Inhibitory Effect of Depolymerized Sulfated Galactans from Marine Red Algae on the Growth and Adhesion of Diarrheagenic Escherichia coli.

Active polysaccharides as safe and natural polymers against bacterial diarrhea have been reconsidered as an alternative to antibiotics. This work investigated the inhibiting effect of depolymerized sulfated galactans from Eucheuma serra and Gracilaria verrucosa on the growth and adhesion of diarrheagenic enterotoxigenic Escherichia coli (ETEC) K88. Results showed that the sulfated polysaccharides with molecular weight distribution ≤20.0 kDa exhibited antibacterial activity against ETEC K88. A structure-activity study revealed that the anti-ETEC K88 activity of sulfated polysaccharides is strictly determined by their molecular weight distribution, sulfate group content, and monosaccharide composition. In addition, the promoted nucleic acid release and the fluorescence quenching of membrane proteins were observed after the treatment with selected polysaccharides. Scanning electron microscopy further confirmed that the depolymerized sulfated galactans can effectively inhibit ETEC K88 adhesion. In conclusion, depolymerized sulfated galactans exhibited an inhibitory effect on the growth and adhesion of ETEC K88.

Experimental noise and vibration characteristics of elevated urban rail transit considering the effect of track structures and noise barriers.

Vibration of the elevated urban rail transit (URT) severely affects the health of nearby residents, threatens the integrity of adjacent historic buildings, and aggravates the performance of vibration-sensitive instruments in buildings, and the accompanied annoying structure-borne noise always arouses public complaint. Vibration and noise mitigation measures through track structures and/or noise barriers are increasingly favored to deal with these challenging issues. This paper presents systematic field measurements on noise and vibrations of elevated URT. The vibration experiment covers vibration of track structures, bridge girders and piers, and ground soil under three different track structures, i.e., embedded sleeper track, ladder sleeper track, and floating slab track (FST) with rubber mats. Noise measurements were also conducted considered the effect of track structures and with or without fully enclosed noise barriers. It is shown that ladder sleeper track and FST were more effective in control bridge vibration than ground vibration. The overall vibration level of the bridge is 8~10 dB greater than the ground vibrations. The noise reduction effect through track structure was limited for far-field ground. Furthermore, it is found that the noise barrier was more effective to reduce near-field wheel/rail rolling noise rather than far-field noise. Good correlation between structure-borne noise and vibration was observed for both the embedded sleeper track and FST at the bottom slab of the box girder bridge.

Environmental noise and vibration characteristics of rubber-spring floating slab track.

The floating slab track is considered one of the most effective track structures to reduce the adverse effects of underground railway noise and vibration. This paper reports a new type of rubber-spring float track (RSFS), which adopts a well-designed rubber-spring vibration isolator and is conceptually designed as a float track structure. The dynamic performance of different track structures, namely RSFS track, fixed slab track, and transition section, were studied. Vibration response of the car body and the track structure was obtained. Internal noise from the train and external noise near the tracks were also recorded. The results show that the measured track structures can ensure the safety of train operation. Compared with the fixed plate track, the RSFS track has a good vibration isolation effect, and the RMS vibration reduction at the tunnel wall was 15.1 dB. However, it amplifies the vibration above the isolation layer and slightly increases the internal noise of the train. RSFS track structure should be evaluated comprehensively before implementation. In addition, the track stiffness has a significant impact on the vibration level of the track, thus affecting the vibration isolation effect. The noise distribution inside the train is not uniform and is not sensitive to the stiffness of the track structure. Due to the uncertainty of train-induced vibration, a probabilistic framework is needed to evaluate or predict the train-induced environmental vibrations.

6q25.1-q25.3 Microdeletion in a Chinese Girl

Deletions of the long arm of chromosome 6 are rare and are characterized by great clinical variability according to the deletion breakpoint. Herein, we reported a 3-year-old girl evaluated for facial dysmorphism (long and connected eyebrows, big mouth, wide nasal bridge, high palatine arch, low set ears, and thin hair), growth retardation, intellectual disability, and language delay. Chromosomal microarray analysis revealed an 8.1-Mb deletion within 6q25.1-q25.3 ([hg19] chr6: 152,307,705-160,422,834) comprising 31 genes. Dysmorphic features, microcephaly, intellectual disability, language delay, growth retardation, and corpus callosum dysgenesis were commonly reported. Hence, 6q25 microdeletion is a rare condition. In patients with dysmorphic features, microcephaly, growth retardation, intellectual disability, language delay and corpus callosum dysgenesis, 6q25 microdeletion should be considered in the differential diagnosis and chromosomal microarray analysis should be performed to confirm the diagnosis.

Cleidocranial dysplasia: report of 3 cases and literature review.

BACKGROUND: Cleidocranial dysplasia (CCD) is an autosomal-dominant skeletal dysplasia syndrome that is characterized by widely patent calvarial sutures, clavicular hypoplasia, supernumerary teeth, and short stature. It is caused by mutations of the transcription factor RUNX2, which is known as a major regulator of bone differentiation. OBJECTIVE: To report on 3 Chinese pediatric cases of CCD with an emphasis on the clinical presentation and diagnostic modalities. CASE SUMMARY: 3 Chinese children were admitted to our hospital because of short stature. All the children had hypoplastic clavicles, absent calvarium, open fontanel, and messy palmprint. Screening laboratory test results for bone mineral density, free thyroxine, and thyroid stimulating hormone were all normal. One child had mental retardation. Two were hereditary, and 1 was sporadic. CONCLUSION: These results showed that CCD should be suspected in patients with short stature and poor clavicles, calvarium, or teeth. Timely recognition and hereditary tendency counseling is required and useful.

[The relationship between age-related stress distribution and fracture incidence of the mandible].

OBJECTIVE: To analyze age-related mandible stress distribution due to midline force. METHODS: Mandibles of children, adults, and elderly individuals were scanned by spiral CT to establish three-dimension imaging models with mesh elements by MIMICS software and HYPERMESH software. The mandible stress distribution was analyzed using ANSIS software. RESULTS: There was no significant difference in mandible stress distribution in various age groups with the greatest stress distribution (Von Mises) present at the mandible angle. Although there was stress present at the mandible neck in adults, no such mandible neck stress was found in children and elderly individuals. CONCLUSION: Mandible stress distribution is closely related to the incidence of fracture in various age groups, i.e., more stress and more fracture.

[Effects of polyacrylamide on soil erosion and soil nutrient loss in sloped apple orchards.] / èšä¸™çƒ¯é °èƒºå¯¹å¡åœ°è‹¹æžœå›­æ°´åœŸæµå¤±å’ŒåœŸå£¤å »åˆ†æµå¤±çš„å½±å“.

In order to improve the soil environment, reduce soil erosion and soil nutrient loss, and explore the suitable dry broadcasting rate of polyacrylamide (PAM) in sloped apple orchard, experiments of different dry broadcasting rates of polyacrylamide were carried out in apple orchards with a slope of 20° in the hilly-gully region of northern Shaanxi from 2010 to 2012. PAM treatment levels included 0, 0.6, 0.8, 1.0, 1.2, 1.4 and 1.6 g·m-2. Surface runoff, eroded sediment, soil nutrient loss, and the growth of apple trees were monitored. Results showed that the surface runoff and runoff yield times from May to July exhibited a "V" shape with the increase of PAM application rate, and reached a minimum at the 1.0 g·m-2 level. However, the sediment yield decreased with increasing the PAM application rate. The concentrations of the ammonium nitrogen, available phosphorus, and available potassium in surface runoff and sediment decreased with increa-sing the PAM application rate. PAM significantly reduced the content of nitrate nitrogen in surface runoff, whereas it had no significant effect on nitrate nitrogen in sediment. Organic matter, total nitrogen, total phosphorus, and total potassium in the sediment decreased with increasing the PAM application rate. Moreover, PAM improved average fruit mass and fruit yields in sloped orchards, but it had no significant effect on the growth of apple trees and apple fruit flavor. An application le-vel of PAM at 1.0 g·m-2 should be suitable in sloped apple orchards.

Self-assembled dual-modality contrast agents for non-invasive stem cell tracking via near-infrared fluorescence and magnetic resonance imaging.

Stem cells hold great promise for treating various diseases. However, one of the main drawbacks of stem cell therapy is the lack of non-invasive image-tracking technologies. Although magnetic resonance imaging (MRI) and near-infrared fluorescence (NIRF) imaging have been employed to analyse cellular and subcellular events via the assistance of contrast agents, the sensitivity and temporal resolution of MRI and the spatial resolution of NIRF are still shortcomings. In this study, superparamagnetic iron oxide nanocrystals and IR-780 dyes were co-encapsulated in stearic acid-modified polyethylenimine to form a dual-modality contrast agent with nano-size and positive charge. These resulting agents efficiently labelled stem cells and did not influence the cellular viability and differentiation. Moreover, the labelled cells showed the advantages of dual-modality imaging in vivo.

ε-Caprolactone-Modified Polyethylenimine as Efficient Nanocarriers for siRNA Delivery in Vivo.

RNA interference (RNAi) therapy is a promising treatment for various diseases. However, its application is still restricted by the lack of efficient and safe delivery systems. A novel siRNA delivery vehicle based on ε-caprolactone-modified polyethylenimine (PEI-CL) is presented here. The PEI-CL macromolecules with different grafting degrees were synthesized via a simple ring-opening reaction. This macromolecule strongly protects the siRNA from degradation in serum and promotes the cellular uptake and endosomal escape detected via chemical exchange saturation transfer magnetic resonance analysis and fluorescence imaging. The in vivo measurement was performed with HCT-116 colon tumor xenograft that stably expressed luciferase. The data showed that the PEI-CL/siRNA nanocomplexes elicited strong RNAi response. More interestingly, enhanced gene transfection efficiency was achieved by simultaneous cotransfection with siRNA and DNA plasmid via this novel nanosystem. Overall, our study suggests the PEI-CL macromolecule with great promise for siRNA delivery.

Preparation and characterization of porous beta-tricalcium phosphate/collagen composites with an integrated structure.

Porous beta-tricalcium phosphate (TCP)/collagen composites with different beta-TCP/collagen weight ratio were prepared. The influences of the preparation conditions on the microstructure of porous composite and the joint status of beta-TCP particles with collagen fibrils were characterized by X-ray diffractometer, scanning electron microscopy and transmission electron microscopy. The results showed: (1) an acid treatment could effectively disassemble collagen fibrils; (2) in the resulting porous composites, beta-TCP particles homogenously existed on the skeleton of the collagen fibril network and bonded tightly to both the fibrils and themselves. The tight bonding formation could be due to the reaction between Ca ions in the particles and carboxyl groups in collagen polypeptide chains and due to the reprecipitation of partially dissolved beta-TCP during synthesis. The tight bonding between beta-TCP particles and collagen fibrils in the composites demonstrated an integrated structure, which was reproducible when beta-TCP/collagen ratio ranged from 2 to 4. Such integrated structure would make significant contributions in reliably tailoring properties of the porous composites by varying beta-TCP content. In addition, the porous composites had large porosity (approximately 95%) and appropriate pore size (approximately 100 microm), showed no negative impact in cytotoxicity assay and complete bone tissue regeneration after 12 weeks in animal test.

Epsilon-caprolactone modified polyethylenimine for highly efficient antigen delivery and chemical exchange saturation transfer functional MR imaging.

Serious challenges remain in immunotherapy, such as to effectively deliver antigens and non-invasively monitor biological processes. Therefore, we aim to design a useful nanocarrier for enhancing antigen-specific immune response and performing functional molecular imaging guided immunotherapy. To achieve this goal, ε-caprolactone modified polyethylenimine (PEI-CL) was prepared based on the ring-opening reaction. This novel macromolecule served as an optimal vehicle that efficiently bound ovalbumin (OVA) antigen forming a controlled nanostructure through electronic self-assembly and resulted in a substantially increased cellular uptake. In vivo, PEI-CL/OVA nanovaccine stimulated inflammatory cytokine production and promoted proliferation of OVA-specific T cells. Moreover, due to the unique chemical and physical properties, PEI-CL was demonstrated as a chemical exchange saturation transfer contrast agent for magnetic resonance imaging. In conclusion, the PEI-CL has synergistic advantages in the effective delivery of antigen and non-invasive imaging for tracking immunotherapeutic cells.

The unusual effect of AgNO3 on the growth of Au nanostructures and their catalytic performance.

Au nanostructures attract much attention due to their potential applications in many fields. The controlled synthesis is critical to their properties modulation and applications. AgNO3-assisted synthesis is a widely used method for controllably preparing Au nanostructures in aqueous system. Herein, the effect of AgNO3 on the growth of Au nanostructures in polyol is studied. We observe an unusual effect that AgNO3 can induce the formation of pentatwinned Au nanostructures (nanorods and decahedra) and block the growth of Au nanorods. More interestingly, this blocking effect can be tuned through controlling the amount of AgNO3. A moderate amount of AgNO3 facilitates the formation of Au nanorods. A large amount of AgNO3 completely blocks the growth of nanorods and favors the formation of high quality decahedra (decahedra can be considered as nanorods with 0 nm longitudinal length). Besides, this blocking effect also allows preparation of different high-index-faceted Au nanobipyramids. These prepared Au nanostructures further serve as starting templates to fabricate other heterostructured Au/Ag nanomaterials, such as Ag-Au-Ag segmental nanorods, Au@Ag core-shelled nanostructures. The prepared nanostructures exhibit size- and structure-dependent catalytic performance in the reduction of p-nitrophenol to p-aminophenol by sodium borohydride.

Outcome of children with melamine-induced urolithiasis: results of a two-year follow-up.

OBJECTIVE: Our purpose is to describe the characteristics and the outcome of melamine-induced renal and urinary tract injury in young children who consumed melamine-contaminated infant formula. METHODS: This is a descriptive longitudinal study over 2 years in 240 children with melamine-induced urolithiasis screened in our hospital from September 15 to October 31, 2008. Ultrasonography and serum creatinine (SCr), urea, ß2-microglobulin (MG), cystatin C (Cys C), urinary Cr (UCr), microalbumin (mALB), α1-MG, ß2-MG, n-acetyl-ß-d-glucosaminidase (NAG) and retinol-binding protein (RBP) measurements were performed. RESULTS: The children ranged in age from 1 to 82 months, and 145 were males. The largest calculus was 33 mm in diameter. X-ray diffraction pattern of the calculi displayed two diffraction peaks at 10.9° and 27.7° (2θ). Surgical management was performed in 14 patients. In 226 patients without surgical management, the calculi were passed in 59.63% patients within 1 month, in 85.40% within 6 and in 91.15% within 24 months. Increased SCr and urea levels were noted in three and six patients, respectively, at the time of diagnosis. The SCr, serum ß2-MG, and Cys C levels at the time of diagnosis were higher than those at 3 and 6 months after diagnosis (P < 0.05, respectively). The levels of mALB/UCr, NAG/UCr, and RBP/UCr at the time of diagnosis were higher than those at 3, 6, 12, and 24 months after diagnosis (P < 0.05, respectively). α1-MG/UCr and ß2-MG/UCr levels at the time of diagnosis were similar to those at 3 months after diagnosis, and significantly higher than those in the follow-up period (P < 0.05, respectively). CONCLUSION: Melamine might injure both the renal glomerulus and the tubule, and that the predominant lesion is urolithiasis. The compositions of melamine-induced urolithiasis are melamine and cyanuric acid crystals. The urolithiasis might persist for over 2 years and cause irreversible damage. Therefore, a long-term follow-up for all patients is required.

Porous beta-tricalcium phosphate/collagen composites prepared in an alkaline condition.

Bone substitute materials with natural bone-like structure are considered to be favorable for bone regeneration. In this work, porous beta-tricalcium phosphate (beta-TCP)/collagen composite consisting of bone-like microstructural units was prepared using nanosized beta-TCP particles and alkaline-disassembled collagen. The resulting composite showed a good interconnecting porous structure with approximately 90% porosity and 100 approximately 300 microm pore size. The pore walls were dense, and the combination status of collagen and nanosized beta-TCP particles demonstrated that nanosized beta-TCP particles tightly connected collagen microfibrils as a bone-like microstructural unit. MTT and alkaline phosphatase (ALP) assays showed that the porous composite had enhanced effects on cellular proliferation and activity of osteoblast compared with a control of pure collagen. It is suggested that the adoption of nanosized beta-TCP particles is a main contribution to the formation of the composite with a bone-like microstructural unit, and the unique microstructure could be a main role for the composite to have the positive influence on osteoblast cell proliferation.

Clinical and molecular analysis of NF-kappaB essential modulator in Chinese incontinentia pigmenti patients.

OBJECTIVE: To analyze clinical manifestation and gene of NF-kappaB essential modulator (NEMO) in 12 pediatric incontinentia pigmenti (IP) patients. METHODS: Twelve pediatric probands with three of their mothers were enrolled in this study. Physical examinations were undertaken for all patients and questionnaires requesting additional medical and developmental data were sent to the patients' families. The deletion of exon 4-10 and all 10 exons of NEMO gene were analyzed in these cases. Skin biopsy was performed in one case. RESULTS: All 15 patients had skin pigmentation abnormality and were diagnosed according to classic skin lesions. The prevalence of the dental, neurologic system, hair abnormality, and definite family history were 80.0%, 41.67%, 58.33%, and 25.0%, respectively. Histopathological examination was consistent with the diagnosis of IP with ectodermal dysplasia. In NEMO gene, deletion of exons 4-10 were noted in three cases and two of their mothers. A deletion of 19545 T in exon 6 was noted in one case and her mother. A 21690 T to C mutation in intron 8 of NEMO were found in another one case and her mother. CONCLUSION: The results suggest that skin lesion are the most prominent findings in clinics and the traditional diagnosis of IP is based on classic melanin pigmentation. Nucleotide deletion of exons 4-10 and single nucleotide mutation/polymorphism were found in these patients, which might account for etiopathogenesis of IP.