bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface engineering of a cutinase from Thermobifida cellulosilytica for improved polyester hydrolysis
Authors: Herrero Acero Enrique , Ribitsch Doris , Dellacher Anita , Zitzenbacher Sabine , Marold Annemarie , Steinkellner Georg , Gruber Karl , Schwab Helmut , Guebitz Georg M.
Published: April 2013

Modeling and comparison of the structures of the two closely related cutinases Thc_Cut1 and Thc_Cut2 from Thermobifida cellulosilytica DSM44535 revealed that dissimilarities in their electrostatic and hydrophobic surface properties in the vicinity to the active site could be responsible for pronounced differences in hydrolysis efficiencies of polyester (i.e., PET, polyethyleneterephthalate). To investigate this hypothesis in more detail, selected amino acids of surface regions outside the active site of Thc_Cut2, which hydrolyzes PET much less efficiently than Thc_Cut1 were exchanged by site‐directed mutagenesis. The mutants were expressed in E. coli BL21‐Gold(DE3), purified and characterized regarding their specific activities and kinetic parameters on soluble substrates and their ability to hydrolyze PET and the PET model substrate bis(benzoyloxyethyl) terephthalate (3PET). Compared to Thc_Cut2, mutants carrying Arg29Asn and/or Ala30Val exchanges showed considerable higher specific activity and higher kcat/KM values on soluble substrates. Exchange of the positively charged arginine (Arg19 and Arg29) located on the enzyme surface to the non‐charged amino acids serine and asparagine strongly increased the hydrolysis activity for 3PET and PET. In contrast, exchange of the uncharged glutamine (Glu65) by the negatively charged glutamic acid lead to a complete loss of hydrolysis activity on PET films. These findings clearly demonstrate that surface properties (i.e., amino acids located outside the active site on the protein surface) play an important role in PET hydrolysis. Biotechnol. Bioeng. 2013;110: 2581–2590. © 2013 Wiley Periodicals, Inc.
Protein cell‐surface display through in situ enzymatic modification of proteins with a poly(Ethylene glycol)‐lipid
Authors: Tomita Urara , Yamaguchi Satoshi , Maeda Yasukazu , Chujo Kazuki , Minamihata Kosuke , Nagamune Teruyuki
Published: April 2013

Cell‐surface display of functional proteins is a powerful and useful tool for regulating and reinforcing cellular functions. Direct incorporation of site‐specifically lipidated proteins from the extracellular medium is more rapid, easily controllable and reliable in displaying active proteins than expression through gene transfer. However, undesirable amphiphilic reagents such as organic co‐solvents and detergents were required for suppressing aggregation of ordinary lipidated proteins in solution. We report here sortase A‐catalyzed modification of proteins with a poly(ethylene glycol)(PEG)‐lipid in situ on the surface of living cells. Proteins fused with a recognition tag were site‐specifically ligated with the PEG‐lipid which was preliminary incorporated into cell membranes. Accordingly, target proteins were successfully displayed on living cells without aggregation under an amphiphilic reagent‐free condition. Furthermore, to demonstrate the availability of the present method, Fc domains of immunoglobulin G were displayed on cancer cells, and the phagocytosis of cancer cells with dendritic cells were enhanced through the Fc–Fc receptor interaction. Thus, the present facile chemoenzymatic method for protein display can be utilized for modulating cell–cell interactions in cell and tissue engineering fields. Biotechnol. Bioeng. 2013;110: 2785–2789. © 2013 Wiley Periodicals, Inc.
A contemporary analysis of morbidity and outcomes in cytoreduction/hyperthermic intraperitoneal chemoperfusion
Authors: Haslinger Michelle , Francescutti Valerie , Attwood Kristopher , McCart Judith Andrea , Fakih Marwan , Kane John M. , Skitzki Joseph J.
Published: April 2013

The risks and benefits of cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (CS/HIPEC) continue to be debated by the oncology community. A retrospective analysis of contemporary data (2003–2011) was performed to provide objective information regarding surgical morbidity, mortality, and survival for patients undergoing CS/HIPEC at a comprehensive cancer center. While procedure‐associated morbidity was comparable to other major surgical oncology procedures, there was no operative or 30‐day mortality and 60‐day mortality was 2.7%. Increasing numbers of bowel resections were found to correlate to an increased incidence of deep surgical site infections (including abscess and enterocutaneous fistula) and need for reoperation which was in turn associated with a decreased overall survival (OS) and progression‐free survival (PFS). Five‐year OS rates varied by site of tumor origin and histology (disseminated peritoneal adenomucinosis [91.3%], Mesothelioma [80.8%], Appendiceal Adenocarcinoma [38.7%], and Colorectal Adenocarcinoma [38.2%]). With an acceptable morbidity and mortality rate, CS/HIPEC should be included as an effective treatment modality in the multidisciplinary care of select patients with peritoneal metastases.
A novel biodegradable stent applicable for use in congenital heart disease: Bench testing and feasibility results in a rabbit model
Authors: Veeram Reddy Surendranath R. , Welch Tre R. , Wang Jian , Bernstein Frederic , Richardson James A. , Forbess Joseph M. , Nugent Alan W.
Published: April 2013

Objectives

A novel double opposed helical (DH) biodegradable stent was designed and fabricated for CHD applications. The primary objective was to evaluate the feasibility of DH stent delivery and deployment in rabbit external iliac arteries (EIA). Secondary objectives were to assess stent patency, thrombosis and inflammation at 1‐week and 1‐month follow‐up.

Background

Biodegradable stents have largely been designed for adult cardiovascular indications, to avoid long term complications of permanent implants. A growing child with congenital heart disease (CHD) would especially derive substantial benefit from this technology.

Methods

DH stents were manufactured to 3, 4, 5, and 6‐mm diameter with poly‐l‐lactic acid (PLLA) fibers. Bench test analysis was performed. Six DH stents were implanted in rabbit EIA. Vessel patency was assessed at 1‐week and 1‐month follow‐up with repeat angiography, intravascular ultrasound (IVUS). Histopathological evaluation was performed.

Results

The elastic recoil and collapse pressure of DH stents were comparable to conventional metal stents. All DH stents were successfully delivered and implanted with good apposition to the vessel wall and no collapse of the proximal, mid or distal ends. All stented vessels remained patent. No acute or early stent thrombosis was noted. Histopathology showed minimal inflammatory response and mild neointimal proliferation at 1 month follow‐up.

Conclusions

In vitro results of DH PLLA biodegradable stents are comparable to conventional metal stents. The pilot animal study confirms the delivery and deployment of the DH stents to the desired location. The DH design can be used to fabricate larger diameter stents needed for CHD. © 2013 Wiley Periodicals, Inc.
Preprocedural statin therapy, inflammation, and myocardial injury in low‐risk stable coronary artery disease patients submitted to coronary stent implantation
Authors: Greque Gilmar V. , Serrano Carlos V. , Strunz Célia M. , Soeiro Alexandre , Santos Márcio , Pivateli Flávio , Jacob José Luis B. , Pesaro Antonio Eduardo P. , Nicolau José Carlos , Kalil‐Filho Roberto
Published: April 2013

Objective

Evaluate if statin therapy prior to elective coronary stent implantation (CSI) reduces the plasma levels of markers of inflammation and of myocardial necrosis in low‐risk stable coronary artery disease patients (CAD).

Background

The elevation of markers of inflammation and of myocardial necrosis after percutaneous coronary intervention may interfere with clinical outcome. Among acute coronary syndrome patients, statins improve clinical outcomes when used before CSI—mostly due to reduction of CSI‐related myocardial infarction. However, little is known concerning preprocedural statin therapy on the reduction of these markers in stable patients at low‐risk.

Methods

In this prospective, observational study, 100 patients (n = 50 on statin therapy vs. n = 50 not on statin) with stable coronary artery disease underwent elective CSI. Inflammatory (C‐reactive protein [CRP], interleukin [IL]‐6, tumor necrosis factor‐α and matrix metalloproteinase‐9) and myocardial necrosis markers (troponin I and CK‐MB) were determined before and 24 hr after CSI.

Results

All patients presented a significant increase of CRP and IL‐6 after CSI. However, this increase was attenuated in patients on statin therapy prior to CSI than those without statin therapy: 75% vs. 150% (P < 0.001) and 192% vs. 300% (P < 0.01). The other pro‐inflammatory markers were similar for both sets of patients. Troponin I and CK‐MB did not change after CSI regardless of previous statin therapy or not.

Conclusions

Pretreatment with statin attenuates procedural inflammation, denoted by markedly lower increases of CRP and IL‐6 levels, in elective CSI within low‐risk stable CAD patients. Periprocedural myocardial injury was irrelevant and was not affected by preprocedural statin therapy in this population. © 2015 Wiley Periodicals, Inc.
Late and very late coronary stent thrombosis: Intravascular ultrasound findings and associations with antiplatelet therapy
Authors: Pesarini Gabriele , Dandale Rajesh , Rigamonti Antonio , Pighi Michele , Zivelonghi Carlo , Mugnolo Antonio , Ferrero Valeria , Vassanelli Corrado , Ribichini Flavio
Published: April 2013

Background and Objective

Late and very‐late stent occlusion remains a serious complication of coronary stenting. Despite their high anti‐restenotic efficacy, drug‐eluting stents (DES) have been associated to more late‐thrombosis as compared to bare‐metal stents (BMS). The aim of this study is to analyze the clinical presentation, angiographic, and intravascular ultrasound (IVUS) findings in patients with late or very late stent thrombosis and the relationship with the antiplatelet regimen.

Methods and Results

Between January 2007 and December 2011, 34 consecutive patients with clinical syndromes compatible with late or very‐late stent occlusion were studied with IVUS during emergency catheterization; 25 had DES and 9 had BMS. Thrombotic total occlusion was more common in DES (16 = 64%) than BMS patients (2 = 22%; P = 0.02) and ST‐segment elevation myocardial infarction was the predominant clinical presentation in the former group (60% compared to 22%; P = 0.05). The time elapsed between implantation and failure was much longer in DES patients: 33 ± 22 versus 17 ± 14 months for BMS; P = 0.05. IVUS analysis showed a higher incidence of incomplete stent apposition (ISA) in the DES group compared to the BMS group (56% vs. 11%; P = 0.005) and in‐stent plaque rupture was the most common finding in the BMS group (78%). In DES group, ISA was found more frequently in patients still under dual antiplatelet therapy (71%).

Conclusions

Very late DES failure often causes ST‐elevation myocardial infarction; these very late events may not correlate with the interruption of antiplatelet therapy. Severe, late acquired ISA belongs to DES and is frequently observed in patients with very late DES thrombosis. © 2013 Wiley Periodicals, Inc.
Adenosine‐induced temporary block to improve accuracy of ostial coronary stent implantation: Adenosine to improve stent implantation accuracy
Authors: Dvir Danny , Badr Salem , Pichard Augusto D.
Published: April 2013

Implantation of coronary stents should be performed with high precision to ensure optimal clinical results. In some clinical conditions, during the cardiac cycle, significant movement of the predeployed stent may impact its implantation accuracy. We describe a case in which a patient had a short ostial left anterior descending artery stenosis and hyperkinetic left ventricle, resulting in significant movement of the stent inside the vessel lumen during the cardiac cycle. Intracoronary adenosine was used to create temporary heart block to enable accurate stent implantation.© 2013 Wiley Periodicals, Inc.
Angioplasty of acquired pulmonary vein stenosis using covered stent
Authors: Tehrani Shana , Lipkin David
Published: April 2013

One of the most serious complications post‐catheter ablation of atrial fibrillation is the development of pulmonary vein stenosis. Controversy currently exists about the optimal treatment approach. The use of balloons and larger stents (∼10 mm) results in more optimal outcome than just balloon angioplasty alone; however, even with stent implantation, recurrent restenosis may occur in 30 to 50% of patients. We report the case of a 28‐year‐old man who developed recurrent left inferior pulmonary vein stenosis following radiofrequency ablation for atrial fibrillation. This was initially stented with good result but soon after developed restenosis and required balloon angioplasty. Following the third episode of restenosis, stenting of the pulmonary vein was performed using a covered stent. The pulmonary vein has remained patent for the last 5 years. © 2013 Wiley Periodicals, Inc.
Magnetic positioning system in coronary angiography and percutaneous intervention
Authors: Weisz Giora , Smilowitz Nathaniel R. , Moses Jeffrey W. , Rabbani LeRoy E. , Collins Michael B. , Herscovici Adrian , Jeron Andreas , Leon Martin B. , Luchner Andreas
Published: April 2013

Objectives

This study sought to evaluate the safety and feasibility of a magnetic medical positioning system (MPS) to determine the three‐dimensional (3D) position and orientation of intracoronary wires and catheters and to guide angiography and percutaneous coronary intervention (PCI).

Background

Coronary angiography relies on fluoroscopy for catheter navigation and often fails to accurately portray vessel tortuosity, overlap, and length because of complex anatomy and foreshortening of curved coronary segments.

Methods

Forty adult participants underwent coronary angiography and/or PCI with MPS guidance. Two interventional cardiologists independently scored (1–5) the accuracy of MPS catheter tracking projected on live fluoroscopy, recorded cine loops, and 3D vessel reconstructions. Measurements from MPS reconstructions were compared to conventional two‐dimensional (2D) quantitative coronary angiography (QCA) measurements. Device procedural success was defined as the ability of the MPS‐enabled catheter to reach the target vessel, perform the intended operations, and be retrieved without major adverse cardiac events.

Results

Diagnostic coronary angiography was performed in 19 (47.5%) and PCI in 21 patients (52.5%). MPS procedural success was achieved in 36 (90%) of the cases. MPS accuracy was highest with the MPS superimposed on live fluoroscopy (4.9 ± 0.2/5) and the 3D vessel reconstruction (4.7 ± 0.5/5). MPS length measurements were more accurate than conventional QCA.

Conclusions

This study demonstrates the feasibility and safety of magnetic catheter tracking with 3D positional data during diagnostic angiography and PCI. Catheter position was accurately projected on real‐time fluoroscopy, recorded cine loops, and 3D reconstructions. An MPS may serve as a platform for device navigation and positioning during PCI. © 2013 Wiley Periodicals, Inc.
Acute outcome of stent therapy for coarctation of the aorta: Results of the coarctation of the aorta stent trial
Authors: Ringel Richard E. , Vincent Julie , Jenkins Kathy J. , Gauvreau Kimberlee , Moses Heidi , Lofgren Kimberly , Usmani Kudret
Published: April 2013

Objectives

The coarctation of the aorta stent trial (COAST) is a pivotal trial of the NuMED Cheatham Platinum Stent® for treatment of coarctation of the aorta (CoA).

Background

CoA is a congenital obstruction to flow through the aorta. Stents have been used since the 1990s to treat CoA; none have been approved by the Food and Drug Administration for this indication.

Methods

In a prospective, multicenter study 105 patients received stents for treatment of CoA. Data was collected in the catheterization laboratory, on discharge and at 1‐month postprocedure.

Results

Of 105 patients, 69% were male; 57% had native CoA. Noninvasive, baseline systolic blood pressure (SBP) showed upper extremity (UE) SBP to be 140 ± 16 mm Hg and UE to lower extremity (LE) SBP difference 29 ± 17 mm Hg. At catheterization, baseline ratio of minimum CoA diameter to diameter of descending aorta (CoA:DAo) was 0.46 ± 0.16. Implants (104/105) were successful with one stent migration. There were no deaths or serious complications. Paradoxical hypertension occurred in 6%. Four percent of patients experienced somewhat serious adverse events related to the procedure. All patients achieved relief of ascending aorta to Dao pressure gradient: mean = 2.0 ± 4.0 mm Hg (P < 0.001). The CoA:DAo increased to 0.84 ± 0.18. At 1‐month, UE SBP was 120 ± 12 mm Hg, UE to LE SBP difference = −1 ± 12 mm Hg. Ninety‐nine percent of patients had UE to LE SBP difference <20 mm Hg.

Conclusions

Stenting of CoA, using the NuMED Cheatham Platinum Stent, is acutely safe and effective for treatment of CoA. © 2013 Wiley Periodicals, Inc.
Stenting an aortopulmonary conduit with peripheral cardiopulmonary bypass support
Authors: Incani Alexander , Lee Joseph C. , Nicolae Mugur J. , Walters Darren L.
Published: April 2013

Although surgically created aortopulmonary (AP) shunts are uncommon in the adult congenital heart disease population, they are often used in patients with pulmonary atresia. For these patients, the shunt is a vital supply of pulmonary blood flow and thus obstruction of the shunt may lead to pulmonary hypoperfusion and hypoxia thereby increasing morbidity and mortality. This report describes a safe and effective method of stenting the conduit with the hemodynamic support of peripheral cardiopulmonary bypass (PCB). Prior to the procedure, a multimodality assessment of a stenosis in a kinked AP conduit using computed tomography, angiography, intravascular ultrasound (IVUS), and pressure wire assessment (PWA) was utilized. While PCB, IVUS, and PWA have all been used to great effect in various clinical scenarios, the combined use of these techniques has not been previously been described in the setting of intervention in adult congenital heart disease. © 2013 Wiley Periodicals, Inc.
Balloon‐assisted tracking: A must‐know technique to overcome difficult anatomy during transradial approach
Authors: Patel Tejas , Shah Sanjay , Pancholy Samir , Rao Sunil , Bertrand Olivier F. , Kwan Tak
Published: April 2013

Objective

To examine the use and outcomes of balloon‐assisted tracking (BAT) technique for dealing with complexities of arm and chest vasculature during transradial approach (TRA) at a single high volume radial center.

Background

TRA has been used for coronary angiography and percutaneous coronary interventions (PCI) around the world. Different techniques have been described to address the anatomical issues and tortuosities for successful completion of coronary angiography and PCI. This study describes the use of BAT technique and associated outcomes during real world clinical practice.

Methods

Subjects comprised 63 patients, (out of total 8,245 patients between January 2011 and December 2012) in whom we encountered significantly complex anatomical course in radial, brachial, or subclavian region, leading to difficult advancement of a diagnostic or a guide catheter despite trying all standard maneuvers. In all of them BAT technique was used and they were retrospectively analyzed for the purpose of this study.

Results

About 63 (0.76%) of 8,245 patients met the study criteria. Twenty‐five (39.7%) patients had very small RA. Twenty‐two (34.9%) had severe RA tortuosity. Four (6.3%) had complex RA loops. Six (9.5%) had severe RA spasm and six (9.5%) had severe subclavian tortuosity and/or stenosis. We encountered technical failure in three (4.8%) patients (two had very small RA and one had 360 degree RA loop).

Conclusion

BAT technique was useful to address the anatomical issues and tortuosities of radial, brachial, and subclavian vasculature during TRA. © 2013 Wiley Periodicals, Inc.
Gd2Ti2O7/In2O3: Efficient Visible‐Light‐Driven Heterojunction‐Based Composite Photocatalysts for Hydrogen Production
Authors: Nashim Amtul , Martha Satyabadi , Parida K. M.
Published: April 2013

A series of Gd2Ti2O7/In2O3heterojunction‐based composite photocatalysts was prepared by using solid‐state reaction methods and their activity was evaluated by measuring the photocatalytic H2production under visible light (λ≥400 nm). The materials were characterised by using XRD, diffuse reflectance UV (DRUV)/Vis spectroscopy, TEM, field emission SEM (FESEM), photoluminescence (PL) spectroscopy, X‐ray photoelectron spectroscopy (XPS), and BET surface area and photocurrent measurements. The modification of Gd2Ti2O7with In2O3resulted in a remarkable enhancement of the activity for H2production with respect to the single components under visible light. The photocurrent and Mulliken electronegativity results show that Gd2Ti2O7and In2O3have a well‐matched band potential to exhibit synergic effects. The enhanced activity may be ascribed to the light absorption properties and the reduction of the recombination of charge carriers at the composite interface. The catalyst Gd2Ti2O7/In2O3with 60 at % In (60 IGTO) showed the highest activity in comparison to the other composite materials prepared.
Binuclear Cooperative Catalysts for the Hydrogenation and Hydroformylation of Olefins
Authors: Hetterscheid Dennis G. H. , Chikkali Samir H. , de Bruin Bas , Reek Joost N. H.
Published: April 2013

Cooperative activation of substrates simultaneously by a (transition) metal and a protein residue is a common strategy in enzyme catalysis. Cooperative dinuclear catalysis for synthetic systems is relatively underdeveloped. Here, we focus on some examples of dinuclear hydrogenation and hydroformylation reactions, with the aim to stimulate the scientific community to develop more catalytic processes based on cooperative dinuclear systems.
Versatile Probes for the Selective Detection of Vicinal‐Dithiol‐Containing Proteins: Design, Synthesis, and Application in Living Cells
Authors: Huang Chusen , Yin Qin , Meng Jiangjiang , Zhu Weiping , Yang Yi , Qian Xuhong , Xu Yufang
Published: April 2013

Endogenous vicinal‐dithiol‐containing proteins (VDPs) that have two thiol groups close to each other in space play a significant importance in maintaining the cellular redox microenvironment. Approaches to identify VDPs mainly rely on monitoring the different concentration of monothiol and total thiol groups or on indirect labeling of vicinal thiols by using p‐aminophenylarsenoxide (PAO). Our previous work has reported the direct labeling of VDPs with a highly selective receptor PAO analogue, which could realize fluorescence detection of VDPs directly in living cells. Herein, we developed a conjugated approach to expand detectable tags to nitrobenzoxadiazole (NBD), fluorescein, naphthalimide, and biotin for the synthesis of a series of probes. Different linkers have also been introduced toward conjugation of VTA2 with these functional tags. These synthesized flexible probes with various features will offer new tools for the potential identification and visualization of vicinal dithiols existing in different regions of VDPs in living cells. These probes are convenient tools for proteomics studies of various disease‐related VDPs and for the discovery of new drug targets.
Analyzing the Vibrational Signatures of Thiophenol Adsorbed on Small Gold Clusters by DFT Calculations
Authors: Tetsassi Feugmo Conrard Giresse , Liégeois Vincent
Published: April 2013

Using density functional theory, we calculate the IR and Raman signatures of the thiophenol (TP) molecule adsorbed on gold clusters by mimicking the different types of adsorption sites, and we analyze these signatures by using advanced tools implemented into the pyvib2 program. First, we follow the evolution of the vibrational normal modes from the isolated TP molecule to those of TP adsorbed on different clusters to highlight the influence of the site of adsorption on the vibrational motions. The use of the overlap matrix between the modes enables mode permutations, mode mixings, and mode splittings to be highlighted, all of which depend not only on the adsorption but also on the type of cluster and its symmetry. Second, the IR and Raman signatures were analyzed by using group coupling matrices and atomic contribution patterns based on the Hug decomposition scheme. Key results include 1) the fact that Raman spectroscopy is more sensitive than IR spectroscopy with respect to the nature of the coordination site, 2) an IR criterion that distinguishes between on‐top coordination (onefold coordinated) with respect to the bridge (twofold coordinated) and hexagonal close‐packed hollow site coordination (threefold coordinated), and 3) the best agreement to the experimental Raman spectrum with regard to signatures in the 500 to 1200 cm−1 region is obtained for bridged, twofold coordination.
Nickel Phosphite Superstructures Assembled by Nanotubes: Original Application for Effective Electrode Materials of Supercapacitors
Authors: Pang Huan , Wei Chengzhen , Ma Yahui , Zhao Shanshan , Li Guochang , Zhang Jiangshan , Chen Jing , Li Sujuan
Published: April 2013

Nickel phosphite (Ni11(HPO3)8(OH)6) superstructures assembled by nanotubes are synthesized under mild hydrothermal conditions with the sodium salt of polystyrene sulfonic acid. More importantly, Ni11(HPO3)8(OH)6 superstructures are applied as electrode materials for supercapacitors. Benefitting from their novel superstructures, in a three‐electrode system, Ni11(HPO3)8(OH)6 superstructure electrodes show a good specific capacitance (1876 F g−1 at 0.625 A g−1), good rate capability, and excellent cycling properties (95 % of the initial specific capacitance at 6.25 A g−1 after 2000 cycles) in 3.0 M KOH. Additionally, asymmetric Ni11(HPO3)8(OH)6–graphene nanosheet supercapacitors are also designed. The specific energy of a cell in 3.0 M KOH reaches about 28.6 Wh kg−1 at 92.5 W kg−1.
Experimental and Theoretical Studies on the Controlled Synthesis of Alkali‐Metal‐Doped Rare‐Earth Oxysulfide Nanocrystals
Authors: Zhang Tao , Gu Jun , Ding Yi , Zhang Ya‐Wen , Yan Chun‐Hua
Published: April 2013

Alkali‐metal (Li, Na, K)‐doped lanthanum oxysulfide nanoplates were obtained in the hexagonal phase by thermolysis of metal acetylacetonates in organic solvents with high boiling points and sulfurization using sulfur powders. The characterization results showed that the size, shape, crystallinity, composition, and phase stability of the La2O2S nanocrystals were affected by the doped alkali metals. Combined with first‐principles calculations of the formation energy of anionic defects in the lattices, the ternary phase diagrams for the formation of rare‐earth oxysulfides (RE2O2S) were calculated. Both the experimental results and the phase diagrams have demonstrated that the doped alkali metals are capable of promoting the formation of RE2O2S nanocrystals in the order of K≈Na>Li. With K acting as the doping alkali metal, the phase‐formation capability for different RE2O2S (e.g., Eu, Gd, Yb, Lu) along the lanthanide series was also explored under the guidance of the hard and soft acid and base (HSAB) theory. Moreover, the as‐developed synthetic route could be applied also to the production of K/Eu‐ and K/Tb‐codoped La2O2S nanoplates, which displayed intense red and green emissions, respectively, under ultraviolet‐light excitations.
Compressive sensing for ultra‐wideband channel estimation: on the sparsity assumption of ultra‐wideband channels
Authors: Başaran Mehmet , Erküçük Serhat , Çırpan Hakan Ali
Published: April 2013

Due to the sparse structure of ultra‐wideband (UWB) multipath channels, there has been a considerable amount of interest in applying the compressive sensing (CS) theory to UWB channel estimation. The main consideration of the related studies is to propose different implementations of the CS theory for the estimation of UWB channels, which are assumed to be sparse. In this study, we investigate the suitability of standardized UWB channel models to be used with the CS theory. In other words, we question the sparsity assumption of realistic UWB multipath channels. For that, we particularly investigate the effects of IEEE 802.15.4a UWB channel models and the selection of channel resolution both on channel estimation and system performances from a practical implementation point of view. In addition, we compare the channel estimation performance with the Cramer‐Rao lower bound for various channel models and number of measurements. The study shows that although UWB channel models for residential environments (e.g., channel models CM1 and CM2) exhibit a sparse structure yielding a reasonable channel estimation performance, channel models for industrial environments (e.g., CM8) may not be treated as having a sparse structure due to multipaths arriving densely. Furthermore, it is shown that the sparsity increased by channel resolution can improve the channel estimation performance significantly at the expense of increased receiver processing. Copyright © 2013 John Wiley & Sons, Ltd.
Hair analysis for THCA‐A, THC and CBN after passive in vivo exposure to marijuana smoke
Authors: Moosmann Bjoern , Roth Nadine , Auwärter Volker
Published: April 2013

Condensation of marijuana smoke on the hair surface can be a source of an external contamination in hair analysis and may have serious consequences for the person under investigation. Δ9‐tetrahydrocannabinolic acid A (THCA‐A) is found in marijuana smoke and in hair analysis, but is not incorporated into the hair through the bloodstream. Therefore it might be a promising marker for external contamination of hair and could facilitate a more accurate interpretation of analytical results. In this study, three participants were exposed to the smoke of one joint every weekday over three weeks. Inhalation was excluded by an alternative breathing source. Hair samples were obtained up to seven weeks after the last exposure and analyzed for THCA‐A, Δ9‐tetrahydrocannabinol (THC) and cannabinol (CBN) by liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) analysis. Additionally 30 hair samples from various regions of the head were obtained seven weeks after the exposure from one participant. The obtained results show that the degree of contamination depends on the hair length, with longer hair resulting in higher THC and CBN concentrations (1300 pg/mg and 530 pg/mg at the end of the exposure period) similar to the ones typically found after daily cannabis consumption. THCA‐A could be detected in relatively low concentrations. Analysis of the distribution of the contamination showed that the posterior vertex region was affected most. The relatively low THCA‐A concentrations in the samples suggest that most of the THCA‐A found in forensic hair samples is not caused by sidestream marijuana smoke, but by other sources. Copyright © 2013 John Wiley & Sons, Ltd.
In vivo identification of an HLA‐G complex as ubiquitinated protein circulating in exosomes
Authors: Alegre Estibaliz , Rebmann Vera , LeMaoult Joel , Rodriguez Carmen , Horn Peter A. , Díaz‐Lagares Angel , Echeveste José I. , González Alvaro
Published: April 2013

The nonclassical human leukocyte antigen‐G (HLA‐G) is a tolerogenic molecule that can be released to the circulation by expressing cells. This molecule can form dimers but some other complexed HLA‐G forms have been proposed to be present in vivo. Here, we further characterized these other complexed HLA‐G forms in vivo. Ascitic and pleural exudates from patients were selected based on positivity for HLA‐G by ELISA. Complexed HLA‐G was detected in exosomes, which indicates an intracellular origin of these forms. 2D‐PAGE analysis of exudates and isolated exosomes showed that these high molecular weight complexes were more heterogeneous than the HLA‐G1 expressed by cell cultures. Treatment with deglycosylating enzymes did not change the molecular weight of HLA‐G complexes. Immunoblot analysis of exudates and exosomes with an anti‐ubiquitin antibody showed that at least some of these structures correspond to ubiquitinated HLA‐G. HLA‐G ubiquitination could be reproduced in vitro in HLA‐G1‐transfected cell lines, although with a lower modified/nonmodified protein proportion than in exudates. In summary, we demonstrate new circulating HLA‐G forms in vivo that open a new perspective in the study of HLA‐G function and analysis.
Galectin‐3 negatively regulates the frequency and function of CD4+CD25+Foxp3+ regulatory T cells and influences the course of Leishmania major infection
Authors: Fermino Marise L. , Dias Fabrício C. , Lopes Carla D. , Souza Maria A. , Cruz Ângela K. , Liu Fu‐Tong , Chammas Roger , Roque‐Barreira Maria Cristina , Rabinovich Gabriel A. , Bernardes Emerson S.
Published: April 2013

Galectin‐3, an endogenous glycan‐binding protein, plays essential roles during microbial infection by modulating innate and adaptive immunity. However, the role of galectin‐3 within the CD4+CD25+Foxp3+ T regulatory (TREG) cell compartment has not yet been explored. Here, we found, in a model of Leishmania major infection, that galectin‐3 deficiency increases the frequency of peripheral TREG cells both in draining lymph nodes (LNs) and sites of infection. These observations correlated with an increased severity of the disease, as shown by increased footpad swelling and parasite burden. Galectin‐3‐deficient (Lgals3−/−) TREG cells displayed higher CD103 expression, showed greater suppressive capacity, and synthesized higher amounts of IL‐10 compared with their wild‐type (WT) counterpart. Furthermore, both TREG cells and T effector (TEFF) cells from Lgals3−/− mice showed higher expression of Notch1 and the Notch target gene Hes‐1. Interestingly, Notch signaling components were also altered in both TREG and TEFF cells from uninfected Lgals3−/− mice. Thus, endogenous galectin‐3 regulates the frequency and function of CD4+CD25+Foxp3+ TREG cells and alters the course of L. major infection.
NK cells – Versatile tools for viral defense and cancer treatment
Authors: Momburg Frank , Watzl Carsten , Cerwenka Adelheid
Published: April 2013

About 150 NK cell researchers met at the German Cancer Research Center (DKFZ) in Heidelberg, Germany from 26–28 September 2012 for the Natural Killer Cell Symposium which was organized by the NK cell study group of the German Society for Immunology (DGfI) and sponsored by the European Journal of Immunology (EJI), the European Federation of Immunological Societies (EFIS) and the DGfI. The meeting was a forum for the discussion of the function and regulation of these fascinating innate immune cells and the opportunities for the transfer of this knowledge to cancer immunotherapy.
Performance of a computer‐based assessment of cognitive function measures in two cohorts of seniors
Authors: Espeland Mark A. , Katula Jeffrey A. , Rushing Julia , Kramer Arthur F. , Jennings Janine M. , Sink Kaycee M. , Nadkarni Neelesh K. , Reid Kieran F. , Castro Cynthia M. , Church Timothy , Kerwin Diana R. , Williamson Jeff D. , Marottoli Richard A. , Rushing Scott , Marsiske Michael , Rapp Stephen R. ,   LIFE Study Group
Published: April 2013

Background

Computer‐administered assessment of cognitive function is being increasingly incorporated in clinical trials; however, its performance in these settings has not been systematically evaluated.

Design

The Seniors Health and Activity Research Program pilot trial (N = 73) developed a computer‐based tool for assessing memory performance and executive functioning. The Lifestyle Interventions and Independence for Elders investigators incorporated this battery in a full‐scale multicenter clinical trial (N = 1635). We describe relationships that test scores have with those from interviewer‐administered cognitive function tests and risk factors for cognitive deficits and describe performance measures (completeness, intraclass correlations [ICC]).

Results

Computer‐based assessments of cognitive function had consistent relationships across the pilot and full‐scale trial cohorts with interviewer‐administered assessments of cognitive function, age, and a measure of physical function. In the Lifestyle Interventions and Independence for Elders cohort, their external validity was further demonstrated by associations with other risk factors for cognitive dysfunction: education, hypertension, diabetes, and physical function. Acceptable levels of data completeness (>83%) were achieved on all computer‐based measures; however, rates of missing data were higher among older participants (odds ratio = 1.06 for each additional year; p < 0.001) and those who reported no current computer use (odds ratio = 2.71; p < 0.001). ICCs among clinics were at least as low (ICC < 0.013) as for interviewer measures (ICC < 0.023), reflecting good standardization. All cognitive measures loaded onto the first principal component (global cognitive function), which accounted for 40% of the overall variance.

Conclusion

Our results support the use of computer‐based tools for assessing cognitive function in multicenter clinical trials of older individuals. Copyright © 2013 John Wiley & Sons, Ltd.
Creation of nanoporous TiO2surface onto polyetheretherketone for effective immobilization and delivery of bone morphogenetic protein
Authors: Han Cheol‐Min , Jang Tae‐Sik , Kim Hyoun‐Ee , Koh Young‐Hag
Published: April 2013

This study evaluated the utility of the creation of a nanoporous TiO2surface to enhance thein vitrobiocompatibility andin vivoosseoconductivity of polyetheretherketone (PEEK) implants by providing favorable sites for the effective immobilization of bone morphogenetic protein‐2 (BMP‐2). A uniform nanoporous TiO2layer with a pore diameter of ∼70 nm was successfully created by anodizing a Ti film, which had been deposited onto a PEEK substrate via electron beam (e‐beam) evaporation technique. This nanoporous, hydrophilic TiO2surface enabled the efficient immobilization of BMP‐2, resulting in a remarkable enhancement inin vitrobiocompatibility that was assessed in terms of cell attachment, proliferation, and differentiation. Thein vivoanimal tests also confirmed that the nanoporous TiO2surface immobilized with BMP‐2 could significantly enhance the osseoconductivity of PEEK implants. The BMP‐immobilized PEEK implant with the nanoporous TiO2surface showed much higher bone‐to‐implant contact (BIC) ratio (60%) than the bare PEEK (30%), PEEK with the nanoporous TiO2surface (50%) and even BMP‐immobilized PEEK without the nanoporous TiO2surface (32%). © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 793–800, 2014.
Hyperdry human amniotic membrane is useful material for tissue engineering: Physical, morphological properties, and safety as the new biological material
Authors: Okabe Motonori , Kitagawa Kiyotaka , Yoshida Toshiko , Suzuki Takuma , Waki Hiroki , Koike Chika , Furuichi Etsuko , Katou Kiyoshi , Nomura Yoshihiro , Uji Yoshinori , Hayashi Atsushi , Saito Shigeru , Nikaido Toshio
Published: April 2013

Human amniotic membrane (AM) has been used widely as graft biomaterial for a variety of clinical applications. But, there are some persistent problems related to the preparation, storage, and sterilization. To resolve these problems, we developed hyperdry AM (HD‐AM) using far‐infrared rays, depression of air, and microwaves and then sterilized by γ‐ray irradiation. To elucidate the benefit of HD‐AM as biological materials, compare with the physical and histological properties of HD‐AM with a freeze‐dried AM (FD‐AM) as typical freeze‐dried methods, evaluate the safety of HD‐AM in vivo experiment used nude mice, and demonstrate the feasibility of HD‐AM transplant in pterygium. The water permeability and the sieving coefficient of HD‐AM were significantly lower than that of FD‐AM. HD‐AM has kept the morphological structure of epithelium and connective tissues. At 18 months after transplanted, single and multilayers of HD‐AM in the intraperitoneal cavity was degraded without any infiltrated cells. For clinical treatment, recurrence of pterygium and regrowth of the subconjunctival fibrosis were not observed during the 6‐month follow‐up periods after the surgery. It was proposed that HD‐AM was a safe and effective new biological material for clinical use including treatment for recurrent pterygium. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 862–870, 2014.
Gelation and biocompatibility of injectable alginate–calcium phosphate gels for bone regeneration
Authors: Alves Cardoso D. , van den Beucken J. J. J. P. , Both L. L. H. , Bender J. , Jansen J. A. , Leeuwenburgh S. C. G.
Published: April 2013

An emerging approach toward development of injectable, self‐setting, and fully biodegradable bone substitutes involves the combination of injectable hydrogel matrices with a dispersed phase consisting of nanosized calcium phosphate particles. Here, novel injectable composites for bone regeneration have been developed based on the combination of ultrapure alginate as the matrix phase, crystalline CaP [monetite and poorly crystalline hydroxyapatite (HA)] powders as both a dispersed mineral phase and a source of calcium for cross‐linking alginate, glucono‐delta‐lactone (GDL) as acidifier and glycerol as both plasticizer and temporary sequestrant. The composites were maximized with respect to CaP content to obtain the highest amount of osteoconductive filler. The viscoelastic and physicochemical properties of the precursor compounds and composites were analyzed using rheometry, elemental analysis (for calcium release and uptake), acidity [by measuring pH in simulated body fluid (SBF)], general biocompatibility (subcutaneous implantation in rabbits), and osteocompatibility (implantation in femoral condyle bone defect of rabbits). The gelation of the resulting composites could be controlled from seconds to tens of minutes by varying the solubility of the CaP phase (HA vs. monetite) or amount of GDL. All composites mineralized extensively in SBF for up to 11 days. In vivo, the composites also disintegrated upon implantation in subcutaneous or bone tissue, leaving behind less degradable but osteoconductive CaP particles. Although the composites need to be optimized with respect to the available amount of calcium for cross‐linking of alginate, the beneficial bone response as observed in the in vivo studies render these gels promising for minimally invasive applications as bone‐filling material. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 808–817, 2014.
Biofilm formation on nanostructured hydroxyapatite‐coated titanium
Authors: Westas Emma , Gillstedt Martin , Lönn‐Stensrud Jessica , Bruzell Ellen , Andersson Martin
Published: April 2013

Biofilm formation on medical devices is a common cause of implant failure, especially regarding implants that breach the epithelial tissue, so‐called transcutaneous implants. Nanotechnology and the development of new nanomaterials have given the opportunity to design nanotextured implant surfaces. Such surfaces have been studied using various in vitro methods showing that nanosized features strongly benefit bone cell growth. However, little is known on how nanostructured features affect biofilm formation. The aim of this study was therefore to examine the shape‐ and chemical‐dependent effect of a nanostructured hydroxyapatite (HA) coating on the degree of Staphylococcus epidermidis biofilm formation. Three different types of nanosized HA particles having different shapes and calcium to phosphate ratios were compared to uncoated turned titanium using safranin stain in a biofilm assay and confocal laser scanning microscopy (CLSM) for assessment of biofilm biomass and bacterial volume, respectively. No difference in biofilm biomass was detected for the various surfaces after 6 h incubation with S. epidermidis. Additionally, image analysis of CLSM Z‐stacks confirmed the biofilm assay and showed similar results. In conclusion, the difference in nanomorphology and chemical composition of the surface coatings did not influence the adhesion and biofilm formation of S. epidermidis. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1063–1070, 2014.
Risk assessment tools to identify women with increased risk of osteoporotic fracture: Complexity or simplicity? A systematic review
Authors: Rubin Katrine Hass , Friis-Holmberg Teresa , Hermann Anne Pernille , Abrahamsen Bo , Brixen Kim
Published: April 2013

A huge number of risk assessment tools have been developed. Far from all have been validated in external studies, more of them have absence of methodological and transparent evidence, and few are integrated in national guidelines. Therefore, we performed a systematic review to provide an overview of existing valid and reliable risk assessment tools for prediction of osteoporotic fractures. Additionally, we aimed to determine if the performance of each tool was sufficient for practical use, and last, to examine whether the complexity of the tools influenced their discriminative power. We searched PubMed, Embase, and Cochrane databases for papers and evaluated these with respect to methodological quality using the Quality Assessment Tool for Diagnostic Accuracy Studies (QUADAS) checklist. A total of 48 tools were identified; 20 had been externally validated, however, only six tools had been tested more than once in a population-based setting with acceptable methodological quality. None of the tools performed consistently better than the others and simple tools (i.e., the Osteoporosis Self-assessment Tool [OST], Osteoporosis Risk Assessment Instrument [ORAI], and Garvan Fracture Risk Calculator [Garvan]) often did as well or better than more complex tools (i.e., Simple Calculated Risk Estimation Score [SCORE], WHO Fracture Risk Assessment Tool [FRAX], and Qfracture). No studies determined the effectiveness of tools in selecting patients for therapy and thus improving fracture outcomes. High-quality studies in randomized design with population-based cohorts with different case mixes are needed.
Building Cohesion Across Representations: A Mechanism for STEM Integration
Authors: Nathan Mitchell J. , Srisurichan Rachaya , Walkington Candace , Wolfgram Matthew , Williams Caro , Alibali Martha W.
Published: April 2013

Purpose

The mechanisms of integration of science, technology, engineering, and mathematics (STEM) remain largely underspecified in the research and policy literatures, despite their purported benefits. Our novel claim is that one key mechanism of STEM integration is producing and maintaining cohesion of central concepts across the range of representations, objects, activities, and social structures in the engineering classroom.

Method

We analyze multiviewpoint videos of multiday classroom activities from Project Lead the Way (PLTW) classes in digital electronics in two urban high schools.

Results

To forge cohesion, teachers use coordination of representations, tools, and materials, and they use projection to reference places and events, past and future. Teachers also perform explicit identification to label central invariant relations that are the conceptual focus of their instruction. Teachers typically perform identification, coordination, and projection on the particular STEM representations used in projects in order to improve the cohesion of the conceptual content of a curriculum unit. Teachers can also represent the larger sequence of project activities within the curriculum to construct a cohesive account of how the various activities and representations relate and build upon key ideas.

Conclusions

This paper found that cohesion‐producing activities promote student understanding by threading conceptual relations through different mathematical representations, scientific laws, technological objects, engineering designs, learning spaces, and social structures. In these ways, cohesion can promote STEM integration in the engineering classroom.