Research on lightweight laminate for car body with excellent cushioning and energy absorption characteristics.

With the development of the economy, car ownership is increasing day by day. In the context of energy shortage and environmental pollution, it is very important to study lightweight and ensure car safety. In this paper, a lightweight fiber metal laminate (FML) with excellent cushioning and energy absorption characteristics for car body is proposed by studying the deformation and energy absorption mechanism of ordinary groove plate under flat pressure. The FML is made up of an M-shaped aluminum alloy sandwich plate and two carbon fiber reinforced composite outer panels. By means of experiment and finite element simulation, it is proved that this structure had good cushioning energy absorption effect. Under the same conditions, the peak force of the M-shaped corrugated core FML with 2.5 mm groove depth is 46.3% of that of the traditional trapezoidal corrugated-core FMLs. Besides, the energy absorption capacity of the M-shaped corrugated core FML with 2 mm groove depth is 1.62 times of that of the traditional trapezoidal corrugated-core FMLs, before the top plate of sandwich unit touches the bottom plate. And cushioning energy absorption mechanism of M-shaped corrugated core FML is further explained by simulation.

Inhibitory effects of a water-soluble jujube polysaccharide against biofilm-forming oral pathogenic bacteria.

Oral diseases caused by infectious pathogens raises significant concerns in public health. In the light of side effects of current antibiotics therapy and growing drug resistance of pathogenic bacteria, natural products have become attractive alternatives for antibiotics agents in dental practice. This current study investigated the effects of polysaccharides extracted from Zizyphus jujuba Mill. on three major oral biofilm-forming pathogenic bacteria including caries-inducing Streptococcus mutans, lesions-causing MRSA, and periodontitis-related Porphyromonas gingivalis, as well as general oral microbiota. Our results demonstrated that jujube polysaccharide prepared in this study was mainly composed by galacturonic acid with an average molecular weight 242 kDa, which were further characterized for structural features by FT-IR spectra and NMR spectroscopy analysis. This jujube polysaccharide was shown to exhibit remarkable inhibitory effects against all the tested oral bacterial pathogens through various mechanisms including growth inhibition, biofilm prevention and disruption, intervention of bacterial infection (adhesion and invasion), attenuation of cytotoxicity, modulation of excessive inflammatory response of LPS-stimulated and MRSA-infected macrophages as well as positive regulation of oral microbiota. The present study paves the way to explore jujube polysaccharides for the prevention and treatment of oral infectious diseases. Graphic Abstract.

Human Enteric Defensin 5 Promotes Shigella Infection of Macrophages.

Human α-defensins are 3- to 5-kDa disulfide-bridged peptides with a multitude of antimicrobial activities and immunomodulatory functions. Recent studies show that human enteric α-defensin 5 (HD5), a host defense peptide important for intestinal homeostasis and innate immunity, aids the highly infectious enteropathogen Shigella in breaching the intestinal epithelium in vitro and in vivo Whether and how HD5 influences Shigella infection of resident macrophages following its invasion of the intestinal epithelium remain poorly understood. Here, we report that HD5 greatly promoted phagocytosis of Shigella by macrophages by targeting the bacteria to enhance bacterium-to-cell contacts in a structure- and sequence-dependent fashion. Subsequent intracellular multiplication of phagocytosed Shigella led to massive necrotic cell death and release of the bacteria. HD5-promoted phagocytosis of Shigella was independent of the status of the type 3 secretion system. Furthermore, HD5 neither inhibited nor enhanced phagosomal escape of Shigella Collectively, these findings confirm a potential pathogenic role of HD5 in Shigella infection of not only epithelial cells but also macrophages, illuminating how an enteropathogen exploits a host protective factor for virulence and infection.

Critical determinants of human neutrophil peptide 1 for enhancing host epithelial adhesion of Shigella flexneri.

Human neutrophil peptides (HNPs), also known as human myeloid α-defensins degranulated by infiltrating neutrophils at bacterial infection loci, exhibit broad antomicrobial activities against bacteria, fungi, and viruses. We have made a surprising recent finding that Shigella, a highly contagious, yet poorly adhesive enteric pathogen, exploits human α-defensins including HNP1 to enhance its adhesion to and invasion of host epithelial cells. However, the critical molecular determinants responsible for HNP1-enhanced Shigella adhesion and invasion have yet to be investigated. Using cultured epithelial cells and polarised Caco2 cells as an in vitro infection model, we demonstrated that HNP1 promoted Shigella infection in a structure- and sequence-dependent manner, with two bulky hydrophobic residues, Trp26 and Phe28 important for HNP1 self-assembly, being most critical. The functional importance of hydrophobicity for HNP1-enhanced Shigella infection was further verified by substitutions for Trp26 of a series of unnatural amino acids with straight aliphatic side chains of different lengths. Dissection of the Shigella infection process revealed that bacteria-rather than host cells-bound HNP1 contributed most to the enhancement. Further, mutagenesis analysis of bacterial surface components, while precluding the involvement of lipopolysaccharides (LPS) in the interaction with HNP1, identified outer membrane proteins and the Type 3 secretion apparatus as putative binding targets of HNP1 involved in enhanced Shigella adhesion and invasion. Our findings provide molecular and mechanistic insights into the mode of action of HNP1 in promoting Shigella infection, thus showcasing another example of how innate immune factors may serve as a double-edged sword in health and disease.

CHARACTERIZATION OF VIRULENCE GENES AND ANTIMICROBIAL RESISTANCE OF LUNG PATHOGENIC ESCHERICHIA COLI ISOLATES IN FOREST MUSK DEER (MOSCHUS BEREZOVSKII).

This study investigated genotypic diversity, 26 virulence genes, and antimicrobial susceptibility of lung pathogenic Escherichia coli (LPEC) isolated from forest musk deer. Associations between virulence factors (VFs) and phylogenetic group, between antimicrobial resistance (AMR) and phylogenetic group, and between AMR and VFs were subsequently assessed. The results showed 30 LPEC isolated were grouped into seven different clusters (A, B, C, D, E, F, and G). The detection rates of crl (90%), kpsMT II (76.67%), mat (76.67%), and ompA (80%) were over 75%. The most frequent types of resistance were to amoxicillin (100%), sulfafurazole (100%), ampicillin (96.67%), and tetracycline (96.67%), with 93.33% (n = 28) of isolates resistant to more than eight types of drugs. There were significant relationships between resistance to cefalotin and the presence of iucD(a) (P < 0.001), papC (P = 0.032), and kpsMT II (P = 0.028); between resistance to chloromycetin and the presence of irp2 (P = 0.004) and vat (P = 0.047); between resistance to nalidixic acid and the presence of crl (P = 0.002) and iucD(a) (P = 0.004); and between resistance to ampicillin/sulbactam and the presence of vat (P = 0.013). These results indicated there could be some association between resistance and VFs, and there is a great need for the prudent use of antimicrobial agents in LPEC.

AMH trend after laparoscopic cystectomy and ovarian suturing in patients with endometriomas.

PURPOSE: To evaluate the ovarian reserve after laparoscopic cystectomy with suturing in patients with endometriomas. METHODS: A total of 80 women with unilateral or bilateral endometriomas underwent laparoscopic cystectomy using sutures for hemostasis after the excision of ovarian cysts. Serum levels of antimullerian hormone (AMH) and FSH were measured at the day 3 of menstrual cycles preoperatively, 6 and 12 months postoperatively. RESULTS: In the bilateral endometrioma group, serum AMH level decreased significantly from the baseline (4.68 ± 2.87 ng/ml) to 6 months (3.05 ± 1.99 ng/ml) and 12 months (2.26 ± 1.88 ng/ml) postoperatively, whereas the FSH level increased significantly from baseline to 12 months postoperatively (P < 0.05). Those patients with unilateral endometriomas also had lower levels of AMH in 6 and 12 months after operation. When compared between unilateral and bilateral endometrioma group, the rate of AMH decline 6 and 12 months and the rate of FSH increase 12 months postoperatively reached statistical significance (P < 0.05). CONCLUSIONS: The changes of the AMH and FSH values suggest that the ovarian reserve is obviously reduced in spite of suturing technology used as a method of hemostasis after stripping ovarian endometriomas, especially in those with bilateral cysts. The protective effect of the ovarian suturing for ovarian reserve may be marginal.

Library of Antifouling Surfaces Derived From Natural Amino Acids by Click Reaction.

Biofouling is of great concern in numerous applications ranging from ophthalmological implants to catheters, and from bioseparation to biosensors. In this report, a general and facile strategy to combat surface fouling is developed by grafting of amino acids onto polymer substrates to form zwitterionic structure through amino groups induced epoxy ring opening click reaction. First of all, a library of poly(2-hydroxyethyl methacrylate-co-glycidyl methacrylate) hydrogels with zwitterionic surfaces were prepared, resulting in the formation of pairs of carboxyl anions and protonated secondary amino cations. The analysis of attenuated total reflectance Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy confirmed the successful immobilization of amino acids on the hydrogel surfaces. After that, the contact angle and equilibrium water content of the modified hydrogels showed that the hydrogels exhibited improved hydrophilicity compared with the parent hydrogel. Furthermore, the protein deposition was evaluated by bicinchoninic acid assay using bovine serum albumin (BSA) and lysozyme as models. The results indicated that the performance of the hydrogels was determined by the nature of incorporated amino acid: the hydrogels incorporated with neutral amino acids had nonspecific antiadsorption capability to both BSA and lysozyme; the hydrogels incorporated with charged amino acids showed antiadsorption behaviors against protein with same charge and enhanced adsorption to the protein with opposite charge; the optimal antiadsorption performance was observed on the hydrogels incorporated with polar amino acids with a hydroxyl residual. The improvement of antiprotein fouling of the neutral amino acids grafted hydrogels can be ascribed to the formation of zwitterionic surfaces. Finally, a couple of soft contact lenses grafted with amino acids were fabricated having improved antifouling property and hydrophilicity. The result demonstrated the success of amino acids based zwitterionic antifouling strategy in ophthalmology. This strategy is also applicable to substrates including filtration membranes, microspheres and nanofibers as well. It is a versatile method for amino acids grafting onto polymer substrates to construct zwitterionic surfaces and achieve antifouling properties.

Electrophysiological and behavioral responses of the whitestriped longhorned beetle, Batocera lineolata, to the diurnal rhythm of host plant volatiles of holly, Viburnum awabuki.

The adsorption method of Tenax-TA absorbent with GC-MS was used to analyze diurnal rhythms of volatiles from undamaged holly plants, Viburnum awabuki Kock (Dipsacales: Adoxaceae) holly infested by the white-striped longhorned beetle, Batocera lineolata Chevrolat (Coleoptera: Cerambycidae). Electroantennography and a Y-tube olfactometer were used to compare and analyze electroantennogram and behavioral responses of unmated male and female adults to the volatiles from V. awabuki (both undamaged and infested plants). The results of the GC-MS analysis showed that phytosterol and alkane are major volatiles for V. awabuki. The relative content of V. awabuki volatiles changed during the day. Electroantennogram and behavioral responses of unmated male and female adults to the volatiles from both undamaged and infested plants of V. awabuki were stronger between 08:00 and 10:00 and 16:00 and 18:00, which is consistent with early morning and evening feeding behaviors of adults in the field.

Management of caesarean scar pregnancies using an intrauterine or abdominal approach based on the myometrial thickness between the gestational mass and the bladder wall.

AIM: To describe our experience with various interventions for caesarean scar pregnancies (CSPs) based on the myometrial thickness between the gestational mass and the bladder. METHODS: All patients were initially administered methotrexate. Then, the appropriate therapies hysteroscopy alone or combined with uterine artery embolization (group A) and direct laparoscopy alone or combined with laparoscopic uterine artery occlusion (group B) was selected based on the myometrial thickness between the gestational mass and the bladder. RESULTS: The uteri of all 53 patients with CSPs were conserved; no conversion to laparotomy or blood transfusion was required. Uterine rupture occurred in one case during surgery in group A. The operative time in group B was longer than group A (42 ± 18 vs. 80 ± 33 min; p = 0.022). The two groups were also similar with respect to other characteristics (p > 0.05). CONCLUSION: Myometrial thickness should be considered during the management of CSPs. Surgical approaches in the treatment of CSPs using 2-mm boundaries may yield an optimal clinical outcome.

Molecular characterization of ß-lactam-resistant Escherichia coli isolated from Fu River, China.

The present study aims to demonstrate the ß-lactam resistance phenotypes and genotypes of Escherichia coli isolates from the Fu River in Chengdu, southwestern China. We obtained 108 E. coli isolates from nine sampling sites during May and December 2010. The total bacterial count varied from 79 colony-forming units (CFU)/ml to 14,550 CFU/ml, and coliform group number from 13 to 1,435 MPN/ml. Among the 108 isolates, 0-31.48% were resistant to ß-lactams and ß-lactam inhibitors, 1.85-7.40% to aminoglycoside, 1-20% to fluoroquinolone, and 50% to trimethoprim- sulfamethoxazole. The total bacterial count and antimicrobial resistance of different sites were significantly correlated (P < 0.05). Among the 34 ampicillin-resistant isolates, polymerase chain reaction (PCR) amplification and DNA sequencing showed that bla (TEM), bla (SHV), and bla (CTX-M) were detected in 85.29% (n = 29), 41.18% (n = 14), and 5.88% (n = 2) of the isolates, respectively, whereas bla (KPC) and bla (GES) were not observed in any of the isolates. Enterobacterial repetitive intergenic consensus-PCR patterns revealed that the 34 ampicillin-resistant E. coli isolates belonged to three distinct groups. Plasmid DNAs from the 14 SHV producer isolates yielded one to five bands of ca. 0.15-40 kb. To our knowledge, the current study is the first to describe the phenotypic and genetic characterizations of ß-lactam resistance in E. coli isolates of river water origin from the Fu River, Chengdu, southwestern China. Results of the present study suggest that the river water may be considered as a reservoir for antibiotic resistance genes.

Analysis of monitoring results of iodine deficiency disorders in Cangzhou city, Hebei province, from 2007 to 2009 / 中国地方病学杂志

Objective To understand the situation of iodine deficiency disorders of Cangzhou city, Hebei province, in order to provide the scientific basis for prevention and control of iodine deficiency disorders. Methods From 2007 to 2009, dynamic monitoring of iodine deficiency disorders was carried out in low iodized salt coverage places Hejian city and Xian county. Nine towns were randomly chosen in each county, 4 administrative villages were randomly selected in each town, 8 household salts were tested in each village. Every year, 1 - 3 copies of residents water samples were collected for determination of iodine; more than 100 students age 8 - 10 years old were checked the situation of goiter and urinary iodine, more than 40 students selected were measured iodine content of salt from their home; more than 50 women of childbearing age 18 - 40 years were tested of urinary iodine. Thyroid was examined with palpation; water iodine and urine iodine concentration were measured with arsenic-Ce catalytic spectrophotometry; salt iodine was detected by direct titration. Results From 2007 to 2009,median household salt iodine were 4.3,15.9,3.6,18.4,4.6,11.7 mg/kg in Hejian city and Xian county, respectively,iodized salt accounted for 34.03% (98/288), 78.82% (227/288), 29.86% (86/288), 84.72% (244/288), 37.15%(107/288),49.31% (142/288), respectively, the consuming rate of iodized salt were 27.08% (78/288),36.46%( 105/288 ), 28.13% (81/288 ), 49.31% ( 142/288 ), 37.15 % ( 107/288 ), 30.90% ( 89/288 ), respectively. Ten samples of drinking water were tested, water iodine were 5.5 - 34.4 μg/L. From 2007 to 2009, the goiter rate of students aged 8 - 10 years old was below 5%, the median of urinary iodine were 138.1,176.6,112.0 μg/L, ＜ 100 μg/L ratio were 31.6% ( 65/206 ), 25.0% ( 52/208 ) and 44.4% (91/205 ). The median of urinary iodine of child-bearing age women were 167.3,164.2,78.1 μg/L, ＜ 100 μg/L ratio were 28.7%(29/101 ), 19.2%(20/104) and 60.0%(60/100).Conclusions In areas with low coverage of iodized salt, iodine nutrition level are affected, the child-bearing age