bluuebunny/crossref_metadata_2025 huggingface dataset:
Face Recognition Using Simplified Probabilistic Linear Discriminant Analysis
Authors: Vesnicer Boštjan , Gros Jerneja Žganec , Pavešić Nikola , Štruc Vitomir
Published: November 2012

Face recognition in uncontrolled environments remains an open problem that has not been satisfactorily solved by existing recognition techniques. In this paper, we tackle this problem using a variant of the recently proposed Probabilistic Linear Discriminant Analysis (PLDA). We show that simplified versions of the PLDA model, which are regularly used in the field of speaker recognition, rely on certain assumptions that not only result in a simpler PLDA model, but also reduce the computational load of the technique and – as indicated by our experimental assessments – improve recognition performance. Moreover, we show that, contrary to the general belief that PLDA-based methods produce well calibrated verification scores, score normalization techniques can still deliver significant performance gains, but only if non-parametric score normalization techniques are employed. Last but not least, we demonstrate the competitiveness of the simplified PLDA model for face recognition by comparing our results with the state-of-the-art results from the literature obtained on the second version of the large-scale Face Recognition Grand Challenge (FRGC) database.
Formation Control and Obstacle Avoidance for Multiple Robots Subject to Wheel-Slip
Authors: Ze-Su Cai , Jie Zhao , Jian Cao
Published: November 2012

An adaptive formation control law for non-holonomic dynamic robots based on an artificial potential function method in the presence of lateral slip and parametric uncertainties is presented to organize multiple robots into formation. It is formulated to achieve the smooth control of the translational and rotational motion of a group of mobile robots while keeping a prescribed formation and avoiding inter-robot and obstacle collisions. In order to improve the formation control method effectively and reduce the distortion shape, the virtual leader-following method is proposed for every robot and an improved optimal assignment algorithm is used to solve multi-targets optimal assignment for the formation problem. Simulation results are provided to validate the theoretical results.
A Ground Experiment System of a Free-Floating Robot for Fine Manipulation
Authors: Liu Houde , Liang Bin , Xu Wenfu , Di Zhang , Wang Xueqian
Published: November 2012

Robotic systems are expected to play an increasingly important role in future space activities with the development of space technology. One broad area of application is in the servicing, construction and maintenance of satellites and large space structures in orbit. Fine manipulation technology is very important for space robots to be able to perform these tasks, since it must ensure safe and reliable interaction with objects or the environment. In order to assure the task is accomplished successfully, ground experimentations are required in order to verify key planning and control algorithms before the space robot is launched. In this paper, based on the concept of a hybrid approach combining the mathematical model with the physical model, a ground experiment system is set up, which is composed of two industrial robots, global and hand-eye visual equipment, six-axis force/torquesensors, guide rail and four computers. Many control approaches of fine manipulation, such as compliance control, impedance control, hybrid force/position control, intelligent control and so on, can be verified using this system. As an example, a contour curves tracking experiment based on the compliance control strategy is performed. Experiment results show that the ground system is very useful for verifying the dexterous manipulation technology of space robots.
Degree of Openness and Performance in the Search for Innovation
Authors: Martini Antonella , Aloini Davide , Neirotti Paolo
Published: November 2012

External knowledge has been the object of increasing attention in the past few years, corresponding to the rise in company innovation models that are based on a higher degree of openness towards external actors. This study investigates the practices that firms adopt in searching for external knowledge to innovate their products, exploring the relationships between performance of innovation processes and the breadth and depth of search practices. In so doing, we explore the role of openness through the lens of search practices, rather than examining the variety of external actors from which firms draw relevant knowledge for product innovation.
ISO14001: Motivations and Benefits in the Italian Metal Industry
Authors: Arena Marika , Azzone Giovanni , Platti Matteo
Published: November 2012

In recent years, metal companies have devoted increasing attention to environmental sustainability and the metal sector has become one of the industries with a higher propensity to certificate ISO 14001. However, at present, only limited research has analysed the implementation of ISO 14001 among metal companies, exploring the dynamics associated with the choice of companies to certificate. This paper aims to fill this gap, analysing motivations and benefits of the implementation of ISO 14001 in the metal industry. Data collection was performed through a survey among certified companies competing in the Italian metal industry. Overall 119 certified companies were contacted and we obtained 46 usable questionnaires (final response rate: 39%). The results of the analysis show priorities for the implementation and benefits of ISO 14001, and also a few areas where there was a decoupling between the importance assigned by companies to the potential benefit and the results achieved.
Intellectual Capital and Innovative Work Behaviour: Opening the Black Box
Authors: Mura Matteo , Lettieri Emanuele , Spiller Nicola , Radaelli Giovanni
Published: November 2012

Continuous improvement initiatives have proliferated among manufacturing and services organizations. In this context, knowledge has been claimed to play a key role, as a significant antecedent of an organization's ability to continuously improve its performance. At the same time, attempts to implement knowledge management initiatives prove fruitless if employees are not fully motivated and engaged, and our present understanding of how to promote and facilitate such behaviours remains limited. This study introduces and empirically tests a theoretical model that links intellectual capital dimensions to employees innovative work behaviour and specifically suggests knowledge sharing behaviour among employees as a key mediator. A survey was used to collect data from 135 employees in three healthcare organizations. The results of our structural equation modelling (SEM) analysis indeed support the notion that intellectual capital is conducive to innovative behaviour by means of knowledge sharing among employees. These findings contribute to the understanding of how behavioural factors operate in organizations, highlighting the relevance of a micro-foundation of continuous improvement, and also suggesting some preliminary guidelines that managers in healthcare organizations can apply to promote employee innovative work behaviour.
Glioma-Initiating Cell Elimination by Metformin Activation of FOXO3 via AMPK
Authors: Sato Atsushi , Sunayama Jun , Okada Masashi , Watanabe Eriko , Seino Shizuka , Shibuya Keita , Suzuki Kaori , Narita Yoshitaka , Shibui Soichiro , Kayama Takamasa , Kitanaka Chifumi
Published: November 2012

Control of the cancer stem/initiating cell population is considered key to realizing the long-term survival of glioblastoma patients. Recently, we demonstrated that FOXO3 activation is sufficient to induce differentiation of glioma-initiating cells having stem-like properties and inhibit their tumor-initiating potential. Here we identified metformin, an antidiabetic agent, as a therapeutic activator of FOXO3. Metformin activated FOXO3 and promoted differentiation of such stem-like glioma-initiating cells into nontumorigenic cells. Furthermore, metformin promoted FOXO3 activation and differentiation via AMP-activated protein kinase (AMPK) activation, which was sensitive to extracellular glucose availability. Importantly, transient, systemic administration of metformin depleted the self-renewing and tumor-initiating cell population within established tumors, inhibited tumor formation by stem-like glioma-initiating cells in the brain, and provided a substantial survival benefit. Our findings demonstrate that targeting glioma-initiating cells via the AMPK-FOXO3 axis is a viable therapeutic strategy against glioblastoma, with metformin being the most clinically relevant drug ever reported for targeting of glioma-initiating cells. Our results also establish a novel, direct link between glucose metabolism and cancer stem/initiating cells.
Facilitators and barriers to cotrimoxazole and nevirapine prophylaxis among HIV exposed babies: a qualitative study from Harare, Zimbabwe
Authors: Sibanda E , Weller I , Bernays S , Hakim J , Cowan F
Published: November 2012

Implementation of cotrimoxazole prophylaxis (CTX‐p) among HIV‐exposed children is poor in southern Africa. We conducted a multi‐methods study to investigate the barriers to delivery of CTX‐p to HIV exposed infants in Zimbabwe at each step of the care cascade. Here we report findings of the qualitative component designed to investigate issues related to adherence conducted among women identified as HIV positive whose babies were started on CTX‐p postnatally. Between Feb–Dec 2011, the first 19 HIV infected mothers identified were invited for in‐depth interview 4–5 months postnatally. Interviews were recorded, transcribed, translated and analysed thematically. Of note, Zimbabwe also provides nevirapine prophylaxis for HIV‐exposed babies, so the majority were giving nevirapine and CTX‐p to their babies. All women desired their baby's health above all else, and were determined to do all they could to ensure their wellbeing. They did not report problems remembering to give drugs. The baby's apparent good health was a huge motivator for continued adherence. Testimonies from women whose babies had tested HIV negative strengthened the resolve to adhere. However, most women reported that their husbands were less engaged in HIV care, refusing to be HIV tested and in some cases stealing drugs prescribed for their wives for themselves. In two instances the man stopped the woman from giving CTX‐p to the baby either because of fear of side effects or not appreciating its importance: “he said if I kept giving CTX‐p he would take the baby away from me and give him to his mother.” Stigma continues to be an important issue. Mothers reported being reluctant to disclose their HIV status to other people so found it difficult to collect prescription refills from the HIV clinic for fear of being seen by friends/relatives. Some women reported that it was hard to administer the drugs if there were people around at home. Other challenges faced were stock‐outs of CTX‐p at the clinic, which occurred four times during the study. The baby would then go without CTX‐p if the woman could not afford buying at a private pharmacy. The study highlights that adherence knowledge and desire alone is insufficient to overcome the familial and structural barriers to maintaining CTX‐p. Improving adherence to CTX‐p among HIV exposed infants will require interventions to improve male involvement, reduce HIV stigma at facilities and ensure adequate supply of drugs.
Benefits of ART simplification on adherence, clinical and economic outcomes
Authors: Vera J , Aragão F , Guimaraes M , Vaz Pinto I
Published: November 2012

Purpose of the study

Fixed‐dose combinations (FDCs) and single‐tablet regimens (STRs) may reduce complete non‐adherence (CNA) but also have the potential additional benefit of avoiding partial non‐adherence (PNA) (some but not all drugs taken). We test this hypothesis and then estimate the impact of PNA‐free regimen (STRs) on clinical and economic outcomes.

Methods

The unit analysis was a person‐regimen of 2 NRTI+(NNRTI, PI/r) lasting ≥90 days. Adherence was measured by the proportion of days covered using pharmacy refill data. The Wilcoxon rank‐sum test was used to compare CNA, PNA and total non‐adherence (TNA) in the following groups: STR vs its components (EFV+TDF/FTC) and non‐FDC vs FDC vs STR. The level of adherence per group and the impact of PNA and CNA on virological failure (VF) were estimated using multivariate regression panel data models (MVRPDM). Control variables included age, gender, hepatitis co‐infection, cumulative comorbidity score, CD4, viral load, regimen duration and calendar year. MVRPDM we also used to access the impact of PNA‐free regimens on the probability of at least one hospitalization and on annualized hospitalization+ART costs. The analysis was performed in Stata 11®.

Summary of results

The retrospective analysis was performed on 2,449 person‐regimens from a cohort of 1,435 HIV‐infected individuals followed in one HIV unit in Portugal, between 2001 and 2011. Median age was 38 years old and median regimen duration was 1.9 years. CNA was higher (23%) in the non‐FDC (p<0.001 vs other groups) and similar in FDC vs STR (15% vs 11%, p=0.951). PNA was higher in non‐FDC than FDC (4.2% vs 3.4%; p=0.020) and obviously null with STR (p<0.001 vs other groups). In the subgroup analysis of EFV+FTC/TDF vs STR, TNA was 16% and 11% (p=0.0025). In MVRPDM, STRs are estimated to result in a decrease of 11% (p<0.001) and 5.3% (p<0.001) in TNA relatively to non‐FDC and FDC, respectively. Both CNA and PNA were found to be predictors of VF (p<0.001 and p=0.020, respectively). The odds ratio of hospitalization with STRs vs other regimens was 0.33 (p=0.019). STRs were associated with lower sum of ART+hospitalization annualized costs (−1,330€; p<0.001) when compared to other regimens.

Conclusions

This study suggests that FDC and STRs are of value in avoiding PNA and TNA, thereby reducing the probability of virological failure, and that PNA‐free regimens are associated with clinical and economic benefits.
Causes of virological failure in a population of 1895 HIV‐infected patients: the experience of an infectious diseases service in Lisbon, Portugal
Authors: Moneti V , Luís N , Rijo J , Miranda A , Baptista T , Farinha H , Mansinho K
Published: November 2012

Despite the increasing optimization of combined antiretroviral therapy (cART) regimens in the last decades, a significant percentage of patients still do not achieve viral replication control. We present a retrospective analysis focusing on human immunodeficiency virus (HIV)‐infected population on cART, followed at our ambulatory care clinic between 1st January and 31st December 2011, in order to identify the causes of virological failure. From the 1895 patients in our population we included 1854 in the study. Ten percent (187) of the included patients had detectable HIV RNA (≥40 cp/mL) at the time of last laboratory evaluation: 70,1% were males, mean age was 46 years and 72,7% were Portuguese. Patients with detectable HIV RNA were divided into group A (HIV RNA <200 cp/mL) ‐ 78 (41,7%) patients and group B (HIV RNA ≥200 cp/mL) 109 (58,3%) patients. The comparison of both groups revealed an higher mean count of TCD4+ (568 vs 334 cells/mm3; p<0,001) in group A, although similar mean TCD4+ count at time of cART initiation (276 vs 262 cells/mm3; p=0,412). Group A patients experienced longer exposure to cART (10 vs 8 years; p<0,05) and have undergone, on average, 3 previous regimens (p<0,05). With regard to cARV current regimen: 32,1% patients in group A and 30,3% in group B were prescribed non‐nucleoside reverse transcriptase inhibitors based regimes and 51,3% patients in Group A and 59,6% in group B were under cARV based on Protease inhibitors. The identified causes of virologic failure for patients with detectable HIV RNA were: poor adherence (54%); unsuccessful retention in care (14,4%); sporadic detectable HIV RNA (40≤viral load<200), “blips” (14,4%); mutations of resistance to ARVs (13,4%); intolerance to the current regimen (2,1%) and pharmacokinetics drug interactions (1,6%). The estimated rate of virological failure was 10,1% in this population. Insufficient adherence and unsuccessful retention in care were identified in 68,4% of treatment failed patients as main causes of virological failure. Failure of therapy due to intolerance or adverse effects was reported in 2,1% of cases, reflecting a better safety profile and tolerability of recent prescribed regimens. Early identification of causes of virologic failure, timely adjustment of therapeutic regimens, and the adoption of measures to promote adherence and retention in care are key factors for successful treatment of HIV‐infected patients.
No significant association between patient self‐reported non‐adherence to antiretrovirals and HIV‐tropism: a preliminary analysis
Authors: Ammassari A , Gori C , Pinnetti C , Lorenzini P , Zaccarelli M , Pierro P , Capobianchi M , Perno C , Antinori A
Published: November 2012

Nonadherence to antiretroviral therapy (ART) may cause virologic failure and disease progression has been associated with switch of viral coreceptor usage from CCR5 to CXCR4. We aimed to assess the association between patient‐reported non‐adherence and HIV tropism. This is a cross‐sectional analysis. HIV‐tropism was performed within routine clinical practice either at start of ART or at virological failure. Adherence questionnaire includes: how many times ART has been taken during the last month, missed doses in the last week, timing deviation, refill interruption, drug holidays. Demographics, epidemiological data, HIV and ART history, CD4 and HIVRNA were collected. To assess co‐receptor tropism, env V3 genotyping from viremic plasma HIVRNA was performed. For the analysis, dual/mixed viruses were considered as X4. We included 102 individuals: 76% males; median age 42 y (IQR, 37–46); transmission was heterosexual 37%, homosexual 31%, intravenous drug use 29%. Median nadir of CD4 154/mmc (IQR, 53–274), median zenith of HIVRNA 5.26 (4.72–5.70), 46% had AIDS. 124 tropism tests were: 78% R5, 17% X4, 5% dual/mixed. In cases with previous ART, mono/dual ART was found in 26%, median number of regimens was 5 (IQR, 2–10), median time on triple‐ART was 54 months (IQR, 0–123) with median time of HIVRNA <50 c/ml of 16 months (IQR, 6.5–34.9). At HIV‐tropism, median CD4 and HIV RNA were 321/mmc (IQR, 210–436) and 2.65 (IQR, 2.65–4.91), respectively. Median time between adherence questionnaire and HIV‐tropism was 68 days (IQR, 23–116). At adherence questionnaire, median percentage of ART taken during the last month was 100% (IQR, 90–100), 39% reported missed doses in the last week, 40% timing deviation, 7% refill interruption, 17% drug holidays. At univariate analysis, no statistically significant association between non‐adherence and dual/mixed‐X4 viruses was found (p>0.1). Also gender, age, HIV transmission, AIDS, CD4 nadir, HIVRNA zenith, mono/dual ART, and number of ART regimens were not associated with type of tropism. Only longer time with undetectable HIVRNA before tropism test showed a lower probability of dual/mixed‐X4 viruses (OR for each month 0.95; 95% CI 0.90–1.00; p=0.06). No significant association between adherence and HIV‐tropism was found in this preliminary analysis. It is possible that patient self‐reported adherence is not able to capture nonadherence behaviors that underlie more pronounced viral replication which may be necessary for tropism switch.
The role of SEAD project intervention in viral suppression of HIV/AIDS patients with follow‐up and adherence barriers
Authors: Elías Casado L , Pérez Elías M , López Pérez D , Pumares Álvarez M , Martinez‐Colubi M , Moreno Zamora A , Muriel A , Dronda F , Marti‐Belda P , Gómez‐Ayerbe C , Rodriguez Sagrado M , Moreno Guillén S
Published: November 2012

Purpose of study

Irregular FUP/ADH were associated with virologic failure [1] leading to an increase in mortality [2]. SEAD was a multidimensional intervention project, designed from the patient's perspective, to specifically attend patients with poor FUP/ ADH in an HIV/AIDS outpatient clinic.

Methods

From Jan 2006 to May 2010, patients with poor FUP/ADH were offered SEAD inclusion, all were evaluated by a nurse or a psychologist (adherence collaborators) who assessed all the reasons and barriers precluding a correct FUP/ADH. For each identified problem, different interventions were planned, using our own resources or coordinating others. Follow‐up was censored in Nov 2011. Univariate and multivariable models were performed to evaluate the influence of SEAD intervention in virological suppression (HIV‐ARN <1.7 log copies/mL) at the end of follow‐up.

Summary of results

Overall, 242 patients were assessed: mean age 46 years, 78% men, 69% IDU, 51% AIDS, baseline ADH >90% 29.3%; median CD4 cell count 333 [164–536] cells/mL and HIV‐RNA <1.57 45%. Patients were admitted in SEAD due to poor ADH 15%, FUP problems 21%, both FUP/ADH 53% and to prevent poor ADH or FUP 11%. Main reasons driving poor FUP/ADH were severe biopsychosocial problems 26%, severe drug and/or alcohol abuse 23%, logistic problems 21.3%, other psychiatric disorders 14%, oversights 10%, unknown 3% and antiretroviral intolerance 2%. Cocaine/heroin and alcohol abuse was reported by 33% and 16%. Only 57% of patients received >50% of planned interventions. After a median follow‐up of 3.9 (3.27–4.43) years 218 patients received 8 (3–12) interventions/year, 95% evaluation interview and 30% psychological counselling (3 sessions/year [2–5]). Virological suppression was achieved by 67% of patients. In logistic regression analysis an intervention higher than 50% of planned HR 0.220 [IC 95% (0.112–0.44)] and receiving psychological counselling HR 0.44 [IC 95% (0.20–0.97)] were independent predictors of virological suppression whereas alcohol 3.11 (95% CI 1.24–7.80) and severe biopsychosocial problems HR 2.39 (95% CI 1.134–5.040) were associated with worse virological response, after adjusting for age, alcohol or cocaine abuse, degree of adherence, baseline virological suppression, median follow–up, intravenous acquisition of HIV, and family support.

Conclusions

General and psychological SEAD intervention resulted in higher virological suppression in patients with severe follow‐up and adherence barriers.
HAART roll‐out in the new fiscal and economic environment
Authors: Gulick R
Published: November 2012

There are 27 approved antiretroviral drugs and combinations of these drugs clearly change the natural history of HIV infection, dramatically decreasing HIV‐related morbidity and mortality and promoting healthy survival. Despite the proven benefits, we continue to consider basic strategic questions about antiretroviral therapy: When should we start ART? What regimen to start? When should we change ART? What ART regimen should we change to?

Also, despite the benefits of treatment, some antiretroviral regimens may be inconvenient, toxic, and/or have suboptimal antiretroviral activity, particularly against drug‐resistant viruses. Thus, newer compounds are needed that continue to improve convenience and tolerability, reduce toxicity, and improve antiretroviral activity, particularly against drug‐resistant viruses. Additionally, new drugs may better penetrate tissue reservoirs (e.g. genital tract, central nervous system) or exploit new targets with new mechanisms of action.

There are a number of HIV drugs in development currently. These include a new pharmacokinetic “boosting” agent and newer antiretroviral agents in a number of existing classes, including new nucleoside reverse transcriptase inhibitors, non‐nucleoside reverse transcriptase inhibitors, protease inhibitors, entry inhibitors, and integrase inhibitors. In addition there are drugs with new mechanisms of action in development, including the CD4 attachment inhibitors. The clinical use of the newer agents will depend on the results of clinical trials, and the timeline for development and availability.
Elvitegravir/cobicistat/emtricitabine/tenofovir DF (Quad) has durable efficacy and differentiated safety compared to efavirenz/emtricitabine/tenofovir DF at week 96 in treatment‐naïve HIV‐1‐infected patients
Authors: Zolopa A , Gallant J , Cohen C , Sax P , Dejesus E , Mills A , Wohl D , Liu H , Rhee M , Szwarcberg J
Published: November 2012

Purpose of the study

The primary Week 48 analysis of this ongoing, randomized, double‐blind, double‐dummy, active‐controlled Phase 3 trial of elvitegravir/cobicistat/emtricitabine/tenofovir DF (Quad) in treatment‐naïve patients demonstrated that Quad was non‐inferior to efavirenz/emtricitabine/tenofovir DF (EFV/FTC/TDF) with a differentiated safety profile. We report the Week 96 interim data.

Methods

Key eligibility criteria included HIV‐1 RNA ≥5,000 c/mL and eGFR ≥70 mL/min. Virologic success (HIV‐1 RNA <50 c/mL) at Week 96 was assessed per snapshot algorithm. Adverse events and laboratory data were collected prospectively.

Results

700 patients (89% male, 63% white, 33% with HIV‐1 RNA >100,000 c/mL) were randomized and treated. At Week 48, Quad was non‐inferior to EFV/FTC/TDF (88% vs 84%, difference +3.6%, 95% CI ‐1.6% to 8.8%). High rates of virologic success were maintained at Week 96 (84% vs 82%, difference 2.7%, 95% CI ‐2.9% to 8.3%). Subgroup analysis revealed similar rates of virologic success in patients with baseline HIV‐1 RNA >100,000 c/mL (81% vs 83%). Mean CD4 cell increase (cells/mm3) was 295 vs 273. Emergent resistance was infrequent (3% vs 3%). Rates of study drug discontinuation due to adverse events (AEs) were low and comparable (5% vs 7%). Rates of neuropsychiatric AEs were lower in Quad than in EFV/FTC/TDF (47% vs 66%, P<0.001), as were rates of rash (21% vs 31%, P=0.006). Drug discontinuation due to renal reasons occurred in 7 (2%) vs 0 patients through Week 96; only two patients discontinued Quad since Week 48 due to serum creatinine (Cr) increase without features of proximal renal tubulopathy. Median changes in serum Cr (µmol/L [mg/dL]) at Week 96 in Quad vs EFV/FTC/TDF (11.5 vs 0.9 [0.13 vs 0.01]) were similar to those at Week 48 (12.4 vs 0.9 [0.14 vs 0.01]). Quad had smaller median increases (mmol/L [mg/dL]) in total (0.23 vs 0.47 [9 vs 18], P<0.001) and LDL cholesterol (0.23 vs 0.41 [9 vs16], P=0.011), and similar increase in triglycerides (0.05 vs 0.09 [4 vs 8], P=0.41).

Conclusions

At Week 96, Quad demonstrated high rates of virologic suppression with low rates of resistance and a differentiated safety and tolerability profile relative to EFV/FTC/TDF. These results support the durable efficacy and long‐term safety of Quad in HIV‐1 infected patients.
Block Copolymer Hydrogels
Authors: Gao Guang Hui , Li Yi , Lee Doo Sung
Published: November 2012

Block copolymer hydrogels are three‐dimensional polymeric networks that can absorb a considerable amount of water to maintain their semisolid morphology. Chemically cross‐linked hydrogels which can be prepared through disulfide bond formation, photopolymerization, or click chemistry, exhibit a nonreversible phase transition state. In contrast, physically cross‐linked hydrogels can be formed via self‐assembly of amphiphilic block copolymers, in response to environmental stimuli, including pH and/or temperature, and show a sol‐gel phase transition. Importantly, these stimuli‐sensitive physical hydrogels can exist as a sol state prior to administration, and subsequently translate to a gel state after administration under the human body condition. Consequently, the stimuli‐sensitive hydrogels have attracted significant interest for their potential applications in the site‐specific pharmaceutical (drug/protein) delivery and tissue regeneration. The article focuses on synthesis, properties, and biomedical applications of stimuli‐responsive block copolymer hydrogels that exhibit a reversible sol‐gel phase transition in response to temperature, pH, pH/temperature, and other stimulus conditions.
Genetic Manipulation of Human Induced Pluripotent Stem Cells
Authors: Wang Angela , Gee Liew Chee
Published: November 2012

Human induced pluripotent stem cells (HIPSC) have tremendous value as a source of autologous cells for cellular transplantation in the treatment of degenerative diseases. The protocols described here address methods for large‐scale genetic modification of HIPSCs. The first is an optimized method for transfecting HIPSCs cultured in feeder‐free conditions. The second method allows nucleofection of trypsinized HIPSCs at an optimal cell density. Both methods enable robust generation of stable HIPSC transfectants within two weeks. Our protocols are highly reproducible and do not require optimization for individual HIPSC and human embryonic stem cell (HESC) lines. Curr. Protoc. Stem Cell Biol. 23:5B.2.1‐5B.2.9. © 2012 by John Wiley & Sons, Inc.
Design, Processing, Microstructure, Properties, and Applications of Advanced Intermetallic TiAl Alloys
Authors: Clemens Helmut , Mayer Svea
Published: November 2012

After almost three decades of intensive fundamental research and development activities, intermetallic titanium aluminides based on the ordered γ‐TiAl phase have found applications in automotive and aircraft engine industry. The advantages of this class of innovative high‐temperature materials are their low density and their good strength and creep properties up to 750 °C as well as their good oxidation and burn resistance. Advanced TiAl alloys are complex multi‐phase alloys which can be processed by ingot or powder metallurgy as well as precision casting methods. Each process leads to specific microstructures which can be altered and optimized by thermo‐mechanical processing and/or subsequent heat treatments. The background of these heat treatments is at least twofold, i.e., concurrent increase of ductility at room temperature and creep strength at elevated temperature. This review gives a general survey of engineering γ‐TiAl based alloys, but concentrates on β‐solidifying γ‐TiAl based alloys which show excellent hot‐workability and balanced mechanical properties when subjected to adapted heat treatments. The content of this paper comprises alloy design strategies, progress in processing, evolution of microstructure, mechanical properties as well as application‐oriented aspects, but also shows how sophisticated ex situ and in situ methods can be employed to establish phase diagrams and to investigate the evolution of the micro‐ and nanostructure during hot‐working and subsequent heat treatments.
N‐Type Self‐Assembled Monolayer Field‐Effect Transistors and Complementary Inverters
Authors: Ringk Andreas , Li Xiaoran , Gholamrezaie Fatemeh , Smits Edsger C. P. , Neuhold Alfred , Moser Armin , Van der Marel Cees , Gelinck Gerwin H. , Resel Roland , de Leeuw Dago M. , Strohriegl Peter
Published: November 2012

This work describes n‐type self‐assembled monolayer field‐effect transistors (SAMFETs) based on a perylene derivative which is covalently fixed to an aluminum oxide dielectric via a phosphonic acid linker. N‐type SAMFETs spontaneously formed by a single layer of active molecules are demonstrated for transistor channel length up to 100 μm. Highly reproducible transistors with electron mobilities of 1.5 × 10−3 cm2 V−1 s−1 and on/off current ratios up to 105 are obtained. By implementing n‐type and p‐type transistors in one device, a complimentary inverter based solely on SAMFETs is demonstrated for the first time.
Carbon‐Based Nanomaterials for Tissue Engineering
Authors: Ku Sook Hee , Lee Minah , Park Chan Beum
Published: November 2012

Carbon‐based nanomaterials such as graphene sheets and carbon nanotubes possess unique mechanical, electrical, and optical properties that present new opportunities for tissue engineering, a key field for the development of biological alternatives that repair or replace whole or a portion of tissue. Carbon nanomaterials can also provide a similar microenvironment as like a biological extracellular matrix in terms of chemical composition and physical structure, making them a potential candidate for the development of artificial scaffolds. In this review, we summarize recent research advances in the effects of carbon nanomaterial‐based substrates on cellular behaviors, including cell adhesion, proliferation, and differentiation into osteo‐ or neural‐ lineages. The development of 3D scaffolds based on carbon nanomaterials (or their composites with polymers and inorganic components) is introduced, and the potential of these constructs in tissue engineering, including toxicity issues, is discussed. Future perspectives and emerging challenges are also highlighted.
Market Development of Biomass Industries
Authors: Altman Ira , Bergtold Jason , Sanders Dwight R. , Johnson Thomas G.
Published: November 2012

Biomass‐based agribusiness industries hold significant potential to contribute to environmentally beneficial renewable energy. The authors explore survey evidence on producer preferences for organizational types that will influence market development. Although there are many features of market development that are important, they focus on understanding their organizational choices, the services producers may be willing to provide, and the assets producers currently own. Results indicate mid‐Missouri producers have higher preferences for spot markets compared to the southern Illinois producers; the southern Illinois producers prefer short‐term and long‐term contracts.
Hydroxyurea treatment decreases glomerular hyperfiltration in children with sickle cell anemia
Authors: Aygun Banu , Mortier Nicole A. , Smeltzer Matthew P. , Shulkin Barry L. , Hankins Jane S. , Ware Russell E.
Published: November 2012

Glomerular hyperfiltration and microalbuminuria/proteinuria are early manifestations of sickle nephropathy. The effects of hydroxyurea therapy on these renal manifestations of sickle cell anemia (SCA) are not well defined. Our objective was to investigate the effects of hydroxyurea on glomerular filtration rate (GFR) measured by 99mTc‐DTPA clearance, and on microalbuminuria/proteinuria in children with SCA. Hydroxyurea study of long‐term effects (HUSTLE) is a prospective study (NCT00305175) with the goal of describing the long‐term cellular, molecular, and clinical effects of hydroxyurea therapy in SCA. Glomerular filtration rate, urine microalbumin, and serum cystatin C were measured before initiating hydroxyurea therapy and then repeated after 3 years. Baseline and Year 3 values for HUSTLE subjects were compared using the Wilcoxon Signed Rank test. Associations between continuous variables were evaluated using Spearman correlation coefficient. Twenty‐three children with SCA (median age 7.5 years, range, 2.5–14.0 years) received hydroxyurea at maximum tolerated dose (MTD, 24.4 ± 4.5 mg/kg/day, range, 15.3–30.6 mg/kg/day). After 3 years of treatment, GFR measured by 99mTc‐DTPA decreased significantly from 167 ± 46 mL/min/1.73 m2 to 145 ± 27 mL/min/1.73 m2 (P = 0.016). This decrease in GFR was significantly associated with increase in fetal hemoglobin (P = 0.042) and decrease in lactate dehydrogenase levels (P = 0.035). Urine microalbumin and cystatin C levels did not change significantly. Hydroxyurea at MTD is associated with a decrease in hyperfiltration in young children with SCA. Am. J. Hematol., 88:116–119, 2013. © 2012 Wiley Periodicals, Inc.
Functional independence of Taiwanese children with VACTERL association
Authors: Lin Hsin‐Yi , Lin Shuan‐Pei , Lin Hsiang‐Yu , Hsu Chyong‐Hsin , Chang Jui‐Hsing , Kao Hsin‐An , Hung Han‐Yang , Peng Chun‐Chih , Lee Hung‐Chang , Chen Ming‐Ren , Tsai Jeng‐Daw
Published: November 2012

VACTERL association is a non‐random association of birth defects, which may include anomalies of the vertebral column, limbs, kidneys, and heart; anal atresia; tracheoesophageal fistula; and esophageal atresia. The presence of two or more of the defects establishes the diagnosis. The aim of our study is to describe the functional independence of children with VACTERL association and compare the results to unaffected children. These results will enable clinicians to provide more realistic prognostic information to parents and families. We used the WeeFIM questionnaire to assess the functional skills of 23 patients who had been diagnosed with VACTERL association at Mackay Memorial Hospital, Taipei, Taiwan, from June 1994 to June 2009. The total WeeFIM scores and sub‐scores for three domains (self‐care, mobility, and cognition) correlated significantly with age (P < 0.01). The scores were generally within the same range as those of unaffected Chinese children, although our subjects had slightly inferior scores on six items, including bowel, chair transfer, stairs, expression, social interaction, and problem solving. In conclusion, the daily functional skills of Taiwanese children with VACTERL association were similar to those of unaffected children. © 2012 Wiley Periodicals, Inc.
N‐Methylierung von Peptiden und Proteinen: ein wichtiges Element für die Regulation biologischer Funktionen
Authors: Chatterjee Jayanta , Rechenmacher Florian , Kessler Horst
Published: November 2012

Die N‐Methylierung ist eine der einfachsten chemischen Modifikationen und kommt häufig in Peptiden und Proteinen von Prokaryoten und höheren Eukaryoten vor. Die Natur hat die N‐Methylierung von Peptiden im Selektionsprozess der Evolution als raffiniertes Element für die Regulation biologischer Funktionen entwickelt, z. B. als Überlebensstrategie durch die Synthese von Antibiotika. Diese kleine strukturelle Veränderung kann nicht nur große Proteinkomplexe mobilisieren (wie im Fall der Methylierung von Histonen), sondern auch enzymatische Aktivitäten durch selektive Erkennung von Protein‐Protein‐Wechselwirkungen inhibieren. Dank neuer neuer Synthesemethoden konnte die N‐Methylierung in den letzten Jahren sowohl zum Modifizieren biologischer Aktivitäten, Selektivitäten und pharmakokinetischer Eigenschaften von Peptiden als auch zur Verbesserung ihrer Pharmakodynamik eingesetzt werden. Wir fassen in diesem Aufsatz den aktuellen Wissensstand über den Einsatz der N‐Methylierung zur Modifizierung biologischer, struktureller und pharmakokinetischer Eigenschaften von Peptiden zusammen.
Determination of dispersion efficiency of cement suspensions by method of centrifugation
Authors: Paravanova Gordana , Hausnerova Berenika , Beltrán‐Prieto Juan Carlos
Published: November 2012

In this research, rheological parameters of cement suspensions modified with different doses of two types of superplasticizers (SPs) were evaluated with an alternative method of centrifugation. It was determined that the critical normal and shear stresses (yield values), and the water/solid ratio alter with the additive dose, the additive type as well and the magnitude of centrifugal forces. The results obtained reveal that the method of centrifugation might serve for determination of dispersing effectiveness of SPs and rheological parameters of suspensions in general. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Edible chitosan/acetylated monoglyceride films for prolonged release of vitamin E and antioxidant activity
Authors: Blanco‐Fernandez Bárbara , Rial‐Hermida Maria Isabel , Alvarez‐Lorenzo Carmen , Concheiro Angel
Published: November 2012

α‐Tocopherol‐loaded chitosan films for pharmaceutical applications and food packaging purposes were designed to attain prolonged antioxidant activity. The films were prepared according to an emulsification/casting‐solvent process from dispersions containing chitosan at 1.0 and 1.5% (w/w), combining five different proportions of α‐tocopherol (ranging from 0 to 40% (w/w) with respect to chitosan) and two acetylated monoglyceride (AM) : α‐tocopherol weight ratios (1 : 1 or 4 : 1). AM is a safe, edible, fully hydrogenated palm‐based oil that provided adequate distribution of α‐tocopherol in the films. Humidity at equilibrium, puncture strength and puncture deformation decreased as the content in α‐tocopherol increased; no relevant effect of cross‐linking in a glutaraldehyde atmosphere was observed. Degree of swelling and α‐tocopherol release were tested in hydroalcoholic medium that mimic the polarity of the skin and certain foods. The films behaved as superabsorbent and sustained the release for more than 5 days; after 20 days, the antioxidant activity of α‐tocopherol in the release medium was in some cases still as higher as that of a freshly prepared solution. The greater the content in α‐tocopherol, the slower the release in percentage was. AM exerted a protective effect on α‐tocopherol, but when incorporated at too high proportion made the films to have an oily aspect. In sum, the chitosan films showed suitable features to be used as components of α‐tocopherol sustained release formulations and long‐term antioxidant packaging materials. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Metacarpophalangeal Joint Orientation in Anthropoid Manual Phalanges
Authors: Rein Thomas R. , McCarty Laura A.
Published: November 2012

The proximal articular surface angle of orientation (AO) of proximal phalanges of the hand and foot has been used to infer the locomotor profile of extinct Miocene catarrhines and early hominins. Previous work has found that joint orientation distinguishes quadrupedal from suspensory anthropoids. The purpose of this study is to expand on previous research by examining this feature within and across several primate clades, allowing us to investigate the potential influences of locomotion, substrate usage, hand posture, and phylogeny. We also report AO measurements in human proximal hand phalanges, allowing us to examine human skeletal variation within a wide comparative context. The angle of orientation was measured on manual proximal third phalanges of 21 extant anthropoid species using a Microscribe digitizer. Comparisons were made between locomotor groups within hominoids, platyrrhines, and cercopithecoids. Proximal phalanges of quadrupedal species were characterized by greater dorsal orientation than those of suspensory taxa in hominoids and atelids. In addition, arboreal quadrupeds had greater AO values than terrestrial quadrupeds within the Cercopithecoidea. However, within the terrestrial locomotor group, mean AO values did not differ between palmigrade and digitigrade taxa. Thus, while there appears to be a functional signal related to substrate usage, differences in use of hand postures when moving on the ground were not reflected in proximal joint orientation of the proximal phalanx. Finally, we measured relatively low AO values in human phalanges, which might be related to integration with serially homologous pedal phalanges that are under strong selective pressure related to bipedalism. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
Factors affecting the adoption of online library resources by business students
Authors: Booker Lorne D. , Detlor Brian , Serenko Alexander
Published: November 2012

The overall goal of this study is to explain how information literacy instruction (ILI) influences the adoption of online library resources (OLR) by business students. A theoretical model was developed that integrates research on ILI outcomes and technology adoption. To test this model, a web‐based survey, which included both closed and open‐ended questions, was administered to 337 business students. Findings indicate that the ILI received by students is beneficial in the initial or early stages of OLR use; however, students quickly reach a saturation point where more instruction contributes little, if anything, to the final outcome, such as reduced OLR anxiety and increased OLR self‐efficacy. Rather, it is the independent, continuous use of OLR after receiving initial, formal ILI that creates continued positive effects. Importantly, OLR self‐efficacy and anxiety were found to be important antecedents to OLR adoption. OLR anxiety also partially mediates the relationship between self‐efficacy and perceived ease of use. Implications for theory and practice are discussed.
Raman spectroscopy in biomedicine – non‐invasive in vitro analysis of cells and extracellular matrix components in tissues
Authors: Brauchle Eva , Schenke‐Layland Katja
Published: November 2012

Raman spectroscopy is an established laser‐based technology for the quality assurance of pharmaceutical products. Over the past few years, Raman spectroscopy has become a powerful diagnostic tool in the life sciences. Raman spectra allow assessment of the overall molecular constitution of biological samples, based on specific signals from proteins, nucleic acids, lipids, carbohydrates, and inorganic crystals. Measurements are non‐invasive and do not require sample processing, making Raman spectroscopy a reliable and robust method with numerous applications in biomedicine. Moreover, Raman spectroscopy allows the highly sensitive discrimination of bacteria. Rama spectra retain information on continuous metabolic processes and kinetics such as lipid storage and recombinant protein production. Raman spectra are specific for each cell type and provide additional information on cell viability, differentiation status, and tumorigenicity. In tissues, Raman spectroscopy can detect major extracellular matrix components and their secondary structures. Furthermore, the non‐invasive characterization of healthy and pathological tissues as well as quality control and process monitoring of in vitro‐engineered matrix is possible. This review provides comprehensive insight to the current progress in expanding the applicability of Raman spectroscopy for the characterization of living cells and tissues, and serves as a good reference point for those starting in the field.
Direct Methyl Formate Formation from Methanol over Supported Palladium Nanoparticles at Low Temperature
Authors: Wojcieszak Roberto , Gaigneaux Eric M. , Ruiz Patricio
Published: November 2012

Palladium nanoparticles of different sizes and supported on TiO2 (2 wt. %) were synthesized by using the water‐in‐oil microemulsion method. The control of palladium nanoparticles was investigated in terms of the nature of organic surfactant and solvent. Attention was paid to the reduction of palladium ions in solution during synthesis. Materials were characterized by N2‐BET at low temperature, XRD, XPS, H2 chemisorption, and TEM and were tested in the gas phase oxidation of methanol. The results confirmed the effect of microemulsion composition on the size of palladium nanoparticles. The direct formation of methyl formate from methanol was observed. Supported palladium catalysts produced methyl formate at low temperature (<150 °C) with a very high selectivity, and, in some cases, a selectivity of approximately 100 %. At higher temperature, methyl formate is not formed at all and the total oxidation to CO2 occurs. A linear correlation between palladium particle size and methanol conversion was observed. Conversion and selectivity were correlated with the acidity of the catalysts. Very small particles were more active but less selective. A mechanism was proposed to explain the formation of methyl formate from methanol.
ChemInform Abstract: A New Environmentally Friendly Method for the Baeyer—Villiger Oxidation of Cyclobutanones Catalyzed by Thioureas Using H2O2 as an Oxidant.
Authors: Sasakura Niiha , Nakano Keiji , Ichikawa Yoshiyasu , Kotsuki Hiyoshizo
Published: November 2012

The present new oxidation method is only applicable to cyclobutanones.
ChemInform Abstract: Microwave‐Assisted Synthesis of 2‐Aminopyrimidines from Silica Gel‐Adsorbed Propargyl Alcohols and Guanidine.
Authors: Chen Qing‐Zhen , Ding Zong‐Cang , Ma Yan‐Li , Wang Zhen‐Dong , Zhan Zhuang‐Ping
Published: November 2012

A diversity of propargyl alcohols undergoes a propargylation—cycloisomerization tandem reaction, offering a facile access to aminopyrimidines (III) and (V) under microwave‐assisted solvent‐free reaction condition.
ChemInform Abstract: Ph2PI as a Reduction/Phosphination Reagent: Providing Easy Access to Phosphine Oxides.
Authors: Wang Feijun , Qu Mingliang , Chen Feng , Xu Qin , Shi Min
Published: November 2012

Efficient methods to prepare phosphorous compounds using Ph2PI, generated from the corresponding chloride, as multifunctional reagent are described.
ChemInform Abstract: Ph3P Catalyzed One‐Pot Synthesis of Heterocyclic Derivatives of Biological Active Curcumin.
Authors: Amiri Rahebeh , Padyab Parnia , Chalabian Firoozeh , Rajabi Nasir Ahmad
Published: November 2012

Reaction of curcumin (I) with electron‐deficient acetylenes provides access towards curcumin derivatives containing coumarin (III), (IV) or benzofuran moieties (VI), (VII).