bluuebunny/crossref_metadata_2025 huggingface dataset:
Does Evidence Permeate All Surgical Areas Equally? Publication Trends in Wound Care Compared to Breast Cancer Care: A Longitudinal Trend Analysis
Authors: Brölmann F. E. , Groenewold M. D. , Spijker R. , van der Hage J. A. , Ubbink D. T. , Vermeulen H.
Published: April 2012

Background

Evidence‐based decision making has permeated the daily practice of healthcare professionals. However, in wound care this seems more difficult than in other medical areas, such as breast cancer, which has a similar incidence, variety of etiologies, financial burden, and diversity of treatment options. This incongruence could be due to a lack in quantity and quality of available evidence. We therefore compared worldwide publication trends to answer whether research in wound care lags behind that in breast cancer.

Methods

In order to assess the trends in quantity and methodological quality of publications as to wound care and breast cancer treatments, we examined relevant publications over the last five decades. Publications in MEDLINE were classified into seven study design categories: (1) guidelines, (2) systematic reviews (SR), (3) randomized (RCT), and controlled clinical trials (CCT), (4) cohort studies, (5) case‐control studies, (6) case series and case reports, and (7) other publications.

Results

We found a 30‐fold rise in publications on wound care, versus a 70‐fold increase in those on breast cancer. High‐quality study designs like SR, RCT, or CCT were less frequent in wound care (difference 1.9, 95 % CI 1.8–2.0 %) as were guidelines; 76 on wound care versus 231 for breast cancer.

Conclusions

Publications on wound care fall behind in quantity and quality as compared to breast cancer. Nevertheless, SR, RCT, and CCT in wound care are becoming more numerous. These high‐quality study designs could motivate clinicians to make evidence‐based decisions and researchers to perform proper research in wound care.
Moving Forward with Systems of Care: Needs and New Directions
Authors: Kilmer Ryan P. , Cook James R.
Published: April 2012

The articles in this Special Issue on system change within systems of care (SOCs) provide guidance regarding strategies for modifying SOCs to address the needs of different populations, and ways for changing systems to support more positive child and family outcomes. This paper frames central needs, unanswered questions, and issues that remain for those working to implement SOCs. Specific needs and new directions considered include: (1) rigorous implementation‐focused research to identify the necessary and sufficient elements of SOCs and the primary practice approach currently used in SOCs, wraparound; (2) applied research to assess SOCs and document their effectiveness in non‐standard or non‐traditional settings (i.e., non‐mental health settings, including child welfare, juvenile justice, local housing authorities); (3) controlled outcome studies for school‐based wraparound initiatives; (4) research to document the effectiveness of the family support efforts that are part of most SOCs; and (5) attention to context, for families, service providers, and collaborative implementation efforts, by researchers and providers alike. Progress in these areas can inform well‐targeted system change efforts in the context of SOCs, a critical need given changes in federal funding for these initiatives.
Nemo‐like kinase promotes etoposide‐induced apoptosis of male germ cell‐derived GC‐1 cells in vitro
Authors: Cheng Xiaowen , Liang Junbo , Teng Yu , Fu Jun , Miao Shiying , Zong Shudong , Wang Linfang
Published: April 2012

Spermatogenesis is an extremely intricate process that is tightly regulated and orchestrated by a series of well‐coordinated gene expression programmes. Nemo‐like kinase (NLK) is an evolutionarily conserved serine/threonine kinase that functions in a wide variety of developmental events. Nevertheless, the function of NLK in spermatogenesis has not been investigated. In this study, we found that the distribution of NLK in mice exhibited a dynamic change during testicular development and gradually became concentrated in the acrosomes of elongated spermatids. NLK overexpression promoted etoposide‐induced apoptosis of male germ cell‐derived GC‐1 cells, while knockdown of NLK by RNA interference (RNAi) attenuated etoposide‐induced apoptosis. Our findings suggest that NLK plays an important role in etoposide‐induced germ cell apoptosis and may be associated with spermatogenesis.
A retrospective analysis of the clinicopathologic characteristics of uterine cellular leiomyomas in China
Authors: Guan Rui , Zheng Weiqiang , Xu Mingjuan
Published: April 2012

Objective

To investigate the clinicopathologic features of uterine cellular leiomyomas (CLs) by comparing them with those of uterine leiomyosarcomas (LMSs).

Methods

A case–control study comparing 78 cases of CL with 10 cases of LMS was conducted. The patients’ records were reviewed to abstract information on tumors features and treatment, immunohistochemical findings, and disease prognosis.

Results

The mean age at diagnosis was 45.3 ± 8.41 years in the CL group. The main clinical CL manifestations were menstrual abnormalities (56.4%), abdominal pain or distension (14.1%), and pelvic pressure (8.9%). Abdominal pain or distension was significantly more common in the LMS than in the CL group (P < 0.05). Generally, CL tumors were smaller in diameter than LMS tumors (P < 0.05). Moreover, lower levels of Ki‐67 and PCNA expression were measured in CL than in LMS tumors (P < 0.05). There were no cases of malignant transformation or metastasis in 41 patients with CL who adhered to long‐tern follow‐up.

Conclusion

No symptoms were found to be specifically associated with CL, and management of CL does not need to differ from that of ordinary leiomyoma. In contrast to malignant disease, CL has a favorable long‐term prognosis. However, given its “borderline” pathologic nature, patients with CL require clinical surveillance.
Instability of secondary vortices generated by a vortex pair in ground effect
Authors: Harris D. M. , Williamson C. H. K.
Published: April 2012

In this work, we investigate the approach of a descending vortex pair to a horizontal ground plane. As in previous studies, the primary vortices exhibit a ‘rebound’, due to the separation of secondary opposite-sign vortices underneath each primary vortex. On each side of the flow, the weaker secondary vortex can become three-dimensionally unstable, as it advects around the stronger primary vortex. It has been suggested in several recent numerical simulations that elliptic instability is the origin of such waviness in the secondary vortices. In the present research, we employ a technique whereby the primary vortices are visualized separately from the secondary vortices; in fact, we are able to mark the secondary vortex separation, often leaving the primary vortices invisible. We find that the vortices are bent as a whole in a Crow-type ‘displacement’ mode, and, by keeping the primary vortices invisible, we are able to see both sides of the flow simultaneously, showing that the instability perturbations on the secondary vortices are antisymmetric. Triggered by previous research on four-vortex aircraft wake flows, we analyse one half of the flow as an unequal-strength counter-rotating pair, noting that it is essential to take into account the angular velocity of the weak vortex around the stronger primary vortex in the analysis. In contrast with previous results for the vortex–ground interaction, we find that the measured secondary vortex wavelength corresponds well with the displacement bending mode, similar to the Crow-type instability. We have analysed the elliptic instability modes, by employing the approximate dispersion relation of Le Dizés & Laporte (J. Fluid Mech., vol. 471, 2002, p. 169) in our problem, finding that the experimental wavelength is distinctly longer than predicted for the higher-order elliptic modes. Finally, we observe that the secondary vortices deform into a distinct waviness along their lengths, and this places two rows of highly stretched vertical segments of the vortices in between the horizontal primary vortices. The two rows of alternating-sign vortices translate towards each other and ultimately merge into a single vortex row. A simple point vortex row model is able to predict trajectories of such vortex rows, and the net result of the model’s ‘orbital’ or ‘passing’ modes is to bring like-sign vortices, from each secondary vortex row, close to each other, such that merging may ensue in the experiments.
LONG-TERM EFFECT OF PULSES AND NUTRIENT MANAGEMENT ON SOIL ORGANIC CARBON DYNAMICS AND SUSTAINABILITY ON AN INCEPTISOL OF INDO-GANGETIC PLAINS OF INDIA
Authors: GHOSH P. K. , VENKATESH M. S. , HAZRA K. K. , KUMAR NARENDRA
Published: April 2012

Continuous cultivation of rice–wheat cropping system in the Indo-Gangetic plains is under threat with decline in soil organic carbon (SOC), total factor productivity and overall sustainability. Pulses, an important component of crop diversification, are known to improve soil quality through their unique ability of biological N2 fixation, leaf litter fall and deep root system. Therefore, the effect of inclusion of pulses in the puddled rice system under organic and inorganic amendments on SOC pool and its management indices were evaluated in a long-term experiment after seven cropping cycles. The results indicated that inclusion of pulses in the rice-based system improved the SOC content, being greater in surface soil (0–20 cm) and declining with soil depth. Among the four carbon fractions determined, less labile carbon fraction (Cfrac3) was the dominant fraction in the puddled rice system, particularly under organic treatments, indicating that it is possible to maintain organic carbon for longer time in this system. The rice–wheat–mung bean system resulted in 6% increase in SOC and 85% increase in soil microbial biomass carbon as compared with the conventional rice–wheat system. Application of crop residues, farm yard manure (5 t ha−1) and biofertilisers had greater amount of carbon fractions and carbon management index (CMI) over control and the recommended inorganic (NPKSZnB) treatment in the soil surface, particularly in the system where pulses are included. Interestingly, in the puddled rice system, passive carbon pool is more in surface soil than deeper layers. The relative proportion of active carbon pool in surface layer (0–20 cm) to subsurface layer (20–40 cm) was highest in rice–wheat–rice–chickpea (1.14:1) followed by rice–wheat–mung bean (1.07:1) and lowest in the rice–wheat system (0.69:1). Replacing wheat with chickpea either completely or during alternate year in the conventional rice–wheat system also had positive impact on SOC restoration and CMI. Therefore, inclusion of pulses in the rice-based cropping system and organic nutrient management practices had significant impact on maintaining SOC in an Inceptisol of the Indo-Gangetic plains of India.
NORMS FOR MULTIVARIATE DIAGNOSIS OF NUTRIENT IMBALANCE IN ARABICA AND ROBUSTA COFFEE IN THE EAST AFRICAN HIGHLANDS
Authors: WAIREGI L. W. I. , VAN ASTEN P. J. A.
Published: April 2012

Poor soil fertility is a constraint to coffee production. Targeting fertiliser recommendations to nutrient deficiencies can contribute to improved crop response to fertiliser. This study aimed to derive and compare the Compositional Nutrient Diagnosis (CND) and Diagnosis and Recommendation Integrated System (DRIS) norms for Arabica and Robusta, and to investigate nutrient interactions using data derived from 164 plots. The high-yield sub-populations of Arabica had significantly (p < 0.01) higher P (0.23 vs. 0.14) and K (2.87 vs. 2.04), and lower N (2.96 vs. 3.61), Ca (0.99 vs. 1.50) and Mg (0.40 vs. 0.23) than those of Robusta. With respect to the CND norms, Arabica had significantly (p < 0.001) higher P and K, and lower N, Ca and Mg means of row-centered log ratios than Robusta. The relationship between the CND and DRIS indices had coefficient of determination (R2) = 0.75–0.99 for both coffee types. The relationship between nutrient imbalance indices for CND and DRIS had R2 of 0.95 (Arabica) and 0.76 (Robusta). Both coffee types had negative N–Ca, P–Mg and K–Mg interactions. Arabica had positive N–Mg and K–Ca interactions and Robusta had positive N–K, P–K and Ca–Mg interactions and negative N–P, N–Mg, P–Ca and K–Ca interactions. The study concludes, there is a need for cultivar-specific norms, but such norms developed under one set of conditions may not be applicable under different conditions. The study also concludes that both CND and DRIS can be used to determine nutrient imbalances, and fertiliser requirements could be cultivar-specific.
Paulinus of Nola, Courtyards, and Canthari
Authors: van den Hoek Annewies , Herrmann John J.
Published: April 2012

Some of the most elaborate and detailed descriptions of early Christian churches by a Latin writer are given by the nobleman Pontius Meropius Paulinus, who is usually known as Paulinus of Nola, after the city where he became bishop in the latter part of his life. He was born in Bordeaux around 353, of a wealthy family that had extensive properties in Aquitania, Gallia Narbonensis, Latium, and Campania. He received an education appropriate to his noble stature and became the prize student of Ausonius, also a native of Bordeaux, who was the tutor of the (future) emperor Gratian and a celebrated poet at court.
Quality of life and psychosocial functioning of children with cardiac arrhythmias
Authors: Pulgaron Elizabeth R. , Wile Diana , Schneider Kerri , Young Ming-Lon , Delamater Alan M.
Published: April 2012

Childhood cardiac arrhythmias may have a long-lasting impact on a family and typically require long-term medical follow-up. Whereas some arrhythmias are benign, others can be life threatening and require significant medical care. As with many chronic illnesses, it is important to study the potential psychosocial effects of childhood arrhythmias and how they may impact a child's quality of life. The purpose of this study was to create a quality of life measure specific to childhood arrhythmias and to describe the current psychosocial functioning of this population. A total of 46 families participated in a one-time paper and pencil assessment during their regularly scheduled clinic visits. Results indicated promise for the validity and reliability of this new measure. Children in the current sample also demonstrated a high degree of resiliency. Additional analyses with larger samples will be needed to verify the psychometric properties of this measure. Overall, the high functioning of many of these children despite medical trauma is promising. Future studies should consider using some screening measures to decide which children may be most in need of intervention.
Policing Separation of Powers: A New Role for the European Court of Human Rights?
Authors: Kosař David
Published: April 2012

European Court of Human Rights — Separation of powers — Stafford/Kleyn and A/Kart strands of case-law — Problematic aspects of both strands — Limitations and institutional deficiencies of the Court in this area — Constitutionalisation of and shift in the role of the Court
The EU and Its Monarchies: Influences and Frictions
Authors: d'Oliveira Hans Ulrich Jessurun
Published: April 2012

Monarchies in Europe — Monarchs as embodiments of sovereignty — Implications for monarchy of the EU as a limitation of sovereignty — Effects of Union law on the prerogatives of monarchs — Monarchs as heads of state in the Union
Older People with Dementia in the Perioperative Care Environment: Key Issues for Perioperative Nursing
Authors: Coffey Alice
Published: April 2012

Ageing is a normal process and much diversity exists in the physical, psychosocial and spiritual needs of older individuals. While many older people remain independent active and well, there is a rise in the prevalence of dementia. Developments in surgical techniques and improved patient outcomes have resulted in larger numbers of older people now undergoing surgery. However, age-related risks and complexities persist including the existence of cognitive impairment and dementia. Perioperative care of older patients with dementia provides additional challenges for nurses and other healthcare professionals. This paper discusses the unique care needs of older people with dementia and the role of perioperative nurses in meeting these needs.
Die Einführung stärkenorientierter Beobachtungsverfahren
Authors: Weltzien Dörte , Viernickel Susanne
Published: April 2012

Mit der Einführung stärkenorientierter Beobachtungs- und Dokumentationsverfahren wird auch eine Professionalisierung des Fachpersonals hinsichtlich der Orientierung von Bildungsangeboten an den individuellen Interessen und Themen der Kinder sowie des Aufbaus wertschätzender Beziehungen und einer partizipativen Beteiligungs- und Dialogkultur in den Einrichtungen angestrebt. Der folgende Beitrag geht der Frage nach, welche diesbezüglichen Kompetenzzuwächse pädagogische Fachkräfte nach der Implementierung eines in Deutschland verbreiteten Beobachtungsverfahrens, der Bildungs- und Lerngeschichten ( Leu et al., 2007 ), berichten und auf welche spezifischen Einflussfaktoren diese zurück geführt werden können. Nach einem Jahr der praktischen Einführung des Beobachtungsverfahrens, die von intensiven In-House-Trainings und zusätzlichen Qualifikationsmaßnahmen begleitet wurde, ergaben sich Kompetenzzuwächse in Bezug auf die Wahrnehmung der kindlichen Aktivitäten und Interessen, der Haltung zu und Unterstützung von kindlichem Lernen und kindlicher Partizipation sowie bezüglich der aktiven Dialoggestaltung mit den Kindern. Kompetenzzuwächse in diesen drei Bereichen konnten zum einen durch den Erwerb von Fachwissen in Entwicklungspsychologie, Kommunikationstheorie und interkultureller pädagogischer Arbeit und zum anderen durch die Quantität und Qualität konzeptioneller Anpassungen während des Projektverlaufs – u. a. Reorganisation von Gruppenstrukturen und Einführung von Projektarbeit – vorhergesagt werden.
Pädagogische Orientierungen als Kernstück pädagogischer Professionalität
Authors: Breitenbach Eva , Bürmann Ilse , Thünemann Silvia
Published: April 2012

Im vorliegenden Beitrag werden erste Ergebnisse aus zwei Gruppendiskussionen aus einem Forschungsprojekt zu Bildungsgeschichten und pädagogischen Orientierungen von ErzieherInnen vorgestellt. Ziel des Projekts ist die Rekonstruktion der pädagogischen Orientierungen und Bildungserfahrungen, die das Professionsverständnis und das pädagogische Handeln von ErzieherInnen bestimmen. Diese Orientierungen werden als Kernstück von Professionalität betrachtet. Professionstheoretisch stützen wir uns auf den strukturtheoretischen Ansatz (Oevermann). Erhebungsmethoden sind Gruppendiskussionen und biographisch-narrative Interviews, die mittels der dokumentarischen Methode (Bohnsack) und der Narrationsanalyse (Schütze) ausgewertet werden. Unsere Befunde zeigen, dass, neben grundlegenden Gemeinsamkeiten, der Geschlechtszugehörigkeit und dem Lebensalter im beruflichen Alltag ein bedeutsamer, aber höchst unterschiedlicher Stellenwert zukommt.
Mass fluxes and isofluxes of methane (CH4) at a New Hampshire fen measured by a continuous wave quantum cascade laser spectrometer
Authors: Santoni Gregory W. , Lee Ben H. , Goodrich Jordan P. , Varner Ruth K. , Crill Patrick M. , McManus J. Barry , Nelson David D. , Zahniser Mark S. , Wofsy Steven C.
Published: April 2012

We have developed a mid‐infrared continuous‐wave quantum cascade laser direct‐absorption spectrometer (QCLS) capable of high frequency (≥1 Hz) measurements of 12CH4 and 13CH4 isotopologues of methane (CH4) with in situ 1‐s RMS precision of 1.5 ‰ and Allan‐minimum precision of 0.2 ‰. We deployed this QCLS in a well‐studied New Hampshire fen to compare measurements of CH4 isoflux by eddy covariance (EC) to Keeling regressions of data from automated flux chamber sampling. Mean CH4 fluxes of 6.5 ± 0.7 mg CH4 m−2 hr−1 over two days of EC sampling in July, 2009 were indistinguishable from mean autochamber CH4 fluxes (6.6 ± 0.8 mgCH4 m−2 hr−1) over the same period. Mean composition of emitted CH4 calculated using EC isoflux methods was −71 ± 8 ‰ (95% C.I.) while Keeling regressions of 332 chamber closing events over 8 days yielded a corresponding value of −64.5 ± 0.8 ‰. Ebullitive fluxes, representing ∼10% of total CH4 fluxes at this site, were on average 1.2 ‰ enriched in 13C compared to diffusive fluxes. CH4 isoflux time series have the potential to improve process‐based understanding of methanogenesis, fully characterize source isotopic distributions, and serve as additional constraints for both regional and global CH4 modeling analysis.
Responses of annual runoff, evaporation, and storage change to climate variability at the watershed scale
Authors: Wang Dingbao , Alimohammadi Negin
Published: April 2012

In this study, the impact of interannual variability of soil water storage change on the annual water balance is assessed for 277 watersheds located in a spectrum of climate regions. The annual water storage change is quantified on the basis of water balance closure given the available data of precipitation, runoff, and evaporation estimated from remote sensing data and meteorology reanalysis. The responses of annual runoff, evaporation, and storage change to the interannual variability of precipitation and potential evaporation are then analyzed. Both runoff and evaporation sensitivities to potential evaporation are higher under energy‐limited conditions, but storage change seems to be more sensitive to potential evaporation under the conditions in which water and energy are balanced. Runoff sensitivity to precipitation is higher under energy‐limited conditions, but both evaporation and storage change sensitivities to precipitation are higher under water‐limited conditions. Therefore, under energy‐limited conditions, most of the precipitation variability is transferred to runoff variability, but under water‐limited conditions, most of the precipitation variability is transferred to storage change, and some of the precipitation variability is transferred to evaporation variability. The main finding is that evaporation variability will be overestimated by assuming negligible storage change in annual water balance, particularly under water‐limited conditions.
Evaluation of short‐term climate change prediction in multi‐model CMIP5 decadal hindcasts
Authors: Kim Hye‐Mi , Webster Peter J. , Curry Judith A.
Published: April 2012

This study assesses the CMIP5 decadal hindcast/forecast simulations of seven state‐of‐the‐art ocean‐atmosphere coupled models. Each decadal prediction consists of simulations over a 10 year period each of which are initialized every five years from climate states of 1960/1961 to 2005/2006. Most of the models overestimate trends, whereby the models predict less warming or even cooling in the earlier decades compared to observations and too much warming in recent decades. All models show high prediction skill for surface temperature over the Indian, North Atlantic and western Pacific Oceans where the externally forced component and low‐frequency climate variability is dominant. However, low prediction skill is found over the equatorial and North Pacific Ocean. The Atlantic Multidecadal Oscillation (AMO) index is predicted in most of the models with significant skill, while the Pacific Decadal Oscillation (PDO) index shows relatively low predictive skill. The multi‐model ensemble has in general better‐forecast quality than the single‐model systems for global mean surface temperature, AMO and PDO.
Overweight in Adolescence Is Related to Increased Risk of Future Urothelial Cancer
Authors: Leiba Adi , Kark Jeremy D. , Afek Arnon , Levi Zohar , Barchana Micha , Tzur Dorit , Derazne Estela , Vivante Asaf , Shamiss Ari
Published: April 2012

Obesity has been linked to various malignancies, but a clear relation of overweight with urothelial cancer has not been established. We assessed the association between adolescent obesity and future risk for urothelial cancer. Medical data on 1,110,835 Israeli adolescents examined for fitness for military duty between 1967 and 2005 were linked to the National Cancer Registry in this nationwide population‐based cohort study. We used Cox proportional hazards modeling to estimate the covariate‐adjusted hazard ratio (HR) for urothelial cancer associated with BMI measured at age 17. The mean follow‐up of 17.6 ± 10.8 years reflected 19,576,635 person years, during which 661 examinees developed urothelial cancer of the bladder, ureter, or renal pelvis. BMI ≥85th standard percentile in adolescence significantly predicted increased risk of urothelial cancer with a HR (adjusted for year of birth, education and religiosity) of 1.42 (95% confidence interval (CI), 1.13–1.77, P = 0.002). Similar results were observed using the ≥25 kg/m2 definition of overweight (HR = 1.36 (95% CI, 1.08–1.72), P = 0.008). Incidence of urothelial cancer was significantly lower in the more educated and among those who attended religious schools. Overweight in adolescence is related to increased risk of future urothelial cancer. In view of the growing incidence of both urothelial cancer and adolescent obesity, our study suggests an avenue for possible prevention of urothelial cancer.
Adiponectin Profile in Asian Patients Undergoing Coronary Revascularization and Its Association With Plaque Vulnerability: IDEAS‐ADIPO Study
Authors: Lee Chi‐Hang , Hau William K.T. , Tai Bee‐Choo , Chan Mark Y. , Saw Betty , Phua Qian‐Hui , Low Adrian F. , Yeo Tiong‐Cheng , Richards A. Mark , Tan Huay‐Cheem
Published: April 2012

Despite potent insulin‐sensitizing, anti‐inflammatory, and antiatherogenic effects in animal studies, the relationship between serum adiponectin level and coronary artery disease in patients remains unclear. We determined the adiponectin profile in a cohort of multiethnic Asian patients with coronary artery disease, and the association between serum adiponectin level and culprit lesion necrotic core (NC) content. Ninety‐four Asian patients (BMI, 25.3 ± 3.7 kg/m2) undergoing percutaneous coronary intervention were recruited. The serum adiponectin level was measured (n = 94), and the baseline virtual histology intravascular ultrasound examination was analyzed (n = 88). The median level of adiponectin was 3.7 µg/ml (interquartile range, 2.8–4.5 µg/ml). The serum adiponectin level was below 10 µg/ml in 90 patients (95.7%) and below 6 µg/ml in 80 patients (85.1%). There was a significant association between ethnicity and serum adiponectin level (P = 0.048). The median adiponectin level was highest among the Chinese, followed by the Malay and the Indians. Serum adiponectin levels were positively associated with culprit lesion NC content. A 1‐µg/ml increase in log adiponectin was associated with a 3.04% (95% confidence interval: 0.33–5.44) increase in culprit lesion NC content. This association remains significant after adjusting for age, sex, ethnicity, low‐density lipoprotein cholesterol, high‐density lipoprotein cholesterol, and procedural indication. We found a low serum level of adiponectin in Asian patients and a significant ethnic effect on serum adiponectin level. Increased serum adiponectin levels were independently associated with increased culprit lesion NC burden, suggesting a role for adiponectin in modulating coronary plaque vulnerability.
Lentiviral vectors: basic to translational
Authors: Sakuma Toshie , Barry Michael A. , Ikeda Yasuhiro
Published: April 2012

More than two decades have passed since genetically modified HIV was used for gene delivery. Through continuous improvements these early marker gene-carrying HIVs have evolved into safer and more effective lentiviral vectors. Lentiviral vectors offer several attractive properties as gene-delivery vehicles, including: (i) sustained gene delivery through stable vector integration into host genome; (ii) the capability of infecting both dividing and non-dividing cells; (iii) broad tissue tropisms, including important gene- and cell-therapy-target cell types; (iv) no expression of viral proteins after vector transduction; (v) the ability to deliver complex genetic elements, such as polycistronic or intron-containing sequences; (vi) potentially safer integration site profile; and (vii) a relatively easy system for vector manipulation and production. Accordingly, lentivector technologies now have widespread use in basic biology and translational studies for stable transgene overexpression, persistent gene silencing, immunization, in vivo imaging, generating transgenic animals, induction of pluripotent cells, stem cell modification and lineage tracking, or site-directed gene editing. Moreover, in the present high-throughput ‘-omics’ era, the commercial availability of premade lentiviral vectors, which are engineered to express or silence genome-wide genes, accelerates the rapid expansion of this vector technology. In the present review, we assess the advances in lentiviral vector technology, including basic lentivirology, vector designs for improved efficiency and biosafety, protocols for vector production and infection, targeted gene delivery, advanced lentiviral applications and issues associated with the vector system.
A novel bispecific single-chain antibody for ADAM17 and CD3 induces T-cell-mediated lysis of prostate cancer cells
Authors: Yamamoto Kosuke , Trad Ahmad , Baumgart Anja , Hüske Linda , Lorenzen Inken , Chalaris Athena , Grötzinger Joachim , Dechow Tobias , Scheller Jürgen , Rose-John Stefan
Published: April 2012

ADAM17 (A disintegrin and metalloproteinase 17) is a membrane-bound protease that cleaves various cell surface proteins, including cytokines and cytokine receptors. Recently it was shown that ADAM17 is highly expressed on the surface of many cancer cells, whereas normal cells express low levels of ADAM17, implying that ADAM17 is a potential immunotherapeutic target. We have generated a monoclonal antibody against human ADAM17, which recognized the membrane proximal cysteine-rich extension of the ADAM17 protein. Unlike normal cells, tumour cell lines, such as a prostate cancer cell line, pancreatic cancer cell lines, a breast cancer cell line and a non-small lung cancer cell line, expressed ADAM17 on the cell surface. Using the sequence of the antibody we generated an ADAM17-specific scFv (single-chain variable fragment) and fused this to a CD3-specific scFv to generate a bispecific T-cell engager antibody [A300E-BiTE (bispecific T-cell engager antibody)]. Specificity was demonstrated on cells in which ADAM17 was knocked down with a specific shRNA (short hairpin RNA). A300E-BiTE recognized ADAM17 and CD3 on the cell surface of tumour cells and T-cells respectively. In the presence of primary human peripheral blood mononuclear cells or human T-cells the addition of A300E-BiTE led to ADAM17-specific killing of prostate tumour cells indicating a novel strategy for the treatment of cancer.
Reliable nucleation of isolated magnetic antivortices
Authors: Pues Matthias , Martens Michael , Kamionka Thomas , Meier Guido
Published: April 2012

Individual magnetic antivortices are reliably generated in φ-shaped microstructures using a specific remagnetization sequence of in-plane fields. The process of antivortex creation is understood by means of micromagnetic simulations and is experimentally demonstrated by magnetic force microscopy on multiple microstructures. The probability of antivortex nucleation is optimized by the variation of the structure geometry and the nucleation field strength. The presented method opens the path to radio frequency absorption measurements which rely on the resonant excitation of an ensemble of antivortices.
Effect of pretreatment of Si interlayer by energetic C+ ions on the improved nanotribological properties of magnetic head overcoat
Authors: Rismani Ehsan , Sinha S. K. , Yang H. , Bhatia C. S.
Published: April 2012

A thin layer of silicon has been used to improve the adhesion between amorphous carbon coatings and different substrates. However, the mechanism responsible for this improved adhesion to ceramic substrates, especially the Al2O3-TiC (AlTiC) substrate of magnetic recording heads, has not been well studied. In this work, this mechanism was investigated by conducting simulation and experimental tests. A tetrahedral amorphous carbon (ta-C) overcoat was deposited on Si-coated ceramic substrates by using filtered cathodic vacuum arc (FCVA) at ion energy of 100 eV. The chemical structure of the ta-C overcoats and interlayers as well as the nanotribological properties of the ta-C coated AlTiC substrate were studied by means of XPS analysis, nanoscratch and ball-on-flat tests. The formation of a Si-C network between the Si interlayer and ta-C overcoat as well as the formation of Al–O–Si and Si–O–C bonds between the interlayer and the substrate were found to be the two main phenomena which strongly bond the ta-C film to its ceramic substrate. Prior to deposition of the ta-C overcoat, surface of the Si interlayer was bombarded (pretreated) by C+ ions with ion energy of 350 eV. Effect of this pretreatment on the structure and tribological properties of the coated surfaces was also studied. The results revealed that pretreatment of the Si interlayer by energetic C+ ions is an effective way to form a mixed interface and enhance the formation of a larger number of strong chemical bonds between the substrate and the overcoat which improves the adhesion of the overcoat to the substrate. In addition, this method increased the sp3 content of the ta-C film which further improves the wear resistance and durability of the coating.
Memory effects during the unbiased translocation of a polymer through a nanopore
Authors: de Haan Hendrick W. , Slater Gary W.
Published: April 2012

Through a detailed Langevin dynamics simulation study, the role of memory effects during unbiased translocation is explored. Tests are devised to uncover the presence of memory effects by directly measuring forward/backward-correlated motion as well as the associated change in the dynamics. Conducting these tests at low and high viscosities, a range of behaviours across different time scales is revealed: short-time forward correlations at all viscosities, quasi-static behaviour at low viscosity, and long-time backward correlations at high viscosity. By applying these tests at different portions of the translocation process, these memory effects are also shown to vary as translocation proceeds. Combining this information with standard measurements, a physical picture of unbiased translocation as the diffusion of a local minimum is proposed.
NO-assisted molecular-beam epitaxial growth of nitrogen substituted EuO
Authors: Wicks R. , Altendorf S. G. , Caspers C. , Kierspel H. , Sutarto R. , Tjeng L. H. , Damascelli A.
Published: April 2012

We have investigated a method for substituting oxygen with nitrogen in EuO thin films, which is based on molecular beam epitaxy distillation with NO gas as the oxidizer. By varying the NO gas pressure, we produce crystalline, epitaxial EuO1-xNx films with good control over the films’ nitrogen concentration. In situ x-ray photoemission spectroscopy reveals that nitrogen substitution is connected to the formation Eu3+4f6 and a corresponding decrease in the number of Eu2+4f7, indicating that nitrogen is being incorporated in its 3− oxidation state. While small amounts of Eu3+ in over-oxidized Eu1-δO thin films lead to a drastic suppression of the ferromagnetism, the formation of Eu3+ in EuO1-xNx still allows the ferromagnetic phase to exist with an unaffected Tc, thus providing an ideal model system to study the interplay between the magnetic f7 (J = 7/2) and the non-magnetic f6 (J = 0) states close to the Fermi level.
The consequences of high injected carrier densities on carrier localization and efficiency droop in InGaN/GaN quantum well structures
Authors: Hammersley S. , Watson-Parris D. , Dawson P. , Godfrey M. J. , Badcock T. J. , Kappers M. J. , McAleese C. , Oliver R. A. , Humphreys C. J.
Published: April 2012

There is a great deal of interest in the underlying causes of efficiency droop in InGaN/GaN quantum well light emitting diodes, with several physical mechanisms being put forward to explain the phenomenon. In this paper we report on the observation of a reduction in the localization induced S-shape temperature dependence of the peak photoluminescence energy with increasing excitation power density. This S-shape dependence is a key fingerprint of carrier localization. Over the range of excitation power density where the depth of the S shape is reduced, we also observe a reduction in the integrated photoluminescence intensity per unit excitation power, i.e., efficiency droop. Hence, the onset of efficiency droop occurs at the same carrier density as the onset of carrier delocalization. We correlate these experimental results with the predictions of a theoretical model of the effects of carrier localization due to local variations in the concentration of the randomly distributed In atoms on the optical properties of InGaN/GaN quantum wells. On the basis of this comparison of theory with experiment we attribute the reduction in the S-shape temperature dependence to the saturation of the available localized states. We propose that this saturation of the localized states is a contributory factor to efficiency droop whereby nonlocalized carriers recombine non-radiatively.
Internal structure of tunable ternary CdSexS1−x quantum dots unraveled by x-ray absorption spectroscopy
Authors: Chen Liang-Yih , Yang Po-An , Tseng Chia-Hong , Hwang Bing-Joe , Chen Ching-Hsiang
Published: April 2012

CdSexS1−x quantum dots (QDs) were synthesized by a simple one-injection non-coordinate solvent method. The composition distribution of Se and S and the internal structures of the CdSexS1−x QDs can be tuned by the Se/S molar ratio. To investigate the internal structure of CdSexS1−x QD, x-ray absorption spectroscopy was used to examine the distribution of Se and S inside CdSexS1−x QDs.
Modified beam theories for bending properties of nanowires considering surface/intrinsic effects and axial extension effect
Authors: Zhan H. F. , Gu Y. T.
Published: April 2012

Several studies of the surface effect on bending properties of a nanowire (NW) have been conducted. However, these analyses are mainly based on theoretical predictions, and there is seldom integration study in combination between theoretical predictions and simulation results. Thus, based on the molecular dynamics (MD) simulation and different modified beam theories, a comprehensive theoretical and numerical study for bending properties of nanowires considering surface/intrinsic stress effects and axial extension effect is conducted in this work. The discussion begins from the Euler-Bernoulli beam theory and Timoshenko beam theory augmented with surface effect. It is found that when the NW possesses a relatively small cross-sectional size, these two theories cannot accurately interpret the true surface effect. The incorporation of axial extension effect into Euler-Bernoulli beam theory provides a nonlinear solution that agrees with the nonlinear-elastic experimental and MD results. However, it is still found inaccurate when the NW cross-sectional size is relatively small. Such inaccuracy is also observed for the Euler-Bernoulli beam theory augmented with both contributions from surface effect and axial extension effect. A comprehensive model for completely considering influences from surface stress, intrinsic stress, and axial extension is then proposed, which leads to good agreement with MD simulation results. It is thus concluded that, for NWs with a relatively small cross-sectional size, a simple consideration of surface stress effect is inappropriate, and a comprehensive consideration of the intrinsic stress effect is required.
Substrate effect on the electronic structures of CuPc/graphene interfaces
Authors: Wu Qi-Hui , Hong Guo , Ng T. W. , Lee S. T.
Published: April 2012

The interfacial electronic structures of copper phthalocyanine (CuPc) deposited on a single-layer graphene (SLG) film prepared on Cu and SiO2 substrates (SLG/Cu and SLG/SiO2) were investigated using ultraviolet photoelectron spectroscopy. The ionization energy of CuPc on SLG/Cu and SLG/SiO2 substrate is, respectively, 5.62 eV and 4.97 eV. The energy level alignments at the two interfaces were estimated. The results revealed that the height of the electron (hole) injection barriers are 1.20 (1.10) and 1.38 (0.92) eV at CuPc/SLG/Cu and CuPc/SLG/SiO2 interfaces, respectively.
Quantum spin holography with surface state electrons
Authors: Brovko Oleg O. , Stepanyuk Valeri S.
Published: April 2012

In a recent paper, Moon et al. [Nat. Nanotechnol. 4, 167 (2009)] have shown that the single-atom limit for information storage density can be overcome by using the coherence of electrons in a two-dimensional electron gas to produce quantum holograms comprised of individually manipulated molecules projecting an electronic pattern onto a portion of a surface. We propose to further extend the concept by introducing quantum spin holography—a version of quantum holographic encoding allowing to store the information in two spin channels independently.
Short wavelength thermography: Theoretical and experimental estimation of the optimal working wavelength
Authors: Serio B. , Hunsinger J. J. , Pfeiffer P.
Published: April 2012

Radiometric temperature measurement methods, such as thermography, use mainly radiation in the infrared spectrum. In this wavelength range, applications are limited by the diffraction to macroscopic devices. The empirical optical resolution limit is given by the Rayleigh criterion. Given the interest in the study of thermal microsystems, we propose an optimization criterion taking into account both the thermal sensitivity and the signal to noise ratio of the considered radiometric methods. The optimization analysis results highlight the opportunity to reduce the working wavelength of thermography applications and, thus, improving the spatial resolution limit of the radiometric method used. This theoretical approach for wavelengths optimization of the radiometric methods is experimentally validated by a phase transition temperature measurement of a fused aluminium bath in both visible and near infrared spectral ranges.
Precision quantization of Hall resistance in transferred graphene
Authors: Woszczyna M. , Friedemann M. , Götz M. , Pesel E. , Pierz K. , Weimann T. , Ahlers F. J.
Published: April 2012

We show that quantum resistance standards made of transferred graphene reach the uncertainty of semiconductor devices, the current reference system in metrology. A large graphene device (150 × 30 μm2), exfoliated and transferred onto GaAs revealed a quantization with a precision of ( − 5.1 ± 6.3) · 10−9 accompanied by a vanishing longitudinal resistance at current levels exceeding 10 μA. While such performance had previously only been achieved with epitaxially grown graphene, our experiments demonstrate that transfer steps, inevitable for exfoliated graphene or graphene grown by chemical vapor deposition, are compatible with the requirements of high quality quantum resistance standards.
Effect of e-beam irradiation on graphene layer grown by chemical vapor deposition
Authors: Iqbal M. Z. , Kumar Singh Arun , Iqbal M. W. , Seo Sunae , Eom Jonghwa
Published: April 2012

We have grown graphene by chemical vapor deposition (CVD) and transferred it onto Si/SiO2 substrates to make tens of micron scale devices for Raman spectroscopy study. The effect of electron beam (e-beam) irradiation of various doses (600 to 12 000 μC/cm2) on CVD grown graphene has been examined by using Raman spectroscopy. It is found that the radiation exposures result in the appearance of the strong disorder D band attributed the damage to the lattice. The evolution of peak frequencies, intensities, and widths of the main Raman bands of CVD graphene is analyzed as a function of defect created by e-beam irradiation. Especially, the D and G peak evolution with increasing radiation dose follows the amorphization trajectory, which suggests transformation of graphene to the nanocrystalline and then to amorphous form. We have also estimated the strain induced by e-beam irradiation in CVD graphene. These results obtained for CVD graphene are in line with previous findings reported for the mechanically exfoliated graphene [D. Teweldebrhan and A. A. Balandin, Appl. Phys. Lett. 94, 013101 (2009)]. The results have important implications for CVD graphene characterization and device fabrication, which rely on the electron microscopy.
Diffraction resonance with strong optical-field enhancement from gain-assisted hybrid plasmonic structure
Authors: Zhang Haixi , Lu Haifei , Ho Ho-Pui , Zhou Yanyan , Yu Xia , Luan Feng
Published: April 2012

We propose and analyze the diffraction coupling of localized plasmon resonances (LPRs) through gain-assisted propagation surface plasmons (PSPs). The coupling process involves localization of incident light by LPR and LPR-PSP interaction. We demonstrate a significantly strong enhancement of electromagnetic power for LPRs in the event of diffraction resonance through incorporation of experimentally feasible optical gain to the PSP. Based on such phenomenon, we propose a hybrid plasmonic structure, which would potentially give rise to device realization of the nano-lasers. In addition, it is also a promising platform for applications such as surface enhanced Raman scattering, nonlinear optics, plasmonic trapping, etc.
Obvious efficiency enhancement of organic light-emitting diodes by parylene-N buffer layer
Authors: Hu Y. M. , He Y. , Chen X. Q. , Zhan Y. Q. , Sun Z. Y. , You Y. T. , Hou X. Y.
Published: April 2012

A parylene-N (PPXN) buffer layer inserted between anode and organic layers in typical organic light-emitting diodes (OLEDs) based on N, N′-bis(naphthalene-1-yl)-N, N′-bis(phenyl) benzidine (NPB) and tris (8-hydroxyquinolato) aluminum (Alq3) results in significant enhancement of the current efficiency. The enhancement can be 1.7 times higher compared to that of the buffer-free structure. Analyzing indicates that the buffer plays a role of blocking both the hole and electron current. Whether hole injection can be enhanced depends on electron accumulation at the buffer-organic interface. Inserting the PPXN buffer modifies carrier balance in the device, leading to the observed efficiency enhancement.
Magnetic domain pattern asymmetry in (Ga, Mn)As/(Ga,In)As with in-plane anisotropy
Authors: Herrera Diez L. , Rapp C. , Schoch W. , Limmer W. , Gourdon C. , Jeudy V. , Honolka J. , Kern K.
Published: April 2012

Appropriate adjustment of the tensile strain in (Ga, Mn)As/(Ga,In)As films allows for the coexistence of in-plane magnetic anisotropy, typical of compressively strained (Ga, Mn)As/GaAs films, and the so-called cross-hatch dislocation pattern seeded at the (Ga,In)As/GaAs interface. Kerr microscopy reveals a close correlation between the in-plane magnetic domain and dislocation patterns, absent in compressively strained materials. Moreover, the magnetic domain pattern presents a strong asymmetry in the size and number of domains for applied fields along the easy [11¯0] and hard [110] directions which is attributed to different domain wall nucleation/propagation energies. This strong influence of the dislocation lines in the domain wall propagation/nucleation provides a lithography-free route to the effective trapping of domain walls in magneto-transport devices based on (Ga, Mn)As with in-plane anisotropy.