beta-sheet structures might be required for the antimicrobial activity. Our results confirmed previous findings indicating that dermcidin-1L could have promising therapeutic potentials and shed new light on the structure-function relationship of dermcidin-1L.

Application of restriction display PCR technique in the preparation of cDNA microarray probes.

AIM: To develop a simplified and efficient method for the preparation of hepatitis C virus (HCV) cDNA microarray probes. METHODS: With the technique of restriction display PCR (RD-PCR), restriction enzyme Sau3A I was chosen to digest the full-length HCV cDNAs. The products were classified and re-amplified by RD-PCR. We separated the differential genes by polyacrylamide gel electrophoresis and silver staining. Single bands cut out from the polyacrylamide gel were isolated. The third-round PCR was performed using the single bands as PCR template. The RD-PCR fragments were purified and cloned into the pMD18-T vector. The recombinant plasmids were extracted from positive clones, and the target gene fragments were sequenced. The cDNA microarray was prepared by spotting RD-PCR products to the surface of amino-modified glass slides using a robot. We validated the detection of microarray by hybridization and sequence analysis. RESULTS: A total of 24 different cDNA fragments ranging from 200 to 800 bp were isolated and sequenced, which were the specific gene fragments of HCV. These fragments could be further used as probes in microarray preparation. The diagnostic capability of the microarray was evaluated after the washing and scanning steps. The results of hybridization and sequence analysis showed that the specificity, sensitivity, accuracy, reproducibility, and linearity in detecting HCV RNA were satisfactory. CONCLUSION: The RD-PCR technique is of great value in obtaining a large number of size-comparable gene probes, which provides a speedy protocol in generating probes for the preparation of microarrays. Microarray prepared as such could be further optimized and applied in the clinical diagnosis of HCV.

[Application of microarrays in screening the tumor-specific genes in the genome of K562 cells].

OBJECTIVE: To screen tumor-specific genes of K562 cells using DNA microarray technique. METHODS: The genomic DNA of normal white blood cells and cultured K562 cells were respectively purified and digested with Sau3A I, and the digested DNA fragments of K562 cells were cloned into TA cloning vector to construct the corresponding genomic DNA library. The insert genomic DNA fragments were amplified from the library to prepare the microarray using Cartesian 5500 Microarrayer. The digested genomic DNA fragments of normal white blood cells were labeled with fluorescent Cy3 by restriction display PCR (RD-PCR), followed by hybridization with the microarray, after which the slide was washed and scanned with ScanArray. RESULTS: Among the 426 target genes, 42 differential genes were identified in the genomic DNA of K562 cells in comparison with the normal white blood cells. One of the genes was identified as the breakpoint cluster gene (BCR) after sequence analysis. CONCLUSIONS: The DNA microarrays we constructed may effectively identify the tumor-specific genes in K562 cells, and DNA microarray technique can be helpful in elucidating the molecular mechanisms of tumorigenesis at the genomic level.

[Amplification and cloning of the N gene of SARS-associated coronavirus].

OBJECTIVE: To amplify and clone the N gene of severe acute respiratory syndrome-associated coronavirus. METHOD: Using primer Premier 5.0 software, two pairs of nested PCR primers were designed to amplify the N gene. After purification, the amplified products were cloned into pMD18-T vectors, and the positive clones with the inserted fragments were identified by sequence analysis. RESULTS: The amplified products was about 1 375 bp in length, and sequence analysis demonstrated that the N gene fragments had been successfully inserted into pMD18-T vectors. CONCLUSION: The successful amplification and cloning of N gene facilitates further investigation of the expression of the N protein and study of its structure and functions.

Application of Agilent 2100 Bioanalyzer in detection of human papilloma virus.

OBJECTIVE: To explore the feasibility of using Agilent 2100 bioanalyzer in the detection and genotyping of human papilloma virus (HPV). METHODS: The consensus sequence of highly conserved region (L1) and genotype-specific gene fragments of all HPV genotypes (including HPV6, 11, 16 and 18) were amplified by PCR technique using general and type-specific primers respectively. Agilent 2100 Bioanalyzer and routine agarose gel electrophoresis were then employed respectively to examine the PCR products, and the accuracy, reproducibility and sensitivity of these 2 detection techniques were compared. RESULTS: Agilent 2100 Bioanalyzer showed better accuracy in determining the length of the gene fragments than agarose gel electrophoresis, the accuracy of the former reaching above 95% while the latter was only 85%. Bioanalyzer was also 100 times more sensitive than agarose electrophoresis. CONCLUSIONS: Agilent 2100 Bioanalyzer combined with PCR is specific, accurate and sensitive for HPV detection and genotyping.

[Investigation of the gene expression profile in spermatocytes].

OBJECTIVE: To investigate the gene expression profile in the mature spermatocytes and the molecular mechanism of the male infertility syndromes. METHODS: Restriction display PCR (RD-PCR), a new method of differential display technique, was used to collect plenty of gene fragments expressed in either normal or abnormal spermatocytes, the gene expression profile of which were demonstrated by these fragments(gene expression sequence tags, ESTs), in the form of cDNA fragments length polymorphism. These ESTs will be used to make DNA microarray as probes to further explore the gene expression profile in spermatocytes and to diagnose the male infertility. RESULTS: Lots of ESTs were expressed in either normal or abnormal spermatocytes and some differentially expressed ESTs have been collected and purified. CONCLUSION: Either for known or unknown genes, RD-PCR is very effective in rapid acquisition of large amount of ESTs with proper and similar length fit for making microarray as the probes.

[Cloning E. coli mRNAs with poly (A) tails by restriction digest polymerase chain reaction].

OBJECTIVE: To investigate the polyadenylation at the 3' terminal of the mRNAs in E.coli. METHODS: mRNAs of E.coli was enriched from total RNA with oligo (dT)-cellulose, and reverse transcription was performed using oligo(dT)18 as primer prior to synthesis of double strands cDNA which was digested with Sau 3A I to produce multiple gene fragments that were then ligated with adapters. Restriction digest-polymerase chain reaction (RD-PCR) was employed to divide the fragments into 10 groups using 10 different combinations of the 4 primers, and the products were cloned into T-vectors. RESULTS: More than 100 gene fragments were cloned, 30 of which were sequenced. CONCLUSION: Polyadenylation of E.coli mRNA is not a biochemical curiosity, and very likely, it is a general attribute of the mRNAs of bacteria.