bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of multilayer rhBMP‐2 DNA coating on the proliferation and differentiation of MC3T3‐E1 cells seeded on roughed titanium surface
Authors: Jiang Qiao‐Hong , Liu Li , Shen Jian‐Wei , Peel Sean , Yang Guo‐Li , Zhao Shi‐Fang , He Fu‐Ming
Published: May 2012

For bone morphogenetic protein (BMP) gene therapy to be a viable approach for enhancing implant osseointegration clinically, requires the development of efficient nonviral delivery vectors that can coat the implant. This study evaluated a multilayer cationic liposome‐DNA complex (LDc) coating as a delivery vehicle for recombinant human BMP‐2 (rhBMP‐2). Multilayered coatings, comprising hyaluronic acid (HA) and LDc, were fabricated onto titanium using a layer‐by‐layer (LBL) assembly technique. Preosteoblastic MC3T3‐E1 cells were cultured on the roughened titanium surfaces coated with multilayers of HA/LDc, or on uncoated or HA/liposome only surfaces as controls. The amount of rhBMP‐2 secreted by the MC3T3‐E1 cells and the effect of the various surfaces on cell viability, proliferation, alkaline phosphatase (ALP) activity, osteocalcin (OC) secretion, and calcium deposition were evaluated. Messenger RNA levels of OC, ALP, Runx2, and Osx were also investigated. The results demonstrated that rhBMP‐2 protein secreted into culture medium at 3 days was significantly higher than control groups. MC3T3‐E1 cells cultured on the HA/LDc coating displayed significantly higher ALP activity and OC secretion at 7 days and 14 days culture, respectively. MC3T3‐E1 cells cultured on HA/LDc upregulated expression of the osteoblast differentiation markers, especially on days 12 for OC and on days 6 and 12 for ALP and Osx. In conclusion, MC3T3‐E1 cell cultured on the multilayer HA/LDc coating surface can secret rhBMP‐2 protein and the protein levels were effective in inducing early osteogenic differentiation. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A: 2766–2774, 2012.
Improved osteoblast compatibility of medical‐grade polyetheretherketone using arc ionplated rutile/anatase titanium dioxide films for spinal implants
Authors: Tsou Hsi‐Kai , Hsieh Ping‐Yen , Chi Meng‐Hui , Chung Chi‐Jen , He Ju‐Liang
Published: May 2012

Titanium dioxide (TiO2), known to exhibit good biocompatibility, is applied in this study as a thin film formed onto polyetheretherketone (PEEK) substrate, which has been widely used in spinal interbody fusion cages. For successful deposition, an arc ionplating (AIP) technique was applied to deposit TiO2 at low deposition temperature without damaging PEEK substrate, while providing satisfactory film adhesion. This study systematically investigates the effects of TiO2 thin film phase composition and surface characteristics, controlled by using different target current and substrate bias, on osteoblast compatibility. Experimental results showed that anatase phase (A‐TiO2) and/or rutile phase (R‐TiO2) TiO2 coatings, respectively, can be prepared in appropriate deposition conditions. Overall, the TiO2‐coated PEEK presented better osteoblast compatibility than the bare PEEK material in terms of cell adhesion, cell proliferation, and cell differentiation abilities, as well as osteogenesis performance (as determined by levels of osteopontin, osteocalcin, and calcium content). Surface roughness and hydrophilicity of the AIP‐TiO2 films were found to be responsible for significant osteoblast cell growth. It is also noticeable that the R‐TiO2 exhibited better osteoblast compatibility than the A‐TiO2 due to the presence of negatively charged hydroxyl groups on R‐TiO2 (110) surface in nature. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A:2787–2792, 2012.
Punch and spindle‐shaped biopsies for collecting oral mucosal tissue for the fabrication of transplantable autologous epithelial cell sheets
Authors: Sasaki Ryo , Yamato Masayuki , Takagi Ryo , Ohki Takashi , Matsumine Hajime , Okano Teruo , Ando Tomohiro
Published: May 2012

The oral mucosa is an easily accessible source of cells. Oral mucosal collection will be an essential surgical procedure for regenerative medicine and cell biological research. However, there is no current report that describes the details of the surgical procedure used for oral mucosal collection. Moreover, the number of cells that can be obtained has not been determined. Two different procedures, the punch biopsy and the spindle‐shaped biopsy, were performed for the fabrication of transplantable autologous epithelial cell sheets. The mean values of the cells collected per square centimeter of tissue using the punch biopsy and the spindle‐shaped biopsy were 76.8 ± 45 × 104 cells/cm2 and 195.7 ± 120 × 104 cells/cm2, respectively. There was no significant difference between the punch biopsy and the spindle‐shaped biopsy. The coefficient of variation of the punch biopsy and the spindle‐shaped biopsy was 58.9% and 69.8%, respectively. This result indicated that both procedures showed variations in the number of collected cells. Although the punch biopsy may be easier and simpler than the spindle‐shaped biopsy, multiple punch biopsies may result in a more complicated procedure, and the spindle‐shaped biopsy may be preferable when a large number of cells is necessary. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A:2849–2854, 2012.
miR‐301a promotes pancreatic cancer cell proliferation by directly inhibiting bim expression
Authors: Chen Zhen , Chen Lian‐Yu , Dai Hai‐Yan , Wang Peng , Gao Song , Wang Kun
Published: May 2012

It is well known that microRNAs (miRNAs) play an important role in many diseases, including tumorigenesis. However, the mechanisms by which miRNAs regulate pancreatic cancer (PC) development remain poorly understood. In the present study, we assayed expression level of miR‐301a in PC tissues by real‐time PCR, and defined the target gene and biological function by luciferase reporter assay and Western blot analysis. We first verified that the expression level of miR‐301a was significantly increased in PC tissues. Moreover, miR‐301a overexpression promoted PC cell proliferation, whereas its depletion decreased cell proliferation. We further demonstrated that miR‐301a directly targeted 3′‐UTR of Bim gene, and inhibited its protein expression in vitro and in vivo. Importantly, Bim re‐expression reduced PC cell proliferation induced by miR‐301a. These data suggest an important role of miR‐301a in the molecular etiology of PC and implicate the potential application of miR‐301a in PC therapy. J. Cell. Biochem. 113: 3229–3235, 2012. © 2012 Wiley Periodicals, Inc.
Density functional theory study of high‐pressure effect on crystalline 4,4′,6,6′‐tetra(azido)hydrazo‐1,3,5‐triazine
Authors: Wang Fang , Du Hong‐Chen , Liu Hui , Gong Xue‐Dong
Published: May 2012

Periodic density functional theory calculations are performed to study the hydrostatic compression effects on the structure, electronic, and thermodynamic properties of the energetic polyazide 4,4′,6,6′‐tetra(azido)hydrazo‐1,3,5‐triazine (TAHT) in the range of 0−100 GPa. At the ambient pressure, the local density approximation/Ceperley‐Alder exchange‐correlation potential parameterized by Perdew and Zunger relaxed crystal structure compares well with the experimental results. The predicted heat of sublimation is 38.68 kcal/mol, and the evaluated condensed phase of formation (414.04 kcal/mol) approximates to the experimental value. The detonation velocity and detonation pressure for the solid TAHT are calculated to be 7.44 km/s and 23.71 GPa, respectively. When the pressure is exerted less than 35 GPa, the crystal structure and geometric parameters change slightly. However, at 36 GPa, the molecular structure, band structure, and density of states change abnormally because of the azide‐tetrazole transformation that has not been observed in gas phase or polar solvents. The azido group cyclizes to form a five‐membered tetrazole ring that is coplanar with the riazine ring and contributes to a larger conjunction system. As the pressure augments further to 80 GPa, the hydrogen transfer is found and a new covalent bond H2N9 is formed. In the studied pressure range, the band gap decreases generally except for some breaks due to the molecular transformation and drops to nearly zero at 100 GPa, which means the electronic character of the crystal changes toward a metallic system. An analysis of the electronic structure shows that an applied pressure increases the impact sensitivity of TAHT. © 2012 Wiley Periodicals, Inc.
Leukocyte Cell Population Analysis From the Coulter Automatic Blood Cell Analyzer DxH800 to Monitor the Effect of G‐CSF
Authors: Lee Sung‐Eun , Lim Jihyang , Kim Yonggoo , Min Woo‐Sung , Han Kyungja
Published: May 2012

Background

Granulocyte colony‐stimulating factor (G‐CSF) induces the formation of toxic granulation neutrophils (TGNs), which are found in many inflammatory responses. Cell population data (CPD) may be able to clarify the effect of G‐CSF, and potentially help doctors in discriminating the effect of G‐CSF from other inflammatory situations.

Methods

To achieve this, we performed analyses of leukocyte CPD from normal controls and healthy donors that had received G‐CSF for peripheral blood stem cells (PBSCs) mobilization (G‐CSF group).

Results

Two hundred and seventy‐one subjects were enrolled as normal controls, and 21 subjects were enrolled in the G‐CSF group. Mean volume (MN‐V)‐neutrophils (NE), mean axial light loss (MN‐AL2)‐NE, and all standard deviation (SD) parameters increased significantly, whereas all light scattering parameters, mean median angle light scatter (MN‐MALS)‐NE, mean upper median angle light scatter (MN‐UMALS)‐NE, mean lower median angle light scatter (MN‐LMALS)‐NE, and mean low angle light scatter (MN‐LALS)‐NE reduced significantly in the G‐CSF group. MN‐V‐lymphocytes (LY) from the G‐CSF group showed no significant difference (P = 0.143), whereas MN‐V‐monocytes (MO) were significantly decreased (P < 0.001). Receiver operating characteristic (ROC) curves for the discrimination of the G‐CSF group from normal controls showed excellent sensitivity in SD‐LALS‐NE (at 30.85, sensitivity 95.2%, specificity 76.0%), MN‐AL2‐NE (at 134.5, sensitivity 90.5%, specificity 83.0%), and SD‐AL2‐NE (at 16.4, sensitivity 95.2%, specificity 95.2). Several CPD parameters of lymphocytes and monocytes, as well as neutrophils can be used as markers for determining the effect of G‐CSF.

Conclusion

Our data show that many CPD of leukocytes can be considered to be useful parameters of the effect of G‐CSF. J. Clin. Lab. Anal. 26:194‐199, 2012. © 2012 Wiley Periodicals, Inc.
Distribution and Effect of apo E Genotype on Plasma Lipid and Apolipoprotein Profiles in Overweight/Obese and Nonobese Chinese Subjects
Authors: Zhang Juan , Xuemei Zhang  , Fan Ping , Liu Rui , Huang Yi , Liang Shanshan , Liu Yu , Wu Yin , Bai Huai
Published: May 2012

Background

Apolipoprotein E (apo E) polymorphism has been reported to influence some lipid profile abnormalities in some ethnic groups. This study was conducted mainly to examine the possible association of apo E polymorphism with overweight/obesity in a South West Chinese population.

Methods

Four hundred and fifty‐four Han Chinese (282 overweight/obese and 172 normal weight control subjects) in Chengdu area were studied using polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) analysis.

Results

The genotype and allele frequencies of apo E polymorphism in cases of overweight/obesity showed no significant statistical difference compared to those of controls. In the control group, both apo E4 and E3 allele carriers had the higher serum LDL‐C and lower triglycerides (TGs) and apo E concentrations than those with apo E2 carriers, while apo E2 allele carriers had higher serum apo C‐II levels than apo E3 carriers (P < 0.05). In overweight/obese group, genotype‐related low density Lipoprotein‐Cholesterol (LDL‐C) variations were also evident, with the changes being in a same direction as the effect in the controls, and apo B100 levels were decreased and apo E increased in apo E2 allele carriers when compared with respective apo E4 and apo E4/apo E3 allele carriers (all P < 0.05).

Conclusion

Polymorphism of the apo E gene is associated with altered plasma LDL‐C and TG, as well as apo B, apo C‐II, and apo E concentrations. The effects on TG, apo B, and apo C‐II levels are BMI dependent in Chinese population of Chengdu area. J. Clin. Lab. Anal. 26:200‐205, 2012. © 2012 Wiley Periodicals, Inc.
Optical and Mechanical Clot Detection Methodologies: A Comparison Study for Routine Coagulation Testing
Authors: Tekkesin Nilgun , Kılınc Cumhur
Published: May 2012

Background

Automated coagulation analyzers are preferred to meet increasing coagulation test volume. Two distinct technological families exist based on optical and mechanical clot detection methodologies. Which one is superior to the other is still a conflict and needs new studies.

Methods

We have compared prothrombin and activated partial thromboplastin results obtained with mechanical method with those obtained by photo‐optical method used routinely in our specialized laboratory.

Results

The instrumental results showed good precision ranging between 0.7% and 1.8% coefficient of variation. Statistical analysis demonstrated an excellent correlation between the photo‐optical and mechanical analyzers for PT (R2 0.97), and aPTT (R2 0.85).

Conclusion

Correlation between the two clot‐detection systems was maintained even when measuring turbid samples (R2 ≥ 0.97 for two tests). J. Clin. Lab. Anal. 26:125‐129, 2012. © 2012 Wiley Periodicals, Inc.
New Sandwich‐Type Enzyme‐Linked Immunosorbent Assay for Human MxA Protein in a Whole Blood Using Monoclonal Antibodies Against GTP‐Binding Domain for Recognition of Viral Infection
Authors: Kawamura Mizuho , Kusano Akira , Furuya Akiko , Hanai Nobuo , Tanigaki Hideki , Tomita Akihito , Horiguchi Akira , Nagata Kyosuke , Itazawa Toshiko , Adachi Yuichi , Okabe Yoshie , Miyawaki Toshio , Kohno Hiroaki
Published: May 2012

Objectives

To develop a clinically significant and practical enzyme‐linked immunosorbent assay (ELISA) for the detection of MxA protein in human whole blood, a biological marker of viral infection.

Design and Methods

A sandwich ELISA suitable for the measurement of human MxA protein in whole blood was developed using mouse monoclonal antibodies (mAbs) raised against the GTP‐binding domain of human MxA protein. Prior to the assay, the whole blood sample was treated with special buffer to extract the MxA protein, improve its stability, and avoid interference from hemoglobin.

Results

This ELISA meets all the requirements for use in routine clinical assays, especially in terms of sensitivity (detection limit: 1.3 ng/ml whole blood), accuracy (recovery: 93.0–100.0%), and rapidity (<1.5 h). The present ELISA had a sensitivity of100% and a specificity of 100% for viral infection when compared to samples from healthy control and 87.1% and 90.9% when compared to samples from the bacterial infection group.

Conclusion

We have developed a new ELISA for measuring MxA protein in human whole blood using mAbs specific for the GTP‐binding domain of MxA. This ELISA has analytical performance enough for routine clinical assay and can be used in detecting the possibility of viral infection. J. Clin. Lab. Anal. 26:174‐183, 2012. © 2012 Wiley Periodicals, Inc.
Signals of tree volume and temperature in a high‐resolution record of pollen accumulation rates in northern Finland
Authors: Mazier F. , Nielsen A. B. , Broström A. , Sugita S. , Hicks S.
Published: May 2012

Pollen accumulation rates (PARs) provide a potential proxy for quantitative tree volume (m3 ha−1) reconstruction with reliable absolute pollen productivity estimates (APPEs). We obtained APPEs for pine, spruce and birch at their range limits in northern Finland under two temperature periods (‘warm’ and ‘cold’) based on long‐term pollen trap and tree volume records within a 14‐km radius of each trap. APPEs (mean ± SE; × 108 grains m−3 a−1) tend to be higher for the ‘warm’ periods (pine 123.8 ± 24.4, birch 528.0 ± 398.4, spruce 434.3 ± 113.7) compared with the ‘cold’ periods (pine 95.5 ± 37.3, birch 317.3 ± 282.6, spruce 119.6 ± 37.6), although the difference is only significant for spruce. Using an independent temperature record and the APPEs obtained, we reconstruct a low‐frequency record of pine volume changes over the last 1000 years at Palomaa mire, where a high‐resolution record of Pinus PARs is available. Five phases are distinguished in the reconstruction: moderate pine volume, AD 1080–1170; high volume, AD 1170–1340; low volume, AD 1340–1630; very low volume, AD 1630–1810; and rising pine volume, AD 1810–1950. These phases do not coincide with periods of high or low June–July–August temperatures, and thus appear to reflect regional variations in tree volume, while high‐frequency changes within each time‐period block show variations in PARs in response to temperature. Copyright © 2012 John Wiley & Sons, Ltd.
Separation and determination of resibufogenin and cinobufagin in Chansu using reversed‐phase liquid chromatography with γ‐cyclodextrin as mobile‐phase modifier
Authors: Xing Jianfeng , Chen Lina , Song Jie , Guo Chenning , Yang Guangde , Zeng Aiguo
Published: May 2012

A simple, accurate, sensitive, and robust reversed‐phase high‐performance liquid chromatography (HPLC) method employing cyclodextrins as mobile phase additives has been developed in order to separate and determine resibufogenin and cinobufagin. Various factors affecting the separation for them, such as the nature of cyclodextrins, organic solvent, the concentration of γ‐cyclodextrin, and temperature, were systematically studied. γ‐cyclodextrin, as an effective mobile phase additive, can markedly improve the separation for resibufogenin and cinobufagin. The role of γ‐cyclodextrin in the developed HPLC method is attributed to the formation of the inclusion complex between resibufogenin (or cinobufagin) and γ‐cyclodextrin. So, the apparent formation constant (Kf) of the resibufogenin (or cinobufagin)/γ‐cyclodextrin inclusion complex and the thermodynamic parameters of the inclusion process also were investigated. Resibufogenin (or cinobufagin) forms the 1:1 inclusion complexes with γ‐cyclodextrin, and the resibufogenin/γ‐cyclodextrin complex is more stable than the cinobufagin/γ‐cyclodextrin complex. The Kf values of resibufogenin and cinobufagin decrease with the increase of the temperature. The thermodynamic parameters of the inclusion reveal that the inclusion process between resibufogenin (or cinobufagin) and γ‐cyclodextrin is spontaneous, exothermic, and enthalpically driven. Finally, the optimized method was successfully applied to separate and determine of resibufogenin and cinobufagin in the different Chansu (Bufonis venenum) samples.
Laryngeal stenosis in a patient with severe congenital neutropenia
Authors: Bando Hideki , Nagao Hikaru , Nishio Takeshi , Hirota Ryuichi , Sakaguchi Hirofumi , Imamura Toshihiko , Hisa Yasuo
Published: May 2012

Objectives/Hypothesis:

We report the first case of laryngeal stenosis with granuloma in a patient with severe congenital neutropenia (SCN).

Study Design:

Case report and retrospective review.

Methods:

Review of medical records.

Results:

A 6‐year‐old female who was diagnosed with SCN presented with a cough and wheezing. An endoscopic study revealed laryngeal stenosis with granuloma. Tracheotomy and direct laryngoscopy were performed under general anesthesia, and administration of granulocyte colony‐stimulating factor was started. The laryngeal granuloma disappeared 3 weeks later, and the tracheal stoma was closed.

Conclusions:

Presence of a laryngeal lesion should be considered in SCN patients with persistent airway symptoms.
Thiol‐Ene Click Chemistry as a Tool for a Novel Family of Polymeric Ionic Liquids
Authors: Shaplov Alexander S. , Vlasov Petr S. , Lozinskaya Elena I. , Shishkan Olga A. , Ponkratov Denis O. , Malyshkina Inna A. , Vidal Frédéric , Wandrey Christine , Godovikov Ivan A. , Vygodskii Yakov S.
Published: May 2012

Functionalized pyrrolidinium compounds, 3‐((2‐hydroxyethylthio)methyl)‐1,1,4‐trimethylpyrrolidinium and 3‐((2‐carboxyethylthio)methyl)‐1,1,4‐trimethylpyrrolidinium chlorides, are prepared from N,N‐diallyl‐N,N‐dimethylammonium chloride by radical thiol‐ene addition and are utilized as building blocks in the synthesis of “ionic liquid‐like monomers.” “Polymeric ionic liquids” with highest molecular weights are obtained in water from chloride monomers followed by ionic exchange with lithium bis(trifluoromethylsulfonyl)imide. Synthesized polymers demonstrate negligible water absorption (<0.1 wt%). Copolymerization with polyethyleneglycol di‐ and monomethacrylates leads to the conductive self‐standing tough films with ionic conductivity up to 2.8 × 10−7/1.3 × 10−6 S cm−1 at 25 °C.
Polysulfone Functionalized With Phosphonated Poly(pentafluorostyrene) Grafts for Potential Fuel Cell Applications
Authors: Dimitrov Ivaylo , Takamuku Shogo , Jankova Katja , Jannasch Patric , Hvilsted Søren
Published: May 2012

A multi‐step synthetic strategy to polysulfone (PSU) grafted with phosphonated poly(pentafluorostyrene) (PFS) is developed. It involves controlled radical polymerization resulting in alkyne‐end functional PFS. The next step is the modification of PSU with a number of azide side groups. The grafting of PFS onto PSU backbone is performed via the “click”‐chemistry approach. In a final step, the PFS‐grafts are subjected to the post phosphonation. The copolymers are evaluated as membranes for potential fuel cell applications through thermal analyses, water uptake, and conductivity measurements. The proposed synthetic route opens the possibility to tune copolymers’ hydrophilic–hydrophobic balance to obtain membranes with an optimal balance between proton conductivity and mechanical properties.
Reeb graphs of curves are stable under function perturbations
Authors: Di Fabio B. , Landi C.
Published: May 2012

Reeb graphs provide a method to combinatorially describe the shape of a manifold endowed with a Morse function. One question deserving attention is whether Reeb graphs are robust against function perturbations. Focusing on one‐dimensional manifolds, we define an editing distance between Reeb graphs of curves, in terms of the cost necessary to transform one graph into another through editing moves. Our main result is that changes in Morse functions induce smaller changes in the editing distance between Reeb graphs of curves, implying stability of Reeb graphs under function perturbations. We also prove that our editing distance is equal to the natural pseudo‐distance and, moreover, that it is lower bounded by the bottleneck distance of persistent homology. Copyright © 2012 John Wiley & Sons, Ltd.
Enhanced refocusing of fat signals using optimized multipulse echo sequences
Authors: Stokes Ashley M. , Feng Yesu , Mitropoulos Tanya , Warren Warren S.
Published: May 2012

Endogenous magnetic resonance contrast based on the localized composition of fat in vivo can provide functional information. We found that the unequal pulse timings of the Uhrig's dynamical decoupling multipulse echo sequences significantly alter the signal intensity compared to conventional, equal‐spaced Carr–Purcell–Meiboom–Gill sequences. The signal increases and decreases depending on the tissue and sequence parameters, as well as on the interpulse spacings; particularly strong differences were observed in fatty tissues, which have a highly structured morphology and a wide range of chemical shifts and J‐couplings. We found that the predominant mechanism for fat refocusing under multipulse echo sequences is the chemical structure, with stimulated echoes playing a pivotal role. As a result, specialized pulse sequences can be designed to optimize refocusing of the fat chemical shifts and J‐couplings, where the degree of refocusing can be tailored to specific types of fats. To determine the optimal time delays, we simulated various Uhrig dynamical decoupling and Carr–Purcell–Meiboom–Gill pulse sequence timings, and these results are compared to experimental results obtained on excised and in vivo fatty tissue. Applications to intermolecular multiple quantum coherence imaging, where the improved echo refocusing translates directly into signal enhancements, are presented as well. Magn Reson Med 69:1044–1055, 2013. © 2012 Wiley Periodicals, Inc.
The Chicago Parent Program: Comparing 1‐year outcomes for African American and Latino parents of young children
Authors: Breitenstein Susan M. , Gross Deborah , Fogg Louis , Ridge Alison , Garvey Christine , Julion Wrenetha , Tucker Sharon
Published: May 2012

Data were merged from two prevention randomized trials testing 1‐year outcomes of a parenting skills program, the Chicago Parent Program (CPP) and comparing its effects for African‐American (n = 291) versus Latino (n = 213) parents and their preschool children. Compared to controls, intervention parents had improved self‐efficacy, used less corporal punishment and more consistent discipline, and demonstrated more positive parenting. Intervention children had greater reductions in behavior problems based on parent‐report, teacher‐report, and observation. Although improvements from the CPP were evident for parents in both racial/ethnic groups, Latino parents reported greater improvements in their children's behavior and in parenting self‐efficacy but exhibited greater decreases in praise. Findings support the efficacy of the CPP for African American and Latino parents and young children from low‐income urban communities. © 2012 Wiley Periodicals, Inc. Res Nurs Health 35:475–489, 2012
Multiwalled carbon nanotubes‐reinforced isotactic polypropylene nanocomposites: Enhancement of crystallization and mechanical, thermal, and electrical properties
Authors: Haque Md. Akramul , Mina Md. Forhad , Moshiul Alam A.K.M. , Rahman Md. Jellur , Bhuiyan Md. Abu Hashan , Asano Tsutomu
Published: May 2012

Multiwalled carbon nanotubes (MWCNTs)‐reinforced isotactic polypropylene (iPP) nanocomposites with low‐content of MWCNTs were fabricated using the melt‐cast techniques. The reinforced plastics were characterized by X‐ray diffraction (XRD) measurements, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, mechanical test, differential thermal analyses (DTA), and electrical tests. XRD studies exhibit the α‐crystal in the injection‐molded neat iPP with lamellar stacks having a long period of 150Å. Both the intensity of lamellar reflection and the thickness of long period increase with increasing the MWCNTs contents, indicating an enhancement of iPP crystallization by MWCNTs addition. This increase of lamellar thickness is analyzed to be consistent with that evaluated by DTA. SEM micrographs display larger MWCNTs aggregates with increasing amount of reinforcements and show a good adhesion between nanoparticles and iPP matrix. FTIR spectra reveal distinct chemical textures for the samples and confirm the existence of α‐crystal. Mechanical strengths, electrical conductivity, and dielectric constants are found to increase with increasing MWCNTs content, representing an improved performance of the nanocomposites. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Interlaminar behavior of infrared welded joints of carbon fabric–reinforced polyphenylene sulfide
Authors: De Baere I. , Allaer K. , Jacques S. , Van Paepegem W. , Degrieck J.
Published: May 2012

The use of fiber‐reinforced thermoplastics for structural applications is continuously increasing and therefore load‐bearing joints cannot be avoided. Because most well‐established joining techniques for metallic structures are not directly applicable to composites, and because thermoplastics are difficult to bond adhesively because of their chemical inertness, another solution is found, namely fusion bonding. This study assesses the use of infrared welding for a carbon fabric–reinforced polyphenylene sulfide (PPS). After a short description of the welding setup, the welding parameters such as heating time, contact pressure, and consolidation time are optimized using lapshear experiments. Two welding procedures are considered, one with and one without prior consolidation of PPS on the specimens. It can be concluded that the infrared process proves interesting for the material under study and that the process with prior consolidation of PPS yields reproducible results. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Water absorption and hygrothermal ageing of ultraviolet cured glass‐fiber reinforced acrylate composites
Authors: Xian Guijun , Li Hui , Su Xiansheng
Published: May 2012

In this article, an ultraviolet curable glass fiber reinforced polymer (UV‐GFRP) composite developed for fast repair or strengthening of concrete structures, was investigated on its water absorption and hygrothermal ageing behaviors. Cured UV‐GFRP coupons were subjected to immersion in distilled water or concrete pore solution (pH value around 13) for 4–8 months at room temperature and elevated temperatures (40 and 60°C), respectively. Water absorption and thermomechanical properties of the samples were tested as a function of immersion time. Water uptake curves of UV‐GFRP exposed to elevated temperatures and/or alkaline solutions show serious mass loss. Debonding of fibers from resin matrix brought in increased coefficient of diffusion along fiber directions, due to the capillary effect. After 4 months of immersion in both media, the tensile strength of UV‐GFRP was deteriorated remarkably, while the tensile modulus was less affected. According to Arrhenius equation, the tensile strength of UV‐GFRP is predicted to remain 77.6% of its original value after50 years when immersed in water at 20°C, but only 24.5% left in the case of alkaline solution. This suggests that the present UV‐GFRP system does not suit for the application in strong alkaline environments. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
PES/SiO2 nanocomposite by in situ polymerization: Synthesis, structure, properties, and new applications
Authors: Shariatmadar F.S. , Mohsen‐Nia M.
Published: May 2012

SiO2 nanoparticles of a quantum size (15 nm or less) were prepared via sol–gel method using tetraethylorthosilicate as a precursor. SiO2 nanoparticles were characterized by X‐ray diffraction (XRD) and field‐emission scanning electron microscopy (FESEM) analyses. Polyethersulfone/silica (PES/SiO2) crystal structure nanocomposite was prepared by in situ polymerization using silica nanoparticles as reinforcement filler. The polymerization reaction was done at 160°C in paraffin bath in the presence of diphenolic monomers. XRD and FESEM analyses were used to study the morphology of the synthesized nanocomposite. The purity and thermal property of the PES/SiO2 nanocomposite were studied by energy dispersion of X‐ray analysis and differential scanning calorimetry, respectively. The effect of silica particles on the hydrophilicity of PES/SiO2 nanocomposite was also investigated. It was showed that the PES/SiO2 nanocomposite had a higher swelling degree when compared with the pure PES. The synthesized PES/SiO2 powder was used to remove Cu(II) ions from its aqueous solution. The effect of experimental conditions such as pH, shaking time, and sorbent mass on adsorption capacity of PES/SiO2 nanocomposite were investigated. It was found that incorporation of a low amount of silica (2 wt%) into the polymer matrix caused the increase of the Cu(II) ions adsorption capacity of PES. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Influence of natural fibers on the mechanical properties and biodegradation of poly(lactic acid) and poly(ε‐caprolactone) composites: A review
Authors: Wahit Mat Uzir , Akos Noel Ibrahim , Laftah Waham Ashaier
Published: May 2012

This article highlights developments in viable poly(lactic acid) (PLA) and poly(ε‐caprolactone) (PCL) ecofriendly products with enhanced mechanical properties and biodegradation based on natural resources for both reinforcements and matrices. In recent times, several techniques have emerged with emphasis on enhancing mechanical, biological, and chemical properties equivalent to or superior to conventional polymers in use. Chemical and physical modifications of the fibers and in some cases polymer matrix or both are used to obtain properties suitable for the intended application. The mechanical properties and biodegradation of PLA and PCL natural fiber composites were enhanced by the treated fibers. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Temperature‐dependent Hall‐effect measurements of p‐type multicrystalline compensated solar grade silicon
Authors: Modanese Chiara , Acciarri Maurizio , Binetti Simona , Søiland Anne‐Karin , Di Sabatino Marisa , Arnberg Lars
Published: May 2012

In this study, we have investigated the Hall majority carrier mobility of p‐type, compensated multicrystalline solar grade silicon (SoG‐Si) wafers for solar cells in the temperature range 70–373 K. At low temperature (~70 K) the difference in the mobilities measured for the compensated and the uncompensated reference samples is the highest, and the measured mobility shows dependence on the compensation ratio. Mobilities decrease with increasing temperature, and towards room temperature, the mobilities of the different samples are in the same range. The measurements show that, for these samples, the contribution from lattice scattering is dominating over ionized impurity scattering at room temperature. In the range of interest for silicon solar cells (above room temperature), the trend in carrier mobility is similar for all the samples, and the measured value for the sample with low compensation ratio and low doping density is comparable to the uncompensated references. A comparison of resistivity and majority carrier density measured by the Hall setup at room temperature and by four‐point probe and glow discharge mass spectroscopy, respectively, is reported as well. Copyright © 2012 John Wiley & Sons, Ltd.
Preventing retention: First grade classroom instruction and student characteristics
Authors: Dombek Jennifer Lucas , Connor Carol McDonald
Published: May 2012

Retention is a frequently used strategy to support children who are struggling academically. However, the strategy is costly, and research findings with regard to positive outcomes are mixed. This study examined whether efficacious reading instruction might reduce rates of retention in first grade. We also evaluated the reading instruction the students received compared with children with similar reading and vocabulary skills who were not retained. Additionally, we examined the impact students' self‐regulation may have on grade retention. Findings reveal that it was significantly less likely for students to be retained at the end of first grade if their teacher was implementing more efficacious reading instruction. Moreover, there were substantial differences in the literacy instruction provided for children who were and were not retained. Finally, students in the efficacious reading condition who were retained exhibited significantly weaker self‐regulation skills than did their matched‐promoted peers. © 2012 Wiley Periodicals, Inc.
Allergic rhinitis and non‐allergic rhinitis in children in the tropics: Prevalence and risk associations
Authors: Chiang Wen Chin , Chen Yu Ming , Tan Henry K.K. , Balakrishnan Abhilash , Liew Woei Kang , Lim Hwee Hoon , Goh Si Hui , Loh Wen Yin , Wong Petrina , Teoh Oon Hoe , Goh Anne , Chay Oh Moh
Published: May 2012

Background

The age‐related comparative prevalence of allergic rhinitis (AR) and non‐allergic rhinitis (NAR) in children is poorly defined. We aimed to characterize AR and NAR in children.

Methods

This study enrolled children with chronic rhinitis who presented to a tertiary paediatric center for a diagnostic skin prick test (SPT). Parents completed a medical history questionnaire for their child, including disease activity for asthma and rhinitis. Sociodemographic data was obtained and all participants underwent a common inhalant SPT panel. A positive SPT indicated AR.

Results

From March 2001 to March 2009, 6,660 children (64% male) were enrolled (aged 6 months to 19 years, mean 7.82 years). Only 3.7% (249) of the children were <2 years old, and almost 30% of these had AR. Most children with AR (73%) presented after age 6.

Males were more likely to have AR (vs. NAR) (OR 1.5; CI 1.39–1.77). Antihistamine and salbutamol use did not differ between children with AR and NAR. Children with AR were more likely to require adjunct therapy with inhaled corticosteroids (51.2% vs. 43.2%, P < 0.001), have drug hypersensitivity (especially antipyretic drugs) (2.5% vs. 1.3%, P = 0.384) or an asthma admission (9.1% vs. 6.0%, P < 0.001).

Conclusions

AR is more common in male children, is relatively rare below the age of 2 years, and accounts for two‐thirds of all childhood chronic rhinitis and 73.3% of all chronic rhinitis in school‐aged children (≥6 years old). Children with AR have more severe rhinitis symptoms and more often suffer from asthma‐related events and admissions. Pediatr Pulmonol. 2012. 47:1026–1033. © 2012 Wiley Periodicals, Inc.
A novel approach to coupled proton–phonon macroscopic system in H‐bonded solids with strong low‐barrier hydrogen bonds on the examples of KH2PO4 and KD2PO4
Authors: Dolin S. P. , Levin A. A. , Mikhailova T. Yu.
Published: May 2012

To describe the proton–phonon coupling (PPC) in the materials at hand, the novel pseudospin Ising‐type Hamiltonian is proposed. It is derived by the vibronic theory of heteroligand molecular systems treating the oxygen atoms O(−) and O(···) [linked with hydrogen atoms by covalent (OH) or by hydrogen (O···H) bond] as substituting ligands in PO4 tetrahedra for 3d KH2PO4‐like species. Using the Hamiltonian obtained, we treat several vibrational modes participating in the structural phase transitions, the Ising parameters dependence on vibronic constants, and the PPC influence on the Tc value. © 2012 Wiley Periodicals, Inc.
Density functional theory and ab initio study on the reaction mechanisms of the homogeneous, unimolecular elimination kinetics of selected 1‐chloroalkenes in the gas phase
Authors: Mora Jose R. , Lezama Jesus , Berroteran Neydher , Cordova Tania , Chuchani Gabriel
Published: May 2012

The mechanisms for the unimolecular elimination kinetics of selected 1‐chloroalkenes in the gas phase were studied at MPW1PW91/6‐31G(d,p), MPW1PW91/6‐31++G(d,p), G3, and G3MP2 levels of theory. Two possible unimolecular mechanisms were considered: mechanism A as a concerted 1,2 elimination process through four‐membered cyclic transition state (TS). mechanism B describing the anchimeric assistance of the double bond in HCl elimination previously suggested in the literature. Calculated parameters suggest that the elimination reactions of 1‐chloroalkenes proceed through mechanism A, in view of the higher energy of activation associated with mechanism B. Density functional method MPW1PW91/6‐31G(d,p) calculated parameters gave a better agreement with the experimental values than G3 and G3MP2. The changes along the reaction path of mechanism A were followed by geometric parameters, natural bond orbital charges, and bond order analysis, suggesting the rate‐determining process is the breaking of CCl bond in the TS. The dehydrochlorination of chloroalkenes occurs in a concerted nonsynchronous fashion with stabilization of the TS by π‐electron delocalization from the neighboring bond. Isomerization reactions for 4‐chloro‐1‐butene, 4‐chloro‐2‐methyl‐1‐butene, and 4‐chloro‐1‐butene are unlikely at the experimental reaction condition because of the higher the enthalpies and energies of activation. © 2012 Wiley Periodicals, Inc.
Thought leaders during crises in massive social networks
Authors: Corley Courtney D. , Farber Robert M. , Reynolds William N.
Published: May 2012

Making vast amounts of online social media data comprehensible to an analyst is a key question in operational analytics. Twitter and micro‐blog conversations can easily be gathered from Internet services such as Spinn3r to create graphs representing the interactions between the entities in an online community that contains billions of vertices and tens of billions of edges. Graphs of this size can easily be represented in a modern laptop or workstation. The challenge lies in making them comprehensible. This paper focuses on methods to assemble social network graphs from online social media to reveal nodes that are ‘interesting’ in the context of operational analysis—meaning that the computational results can be interpreted by a human analyst wishing to answer some operational questions. Only metrics based on the structure of the graph are utilized, which avoid the challenges and costs involved in message content analysis. We further restrict ourselves to the use of metrics that are computational tractable on billion node graphs. The reported results demonstrate that nodes with a high impact or disproportionally large agency on the whole network (e.g., online community) can be found in a variety of online communities. Validation of the importance of these high‐agency nodes by human and computational methods is discussed, and the efficacy of our approach by both quantitative methods and tests against the null hypothesis is reported. © 2012 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 5: 205–217, 2012
Management of male LUTS in general practice
Authors: Speakman Mark J. , McMeekin Faith
Published: May 2012

The initial management of lower urinary tract symptoms in men is usually carried out in primary care. The authors explain that the primary goal of treatment is to improve bothersome symptoms; more recently, however, treatment has also focused on the alteration of disease progression and the prevention of complications. Copyright © 2012 John Wiley & Sons
Evolving medical ethics
Authors: Bolsin Stephen , Saunders Kym
Published: May 2012

Have doctors ignored or abandoned their ethical code at the cost of decreasing influence in healthcare management? Professor Bolsin proposes that wise, conscientious, brave and moderate medical input should always be valued in planning and managing better healthcare for patients. Copyright © 2012 John Wiley & Sons
The Prostate Cancer Charity
Authors: Eshelby Jane
Published: May 2012

The Prostate Cancer Charity was founded in 1996 in response to the urgent need to invest more in prostate cancer research and to raise public and political awareness of a long‐neglected disease. It is now the UK's leading voluntary organisation working with people affected by prostate cancer. Copyright © 2012 John Wiley & Sons
Musculoskeletal manifestations of neonatal nonketotic hyperglycinemia
Authors: Ramirez Norman , Flynn John M. , Casalduc Francisco , Rodriguez Stephanie , Cornier Alberto S. , Carlo Simón
Published: May 2012

Purpose

Neonatal nonketotic hyperglycinemia is an autosomal recessive inborn disorder of glycine metabolism in which large quantities of glycine accumulate in all body tissues. It is characterized by a progressive lethargy, hypotonia, myoclonic jerks, and early death secondary to respiratory problems. As a result of early diagnosis and treatment protocols, more patients survive the critical neonatal period with profound mental retardation, delayed developmental milestones, seizures, and spasticity. There are no reports about the orthopaedic manifestations of neonatal nonketotic hyperglycinemia. The purpose of this study is to evaluate the musculoskeletal findings of neonatal nonketotic hyperglycinemia.

Methods

This is a retrospective IRB-approved study of all patients in our Orthopaedic and Genetics Clinics with the diagnosis of neonatal nonketotic hyperglycinemia during a 10-year period. Demographic, clinical, and imaging data were analyzed.

Results

Twelve patients with neonatal nonketotic hyperglycinemia were evaluated, with a mean age of 7 years and 2 months (range: 5 months to 21 years). Seven were male and five were female. Eleven patients (92 %) have evidence of progressive early-onset neuromuscular scoliosis with a mean Cobb angle of 55° (range: 30–95°). Five children (42 %) presented evidence of progressive hip dislocation secondary to spasticity. All the patients have severe multiple joint contractures.

Conclusion

Neonatal nonketotic hyperglycinemia is a rare metabolic disorder presented in the past as a lethal condition. Recent advances in early diagnosis and neonatal care improve overall outcome. As pediatric orthopaedic surgeons, we need to establish treatment based on update information of the disease and probability to improve quality of life.
Response of Osteoclasts to Titanium Surfaces with Increasing Surface Roughness: An In Vitro Study
Authors: Brinkmann Jenny , Hefti Thomas , Schlottig Falko , Spencer Nicholas D. , Hall Heike
Published: May 2012

Osteoclasts are responsible for bone resorption and implant surface roughness promotes osseointegration. However, little is known about the effect of roughness on osteoclast activity. This study aims at the characterization of osteoclastic response to surface roughness. The number of osteoclasts, the tartrate-resistant acid phosphatase and matrix metalloproteinase (MMP) activities, the cell morphology and the actin-ring formation were examined on smooth (TS), acid-etched (TA) and sandblasted acid-etched (TLA) titanium and on native bone. Cell morphology was comparable on TA, TLA and bone, actin rings being similar in size on TLA and bone, but smaller on TA and virtually absent on TS. Gelatin zymography revealed increased proMMP-9 expression on TA, TLA, and bone compared to TS. In general, osteoclasts show similar characteristics on rough titanium surfaces and on bone, but reduced activity on smooth titanium surfaces. These results offer some insight into the involvement of osteoclasts in remodeling processes around implant surfaces.
Assessment of Protein Entrapment in Hydroxyapatite Scaffolds by Size Exclusion Chromatography
Authors: Espanol Montserrat , Casals Isidre , Lamtahri Sarah , Valderas Maria-Teresa , Ginebra Maria-Pau
Published: May 2012

Although it is well known that the textural properties of scaffolds play an important role in the process of tissue regeneration, the investigation of such effects remain difficult especially at the micro/nano level. Texture confers the material the additional ability to entrap/concentrate molecules circulating in the body fluid regardless of their binding affinity to the material. The goal of the present work is to isolate protein entrapment from protein adsorption phenomena in two macroporous hydroxyapatite scaffolds with identical chemical structure, similar macroporosity but different micro/nanoporosity using proteins of different sizes. This was achieved implementing size exclusion chromatography and using the scaffolds as chromatographic columns. The results showed that the larger the crystal size and the lower the packing density of the crystals composing the scaffold increased protein retention but decreased the protein dwelling time in the column. Differences in the amount of protein retained depended on the protein type.
A two‐method investigation of early adolescents' responses upon witnessing peer victimization in school
Authors: Bellmore Amy , Ma Ting‐Lan , You Ji‐in , Hughes Maria
Published: May 2012

Given the passivity of many adolescents upon witnessing peer victimization, the goal of this study was to evaluate the features of school‐based peer victimization events that promote helping. A sample of 470 early adolescents (52% girls; 71% White, 9% Black, 6% Latino, 2% Asian, 1% American Indian, 8% Multiethnic, and 3% Other) reported likelihood of helping and specific helping and non‐helping behaviors with an experimental vignette method and through descriptions of recently witnessed real‐life victimization events. With both methods, an adolescent's relationship with the victim predicted likelihood of helping and specific helping behaviors above and beyond the contribution of other key personal characteristics including gender, empathy, communal goal orientation, and previous victimization experiences. Examination of adolescents' real‐life experiences yielded systematic patterns between their responses and their reasoning about the responses undertaken. The results illustrate the relevance of taking into account peer victimization event characteristics for promoting witness intervention in adolescence.