Ultrasonographic Features and Pregnancy Outcomes of Complications in Monochorionic Twin Pregnancy During Various Pregnancy Periods.

Objective: It was to explore the ultrasonic characteristics of complications of twin pregnancies with monochorionic diamniotic (MCDA) during various pregnancy periods and the differences in pregnancy outcomes. Methods: One hundred pregnant women with MCDA were included in the study. They were rolled into a complication group (44 cases) and a non-complication group (56 cases) according to whether they had complications. The pulsatility index (PI), resistance index (RI), and systolic/diastolic (S/D) values of ultrasound in pregnant women and the final neonatal situation at each time period were compared and analyzed. Results: In pregnant women with twin-twin transfusion syndrome (TTTS), there was no significant difference in RI and S/D values between the larger and smaller twin during pregnancy (P > .05). Compared to the group without complications, the incidence of neonatal death was significantly increased in the complication group, and the newborn's weight, length, head circumference, and Apgar score were significantly lower (P < .05). In pregnant women with selective intrauterine growth restriction (sIUGR), the RI and PI values of the larger twin were significantly higher than those of the smaller twin during pregnancy, and S/D values were significantly lower (P < .05). The newborns in the group without complications had significantly higher body weight, length, and head circumference (P < .05). In pregnant women with gestational diabetes mellitus (GDM), there was no significant difference in RI and S/D values between the larger and smaller twin during pregnancy (P > .05), and there were no significant differences in other indicators compared to the group without complications. In pregnant women with premature rupture of membrane (PROM), there was no significant difference in RI and S/D values between the larger and smaller twin during pregnancy (P > .05), but the newborns in the group without complications had significantly higher weight, length, Apgar score, and lower incidence of neonatal death (P < .05). In pregnant women with preeclampsia (PE), there was no significant difference in RI and S/D values between the larger and smaller twin during pregnancy (P > .05), and there were no significant differences in other indicators compared to the group without complications (P > .05). Conclusion: Pregnant women with sIUGR had significantly higher RI and PI values in the larger twin and significantly lower S/D values compared to the smaller twin during pregnancy, while no significant differences were observed for other complications. The combination of TTTS and PROM decreased the birth weight, body length, head circumference, and Apgar score of twins and increased the mortality rate.

Study on infection risk in a negative pressure ward under different fresh airflow patterns based on a radiation air conditioning system.

COVID-19 and other respiratory infectious viruses are highly contagious, and patients need to be treated in negative pressure wards. At present, many negative pressure wards use independent air conditioning equipment, but independent air conditioning equipment has problems such as indoor air circulation flow, condensate water accumulation, and improper filter maintenance, which increase the risk of infection for healthcare workers and patients. The radiation air conditioning system relies on the radiation ceiling to control the indoor temperature and uses new air to control the indoor humidity and air quality. The problems caused by the use of independent air conditioning equipment should be avoided. This paper studies the thermal comfort, contaminant distribution characteristics, contaminant removal efficiency, and accessibility of supply air in a negative pressure ward with a radiation air conditioning system under three airflow patterns. In addition, the negative pressure ward was divided into 12 areas, and the infection probability of healthcare workers in different areas was analyzed. The results show that the application of radiation air conditioning systems in negative pressure wards can ensure the thermal comfort of patients. Stratum ventilation and ceiling-attached jets have similar effects in protecting healthcare workers; both can effectively reduce the contaminant concentrations and the risk of infection of healthcare workers. Ceiling-attached jets decreases the contaminant concentrations by 10.73%, increases the contaminant removal efficiency by 12.50%, and decreases the infection probability of healthcare workers staying indoors for 10 min by 23.18%, compared with downward ventilation.

Defective Biphenylene as High-Efficiency Hydrogen Evolution Catalysts.

Electrocatalysts play a pivotal role in advancing the application of water splitting for hydrogen production. This research unveils the potential of defective biphenylenes as high-efficiency catalysts for the hydrogen evolution reaction. Using first-principles simulations, we systematically investigated the structure, stability, and catalytic performance of defective biphenylenes. Our findings unveil that defect engineering significantly enhances the electrocatalytic activity for hydrogen evolution. Specifically, biphenylene with a double-vacancy defect exhibits an outstanding Gibbs free energy of -0.08 eV, surpassing that of Pt, accompanied by a remarkable exchange current density of -3.08 A cm-2, also surpassing that of Pt. Furthermore, we find the preference for the Volmer-Heyrovsky mechanism in the hydrogen evolution reaction, with a low energy barrier of 0.80 eV. This research provides a promising avenue for developing novel metal-free electrocatalysts for water splitting with earth-abundant carbon elements, making a significant step toward sustainable hydrogen production.

Ultrasound-assisted fermentation of Porphyra yezoensis sauce at different growth stages using Lactiplantibacillus plantarum: Metabolic response and biological activity.

This study first employed ultrasonic-assisted fermentation of seaweed foot material with Lactiplantibacillus plantarum to produce Porphyra yezoensis sauce. The aim was to examine L. plantarum's growth and metabolism of nutritional components at different growth stages under low- (133.99 W/L) and high-ultrasonic power densities (169.17 W/L). After 24-h fermentation, L. plantarum exhibited a 21.32 % increase in the sonicated P. yezoensis sauce at 133.99 W/L and the logarithmic growth phase compared to that at 169.17 W/L. In addition, compared to the non-sonicated sauce, total phenolic and flavonoid contents increased by around 58 % and 27 % in sonicated sauce at 133.99 W/L, reaching 92.38 mg GEA/g DW and 111.08 mg RE/g DW, respectively. Principal Component Analysis (PCA) of the evaluation criteria for different fermentation stages under 133.99 W/L power ultrasonication revealed that the P. yezoensis sauce generated more phenolic compounds and exhibited stronger antioxidant capabilities in the sonicated sample at the logarithmic phase of L. plantarum. Compared to the traditional treated P. yezoensis sauce, the content of free amino acids was significantly increased in sonicated sauce, especially for logarithmic phase. Finally, GC-IMS analysis demonstrated that the ultrasonication at logarithmic phase released more volatile compounds compared to the non-sonicated sauce. This led to a reduction in the fishy odour of the Porphyra yezoensis sauce and an improved release of favourable flavour compounds.

Ultrasound-assisted fermentation of ginkgo kernel juice by Lactiplantibacillus plantarum: Microbial response and juice composition development.

This study is aimed to explore the feasibility of ultrasound on enhancing the fermentation properties of ginkgo kernel juice by Lactiplantibacillus plantarum Y2. Specifically, ultrasound at 20 kHz and different intensities (mild ultrasound intensity-84.42 W/L, moderate ultrasound intensity-115.50 W/L, high ultrasound intensity-173.88 W/L) with a pulse mode were applied to facilitate the fermentation process. The number of viable cells of Lactiplantibacillus plantarum Y2 increased by 5.06, 5.05 and 2.19% in the sonicated groups at 173.88, 115.50 and 84.42 W/L, compared with the non-sonicated juice after 24-h fermentation. Furthermore, mild intensity ultrasonication improved the permeability of the cell membrane, which is beneficial for the metabolism of phenolics, amino acids and organic acids. Ultrasonication increased in-vitro antioxidant activity of fermented ginkgo kernel juice by promoting the metabolism of phenolic acids, such as ferulic acid, chlorogenic and caffeic acids. At the end of fermentation, the sonicated group at 84.42 W/L has the maximum consumptions of total sugars and proteins (increased by 12.52 and 18.73%). Moreover, the reduction rate of the poison material 4'-O-methylpyridoxine (MPN) in ginkgo kernel juice increased by more than 16.40% with ultrasound treatment at 173.88 W/L after the fermentation for 48 h. Overall, ultrasound can improve the metabolizations of Lactobacillus plantarum and reduce the toxic substances, which promoted the nutritional value and flavors of ginkgo kernel juice.

Densification of SiCp/Al-Fe-V-Si Composites by the Wedge Rolling Method.

The densification of a SiCp/Al-Fe-V-Si billet was achieved by reducing the pores and oxide film between the particles by rolling. The wedge pressing method was used to improve the formability of the composite after jet deposition. The key parameters, mechanisms, and laws of wedge compaction were studied. The results showed that the pass rate was reduced by 10 to 15 percent when using steel molds during the wedge pressing process if the distance between the two ends of the billet was about 10 mm, which was beneficial to improve the compactness and formability of the billet. The density and stress of the surface of the material were higher than those of the interior, where the distribution of density and stress tended to be uniform as the overall volume of the material shrank. During the wedge extrusion process, the material in the preforming area was thinned along the thickness direction, while the material in the main deformation area was lengthened along the length direction. Under plane strain conditions, the wedge formation of spray-deposited composites follows the plastic deformation mechanism of porous metals. The true relative density of the sheet was higher than the calculated value during the initial stamping phase, but was lower than the calculated value when the true strain exceeded 0.55. This was due to the accumulation and fragmentation of SiC particles, which made the pores difficult to remove.

Metabolic profiles in plasma of patients with herpes labialis based on GC-MS.

OBJECTIVE: This study aims to compare the plasma metabolic profiles of patients with herpes labialis with healthy controls and identify the biomarkers of herpes labialis. SUBJECTS AND METHODS: We collected 18 patients with herpes labialis and 20 healthy individuals. Plasma samples from both groups were analyzed using gas chromatography-mass spectrometry (GC-MS). RESULTS: According to the principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA), we found that metabolic profiles had changed in patients with herpes labialis compared to the controls. By further selecting the different metabolites according to the variable importance in the projection (VIP) and p valve of t-tests, we found that acetic acid, pyroglutamic acid, alanine, ethanedioic acid, cyclohexaneacetic acid, pyruvic acid, d-mannose, phosphoric acid, l-amphetamine, and citric acid were decreased in patients with herpes labialis, while sedoheptulose and ethylamine were increased. Pathway analysis showed that herpes labialis may affect the amino acid and energy metabolism. CONCLUSIONS: Our findings may contribute to elucidating the metabolic basis of herpes labialis and provide a new perspective for further research on the "Shang-Huo" state in traditional Chinese medicine (TCM).

Characteristics of the complete mitochondrial genome of Douhua chicken (Gallus gallus) and phylogenetic considerations.

Douhua chicken is a unique local breed from Anhui Province, China. This study aimed to illustrate the Douhua chicken mitogenome and clarify its phylogenetic status by sequencing and annotating the complete mitochondrial genome using high-throughput sequencing and primer walking. Phylogenetic analysis through the Kimura 2-parameter model indicated the maternal origin of Douhua chicken. The results revealed that the mitochondrial genome is a closed circular molecule (16,785 bp) that consists of 13 protein-coding genes, 22 transfer RNA (tRNA) coding genes, two ribosomal RNA (rRNA) coding genes, and a control region. The base composition of the Douhua chicken mitogenome contains 30.3% A, 23.7% T, 32.5% C, and 13.5% G, and the haplotype and nucleotide diversity values are 0.829 (Hd) and 0.00441 (Pi), respectively. Furthermore, 10 haplotypes of D-loop sequences among 60 Douhua chickens were identified and distributed into four haplogroups (A, C, D, and E). Overall, the result of the present study indicates that Douhua chicken may have originated from Gallus gallus, and this process was influenced by Gallus gallus spadiceus, Gallus gallus murghi, and Gallus gallus bankiva. This study provides novel mitogenome data to support further phylogenetic and taxonomic studies on Douhua chicken. Additionally, the findings of this study will provide deeper insights for identifying the genetic relationships among populations and tracing maternal origins based on phylogenetic considerations for use in studies on the geographic conservation, utilization, and molecular genetics of poultry species.

In the modern poultry industry, resources of native varieties have become major aspects. Douhua chicken is a medium-sized, slow-growing, and white-feathered local breed that represents a popular local chicken breed in Anhui Province, China. This breed is adaptable and exhibits important production traits and a stable inheritable characteristics, such as delicious meat and stable egg-laying performance. The present study aimed to provide a better understanding of the germplasm characteristics and phylogenetic relationships of Douhua chicken by analyzing its complete mitochondrial genome sequence and a describing its genomic composition, nucleotide composition, and gene structure. The present study provides theoretical support for the protection, development, and utilization of Douhua chicken resources. Additionally, this study provides new mitochondrial genome data to support further phylogenetic and taxonomic studies conducted on Douhua chicken.

Mixed Mulberry Fruit and Mulberry Leaf Fermented Alcoholic Beverages: Assessment of Chemical Composition, Antioxidant Capacity In Vitro and Sensory Evaluation.

The fruit and leaves of mulberry (Morus alba L.) contain a variety of health-beneficial components. At present, although both alcoholic and non-alcoholic mulberry beverages are commercially available, studies on fermented alcoholic beverages mixed with both mulberry fruit and mulberry leaf are rare. In this study, different amounts (1, 2 and 3%, g/mL dry weight) of mulberry leaves were added during the alcoholic fermentation of mulberry juice. After 9 days of fermentation, the 1-deoxynojirimycin (DNJ) content increased from 61.12 ± 3.10 to 153.39 ± 3.98 µg/mL, and the quercetin content increased from 0.45 ± 0.01 to 20.14 ± 0.08 mg/L in the mulberry alcoholic beverages with the addition of mulberry leaves at 2%. Moreover, the ABTS+ scavenging capacity at the end of fermentation for the same sample was enhanced by 40.9%. In addition, the total sugar, total phenols, total anthocyanins, and γ-aminobutyric acid (GABA) contents of the fermented samples all decreased significantly at the end of fermentation. A total of 33 volatile compounds and 17 free amino acids were detected in the fermented alcoholic beverages with mulberry leaves added. The total free amino acid content increased with the increase in mulberry leaf addition. Principal component analysis showed that the addition of mulberry leaves during fermentation increased the contents of GABA, DNJ, total flavonols and protocatechuic acid in mulberry alcoholic beverages. All these studies revealed the dynamic changes in functional components in the alcoholic fermentation of mulberry juices with the addition of mulberry leaves. Overall, the addition of mulberry leaf powder at 2% was selected as the appropriate addition for producing mulberry alcoholic beverages with enhanced nutritional value.

Efficacy and safety of bisphosphonates on childhood osteoporosis secondary to chronic illness or its treatment: a meta-analysis.

Background: Bisphosphonates are a type of medication that prevents the loss of bone density. Secondary childhood osteoporosis reduces bone strength and results in an increased risk of fragility fracture. This meta-analysis aims to explore the efficacy and safety of bisphosphonates on secondary childhood osteoporosis. Methods: We performed a systematic search of PubMed, Cochrane library, and Web of Science databases up to 31 July 2022 to screen for random clinical trials (RCTs) on bisphosphonate treatment for childhood secondary osteoporosis. Data from selected studies, mainly changes in lumbar spine (LS) bone mineral density (BMD), changes in LS BMD Z-scores, fracture events, and adverse events (AEs), were extracted and analyzed. Results: Nine RCTs (n = 429 in total) were included in our meta-analysis. The meta-analysis indicated that bisphosphonates improved the changes in LS BMD [mean difference (MD) = 0.04, 95% confidence intervals (CIs) = 0.01-0.07, p < 0.01] and LS BMD Z-scores [MD = 0.52, 95% CI = 0.23-0.81, p < 0.01]. Use of bisphosphonates did not increase the risk of AEs [odds ratio (OR) = 1.61, 95% CI = 0.87-2.99, p = 0.13]. Subgroup analysis showed that routes of administration, but not causes of secondary osteoporosis, might influence the efficacy of bisphosphonates. IV bisphosphonates close to significantly improved the incidence of fracture (OR = 0.34, 95% CI: 0.11-1.08, p = 0.07). Conclusions: The use of bisphosphonates improves LS BMD without increasing AE rates, which supports the clinical use of bisphosphonates in secondary childhood osteoporosis. Further large RCTs are still warranted, especially for their long-term effects on fracture rates.

Tissue distribution of polystyrene nanoplastics in mice and their entry, transport, and cytotoxicity to GES-1 cells.

With the widespread use of plastics and nanotechnology products, nanoplastics (NPs) have become a potential threat to human health. It is of great practical significance to study and evaluate the distribution of NPs in mice as mammal models and their entry, transport, and cytotoxicity in human cell lines. In this study, we detected the tissue distribution of fluorescent polystyrene nanoplastics (PS-NPs) in mice and assessed their endocytosis, transport pathways, and cytotoxic effects in GES-1 cells. We found that PS-NPs were clearly visible in gastric, intestine, and liver tissues of mice and in GES-1 cells treated with PS-NPs. Entry of PS-NPs into GES-1 cells decreased with the inhibition of caveolae-mediated endocytosis (nystatin), clathrin-mediated endocytosis (chlorpromazine HCl), micropinocytosis (ethyl-isopropyl amiloride), RhoA (CCG-1423), and F-actin polymerization (lantrunculin A). Rac1 inhibitors (NSC 23766) had no significant effect on PS-NPs entering GES-1 cells. F-actin levels significantly decreased in CCG-1423-pretreated GES-1 cells exposed to PS-NPs. GES-1 cell ultrastructural features indicated that internalized PS-NPs can be encapsulated in vesicles, autophagosomes, lysosomes, and lysosomal residues. RhoA, F-actin, RAB7, and LAMP1 levels in PS-NPs-treated GES-1 cells were remarkably up-regulated and the Rab5 level was significantly down-regulated compared to levels in untreated cells. PS-NPs treatment decreased cell proliferation rates and increased cell apoptosis. The formation of autophagosomes and autolysosomes and levels of LC3II increased with the length of PS-NPs treatment. The results indicated that cells regulated endocytosis in response to PS-NPs through the RhoA/F-actin signaling pathway and internalized PS-NPs in the cytoplasm, autophagosomes, or lysosomes produced cytotoxicity. These results illustrate the potential threat of NPs pollution to human health.

Polyethylene microplastics affect the distribution of gut microbiota and inflammation development in mice.

Environmental pollution caused by plastics has become a public health problem. However, the effect of microplastics on gut microbiota, inflammation development and their underlying mechanisms are not well characterized. In the present study, we assessed the effect of exposure to different amounts of polyethylene microplastics (6, 60, and 600 µg/day for 5 consecutive weeks) in a C57BL/6 mice model. Treatment with a high concentration of microplastics increased the numbers of gut microbial species, bacterial abundance, and flora diversity. Feeding groups showed a significant increase in Staphylococcus abundance alongside a significant decrease in Parabacteroides abundance, as compared to the blank (untreated) group. In addition, serum levels of interleukin-1α in all feeding groups were significantly greater than that in the blank group. Of note, treatment with microplastics decreased the percentage of Th17 and Treg cells among CD4+ cells, while no significant difference was observed between the blank and treatment groups with respect to the Th17/Treg cell ratio. The intestine (colon and duodenum) of mice fed high-concentration microplastics showed obvious inflammation and higher TLR4, AP-1, and IRF5 expression. Thus, polyethylene microplastics can induce intestinal dysbacteriosis and inflammation, which provides a theoretical basis for the prevention and treatment of microplastics-related diseases.

Investigation on the role of gene hp0788 in Helicobacter pylori in infecting gastric epithelial cells.

Helicobacter pylori infection can cause a wide range of digestive diseases. Gene hp0788 encodes an outer membrane protein HofF, which can reduce the bacterial adherence to the GES-1 cells and affect pathogenesis of H. pylori. In this study, the role of hp0788 in H. pylori infection was further analyzed. RNA-seq data showed that two genes (hp0523 and hp0539), located on the cagPAI, were down-regulated in Δ0788 mutant. The changes were confirmed through qRT-PCR, and the expression of these two genes will be almost recovered to the normal level in complemented strain. These two genes, hp0523 and hp0539, are known to be necessary for integrated T4SS, which related to CagA translocation and IL-8 induction. In H. pylori infected assay, lower amount of phosphorylated CagA and lower induction of IL-8 were both detected in GES-1 cells infected by Δ0788 mutant, compared with the wild type strain. Meanwhile, these reductions almost recovered to the wild-type level in complemented strain. These results reveal that there is a correlation between hp0788 disruption and CagA/IL-8 decline. Deletion of CagA-encoding gene (hp0547) in Δ0788 mutant was further constructed. The double deleted mutant shows lower IL-8-inducing capability than Δ0788 mutant, indicated the correlation between deficiency of CagA and reduced IL-8 production. These results together imply that disruption of hp0788 might affect the efficiency of T4SS and CagA injection, then weaken the induction of IL-8 in infected GES-1 cells.

Aureibaculum marinum gen. nov., sp. nov., a Novel Bacterium of the Family Flavobacteriaceae Isolated from the Bohai Gulf.

A novel Gram-stain-negative bacterium, designated strain BH-SD17T, was isolated from a marine sediment sample in the Bohai Gulf, Yellow Sea, China. Cells of strain BH-SD17T are aerobic, yellow-colored, non-flagellated rods. Growth occurs between 15 and 40 °C (optimum, 30 °C), at pH 6.0-8.5 (optimum, 7.5) and with 1.0-8.0% (w/v) NaCl (optimum, 3.0%). Strain BH-SD17T contains phosphatidylethanolamine and two unidentified lipids as the major polar lipids. The predominant fatty acids are iso-C15:0 (28.5%), iso-C15:1 G (24.4%), and iso-C17:0 3-OH (12.3%). The major respiratory quinone is MK-6. Strain BH-SD17T shows moderate 16S rRNA gene sequence similarity to existing identified strains, is most closely related to the genera Lutimonas (92.1-92.4%), Lutibacter (91.6-92.3%), and Taeania (91.9%). Phylogenetic trees based on 16S rRNA gene sequences show that strain BH-SD17T forms a distinct lineage within the family Flavobacteriaceae. Based on the results of phenotypic, chemotaxonomic and phylogenetic analysis, strain BH-SD17T is considered to represent a novel genus and species in the family Flavobacteriaceae, for which the name Aureibaculum marinum is proposed. The type strain is BH-SD17T (=CCTCC AB 2017072T=KCTC 62204T).

The regulatory role of C1q on Helicobacter pylori-induced inflammatory cytokines secretion in THP-1 cells.

C1q, as a LAIR-1 ligand, maintains monocytes quiescence and possess immunosuppressive properties. To understand the roles and molecular mechanisms, C1q mediated inflammation cytokines and several pivotal proteins in THP-1 cells after H. pylori infection were detected. The results showed that the expression of IL-8, IL-10, LAIR-1, phosphorylated/total JNK, phosphorylated/total p38-MAPK, phosphorylated/total AKT and phosphorylated/total NF-κB were up-regulated significantly in THP-1 cells after H. pylori infection. There was significant upregulation in IL-10 concentration, phosphorylated/total p38-MAPK and phosphorylated/total AKT, and downregulation in phosphorylated/total JNK in non-H. pylori infected THP-1 cells pretreated with C1q. C1q was also able to increase IL-8 and IL-10 production, and reduce LAIR-1 and phosphorylated/total p38-MAPK expression in pretreatment-C1q THP-1 cells after H. pylori infection. These results together indicated that H. pylori might induce IL-8 and IL-10 production through JNK, p38-MAPK, PI3K/AKT and NF-κB signaling pathway. C1q manipulate LAIR-1 to regulation IL-8 and IL-10 secretion in THP-1 cells after H. pylori infection through the p38-MAPK signaling pathway. This information is helpful to further understand the role and mechanisms of C1q on inflammation cytokines secretion in monocytes after H. pylori infection.

Thalassorhabdomicrobium marinisediminis gen. nov., sp. nov., a member of the family Hyphomonadaceae isolated from the Bohai Sea.

A novel Gram-stain-negative bacterium, designated strain BH-SD16T, was isolated from a marine sediment sample collected in the Bohai Sea. Cells of strain BH-SD16T are aerobic, non-flagellated oval-shaped rods, showing oxidase- and catalase-positive activities. Growth occurs between 15-45 °C (optimum, 30 °C), at pH 6.0-9.0 (pH 7.0-7.5) and with 1-10 % (w/v) NaCl (3.0 %). Strain BH-SD16T contains C18 : 1ω7c (49.2 %), C16 : 0 (17.7 %) and C18 : 1ω7c 11-methyl (16.6 %) as the predominant fatty acids and ubiquinone-10 as the major respiratory quinone. The major polar lipids comprise phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, diphosphatidylglycerol and two glycolipids. The size of the draft genome is 3 442 538 bp, including 3213 protein-coding genes, 40 tRNA genes and three rRNA genes, and the DNA G+C content is 63.4 mol%. Strain BH-SD16T shows the highest 16S rRNA gene sequence similarity to Pseudooctadecabacter jejudonensis (95.7 %), strains of the genus Octadecabacter(95.4-95.6 %) and strains of the genus Loktanella(93.8-95.4 %). Phylogenetic trees based on 16S rRNA gene sequences show that strain BH-SD16T forms a distinct lineage within the family Hyphomonadaceae, which is also confirmed in the multigenic phylogenetic tree calculated by RAxML. Based on the results of phenotypic, chemotaxonomic and phylogenetic analysis, strain BH-SD16T is considered to represent a novel genus and species in the family Hyphomonadaceae, for which the name Thalassorhabdomicrobium marinisediminis gen. nov., sp. nov. is proposed. The type strain is BH-SD16T (=CCTCC AB 2017073T=KCTC 62201T).

Mechanistic Insight Into the Interaction Between Helicobacter pylori Urease Subunit α and Its Molecular Chaperone Hsp60.

Helicobacter pylori is the etiologic agent in a variety of gastroduodenal diseases. As its key pathogenic factors, both urease and Hsp60 play important roles in the pathogenesis of H. pylori. Previous studies have suggested that there is close relationship between urease and Hsp60, which implied that Hsp60 may act as a chaperone in urease stabilization and assembly. However, how these two proteins interact remains unclear. In this study, the impact of Hsp60 on urease activity of H. pylori lysate was first detected to confirm the interaction between urease and Hsp60. Pull-down assays further indicated that Hsp60 could bind to UreA subunit but not UreB. Then, the 3D structure of Hsp60 was modeled using I-TASSER to simulate the binding complex with UreA by molecular docking. The results showed that UreA is a perfect fit for the cavity of Hsp60. Analysis of the resulting model demonstrated that at least seven residues of UreA, located on two interfaces, participate in the interaction. Site-directed mutagenesis of these potential residues showed reduced affinity with Hsp60 than the wild type UreA through surface plasmon resonance (SPR) experiments, and D68 appears to have an important role in the affinity. Further analysis also showed that mutation of E25 and K26 caused a more rapid association and dissociation than with wild UreA, implying that they have roles in stabilizing the interaction complex. These affinity comparisons suggested that the interfaces predicted by molecular docking are credible. Our study indicated a direct interaction between Hsp60 and urease and revealed the binding interfaces and key residues involved in the interaction. These results provide further evidence for the chaperone activity of Hsp60 toward urease and lay a foundation to better understand the maturation mechanism of urease in H. pylori.

Novel ß-Ti35Zr28Nb alloy scaffolds manufactured using selective laser melting for bone implant applications.

Titanium (Ti) based tissue engineering scaffolds can be used to repair damaged bone. However, successful orthopedic applications of these scaffolds rely on their ability to mimic the mechanical properties of trabecular bone. Selective laser melting (SLM) was used to manufacture scaffolds of a new ß-Ti35Zr28Nb alloy for biomedical applications. Porosity values of the scaffolds were 83% for the FCCZ structure (face centered cubic unit cell with longitudinal struts) and 50% for the FBCCZ structure (face and body centered cubic unit cell with longitudinal struts). The scaffolds had an elastic modulus of ∼1 GPa and a plateau strength of 8-58 MPa, which fall within the values of trabecular bone (0.2-5 GPa for elastic modulus and 4-70 MPa for compressive strength). The SLM-manufactured ß-Ti35Zr28Nb alloy showed good corrosion properties. MTS assay revealed that both the FCCZ and FBCCZ scaffolds had a cell viability similar to the control. SEM observation indicated that the osteoblast-like cells adhered, spread and grew healthily on the surface of both scaffolds after culture for 7, 14 and 28 d, demonstrating good biocompatibility. Overall, the SLM-manufactured Ti35Zr28Nb scaffolds possess promising potential as hard-tissue implant materials due to their appropriate mechanical properties, good corrosion behavior and biocompatibility. STATEMENT OF SIGNIFICANCE: Novel ß Ti35Zr28Nb alloy scaffolds with FCCZ and FBCCZ structures were successfully fabricated by selective laser melting (SLM) for biomedical applications. The scaffolds showed values of elastic modulus of ∼1 GPa and plateau strength of 8-58 MPa, which fall within the ranges of the mechanical properties of trabecular bone. The SLM-manufactured ß Ti35Zr28Nb alloy showed good corrosion properties. Both SLM-manufactured FCCZ and FBCCZ scaffolds exhibited good biocompatibility, with osteoblast-like cells attaching, growing, and spreading in a healthy way on their surfaces after culturing for different periods up to 28 d.

Pelagivirga sediminicola gen. nov., sp. nov. isolated from the Bohai Sea.

A Gram-stain-negative bacterium, strain BH-SD19T, that was isolated from a marine sediment sample collected from the Bohai Sea, was subjected to a polyphasic taxonomic study. Cells of BH-SD19T are non-flagellated, non-gliding, oval-shaped rods, 0.5-1.0 µm wide and 1.0-2.0 µm long. BH-SD19T is strictly aerobic, and oxidase- and catalase-positive. Growth occurs at 15-40 °C (optimum 35 °C), at pH 6.0-8.5 (optimum 7.0-7.5) and with 1-10 % (w/v) NaCl (optimum 2 %). The predominant fatty acids are C19 : 0cyclo ω8c (46.5 %), C16 : 0 (20.3 %) and C18 : 1ω7c and/or C18 : 1ω6c (10.6 %). The major respiratory quinone is Q-10. The major polar lipids are phosphatidylglycerol, phosphatidylethanolamine and an unidentified phospholipid. The DNA G+C content is 64.0 mol%. BH-SD19T shows the highest 16S rRNA sequence similarity to Pontibaca methylaminivorans (95.2 %) and strains of species of the genus Roseovarius(93.4-95.2 %). Sequence similarity values between BH-SD19T and other phylogenetically related species are all below 95.0 %. Phylogenetic trees based on 16S rRNA gene sequences indicate that BH-SD19T forms a distinct lineage and does not join any known genera in the trees. Phenotypic, chemotaxonomic and phylogenetic data indicate that BH-SD19T represents a novel genus and species in the family Rhodobacteraceae, for which the name Pelagivirga sediminicola gen. nov., sp. nov. is proposed. The type strain is BH-SD19T (=CCTCC AB 2017074T=KCTC 62202T).

Application of methylation in improving plasmid transformation into Helicobacter pylori.

Helicobacter pylori is an important gastrointestinal pathogen. Its strains possess different levels of powerful restriction modification systems, which are significant barriers to genetic tools used for studying the role of functional genes in its pathogenesis. Methylating vectors in vitro was reported as an alternative to overcome this barrier in several bacteria. In this study we used two H. pylori-E. coli shuttle plasmids and several single/double-crossover homologous recombination gene-targeting plasmids, to test the role of methylation in H. pylori transformation. According to our results, transformants could be obtained only after shuttle plasmids were methylated before transformation. It is helpful in gene complementation and over-expression although at a low frequency. The frequency of gene-targeting transformation was also increased after methylation, especially for the single-crossover recombination plasmids, the transformants of which could only be obtained after methylation. For the double-crossover recombination targeting plasmids, the initial yield of transformants was 0.3-0.8 × 102 CFUs per microgram plasmid DNA. With the help of methylation, the yield was increased to 0.4-1.3 × 102 CFUs per microgram plasmid DNA. These results suggest that in vitro methylation can improve H. pylori transformation by different plasmids, which will benefit the pathogenic mechanism research.