bluuebunny/crossref_metadata_2025 huggingface dataset:
Biodegradable poly(L‐lactic acid)/TiO2 nanocomposites: Thermal properties and degradation
Authors: Buzarovska Aleksandra , Grozdanov Anita
Published: August 2011

Poly(L‐lactic acid)‐titanium dioxide nanocomposites (with various loadings of TiO2: 0.5, 1, 2, 5, and 10 wt %) were produced by solution casting method. The influence of TiO2 on thermal properties and crystallinity of PLA was investigated by DSC and FTIR spectroscopy. The TiO2 nano filler has no significant influence on the characteristic temperatures (Tg, Tc, and Tm), but has high impact on the crystallinity of these systems. The degree of crystallinity Xc significantly increases for PLA nanocomposites loaded with up to 5 wt % of TiO2, while for 10 wt % load of TiO2 it drops below Xc of the pure resin. The degradation of the prepared composites was evaluated hydrolytically in 1N NaOH, enzymatically in α‐amylase solutions, and under UV irradiation. The catalytic effect of TiO2 nano particles on the degradation processes under UV light exposure (λ = 365 nm) and hydrolytic degradation was confirmed with the increase of the filler content. The opposite effect was identified in enzymatic degradation experiments. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Preparation and characterization of dual responsive sodium alginate‐g‐poly(vinyl alcohol) hydrogel
Authors: Xia Cunping , Xiao Congming
Published: August 2011

Poly(vinyl alcohol) (PVA) was chosen as a controllable gelator to prepare sodium alginate (SA)‐based physically cross‐linked dual‐responsive hydrogel by three steps. First, polyvinyl acetate (PVAc) was grafted onto SA via radical copolymerization. Then, the copolymer was subsequently converted into SA‐g‐poly(vinyl alcohol) (SAPVA) by alcoholysis reaction. PVA content of SAPVA was tailored by controlling the graft percentage of PVAc, i.e. through varying the amount of vinyl acetate during copolymerization. Finally, SAPVA hydrogels were formed by freezing‐thawing cycles. The structure of the graft copolymers was verified with FTIR spectroscopy. X‐ray diffraction analysis results revealed that the crystallinity of SAPVA hydrogels depended on the PVA content of SAPVA. The swelling test showed that SAPVA hydrogels were pH‐responsive, and the swelling was reversible. SAPVA hydrogels also behaved electric‐responsive. In addition, the pH‐sensitivity of SAPVA hydrogels was able to be controlled with the composition of the hydrogels. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Using FTIR to predict saccharification from enzymatic hydrolysis of alkali‐pretreated biomasses
Authors: Sills Deborah L. , Gossett James M.
Published: August 2011

Fourier transform infrared, attenuated total reflectance (FTIR‐ATR) spectroscopy combined with partial least squares (PLS) regression accurately predicted 72‐h glucose and xylose conversions (g sugars/100 g potential sugars) and yields (g sugars/100 g dry solids) from cellulase‐mediated hydrolysis of alkali‐pretreated lignocellulose. Six plant biomasses that represent a variety of potential biofuel feedstocks—two switchgrass cultivars, big bluestem grass, a low‐impact, high‐diversity mixture of 32 species of prairie biomasses, mixed hardwood, and corn stover—were subjected to four levels of low‐temperature NaOH pretreatment to produce 24 samples with a wide range of potential digestibility. PLS models were constructed by correlating FTIR spectra of pretreated samples to measured values of gluose and xylose conversions and yields. Variable selection, based on 90% confidence intervals of regression‐coefficient matrices, improved the predictive ability of the models, while simplifying them considerably. Final models predicted sugar conversions with coefficient of determination for cross‐validation (Q2) values of 0.90 for glucose and 0.89 for xylose, and sugar yields with Q2 values of 0.92 for glucose and 0.91 for xylose. The sugar‐yield models are noteworthy for their ability to predict enzymatic saccharification per mass dry solids without a priori knowledge of the composition of the solids. All peaks retained in the final regression coefficient matrices were previously assigned to chemical bonds and functional groups in lignocellulose, demonstrating that the models were based on real chemical information. This study demonstrates that FTIR spectroscopy combined with PLS regression can be used to rapidly estimate sugar conversions and yields from enzymatic hydrolysis of pretreated plant biomass. Biotechnol. Bioeng. 2012; 109:353–362. © 2011 Wiley Periodicals, Inc.
Venous reconstruction based on virtual liver resection to avoid congestion in the liver remnant
Authors: Mise Y , Hasegawa K , Satou S , Aoki T , Beck Y , Sugawara Y , Makuuchi M , Kokudo N
Published: August 2011

Background

Hepatic vein (HV) reconstruction may prevent venous congestion following resection of liver tumours that encroach on major HVs. This study aimed to identify criteria for venous reconstruction based on preoperative evaluation of venous congestion.

Methods

A volumetric analysis using image-processing software was performed in selected patients with liver tumours suspected on preoperative imaging of major HV invasion. The size of the non-congested liver remnant (NCLR) was calculated by subtracting the congested area from the liver remnant. Venous reconstruction was scheduled in patients who met the following criteria: normal liver function (indocyanine green retention rate at 15 min (ICGR15) of less than 10 per cent) with a NCLR smaller than 40 per cent of total liver volume (TLV), or liver dysfunction (ICGR15 10–20 per cent) with a NCLR smaller than 50 per cent of TLV. Surgical outcomes and liver regeneration were investigated.

Results

A total of 55 patients with suspected HV invasion were enrolled. Sacrifice of one or more HVs was deemed possible in 37 patients. Venous reconstruction was scheduled in 18 patients. At operation, there was seen to be no venous involvement in 11 patients. The HV was sacrificed in 29 patients, and preserved or reconstructed in 24. Volume restoration ratios at 3 months were similar in the sacrifice (88 per cent) and preserve (87 per cent) groups. Operating time was shorter (465 min) and blood loss was lower (580 ml) in the sacrifice than in the preserve group (523 min and 815 ml respectively).

Conclusion

The HV can be sacrificed safely according to the proposed criteria, reducing surgical invasiveness without influencing the postoperative course.
Stannylium Ions, a Tin(II) Arene Complex, and a Tin Dication Stabilized by Weakly Coordinating Anions
Authors: Schäfer Annemarie , Winter Florian , Saak Wolfgang , Haase Detlev , Pöttgen Rainer , Müller Thomas
Published: August 2011

The reactivity of aryl‐substituted stannylenes, Ar2Sn (4), towards silylarenium borates, [R3SiArH][B(C6F5)4] (3), was investigated. The reaction with 2,3,4‐trimethyl‐6‐tert‐butylphenyl (mebp)‐substituted stannylene gave silyl‐substituted stannylium ions2 a,b, which were characterized by NMR spectroscopy supported by the results of quantum‐mechanical computations of molecular structures and magnetic properties. The tri‐iso‐propylphenyl‐substituted stannylium ions2 c,dundergo a decomposition reaction in toluene to give the dicationic tin–arene complex [Sn(C7H8)3]2+(5) in the form of the [B(C6F5)4] salt in high yields. The5[B(C6F5)4]2salt was identified by single crystal X‐ray diffraction analysis and by Mössbauer spectroscopy. The bonding situation was investigated by using natural bond orbital (NBO) and quantum theory of atoms in molecules (QTAIM) calculations. The substitution of the weakly coordinating borate anion by the carboranate [CB11H6Br6]−results in replacement of the toluene ligands and formation of tin(II) carboranate with only weak Sn2+–anion interactions as suggested by the solid‐state structure of the isolated salt.
Considerations concerning the Energy Demand and Energy Mix for Global Welfare and Stable Ecosystems
Authors: Jess Andreas , Kaiser Philipp , Kern Christoph , Unde Rajabhau Bajirao , von Olshausen Christian
Published: August 2011

Social indicators show that an annual energy consumption of 2 t of oil equivalent per capita (toe pc) should be enough to ensure a sufficient global average level of welfare and happiness. Hence, rich countries with currently up to 8 toe pc should reduce and poor should legitimately increase their energy demand until 2 toe pc are reached. At today's global energy mix with 80 % fossil fuels, even this optimistic scenario will inevitably lead to a conflict between welfare and stable ecosystems. The population will be 9 billion by 2050 and the ecological footprint would rise from today 1.5 in 2010 to 2 planet Earths. The only option to reach the desired footprint of one planet Earth is a complete shift from fossil fuels to renewables, presumably to solar power. One option is a technology based on four steps: separation of CO2 from flue gases (in the long run from air), H2 production by water electrolysis driven by solar power or other renewables, CO production by reverse water gas shift, and finally synthesis of renewable liquid fuels (gasoline and diesel oil) by Fischer‐Tropsch synthesis.
Impact of preexisting tumor necrosis on the efficacy of stereotactic radiosurgery in the treatment of brain metastases in women with breast cancer
Authors: Xu Zhiyuan , Marko Nicholas F. , Angelov Lilyana , Barnett Gene H. , Chao Samuel T. , Vogelbaum Michael A. , Suh John H. , Weil Robert J.
Published: August 2011

BACKGROUND:

Breast cancer is the second most common source of brain metastasis. Stereotactic radiosurgery (SRS) can be an effective treatment for some patients with brain metastasis (BM). Necrosis is a common feature of many brain tumors, including BM; however, the influence of tumor necrosis on treatment efficacy of SRS in women with breast cancer metastatic to the brain is unknown.

METHODS:

A cohort of 147 women with breast cancer and BM treated consecutively with SRS over 10 years were studied. Of these, 80 (54.4%) had necrosis identified on pretreatment magnetic resonance images and 67 (46.4%) did not. Survival times were computed using the Kaplan‐Meier method. Log‐rank tests were used to compare groups with respect to survival times, Cox proportional hazards regression models were used to perform univariate and multivariate analyses, and chi‐square and Fisher exact tests were used to compare clinicopathologic covariates.

RESULTS:

Neurological survival (NS) and survival after SRS were decreased in BM patients with necrosis at the time of SRS compared with patients without necrosis by 32% and 27%, respectively (NS median survival, 25 vs 17 months [log‐rank test, P = .006]; SRS median survival, 15 vs 11 months [log‐rank test, P = .045]). On multivariate analysis, HER2 amplification status and necrosis influenced NS and SRS after adjusting for standard clinical features, including BM number, size, and volume as well as Karnofsky performance status.

CONCLUSION:

Neuroimaging evidence of necrosis at the time of SRS significantly diminished the efficacy of therapy and was a potent prognostic marker. Cancer 2012. © 2011 American Cancer Society.
Numerical simulation of red blood cell behavior in a stenosed arteriole using the immersed boundary–lattice Boltzmann method
Authors: Vahidkhah Koohyar , Fatouraee Nasser
Published: August 2011

Because of their deformability and tendency to form aggregates, red blood cells (RBCs) immensely affect the hydrodynamic properties of blood flow in microcirculation. In this paper, RBCs' two‐dimensional deformation and motion in Poiseuille flow and in a stenosed arteriole is numerically investigated by the immersed boundary–lattice Boltzmann method. The RBCs are modeled as suspended capsules of fluid in plasma flow. A neo‐Hookean elastic model with bending resistance is utilized for the RBC membrane. Also, the suspending plasma is modeled as an incompressible Newtonian fluid. To take the effects of aggregation and dissociation of RBCs into account, intercellular interaction is modeled by the Morse potential. The effects of essential parameters namely, mechanical resistance of the RBC membrane, plasma viscous forces, and cell membrane adhesion strength on RBC behavior are presented. Motions and deformations of RBCs in a stenosis and the effects of the stenosed zone on the behavior of cell aggregates were also simulated and analyzed in this study. Copyright © 2011 John Wiley & Sons, Ltd.
Renewable Chemicals: Dehydroxylation of Glycerol and Polyols
Authors: ten Dam Jeroen , Hanefeld Ulf
Published: August 2011

The production of renewable chemicals is gaining attention over the past few years. The natural resources from which they can be derived in a sustainable way are most abundant in sugars, cellulose and hemicellulose. These highly functionalized molecules need to be de‐functionalized in order to be feedstocks for the chemical industry. A fundamentally different approach to chemistry thus becomes necessary, since the traditionally employed oil‐based chemicals normally lack functionality. This new chemical toolbox needs to be designed to guarantee the demands of future generations at a reasonable price. The surplus of functionality in sugars and glycerol consists of alcohol groups. To yield suitable renewable chemicals these natural products need to be defunctionalized by means of dehydroxylation. Here we review the possible approaches and evaluate them from a fundamental chemical aspect.
On the other hand: Overflow movements of infants' hands and legs during unimanual object exploration
Authors: Soska Kasey C. , Galeon Margaret A. , Adolph Karen E.
Published: August 2011

Motor overflow is extraneous movement in a limb not involved in a motor action. Typically, overflow is observed in people with neurological impairments and in healthy children and adults during strenuous and attention‐demanding tasks. In the current study, we found that young infants produce vast amounts of motor overflow, corroborating claims of symmetry being the default state of the motor system. While manipulating an object with one hand, all 27 of the typically developing 4.5‐ to 7.5‐month‐old infants who we observed displayed overflow movements of the free hand (on 4/5 of unimanual actions). Mirror‐image movements of the hands occurred on 1/8 of unimanual actions, and the hands and legs moved in synchrony on 1/3 of unimanual acts. Motor overflow was less frequent when infants were in a sitting posture and when infants watched their acting hand, suggesting that upright posture and visual examination may help to alleviate overflow and break obligatory symmetry in healthy infants. © 2011 Wiley Periodicals, Inc. Dev Psychobiol 54:372–382, 2012.
Tcf7l1 is required for spinal cord progenitor maintenance
Authors: Kim Hyung‐Seok , Dorsky Richard I.
Published: August 2011

Neural progenitor cells must be maintained during development in order to produce the full complement of neuronal and glial derivatives. While molecular pathways have been identified that inhibit progenitor differentiation, it is unclear whether the progenitor state itself is actively maintained. In this study, we have investigated the role of Tcf7l1 (formerly named Tcf3) in maintaining spinal progenitor characteristics and allowing the continued production of neurons and glia following primary neurogenesis. We find that spinal cord progenitor markers are progressively lost in embryos lacking Tcf7l1, and that the number of proliferative progenitors decreases accordingly. Furthermore, we show that the production of both neuronal and glial secondary derivatives of the pMN progenitor pool requires Tcf7l1. Together, these results indicate that Tcf7l1 plays an important role in spinal cord progenitor maintenance, indicating that this core function is conserved throughout multiple epithelial cell populations. Developmental Dynamics 240:2256–2264, 2011. © 2011 Wiley‐Liss, Inc.
The Uncatalyzed Direct Amide Formation Reaction – Mechanism Studies and the Key Role of Carboxylic Acid H‐Bonding
Authors: Charville Hayley , Jackson David A. , Hodges George , Whiting Andrew , Wilson Mark R.
Published: August 2011

Calorimetric studies of the mixing of a series of carboxylic acids and amines have been carried out to measure heat output, which has been compared with their ability to react to form carboxylate ammonium salts and amides. In order to identify which species (salt or H‐bonded species) were formed, 1H NMR studies were also carried out by mixingcarboxylic acids and amines in [D8]toluene and monitoring the resulting reactions. These experiments were also compared to DFT computational studies, from which the relative merits of different mechanistic schemes for direct amide formation could be assessed. A reaction mechanism involving zwitterionic intermediates could be eliminated on the basis of calculated energies in toluene, however, a neutral intermediate pathway, involving carboxylic acid dimerization by mutual hydrogen bonding was found to be accessible and may explain how the direct amide formation reaction occurs. Such a mechanism is not inconsistent with kinetic modelling of direct amide formation under different reactions conditions.
Asymmetric Synthesis of Functionalized Bicyclic β‐Amino Alcohols by Cascade Hydrometallation–Cyclization–Reduction of Glycinyl‐Substituted Alkenylsulfox­imines – Application to the Synthesis of an Aggrecanase Inhibitor Mimic
Authors: Acikalin Serdar , Raabe Gerhard , Runsink Jan , Gais Hans‐Joachim
Published: August 2011

The treatment of exocyclic alkenylsulfoximines, which carry an α‐glycinyl group at the allylic position, with HAliBu2 caused cascade hydroalumination–cyclization–reduction and delivered the corresponding enantio‐ and diastereopure sulfoximine‐substituted bicyclic β‐amino alcohols with a bicyclo[3.3.0]octane and bicyclo[4.3.0]nonane skeleton in high yields. Three consecutive stereogenic C atoms of the bicyclic β‐amino alcohols were generated in the cascade reactions with high diastereoselectivities. Application of the hydroalumination–cyclization–reduction to a ketal‐substituted six‐membered exocyclic alkenylsulfoximine afforded the corresponding sulfoximine‐substituted β‐amino alcohol with aketal‐functionalized bicyclo[4.3.0]nonane skeleton. Reduction of a sulfoximine‐substituted β‐amino alcohol gave the parent β‐amino alcohol, whereas its oxidative deamination afforded the corresponding sulfonyl‐substituted β‐amino alcohol. The treatment of a sulfoximine‐substituted β‐amino alcohol with chloro‐ and iodoformates stereoselectively furnished the corresponding chloro‐ and iodo‐substituted β‐amino alcohols. Finally, the feasibility of a dehydration and elimination of sulfoximine‐substituted β‐amino alcohols with formation of the corresponding amino‐substituted alkenylsulfoximine and allylic amine was demonstrated. An enantio‐ and diastereopure protected aggrecanase inhibitor mimic was synthesized in high yield starting from the sulfoximine‐substituted bicyclic β‐amino alcohol with a bicyclo[4.3.0]nonane skeleton and (R)‐2‐(3‐benzyloxy)benzyl‐4‐tert‐butoxy‐4‐oxobutanoic acid. Coupling of both building blocks gave the corresponding succinamide, the tert‐butoxycarbonyl group of which was converted into the corresponding O‐benzyl‐hydroxycarbamoyl group.
Insulator‐based dielectrophoretic single particle and single cancer cell trapping
Authors: Bhattacharya Sanchari , Chao Tzu‐Chiao , Ros Alexandra
Published: August 2011

Trapping of individual cells at specific locations in a microfluidic lab‐on‐a‐chip platform is essential for single cell studies, especially those requiring individual stimulation followed by downstream analysis. To this aim, we have designed microdevices based on direct current (DC) insulator‐based dielectrophoresis (iDEP) acting as individual single cell traps. We present both the design of a negative iDEP trap and a positive iDEP trap using insulating posts integrated at microchannel intersections. We obtained electric field distributions via numerical simulations adapted to the intersection and trap geometry with which we predict single particle pathlines. With polystyrene particles of 10 μm diameter, we demonstrated an effective design for a single particle trap in the case of negative dielectrophoresis. The onset trapping voltage shows an inverse relation to the buffer conductivity, thus indicating the influence of electrokinetic effects on the trapping behavior. Additionally, we demonstrated the proof‐of‐principle of single MCF‐7 breast cancer cell trapping in a positive iDEP trap. Our single particle trapping experiments were further in very good agreement with numerical simulations. To ensure that no significant damage occurred to the cells during the experiment, we further optimized medium conditions to ensure viability of the cells for at least 1 h, more than sufficient for microfluidic trapping experiments. Our results thus indicated the successful design of DC iDEP traps, which can easily be integrated into a variety of microchip operations for single cell analysis.
Explorations of ABO‐Rh antigen expressions on erythrocyte dielectrophoresis: Changes in cross‐over frequency
Authors: Leonard Kaela M. , Minerick Adrienne R.
Published: August 2011

A quadrupole dielectrophoretic microdevice was utilized to examine the ABO‐Rh dependencies on erythrocyte polarizations. This important step toward medical microdevice technology would transform key clinical blood tests from the laboratory into the field. Previous work in dielectrophoretic microdevices demonstrated that the large number of ABO antigens on erythrocyte membranes impacts their dielectrophoretic signature at 1 MHz. This work explores the dielectrophoretic behavior of native human erythrocytes categorized by their ABO‐Rh blood types and directly compares these responses to the same erythrocyte sample modified to remove the A and B antigens. A β(1–3)‐galactosidase enzyme was utilized to cleave the ABO polysaccharide backbone at the galactosidase bonds. The enzymatic reaction was optimized by comparing agglutination of the native and modified blood cells in addition to UV–Vis and HPLC analysis of the reaction effluent for saccharide residues. Next, the dielectrophoretic behaviors of the native and modified erythrocytes were visually verified in a quadrupole electrode microdevice over a frequency range from 100 kHz to 80 MHz. The lower cross‐over frequency (COF), which transitions from negative to positive dielectrophoresis, for ABO blood types tested (A+, A−, B+, B−, AB+, O+ and O−) differed over the range from 17 to 47 MHz. The COFs of the corresponding enzyme‐modified erythrocytes were also determined and the range narrowed to 29–41 MHz. A second COF in the 70–80 MHz range was observed and was reduced in the presence of the transmembrane Rhesus factor. These results suggest that antigen expression on erythrocyte membrane surfaces influence cell polarizations in nonuniform AC fields.
Separation of mixtures of particles in a multipart microdevice employing insulator‐based dielectrophoresis
Authors: Gallo‐Villanueva Roberto C. , Pérez‐González Victor H. , Davalos Rafael V. , Lapizco‐Encinas Blanca H.
Published: August 2011

Dielectrophoresis is the electrokinetic movement of particles due to polarization effects in the presence of non‐uniform electric fields. In insulator‐based dielectrophoresis (iDEP) regions of low and high electric field intensity, i.e. non‐uniformity of electric field, are produced when the cross‐sectional area of a microchannel is decreased by the presence of electrical insulating structures between two electrodes. This technique is increasingly being studied for the manipulation of a wide variety of particles, and novel designs are continuously developed. Despite significant advances in the area, complex mixture separation and sample fractionation continue to be the most important challenges. In this work, a microchannel design is presented for carrying out direct current (DC)‐iDEP for the separation of a mixture of particles. The device comprises a main channel, two side channels and two sections of cylindrical posts with different diameters, which will generate different non‐uniformities in the electric field on the main channel, designed for the discrimination and separation of particles of two different sizes. By applying an electric potential of 1000 V, a mixture of 1 and 4 μm polystyrene microspheres were dielectrophoretically separated and concentrated at the same time and then redirected to different outlets. The results obtained here demonstrate that, by carefully designing the device geometry and selecting operating conditions, effective sorting of particle mixtures can be achieved in this type of multi‐section DC‐iDEP devices.
Characterization of lead induced metal–phytochelatin complexes in Chlamydomonas reinhardtii
Authors: Scheidegger Christian , Sigg Laura , Behra Renata
Published: August 2011

Accumulation of Pb and induction of phytochelatin synthesis were observed in Chlamydomonas reinhardtii upon Pb(II) exposure. Our aim was to examine whether Pb(II) is bound by phytochelatins (PCs) in C. reinhardtii and to examine formed complexes for their stoichiometry and composition. Metal–phytochelatin (Me-PC) complexes induced by Pb were isolated by size-exclusion chromatography in 13 collected fractions, which were analyzed for their PC and metal content by high-performance liquid chromatography and inductively coupled plasma mass spectrometry. A recovery of more than 90% of Pb from standard Pb-PC2 complexes within the total volume of the size-exclusion column indicated the adequacy of the method for Pb-PCn complex separation and characterization. Phytochelatins were detected mainly in a molecular weight ranging from 1,000 to 5,300 daltons (Da), indicating the formation of complexes with various stoichiometries. Approximately 72% of total PC2 eluted in the range from 1,000 to 1,600 Da, and 80% of total PC3 eluted in the molecular weight range from 1,600 to 2,300 Da. The distribution of Cu, Zn, and Pb showed that more than 70% of these metals were associated with the high-molecular-weight fractions. Copper, zinc, and lead were also observed in PC-containing fractions, suggesting the formation of various Me-PC complexes. The results of the present study indicate that the role of PCs in Pb detoxification is minor, because only 13% of total Pb was associated with PCs. Environ. Toxicol. Chem. 2011;30:2546–2552. © 2011 SETAC
Epidermal growth factor receptor expression in acute myelogenous leukaemia is associated with clinical prognosis
Authors: Sun Jun‐Zhong , Lu Ying , Xu Yin , Liu Fang , Li Fu‐Quan , Wang Quan‐Li , Wu Chu‐Tse , Hu Xian‐Wen , Duan Hai‐Feng
Published: August 2011

The epidermal growth factor receptor (EGFR) family belongs to type I receptor tyrosine kinases. Overexpression or mutation of EGFR/ErbB1 gene has been detected in a large number of human solid tumours. According to some previous report, this gene is not expressed in hematological malignancies. However, two recent clinical case reports showed that erlotinib caused complete remission of acute myeloid leukaemia (AML)‐M1 in patients who had both AML‐M1 and non‐small‐cell lung cancer. These results are supported by preclinical studies in which EGFR tyrosine kinase inhibitors have anti‐proliferative effects on AML. These findings prompted us to determine whether EGFR is expressed in human AML, through a large‐scale screening of both leukaemic cell lines and clinical samples. Our results show that EGFR is expressed by about 33% of human AML (containing M1 to M7 subtypes) and by some human leukaemia cell lines (K562, MEG‐01, CEM and SKO‐007). Its expression is not limited to certain AML types but has been detected in many leukaemic cells. In addition, EGFR expression was intimately associated with the poor clinical outcomes. Finally, we find that only EGFR‐positive leukaemic cells respond to antibody‐dependent cellular cytotoxicity of cetuximab, the monoclonal antibodies against EGFR. Copyright © 2011 John Wiley & Sons, Ltd.
Repeated transfusions of autologous cytokine‐induced killer cells for treatment of haematological malignancies in elderly patients: a pilot clinical trial
Authors: Yang Bo , Lu Xue‐chun , Yu Rui‐li , Chi Xiao‐hua , Liu Yang , Wang Yao , Dai Han‐ren , Zhu Hong‐li , Cai Li‐li , Han Wei‐dong
Published: August 2011

The elderly population is susceptible to haematological malignancies, and these elderly patients are intolerant to cytotoxic drugs. Therefore, the exploration of a safe and reliable strategy exclusive of chemotherapy is critical in improving the prognosis of elderly patients with haematological malignancies. We evaluated the safety and the efficacy of autologous cytokine‐induced killer (CIK) cells combined with recombinant human interleukin 2 (rhIL‐2) in the treatment of haematological malignancies in elderly patients. Peripheral blood mononuclear cells were isolated from 20 elderly patients with haematological malignancies, then augmented by priming with interferon gamma, rhIL‐2 and CD3 monoclonal antibody. The autologous CIK cells (2–3 × 109) were transfused back to patients, followed by a subcutaneous injection of IL‐2 (1 mU/day) for 10 consecutive days. The regimen was repeated every 4 weeks. The host cellular immune function, tumour‐related biological parameters, imaging characteristics, disease condition, quality of life and survival time were assessed. Fourteen patients received 8 cycles of transfusion and 6 received 4 cycles. No adverse effects were observed. The percentages of CD3+, CD3+CD8+ and CD3+CD56+ cells were significantly increased (p < 0.05), and the levels of serum β2 microglobulin and lactate dehydrogenase (LDH) were markedly decreased (p < 0.05) after autologous CIK cell transfusion. Cancer‐related symptoms were profoundly alleviated, as demonstrated by the improved quality of life (p < 0.01). Complete remission was observed in 11 patients, persistent partial remission in 7 patients and stable disease in 2 patients. At the end of follow‐up, the mean survival time was 20 months. Transfusion with autologous CIK cells plus rhIL‐2 treatment is safe and effective for treating haematological malignancies in elderly patients. Copyright © 2011 John Wiley & Sons, Ltd.
Polyimine Container Molecules and Nanocapsules
Authors: Rue Nicholas M. , Sun Junling , Warmuth Ralf
Published: August 2011

The field of dynamic covalent nanocapsule synthesis is very young, and most contributions to the development of reliable approaches for the assembly of dynamic covalent capsules have been made during the past five years. In 1991, Quan and Cram published the first Schiff base molecular container compound. Over the past six years, a large number of multi‐component polyimine hemicarcerand and polyhedron syntheses have been developed. This review will focus primarily on recent achievements in the area of pure Schiff base nanocapsules and highlight different synthetic approaches and design strategies, as well as first applications of these capsules in molecular recognition, gas storage, and gas separation.
Tissue distribution and histopathological effects of titanium dioxide nanoparticles after intravenous or subcutaneous injection in mice
Authors: Umbreit T. H. , Francke‐Carroll S. , Weaver J. L. , Miller T. J. , Goering P. L. , Sadrieh N. , Stratmeyer M. E.
Published: August 2011

Nanoparticles can be formed following degradation of medical devices such as orthopedic implants. To evaluate the safety of titanium alloy orthopedic materials, data are needed on the long‐term distribution and tissue effects of injected titanium nanoparticles in experimental animals. In this study, we evaluated the tissue distribution and histopathological effects of titanium dioxide (TiO2) nanoparticles (approximately 120 nm diameter) in mice after intravenous (i.v.; 56 or 560 mg kg−1 per mouse) or subcutaneous (s.c.; 560 or 5600 mg kg−1 per mouse) injection on two consecutive days. Animals were examined 1 and 3 days, and 2, 4, 12 and 26 weeks after the final injection. When examined by light microscopy, particle agglomerates identified as TiO2 were observed mainly in the major filtration organs – liver, lung and spleen – following i.v. injection. Particles were still observed 26 weeks after injection, indicating that tissue clearance is limited. In addition, redistribution within the histological micro‐compartments of organs, especially in the spleen, was noted. Following s.c. injection, the largest particle agglomerates were found mainly in the draining inguinal lymph node, and to a lesser extent, the liver, spleen and lung. With the exception of a foreign body response at the site of s.c. injection and the appearance of an increased number of macrophages in the lung and liver, there was no histopathological evidence of tissue damage observed in any tissue at any time point. Published 2011. This article is a US Government work and is in the public domain in the USA.
Polypyrrole‐contained electrospun conductive nanofibrous membranes for cardiac tissue engineering
Authors: Kai Dan , Prabhakaran Molamma P. , Jin Guorui , Ramakrishna Seeram
Published: August 2011

Cardiac tissue engineering (TE) is one of the most promising strategies to reconstruct infarct myocardium and the major challenge is to generate a bioactive substrate with suitable chemical, biological, and conductive properties, thus mimicking the extracellular matrix (ECM) both structurally and functionally. In this study, polypyrrole/poly(ε‐caprolactone)/gelatin nanofibrous scaffolds were electrospun by incorporating different concentrations of polypyrrole (PPy) to PCL/gelatin (PG) solution. Morphological, chemical, mechanical, and biodegradation properties of the electrospun nanofibers were evaluated. Our data indicated that by increasing the concentration of PPy (0–30%) in the composite, the average fiber diameters reduced from 239 ± 37 nm to 191 ± 45 nm, and the tensile modulus increased from 7.9 ± 1.6 MPa to 50.3 ± 3.3 MPa. Conductive nanofibers containing 15% PPy (PPG15) exhibited the most balanced properties of conductivity, mechanical properties, and biodegradability, matching the requirements for regeneration of cardiac tissue. The cell proliferation assay, SEM, and immunostaining analysis showed that the PPG15 scaffold promote cell attachment, proliferation, interaction, and expression of cardiac‐specific proteins better than PPG30. Electrospun PPG15 conductive nanofibrous scaffold could be desirable and promising substrates suitable for the regeneration of infarct myocardium and cardiac defects. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.
Ubiquitination-deubiquitination balance dictates ligand-stimulated PTHR sorting
Authors: Alonso Verónica , Magyar Clara E , Wang Bin , Bisello Alessandro , Friedman Peter A
Published: August 2011

Parathyroid hormone receptors (PTHR) are promptly internalized upon stimulation by activating (PTH[1-84], PTH[1-34]) and non-activating (PTH[7-84], PTH[7-34]) ligands. Here, we characterized the mechanism regulating the sorting of internalized receptors between recycling and degradative pathways. PTHR recycles faster after challenge with PTH(1-34) than with PTH(7-34). PTHR recycling is complete by 2 h after PTH(1-34) stimulation, but incomplete at this time in cells treated with PTH(7-34). The slower and incomplete recycling induced by PTH(7-34) is due to proteasomal degradation. Both PTH(1-34) and PTH(7-34) induced PTHR polyubiquitination. Ubiquitination by PTH(1-34) was transient, whereas receptor ubiquitination after PTH(7-34) was sustained. PTH(1-34), but not PTH(7-34), induced expression of the PTHR-specific deubiquitinating enzyme USP2. Overexpression of USP2 prevented PTH(7-34)-induced PTHR degradation. We conclude that PTH(1-34) promotes coupled PTHR ubiquitination and deubiquitination, whereas PTH(7-34) activates only ubiquitination, thereby leading to PTHR downregulation. These findings may explain PTH resistance in diseases associated with elevated PTH(7-84) levels. © 2011 American Society for Bone and Mineral Research
miR‐520c and miR‐373 upregulate MMP9 expression by targeting mTOR and SIRT1, and activate the Ras/Raf/MEK/Erk signaling pathway and NF‐κB factor in human fibrosarcoma cells
Authors: Liu Ping , Wilson Michael J.
Published: August 2011

MicroRNA 520c and 373 (miR‐520c and miR‐373) have been characterized as oncogenes and play critical roles in cancer cell metastasis. However, the relationship between these two microRNAs and matrix metalloproteinases (MMPs), which are important in cancer cell metastasis, remains unknown. Here, we report new evidence in which miR‐520c and miR‐373 effects in human fibrosarcoma HT1080 cells are associated with MMP9 activity, and this upregulation of MMP9 is not only at the activity and protein levels, but also at that of its mRNA. Our experimental data demonstrate that these effects occur not by direct binding to the MMP9 promoter, but by miR‐520c and miR‐373 directly targeting the 3′‐untranslational region (UTR) of mRNAs of mTOR and SIRT1 (negative regulators of expression of MMP9 via inactivating the Ras/Raf/MEK/Erk signaling pathway and transcription factor NF‐κB activity); and thus suppressing translation levels of SIRT1 and mTOR. Moreover, inhibition of key kinases of the Ras/Raf/MEK/Erk signaling pathway and Western blots for selected proteins further identified miR‐520c and miR‐373 as activating this signaling pathway and NF‐κB. In conclusion, miR‐520c and miR‐373 increased the expression of MMP9 by directly targeting the 3′‐UTRs of mRNAs of mTOR and SIRT1 and suppressing their translation; resulting in activation of the Ras/Raf/MEK/Erk signaling pathway and NF‐κB; and, finally, increasing the mRNA, protein, and activity of MMP9 and enhancing cell migration and cell growth in 3D type I collagen gels. J. Cell. Physiol. 227: 867–876, 2012. © 2011 Wiley Periodicals, Inc.
Clinical and economic outcomes of low‐field intraoperative MRI‐guided tumor resection neurosurgery
Authors: Makary Mina , Chiocca E. Antonio , Erminy Natali , Antor María , Bergese Sergio D. , Abdel‐Rasoul Mahmoud , Fernandez Soledad , Dzwonczyk Roger
Published: August 2011

Purpose:

To compare low‐field (0.15 T) intraoperative magnetic resonance imaging (iMRI)‐guided tumor resection with both conventional magnetic resonance imaging (cMRI)‐guided tumor resection and high‐field (1.5 T) iMRI‐guided resection from the clinical and economic point of view.

Materials and Methods:

We retrospectively compared 65 iMRI patients with 65 cMRI patients in terms of hospital length of stay, repeat resection rate, repeat resection interval, complication rate, cost to the patient, cost to the hospital, and cost effectiveness. In addition, we compared our low‐field results with previously published high‐field results.

Results:

The complication rate was lower for iMRI vs. cMRI in patients presenting for their initial tumor resection (45 vs. 57 complications, P = 0.048). The iMRI repeat resection interval was longer for this cohort (20.1 vs. 6.7 months, P = 0.020). iMRI was more cost‐effective than cMRI for patients who had repeat resections ($10,690/RFY vs. $76,874/RFY, P < 0.001). We found no other clinical or economic differences between iMRI‐ and cMRI‐guided tumor resection surgeries. Overall, we did not find the advantages to low‐field iMRI that have been reported for high‐field iMRI.

Conclusion:

There is no adequate justification for the widespread installation of low‐field iMRI in its current development state. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.
Molecularly imprinted solid‐phase extraction coupled with HPLC for the selective determination of monobutyl phthalate in bottled water
Authors: Qi Peipei , Wang Jincheng , Li Yun , Su Fan , Jin Jing , Chen Jiping
Published: August 2011

A molecularly imprinted polymer (MIP) was prepared using monobutyl phthalate as template. The synthesis was optimized by using different porogens and functional monomers. The MIP was used as a selective sorbent in molecularly imprinted solid‐phase extraction (MIP‐SPE) for pre‐concentration and determination of monobutyl phthalate (mBP) from the bottled water. The difference in recognition selectivity of the polymer columns was observed in HPLC system, and the effect of the mobile phase on the performance of MIP columns was also investigated. Control of the MIP‐SPE process is seen as important in helping to facilitate the selective extraction of mBP from water samples. Thereafter, the choice of washing solvent, eluting solvent amount, pH of loading sample, flow rate of loading solution and the loading sample volume was presented. The optimized procedure was described as follows: 25 mL spiked aqueous solution was percolated through the MIP‐SPE cartridge at the flow rate of 1.5 mL/min. After rinsing with acetonitrile/methanol mixture (1:1, v/v), the bound analyte was desorbed with 3 mL methanol. The developed MIP‐SPE method was demonstrated to be applicable for the analysis of mBP in the bottled water.
Estimation of dermal and oral exposure of children to scented toys: Analysis of the migration of fragrance allergens by dynamic headspace GC–MS
Authors: Masuck Ines , Hutzler Christroph , Luch Andreas
Published: August 2011

Fragrances capable of inducing contact allergy in skin potentially can migrate from the toy to the child via oral or dermal contacts. The goal of this work was the developing of an analytical method based on dynamic headspace GC–MS to determine the concentration of 24 fragrances in saliva or sweat simulant. Under optimized conditions, 5 mL of the migration simulant with 2 g sodium chloride were incubated for 10 min at 30°C. The headspace was purged at a flow rate of 50 mL/min. The compounds were quantified by internal calibration resulting in good linearity (>0.991). The recovery was greater than 66.3% for most of the compounds. The limits of detection ranged between 0.5 ng/mL for hydrophobic and 196.0 ng/mL for hydrophilic fragrances. The method was subsequently applied to seven real toys purchased from the market. The highest migration rate could be observed for benzyl benzoate with 268.0 ng/cm2/min. Based on the migration data measured, the ranges of dermal and oral exposure of children to fragrances in scented toys were calculated. The maximum oral and dermal exposure levels were estimated at 22.2 μg per kg body weight (BW) and day (d) for benzyl benzoate and 605.0 μg/kg BW/d for benzyl alcohol, respectively.
Organ Quality and Quality of Life After Liver Transplantation†
Authors: Volk Michael L. , Hagan Michael
Published: August 2011

Not only is there a limited supply of organs for liver transplantation, but the quality of the available organs is not uniform. Risk factors such as donor age and cause of death are known to predict graft failure, but their impact on the recipient's quality of life (QOL) has not been reported. We sent a QOL survey to 299 adults at our institution who had received a liver transplant 1 to 7 years before the study. For the 171 patients (57%) who completed the Medical Outcomes Study Short Form 36 (SF-36), the mean Physical Composite Score (PCS) and the mean Mental Composite Score (MCS) were 61 and 66, respectively; the highest scores were for the Social Functioning subscale, and the lowest scores were for the Role Functioning/Physical and Energy/Fatigue subscales. The mean donor risk index (DRI) of the organs that the subjects received was 1.4 (range = 0.8-2.4). There was no correlation between the SF-36 scores and the DRI [there were changes of −4.8 and −2.8 in the PCS and MCS per unit increase in the DRI (P = 0.4 and 0.6, respectively)], even though we controlled for potential confounders such as age, sex, hospitalization before transplantation, the Model for End-Stage Liver Disease score at transplantation, years since transplantation, previous transplantation, and the Charlson comorbidity index. In conclusion, we found no association between organ quality and QOL after liver transplantation. If this finding is confirmed in prospective, multicenter studies, it will be useful in counseling patients about the decision to accept or not accept high-risk organ offers. Liver Transpl, 2011. © 2011 AASLD.
Submaximal cardiopulmonary exercise testing predicts 90-day survival after liver transplantation
Authors: Prentis James M. , Manas Derek M. D. , Trenell Michael I. , Hudson Mark , Jones David J. , Snowden Chris P.
Published: August 2011

Liver transplantation has a significant early postoperative mortality rate. An accurate preoperative assessment is essential for minimizing mortality and optimizing limited donor organ resources. This study assessed the feasibility of preoperative submaximal cardiopulmonary exercise testing (CPET) for determining the cardiopulmonary reserve in patients being assessed for liver transplantation and its potential for predicting 90-day posttransplant survival. One hundred eighty-two patients underwent CPET as part of their preoperative assessment for elective liver transplantation. The 90-day mortality rate, critical care length of stay, and hospital length of stay were determined during the prospective posttransplant follow-up. One hundred sixty-five of the 182 patients (91%) successfully completed CPET; this was defined as the ability to determine a submaximal exercise parameter: the anaerobic threshold (AT). Sixty of the 182 patients (33%) underwent liver transplantation, and the mortality rate was 10.0% (6/60). The mean AT value was significantly higher for survivors versus nonsurvivors (12.0 ± 2.4 versus 8.4 ± 1.3 mL/minute/kg, P < 0.001). Logistic regression revealed that AT, donor age, blood transfusions, and fresh frozen plasma transfusions were significant univariate predictors of outcomes. In a multivariate analysis, only AT was retained as a significant predictor of mortality. A receiver operating characteristic curve analysis demonstrated sensitivity and specificity of 90.7% and 83.3%, respectively, with good model accuracy (area under the receiver operating characteristic curve = 0.92, 95% confidence interval = 0.82–0.97, P = 0.001). The optimal AT level for survival was defined to be >9.0 mL/minute/kg. The predictive value was improved when the ideal weight was substituted for the actual body weight of a patient with refractory ascites, even after a correction for the donor's age. In conclusion, the preoperative cardiorespiratory reserve (as defined by CPET) is a sensitive and specific predictor of early survival after liver transplantation. The predictive value of CPET requires further evaluation. Liver Transpl 18:152–159, 2012. © 2011 AASLD.
Vibrational Spectroscopic and Mechanical Investigation of Carbon Nanotube‐Reinforced Styrene‐Butadiene Rubbers
Authors: Bokobza Liliane
Published: August 2011

This paper reports investigations carried out on elastomeric matrices based on a styrene‐butadiene copolymer filled with multiwall carbon nanotubes. Stress‐strain measurements of the composites demonstrate that carbon nanotubes bring significantly improvements in the mechanical properties with regard to the pure polymer. Raman spectroscopy, which is one of the most extensively employed methods for the characterization of carbon materials, has been applied for the analysis of the dependence of the Raman spectra on the nanotube content and on application of an uniaxial deformation. The results reveal a negligible stress transfer suggesting a weak interface between the tubes and the polymer chains.
Hydrogen Bonding in Polyurethane‐Silica Nanocomposites
Authors: Bistričić Lahorija , Baranović Goran , Leskovac Mirela , Bajsić Emi Govorčin
Published: August 2011

Thin films of polyester‐based polyurethane‐silica nanocomposites with 34% hard segments and different concentrations of nano SiO2 filler (0, 0.5, 1.0 and 3 vol.%) have been prepared. The hydrogen bonding and orientational behaviour of hard and soft segments were analysed using infrared linear dichroic measurements. The number of hydrogen bonded NH and CO groups and orientation function were calculated from polarized FTIR spectra. The presence of nanosilica slightly increased the number of hydrogen bonded carbonyls. The soft segments in nanocomposite films display increased orientation in comparison to the neat polymer film. The addition of 3% nanosilica significantly reduced elongation at break. The results were compared with hydrogen bonding and orientational behaviour of thin film of polyether‐based silica nanocomposites.