[Removal Performance of Antibiotic Resistance Genes and Heavy Metal Resistance Genes in Municipal Wastewater by Magnetic-Coagulation Process].

Antibiotic resistance genes (ARGs) in municipal wastewater pose a potential threat to the environment. In this study, the change in absolute and relative abundance of ARGs, metal resistance genes (MRGs), and mobile genetic elements (MGTs) were investigated during an emergent municipal wastewater treatment by the magnetic separation process. Results indicate that all the concentrations of targeted ARGs, MRGs, and MGTs decreased significantly in the primary and secondary stirring tank. However, the absolute abundance of some ARGs and MRGs increased in the effluent, which is likely caused by the presence of ample MGTs, in the order of int1 (2.00×1010 copies·mL-1) > int2 (1.91×108 copies·mL-1) > Tn 916/1545e(5.38×108 copies·mL-1). The results obtained from network and PCA analysis showed that the removal of ARGs and MRGs were significantly associated with variations in the microbial community and common pollutants in urban wastewater, such as suspended solids, phosphorus, and COD, which are important factors for affecting the removal efficiency of antibiotic resistance genes and metal heavy resistance genes. These results show that magnetic separation can effectively reduce common pollutants in urban wastewater and might further restrict the transmission and transfer of ARGs. Moreover, it is necessary to strengthen the subsequent management of magnetic separation effluent and dehydrated sludge by disinfection technologies to lessen the risk of antimicrobial contamination.

Graphene Oxide Quantum Dots Exfoliated From Carbon Fibers by Microwave Irradiation: Two Photoluminescence Centers and Self-Assembly Behavior.

Graphene oxide quantum dots (GOQDs) attract great attention for their unique properties and promising application potential. The difficulty in the formation of a confined structure, and the numerous and diverse oxygen-containing functional groups results in a low emission yield to GOQDs. Here, GOQDs with a size of about 5 nm, exfoliated from carbon fibers by microwave irradiation, are detected and analyzed. The exfoliated GOQDs are deeply oxidized and induce large numbers of epoxy groups and ether bonds, but only a small amount of carbonyl groups and hydroxyl groups. The subdomains of sp2 clusters, involving epoxy groups and ether bonds, are responsible for the two strong photoluminescence emissions of GOQDs under different excitation wavelengths. Moreover, GOQDs tend to self-assemble at the edges of their planes to form self-assembly films (SAFs) with the evaporation of water. SAFs can further assemble into different 3D patterns with unique microstructures such as sponge bulk, sponge ball, microsheet, sisal, and schistose coral, which are what applications such as supercapacitors, cells, catalysts, and electrochemical sensors need. This method for preparation of GOQDs is easy, quick, and environmentally friendly, and this work may open up new research interests about GOQDs.

Enhanced biocompatibility and osseointegration of calcium titanate coating on titanium screws in rabbit femur.

This study aimed to examine the biocompatibility of calcium titanate (CaTiO3) coating prepared by a simplified technique in an attempt to assess the potential of CaTiO3 coating as an alternative to current implant coating materials. CaTiO3-coated titanium screws were implanted with hydroxyapatite (HA)-coated or uncoated titanium screws into medial and lateral femoral condyles of 48 New Zealand white rabbits. Imaging, histomorphometric and biomechanical analyses were employed to evaluate the osseointegration and biocompatibility 12 weeks after the implantation. Histology and scanning electron microscopy revealed that bone tissues surrounding the screws coated with CaTiO3 were fully regenerated and they were also well integrated with the screws. An interfacial fibrous membrane layer, which was found in the HA coating group, was not noticeable between the bone tissues and CaTiO3-coated screws. X-ray imaging analysis showed in the CaTiO3 coating group, there was a dense and tight binding between implants and the bone tissues; no radiation translucent zone was found surrounding the implants as well as no detachment of the coating and femoral condyle fracture. In contrast, uncoated screws exhibited a fibrous membrane layer, as evidenced by the detection of a radiation translucent zone between the implants and the bone tissues. Additionally, biomechanical testing revealed that the binding strength of CaTiO3 coating with bone tissues was significantly higher than that of uncoated titanium screws, and was comparable to that of HA coating. The study demonstrated that CaTiO3 coating in situ to titanium screws possesses great biocompatibility and osseointegration comparable to HA coating.

Enhanced Biocompatibility and Osseointegration of Calcium Titanate Coating on Titanium Screws in Rabbit Femur / 华中科技大学学报（医学）（英德文版）

This study aimed to examine the biocompatibility of calcium titanate (CaTiO3) coating prepared by a simplified technique in an attempt to assess the potential of CaTiO3 coating as an alternative to current implant coating materials.CaTiO3-coated titanium screws were implanted with hydroxyapatite (HA)-coated or uncoated titanium screws into medial and lateral femoral condyles of 48 New Zealand white rabbits.Imaging,histomorphometric and biomechanical analyses were employed to evaluate the osseointegration and biocompatibility 12 weeks after the implantation.Histology and scanning electron microscopy revealed that bone tissues surrounding the screws coated with CaTiO3 were fully regenerated and they were also.well integrated with the screws.An interfacial fibrous membrane layer,which was found in the HA coating group,was not noticeable between the bone tissues and CaTiO3-coated screws.X-ray imaging analysis showed in the CaTiO3 coating group,there was a dense and tight binding between implants and the bone tissues;no radiation translucent zone was found surrounding the implants as well as no detachment of the coating and femoral condyle fracture.In contrast,uncoated screws exhibited a fibrous membrane layer,as evidenced by the detection of a radiation translucent zone between the implants and the bone tissues.Additionally,biomechanical testing revealed that the binding strength of CaTiO3 coating with bone tissues was significantly higher than that of uncoated titanium screws,and was comparable to that of HA coating.The study demonstrated that CaTiO3 coating in situ to titanium screws possesses great biocompatibility and osseointegration comparable to HA coating.

[Sequencing analysis and identification of a novel HLA-B(*)40:162 allele].

The aim of this study was to identify a novel HLA-B allele in Chinese population. The HLA typing of bone marrow donors was performed by PCR-SBT. The ambiguous novel HLA allele was confirmed with GSSP and single stranded SBT method. The result indicated that there was a sample, the sequence of which was different from all alleles in the HLA databases. The sequence analysis showed that it differed from the closet matching allele B(*)40:06:01 in one nucleotide substitution, 272 C>T in Exon 2, which resulted in an amino acid change from Serine (Ser) to Phenylalanine (Phe) at codon 63. It is concluded that the novel allele has been identified and is named HLA-B(*)40:162 by the WHO Nomenclature Committee.

[Benefits of placing intra-aortic vacant guide wire on interventional treatment of aorto-ostial lesions].

OBJECTIVE: To evaluate the potential benefits of placing intra-aortic vacant guide wire on interventional treatment of aorto-ostial lesions. METHODS: A total of 86 consecutive patients underwent percutaneous coronary interventions (PCI) for aorto-ostial lesions were randomly divided into conventional treatment group (group A) and intra-aortic vacant guide wire group (group B). Standard PCI techniques were applied in group A and an intra-aortic vacant guide wire was placed outside the guiding catheter before the guiding catheter into the target coronary artery in group B on basis of standard PCI techniques. The number of guiding catheter, guide wire, X-ray exposure time, total PCI time, the incidence of pressure drop and malignant arrhythmia, contrast agent dose and the number of failure cases were compared between the two groups. RESULTS: The number of used guide wire was similar between the groups (2.0 ± 1.1 vs. 2.2 ± 0.4, P > 0.05) and the number of guiding catheter used was significantly more in group A than in group B (2.3 ± 1.1 vs. 1.3 ± 0.5, P < 0.01). The X-ray exposure time (18.8 min ± 6.9 min vs. 14.2 min ± 5.7 min, P < 0.01) was significantly less in groups B and the total PCI time (31.2 min ± 8.1 min vs. 20.1 min ± 4.5 min, P < 0.01) and the amount of contrast agent (193.5 ml ± 25.4 ml vs. 130.6 ml ± 32.8 ml, P < 0.01) and the frequency of pressure drop (19 cases vs. 2 cases, P < 0.01) were all significantly higher in group A than in group B. Incidence of malignant ventricular arrhythmia (8 vs. 0) and procedure failure (6 vs. 0) was also higher in group A compared to group B. CONCLUSION: The method of using Intra-aortic vacant guide wire is associated with reduced risk and improved success rate of PCI for aorto-ostial lesions.

[Relationship between myocyte proliferation and cardiac function in adult rats with heart failure].

OBJECTIVE: To confirm whether there is myocytes proliferation in the adult rat with heart failure or not, and to investigate the relationship between myocyte proliferation and heart function. METHODS: Descending anterior branch of left coronary artery was ligated in 20 adult male SD rats so as to establish an heart failure models. Eight rats were used as controls. Hemodynamic parameters, blood pressure (BP), left ventricle end systolic pressure (LVESP), left ventricle end diastolic pressure (LVEDP), +LVdp/dt(max), and -LVdp/dt(max), were measured 30 days after the coronary occlusion. Based on the results of heart function examination, the heart infarct rats were divided into 2 subgroups: cardiac functional compensation subgroup (8 rats), and cardiac functional decompensation subgroup (6 rats). Then the rats were killed and their hearts were taken out and stained with propidium iodide (PI) and antibody to alpha-sarcomeric actin. Immunohistochemistry was used to detect the proliferation cell nuclear antigen (PCNA). Confocal microscopy was used to observe the mitotic image. Light microscopy was used to observe the PCNA positive rate in the myocardium. RESULTS: (1) Mitotic images of myocytes could be identified by confocal microscopy in the left ventricle of all rats. (2) PCNA expression was detected in the nuclei of both infarct and normal hearts. The PCNA positive rate of the cardiac functional compensation subgroup was 7.2% +/- 1.4%, significantly higher than that of the control group (2.2% +/- 0.8%, P = 0.648). However, the PCNA positive rate of the cardiac functional decompensation subgroup was 3.0% +/- 1.3%, not significantly different from that of the control group (P = 0.648). (3) The correlation coefficient between PCNA-positivity of cardiomyocytes and +LVdp/dt(max) in the infarct rats were 0.80 (P < 0.01) and the correlation coefficient between PCNA-positivity of cardiomyocytes and -LVdp/dt(max) was -0.76 (P = 0.01). CONCLUSION: (1) There is myocyte proliferation in the adult rat heart. (2) Myocyte proliferation is positively correlated with heart systolic function, and negatively correlated with heart diastolic function in chronic heart failure.