bluuebunny/crossref_metadata_2025 huggingface dataset:
Single chain self‐assembly of well‐defined heterotelechelic polymers generated by ATRP and click chemistry revisited
Authors: Altintas Ozcan , Rudolph Tobias , Barner‐Kowollik Christopher
Published: April 2011

Well‐defined heterotelechelic poly(styrene) carrying thymine/diaminopyridine (DAP) (Mn,SEC = 9300, PDI = 1.04) and Hamilton wedge (HW)/cyanuric acid (CA) (Mn,SEC = 8200, PDI = 1.04) bonding motifs are prepared via a combination of controlled/living radical polymerization and copper catalyzed azide/alkyne “click” chemistry and are subsequently self‐assembled as single chains to emulate—on a simple level—the self‐folding behavior of natural biomacromolecules. Hydrogen nuclear magnetic resonance (1H NMR) in deuterated dichloromethane and dynamic light scattering analyses provides evidence for the hydrogen bonding interactions between the α‐thymine and ω‐DAP as well as α‐CA and ω‐HW chain ends of the heterotelechelic polymers leading to circular entropy driven single chain self‐assembly. This study demonstrates that the choice of NMR solvent is important for obtaining well‐resolved NMR spectra of the self‐assembled structures. In addition, steric effects on the HW can affect the efficiency of the self‐assembly process. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Functionalization of polymeric surfaces by simple photoactivation of CH bonds
Authors: Xu Jing , Ma Yuhong , Xie Jingyi , Xu F.J. , Yang Wantai
Published: April 2011

A universal photoassisted pathway to functionalize polymeric surfaces is presented by transferring the inert surface sp3 CH bonds into reactive groups, such as SO3H, NH2, SH, and COOH. The proposed method uses acetone as photoinitiator and different phenols with a para substituent XR as the reactants. Acetone excited by UV irradiation acts as a pair of scissors cutting both the surface CH bonds of the polymer substrate and the OH bonds of phenol, leading to the formation of carbon‐centered surface chain free radicals and oxygen‐centered phenoxy free radicals. By coupling of these two radicals, a variety of functional X groups with an R spacer from XR species of different phenol reactants were readily bonded to the polymeric surfaces, where phenol reactants included 4‐hydroxylbenzene sulfonic acid for SO3H, p‐aminophenol and tyramine for NH2, 4‐hydroxythiophenol for SH, and tyrosine for COOH. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Effects of infant formula on cell homeostasis and cytokine levels in an in vivo and in vitro murine aspiration model
Authors: Pepiak Derek L. , Alcorn Joseph L. , Atkins Constance L. , Xue Hasen , Colasurdo Giuseppe N. , Khan Amir M.
Published: April 2011

Rationale

The role of infant formula aspiration in lung injury has not been studied extensively. We evaluated the effects of a single infant formula aspiration into the lungs of mice and the effect of infant formula exposure on cell lines representing murine alveolar macrophages and type II epithelial cells.

Objectives

To study the effects of exposure to infant formula on cell count histology and cytokine levels in an in vivo and in vitro model of aspiration.

Methods

In vivo: Juvenile mice received 2.5 µl/g of 50% infant formula intranasally. Bronchoalveolar lavage samples were collected at 1, 2, and 7 days after aspiration and evaluated for cell count and differential. In vitro: RAW 264.7 and MLE‐15 cells were exposed to 1% infant formula for 6 hr. Extracellular levels of IL‐6, TNF‐α, MIP‐2, and KC were measured in lavage fluid and cell media using ELISA assays.

Results

In vivo: An increase in neutrophils, IL‐6 and KC levels were noted 24 hr after infant formula exposure. In vitro: An increase in TNF‐α levels from RAW 264.7 and MIP‐2 and KC levels from MLE‐15 cells was noted after infant formula exposure.

Conclusions

A single aspiration of infant formula into the lungs leads to an acute inflammatory response involving both lung macrophages and epithelial cells. Pediatr. Pulmonol. 2011; 46:927–933. © 2011 Wiley‐Liss, Inc.
Portopulmonary hypertension secondary to congenital extrahepatic portosystemic shunt with heterotaxy and polysplenia: A cause of sudden death in an infant
Authors: Kobayashi Daisuke , Edwards Henry D. , Singh Jasmeet , Nadkarni Milan D. , Lantz Patrick E. , Cook Amanda L.
Published: April 2011

Congenital extrahepatic portosystemic shunt (CEPS) is associated with polysplenia and heterotaxy and can cause portopulmonary hypertension. We report a 12‐month‐old girl who acutely died likely due to portopulmonary hypertension secondary to CEPS associated with heterotaxy and polysplenia. A retrospective radiographic review following her autopsy identified an anatomical explanation for the acute death in an infant. Pediatr. Pulmonol. 2011; 46:1041–1044. © 2011 Wiley‐Liss, Inc.
Kallikrein‐related peptidase 4 gene (KLK4) in prostate tumors: Quantitative expression analysis and evaluation of its clinical significance
Authors: Avgeris Margaritis , Stravodimos Konstantinos , Scorilas Andreas
Published: April 2011

BACKGROUND

Recently accumulating evidences underline the central role of the kallikrein‐related peptidases family (KLKs) in prostate cancer (PCa) development and progression. The KLK4 is a prostate highly expressed gene under the transcriptional control of androgens, encoding for the KLK4 extracellular serine protease. The aim of this study is to investigate the expression status of KLK4 in PCa patients in order to reveal its utility in PCa establishment and clinical management.

METHODS

Prostatic tissue specimens were obtained from 60 PCa and 59 benign prostate hyperplasia (BPH) randomly chosen patients. Using a developed quantitative real‐time RT‐PCR method, KLK4 expression levels were determined in the specimens of the two patients' cohorts. Advance biostatistical analysis was completed to explore the clinical value of KLK4 expression in PCa and BPH patients.

RESULTS

PCa patients presented a statistically significant (P = 0.002) elevation, more than threefold, of the KLK4 transcripts compared to BPH ones. The KLK4 expression levels were also positive correlated with PCa patients' stage (P = 0.031) and preoperative prostate‐specific antigen (PSA) serum concentrations (P < 0.001). ROC curve and logistic regression analysis revealed the significant (P = 0.002) and the independent (P = 0.044) clinical value of the KLK4 expression for the discrimination of PCa from BPH patients.

CONCLUSIONS

The KLK4 expression analysis reveals its up‐regulation in PCa cells, which is significantly associated with the advanced stages of the disease and the patients' preoperative PSA serum levels. KLK4 quantification serves as an independent biomarker for the discrimination between the malignant and the benign nature of prostate tumors. Prostate 71:1780–1789, 2011. © 2011 Wiley Periodicals, Inc.
Impact of diabetes mellitus on the detection of prostate cancer via contemporary multi (≥12)‐core prostate biopsy
Authors: Hong Sung Kyu , Oh Jong Jin , Byun Seok‐Soo , Hwang Sung Il , Lee Hak Jong , Choe Gheeyoung , Lee Sang Eun
Published: April 2011

BACKGROUND

Currently, controversy continues regarding the association between diabetes mellitus (DM) and prostate cancer (PCa). We investigated the impact of DM in PCa detection among men who underwent contemporary multi‐core prostate biopsy.

METHODS

In this retrospective study, we reviewed records of 3,925 men who underwent multi (≥12)‐core prostate biopsy at our institution. Biopsy outcomes were analyzed with respect to various variables, including DM, patient age, body mass index (BMI), prostate‐specific antigen (PSA), digital rectal exam (DRE) finding, ultrasound finding, and prostate volume.

RESULTS

Among 3,925 subjects, 607 (15.5%) reported having DM at biopsy. Overall PCa was detected from biopsy in 1,387 (35.3%) patients, and high grade (biopsy Gleason score ≥7) PCa in 781 (19.9%). In multivariate analysis incorporating variables of patient age, BMI, PSA, DRE finding, ultrasound finding, and prostate volume, DM was observed to be significantly associated with higher odds of overall PCa detection via contemporary prostate biopsy (OR = 1.46, P = 0.019). When analyzed by tumor grade, DM was significantly associated with higher rate of high grade PCa detection from biopsy in multivariate analysis (OR = 1.54, P = 0.036) whereas DM and detection of low grade (biopsy Gleason score ≤6) PCa demonstrated no significant association (OR = 1.11, P = 0.558).

CONCLUSIONS

Our results showed DM was independently associated with the detection of high grade PCa via contemporary multi‐core prostate biopsy. Further investigations would be needed to elucidate exact biologic basis of relationship between the two diseases. Prostate 72:51–57, 2012. © 2011 Wiley Periodicals, Inc.
Bond order uniform grids for quantum reactive scattering
Authors: Rampino S. , Laganà A.
Published: April 2011

The adoption of evenly spaced grids in the so‐called bond order coordinates for the calculation of diatomic eigenfunctions in reactive scattering problems is investigated. These grids (used here for the first time in reactive dynamics) sample the accessible space better than traditional bond length coordinates. A comparison between the bond order and the bond length method on the test H + H2 system using an asymptotically Morse‐like potential singles out the advantages of adopting the former when a limited number of grid points is chosen. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem 112:1818–1828, 2012
Bound‐states of diatomic molecules in the Dirac equation with the q‐deformed Morse potential
Authors: Agboola D.
Published: April 2011

We present the solutions of the ro‐vibrational motion of a diatomic molecule with a spatially dependent mass by solving the Dirac equation with position‐dependent mass for repulsive vector
$V(r)$
and attractive scalar $S(r)$ q‐deformed Morse potential for any $\kappa$
value, within the framework of Pekeris approximation of the spin‐orbitcoupling term. The relativistic energy spectra are obtained using theNikiforov‐Uvarov method and the two‐component spinor wavefunctions are obtained in terms of the Laguerre polynomials. It is found that there exist only negative energy states for bound states, and the energy values for a fixed value of $n_r$
increase with decrease in $\kappa$. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
Full spin and spatial symmetry adapted technique for correlated electronic hamiltonians: Application to an icosahedral cluster
Authors: Sahoo Shaon , Ramasesha S.
Published: April 2011

One of the long standing problems in quantum chemistry had been the inability to exploit full spatial and spin symmetry of an electronic Hamiltonian belonging to a non‐Abelian point group. Here, we present a general technique which can utilize all the symmetries of an electronic (magnetic) Hamiltonian to obtain its full eigenvalue spectrum. This is a hybrid method based on Valence Bond basis and the basis of constant z‐component of the total spin. This technique is applicable to systems with any point group symmetry and is easy to implement on a computer. We illustrate the power of the method by applying it to a model icosahedral half‐filled electronic system. This model spans a huge Hilbert space (dimension 1,778,966) and in the largest non‐Abelian point group. The C60 molecule has this symmetry and hence our calculation throw light on the higher energy excited states of the bucky ball. This method can also be utilized to study finite temperature properties of strongly correlated systems within an exact diagonalization approach. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
State‐ and property‐specific quantum chemistry: Basic characteristics, and sample applications to atomic, molecular, and metallic ground and excited states of beryllium
Authors: Nicolaides Cleanthes A.
Published: April 2011

Many problems in Atomic and Molecular Physics can be understood conceptually and quantitatively by using symmetry‐adapted, state‐specific wavefunctions whose computation is geared so as to account for at least those parts which describe reliably the characteristics of closed‐and open‐(sub)shell electronic structures that contribute overwhelmingly to the property or phenomenon of interest. If additional terms in the wavefunction are required by the problem, this is feasible via methods of configuration‐interaction or low‐order perturbation theory. This is the main argument of the state‐ and property‐specific approach (SPSA) to Quantum Chemistry. In this framework, the aim is to obtain the state wavefunction, Ψn, in the form a0Ψ + Φ, where a0 ≈ 1. Ψ is a state‐specific zero‐order description of ground and excited states of the discrete as well as of the continuous spectrum. In general, it is multiconfigurational and its construction follows from the “Fermi‐sea” set of orbitals. The Ψ is used as reference for analysis and/or for further improvement of the overall calculation, if necessary. The level of accuracy of the computation of the remaining Φ depends on the property under investigation. The arguments are supported by characteristic examples on ground and excited states of atomic, molecular and metallic Beryllium. Some of these SPSA results are compared with results from more conventional methods of electronic structure. Special attention is given to the weak bond of the Be2 X1Σ state, which has attracted the interest of quantum chemists for decades. By asserting that the formation of the bond at about 2.5 A˚´ is influenced by the interactions involving excited states, I point to the corresponding significance in zero‐order (“Fermi‐sea”) not only of p‐waves but also of d‐waves whose origin is in the valence‐Rydberg state mixing of the lowest 1D and 1Po states of Be. Therefore, the “Fermi‐sea” (“active space”) is represented by the Be set of {2s,2p,3s,3p,3d} orbitals. The initially heuristic predictions are supported by calculations (using the MOLPRO code) of the lowest seven Be21Σ states, whose Ψ are obtained at the state‐averaged complete active space self‐consistent field level. These results are verified by the computation of a0Ψ + Φ at the MRCISD level, where indeed a0 ≈ 1 over the whole potential energy curve. This type of analysis and the corresponding results imply that by a properly justified choice of the zero‐order orbital set, the origin of the Be2 bond is to be found in “nondynamical” – type correlations. This conclusion differs from that of Schmidt et al. [J Phys Chem A, 2010, 114, 8687], who argued that the formation of the Be2 weak bond should be attributed exclusively to “dynamical” correlations that are defined with respect to the {2s,2p} “active space” associated with the Be 1S ground state. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem 111:3347–3361, 2011
CREATING AND EVALUATING DIGITAL ELEVATION MODEL‐BASED STREAM‐POWER MAP AS A STREAM ASSESSMENT TOOL
Authors: Vocal Ferencevic M. , Ashmore P.
Published: April 2011

As urban development increases, a need is emerging to understand and predict river behaviour in order to focus rehabilitation efforts and protect the natural river system while preserving urban infrastructure. Stream assessment methods are reviewed to demonstrate the need for a physically based and objective method that is also accessible in terms of time, data requirements and expertise. The case of Highland Creek near Toronto, Canada, is used to demonstrate a new type of initial stream assessment method that is based on the concept of stream power and performed entirely in a geographic information system using information from a digital elevation model (DEM). The results from this analysis are tested against existing information for Highland Creek. This includes a hydraulic model (Hydraulic Engineering Center's ‘River Analysis System’), field‐measured slopes, air photos and the geomorphic effects of an extreme flood. In addition, the results are presented in map form to demonstrate the effectiveness of visualizing the stream‐power distribution over the entire basin and also the usefulness of overlaying stream power onto other available information. The slopes extracted from the DEM are found to be statistically similar to those from a one‐dimensional hydraulic model and field‐measured slopes. Individual peaks in slope as well as locations of stream‐power maxima and minima are found to correlate to actual channel features as seen in air photos. The extreme flood event of August 2005 caused a dramatic change in channel form at the exact location of maximum energy predicted by the DEM‐based stream‐power analysis. The case of Highland Creek illustrates how this approach yields a useful outcome for understanding stream dynamics and stability as part of a stream assessment process. Copyright © 2011 John Wiley & Sons, Ltd.
When does corporate venture capital add value for new ventures?
Authors: Park Haemin Dennis , Steensma H. Kevin
Published: April 2011

New ventures face a trade‐off when considering corporate venture capital (CVC) funding. Corporate investors can provide complementary assets that enhance the commercialization of new venture technologies. However, tight links with a particular corporate investor has drawbacks and may constrain new ventures from accessing complementary assets from diverse sources in an open market. Taking this trade‐off into account, we explore conditions under which CVC funding is beneficial to new ventures. Using a sample of computer, semiconductor, and wireless ventures, we find that CVC funding is particularly beneficial for new ventures when they require specialized complementary assets or operate in uncertain environments. Copyright © 2011 John Wiley & Sons, Ltd.
Investigation of indoor aerosols collected at various educational institutions in Debrecen, Hungary
Authors: Szoboszlai Z. , Furu E. , Angyal A. , Szikszai Z. , Kertész Zs.
Published: April 2011

In this study, atmospheric aerosol concentration levels in two schools (a primary and a secondary grammar) and a kindergarten were investigated. The selected institutions are located close to the center of Debrecen, where the traffic density is rather high. Coarse and fine mass concentrations (PM), elemental composition and mass size distributions were determined in the selected microenvironments. These were different classrooms, school yards, gymnasiums, a computer lab, a chemical lab and a so‐called salt room. The elemental composition (for Z ≥ 13) was determined by PIXE. In all cases, the coarse concentrations of PM were found to be higher inside the educational buildings than in the outer air. In every case, the indoor PM10 concentrations exceeded the EU air quality standard. The fine and coarse elemental concentrations did not exhibit marked variability in the selected microenvironments. On the basis of the mass size distribution, we found significant differences between the two rooms of the kindergarten. On the basis of the mass size distribution data, a stochastic lung deposition model was used to calculate the total and regional deposition efficiencies of the different types of particles along the human respiratory system. Copyright © 2011 John Wiley & Sons, Ltd.
Speciation and determination of Cr(III) and Cr(VI) in water by energy‐dispersive PIXE analysis
Authors: Thomyasirigul S. , Fukuda H. , Hasegawa J. , Oguri Y.
Published: April 2011

Recently, water contamination by Cr(VI) has resulted in serious environmental problems. Therefore, many countries are changing the regulation of water quality standard from total chromium to Cr(VI). This study was conducted to develop a sample preparation method for the determination of Cr(III) and Cr(VI) in water by energy‐dispersive proton‐induced X‐ray emission spectrometry. Whatman ion exchange celluloses (P81 and DE81) were used for separation and pre‐concentration of Cr(III) and Cr(VI) species by filtration, respectively. The dependences of the limit of detection for both chemical species on the incident proton energy, beam current, and measuring time were examined. The accuracy and precision of the proposed method were determined. The results showed that the proposed method allows the separation and determination of Cr(III) and Cr(VI) with a high accuracy and precision. Copyright © 2011 John Wiley & Sons, Ltd.
A new colour assay for [URE3] prion in a genetic background used to score for the [PSI+] prion
Authors: Hong Joo Y. , Mathur Vidhu , Liebman Susan W.
Published: April 2011

Most scoring assays for yeast prions are dependent on specific genetic markers and constructs that differ for each prion. Here we describe a simple colour assay for the [URE3] prion that works in the 74D‐964 strain frequently used to score the [PSI+] prion. Although this assay can only be used to score for [URE3] in the [psi−] version of the strain, it makes it easier to examine the effects of host mutations or environmental changes on [URE3] or [PSI+] using a colour assay in the identical genetic background. Copyright © 2011 John Wiley & Sons, Ltd.
Risk Factors for Persistent Anal Incontinence After Restorative Proctectomy in Rectal Cancer Patients with Anal Incontinence: Prospective Cohort Study
Authors: Lee Taek‐Gu , Kang Sung‐Bum , Heo Seung Chul , Jeong Seung‐Yong , Park Kyu Joo
Published: April 2011

Background

This study evaluated the notion that preoperative anal incontinence might be a potent predictive factor for anal incontinence (AI) after restorative proctectomy in rectal cancer patients. The principal objective of this study was to determine the risk factors for persistent anal incontinence following restorative proctectomy.

Methods

This study was designed as a single‐center, prospective cohort study of a single group of 93 patients who had AI before restorative proctectomy for rectal cancer. The study group was re‐evaluated for the presence of AI 12 months after restorative proctectomy or ileostomy takedown. Incontinence severity was determined using the Fecal Incontinence Severity Index (FISI). Logistic regression analysis was performed to identify the clinicopathologic factors associated with persistent AI.

Results

Fifteen patients were excluded from analysis due to death within the 12 months after surgery (n = 7), no ileostomy repair (n = 5), loss to follow‐up (n = 2), or previous treatment for anal incontinence (n = 1). At 12 months, 53 of 78 patients (67.9%) had persistent AI and 25 patients (32.1 %) had recovered. Multivariate analysis demonstrated that preoperative FISI scores higher than 30 (OR = 11.61, 95% CI 1.43‐94.01, p = 0.022) and lower tumor location 5 cm or less from the anal verge (OR = 84.46, 95% CI 3.91‐1822.85, p = 0.005) were independent factors for persistent AI.

Conclusions

Anal incontinence may persist after restorative proctectomy in rectal cancer patients with high preoperative incontinence scores and lower tumor location. Therefore, this information should be provided when restorative proctectomy is offered for rectal cancer patients.
Life‐threatening hemorrhage from the papilla following stent removal (with video)
Authors: Tsuji Shujiro , Itoi Takao , Sofuni Atsushi , Itokawa Fumihide
Published: April 2011

A 73‐year‐old man was admitted with acute cholangitis due to stent occlusion. He had had type B chronic hepatitis for 14 years but no liver cirrhosis or coagulopathy. The stent was placed 2 months previously for the treatment of obstructive jaundice due to a very large hepatoma. Emergency endoscopic retrograde cholangiopancreatography was performed. Immediately after removing the stent, using snare forceps through the working channel of the endoscope, spurting and continuous bleeding was seen from the papilla. Biliary deep cannulation was successfully performed using a conventional catheter and guidewire. The tip of the catheter was advanced into the left intrahepatic bile duct for pressure hemostasis. Ten minutes later, the bleeding completely stopped and a 10‐Fr stent was inserted into the bile duct.
A Joint Modeling Approach for Reaction Time and Accuracy in Psycholinguistic Experiments
Authors: Loeys T. , Rosseel Y. , Baten K.
Published: April 2011

In the psycholinguistic literature, reaction times and accuracy can be analyzed separately using mixed (logistic) effects models with crossed random effects for item and subject. Given the potential correlation between these two outcomes, a joint model for the reaction time and accuracy may provide further insight. In this paper, a Bayesian hierarchical framework is proposed that allows estimation of the correlation between time intensity and difficulty at the item level, and between speed and ability at the subject level. The framework is shown to be flexible in that reaction times can follow a (log-) normal or (shifted) Weibull distribution. A simulation study reveals the reduction in bias gains possible when using joint models, and an analysis of an example from a Dutch–English word recognition study illustrates the proposed method.
Successful infertility treatment following fertility‐sparing surgery and chemotherapy for ovarian immature teratoma: a case report and a literature review
Authors: Matsushita Hiroshi , Tani Hirohiko
Published: April 2011

Introduction

Malignant ovarian germ cell tumors (MOGCTs) are highly chemosensitive tumors most commonly found in adolescent girls and young women. However, patients with advanced disease can now be successfully cured with fertility‐sparing surgery and adjuvant chemotherapy, resulting in childbearing.

Case

A 24‐year‐old nulliparous Japanese woman was diagnosed as having a stage IIIc immature teratoma. After fertility‐sparing surgery, she received four cycles of chemotherapy consisting of cisplatin, etoposide, and pepleomycin. She married at the age of 34, but did not conceive due to sexual dysfunction of her husband. At the age of 38, intrauterine insemination was performed following ovulation induction with clomid and human menopausal gonadotrophin, which resulted in a singleton pregnancy. A healthy female infant was delivered at 38 weeks’ gestation.

Conclusion

Treatment might sometimes be needed for infertile women with a history of MOGCTs, but further studies are needed to determine whether infertility treatment, including ovulation induction, is appropriate.
Stem cell research for male infertility
Authors: Kobayashi Hideyuki , Nagao Koichi , Nakajima Koichi
Published: April 2011

Stem cells have the ability both to differentiate into numerous tissues and to self‐renew. Because of these unique properties, stem cells are promising candidates for use in regenerative medicine. Among stem cell types, embryonic stem (ES) cells have been the most studied; however, alternatives such as induced pluripotent stem cells or other adult stem cells are now being established. In this review, we focus on stem cell research that may have applications in treating male infertility. Stem cells with ES‐like properties have been generated from adult human testis tissue. We expect that breakthroughs in stem cell research will increase our understanding of male infertility and lead to treatments in the near future.
Ubiquitylation of DNA polymerase λ
Authors: Markkanen Enni , van Loon Barbara , Ferrari Elena , Hübscher Ulrich
Published: April 2011

DNA polymerase (pol) λ, one of the 15 cellular pols, belongs to the X family. It is a small 575 amino‐acid protein containing a polymerase, a dRP‐lyase, a proline/serine rich and a BRCT domain. Pol λ shows various enzymatic activities including DNA polymerization, terminal transferase and dRP‐lyase. It has been implicated to play a role in several DNA repair pathways, particularly base excision repair (BER), non‐homologous end‐joining (NHEJ) and translesion DNA synthesis (TLS). Similarly to other DNA repair enzymes, pol λ undergoes posttranslational modifications during the cell cycle that regulate its stability and possibly its subcellular localization. Here we describe our knowledge about ubiquitylation of pol λ and the impact of this modification on its regulation.
Why is PTPN22 a good candidate susceptibility gene for autoimmune disease?
Authors: Burn Garth L. , Svensson Lena , Sanchez-Blanco Cristina , Saini Manoj , Cope Andrew P.
Published: April 2011

The PTPN22 locus is one of the strongest risk factors outside of the major histocompatability complex that associates with autoimmune diseases. PTPN22 encodes lymphoid protein tyrosine phosphatase (Lyp) which is expressed exclusively in immune cells. A single base change in the coding region of this gene resulting in an arginine to tryptophan amino acid substitution within a polyproline binding motif associates with type 1 diabetes, rheumatoid arthritis, systemic lupus erythematosis, Hashimotos thyroiditis, Graves disease, Addison's disease, Myasthenia Gravis, vitiligo, systemic sclerosis juvenile idiopathic arthritis and psoriatic arthritis. Here, we review the current understanding of the PTPN22 locus from a genetic, geographical, biochemical and functional perspective.
The diagnosis of dementia due to Alzheimer's disease: Recommendations from the National Institute on Aging‐Alzheimer's Association workgroups on diagnostic guidelines for Alzheimer's disease
Authors: McKhann Guy M. , Knopman David S. , Chertkow Howard , Hyman Bradley T. , Jack Clifford R. , Kawas Claudia H. , Klunk William E. , Koroshetz Walter J. , Manly Jennifer J. , Mayeux Richard , Mohs Richard C. , Morris John C. , Rossor Martin N. , Scheltens Philip , Carrillo Maria C. , Thies Bill , Weintraub Sandra , Phelps Creighton H.
Published: April 2011

The National Institute on Aging and the Alzheimer's Association charged a workgroup with the task of revising the 1984 criteria for Alzheimer's disease (AD) dementia. The workgroup sought to ensure that the revised criteria would be flexible enough to be used by both general healthcare providers without access to neuropsychological testing, advanced imaging, and cerebrospinal fluid measures, and specialized investigators involved in research or in clinical trial studies who would have these tools available. We present criteria for all‐cause dementia and for AD dementia. We retained the general framework of probable AD dementia from the 1984 criteria. On the basis of the past 27 years of experience, we made several changes in the clinical criteria for the diagnosis. We also retained the term possible AD dementia, but redefined it in a manner more focused than before. Biomarker evidence was also integrated into the diagnostic formulations for probable and possible AD dementia for use in research settings. The core clinical criteria for AD dementia will continue to be the cornerstone of the diagnosis in clinical practice, but biomarker evidence is expected to enhance the pathophysiological specificity of the diagnosis of AD dementia. Much work lies ahead for validating the biomarker diagnosis of AD dementia.
The diagnosis of mild cognitive impairment due to Alzheimer's disease: Recommendations from the National Institute on Aging‐Alzheimer's Association workgroups on diagnostic guidelines for Alzheimer's disease
Authors: Albert Marilyn S. , DeKosky Steven T. , Dickson Dennis , Dubois Bruno , Feldman Howard H. , Fox Nick C. , Gamst Anthony , Holtzman David M. , Jagust William J. , Petersen Ronald C. , Snyder Peter J. , Carrillo Maria C. , Thies Bill , Phelps Creighton H.
Published: April 2011

The National Institute on Aging and the Alzheimer's Association charged a workgroup with the task of developing criteria for the symptomatic predementia phase of Alzheimer's disease (AD), referred to in this article as mild cognitive impairment due to AD. The workgroup developed the following two sets of criteria: (1) core clinical criteria that could be used by healthcare providers without access to advanced imaging techniques or cerebrospinal fluid analysis, and (2) research criteria that could be used in clinical research settings, including clinical trials. The second set of criteria incorporate the use of biomarkers based on imaging and cerebrospinal fluid measures. The final set of criteria for mild cognitive impairment due to AD has four levels of certainty, depending on the presence and nature of the biomarker findings. Considerable work is needed to validate the criteria that use biomarkers and to standardize biomarker analysis for use in community settings.
Der Kaiserschnitt eine gesundheitswissenschaftliche Sicht
Authors: Kolip Petra
Published: April 2011

Einleitung

Die Kaiserschnittraten sind in Deutschland in den vergangenen Jahren konstant gestiegen und liegen mittlerweile bei über 30%. Die Gründe hierfür sind vielfältig. So spielen neben medizinischen und ökonomischen Faktoren auch psychologische Aspekte eine Rolle. Aus gesundheitswissenschaftlicher Perspektive stellt sich die Frage, wie eine Medikalisierung der Geburt verhindert werden kann. Neue Versorgungsmodelle wie der Hebammenkreißsaal bieten hier vielversprechende Ansätze.
Isotopy of lead from the Sora porphyry Cu-Mo magmatic center (Kuznetsk Alatau)
Authors: Berzina A.P. , Berzina A.N. , Gimon V.O. , Krymskii R.Sh.
Published: April 2011

We studied the isotopic composition of lead in feldspars from the intrusive rocks of enclosing, ore-bearing porphyry, and post-ore complexes and in sulfides from the Sora magmatic center including the Sora porphyry Cu-Mo deposit. The arrangement of the isotopic composition points below the orogen evolution curve on the uranogenic lead diagram evidences a predominance of lead of mantle genesis in the igneous rocks and a minor content of crustal lead. On the 207Pb/204Pb–206Pb/204Pb diagram, the lead of magmatites form a linear sequence (trend), which is interpreted as mixing of lead from different sources. According to the geochemical parameters, weakly depleted mantle metasomatized by subduction fluids was a source of magmatism. The linear correlation between the ratios of Pb isotopes in the igneous rocks of the Sora magmatic center is explained by the mixing of lead of the mantle and subduction fluids. Mantle lead is predominant in the basites of the enclosing, porphyry, and post-ore complexes and in the leucogranites of the enclosing complex. According to lead isotopy data, the differentiated magmatites (enclosing monzonitoids, ore-bearing porphyry, and post-ore syenite-porphyry) contain a subduction component, whose content increases in passing from early to late complex. The Pb-isotopic composition of sulfides suggests the mantle source of Pb in molybdenite of the breccia ores and the heterogeneous source (mantle and subduction fluids) of Pb in chalcopyrite of the veinlet ores.
Experimental study of the leak-tightness of water-containing silicate-melt inclusions under the pressure of D2O at 650 °C and 3 kbar
Authors: Smirnov S.Z. , Tomas V.G. , Sokolova E.N. , Kupriyanov I.N.
Published: April 2011

The paper is devoted to the experimental study of the leak-tightness of water-containing melt inclusions heated in the autoclave at high temperature and under the pressure of D2O. Quartz-hosted silicate-melt inclusions from the rhyolite tuffs of the Taupo volcanic zone (New Zealand) and a tourmaline-pegmatite vein from the SW Pamirs were heated at 650 °C and 3 kbar. The penetration of heavy water into the inclusions was controlled by IR spectroscopy. The studies have demonstrated that the inclusions can remain leak-tight under these conditions and not exchange water with the environment even if the confining pressure is 1.5–3 times above their internal pressure. The influence of water diffusion through the quartz lattice and dislocations on the leak-tightness can be neglected in the thermometry of water-containing melt inclusions. The crucial factors determining the water exchange between the inclusions and the environment in the experiments performed are mechanical defects (open and healed cracks). Using D2O as a pressurizing medium makes it possible to control the leak-tightness of the heated inclusions. To do this, it is recommended that melt inclusions be homogenized under the pressure of D2O above the expected entrapment pressure and studied by IR spectroscopy after the heating.
Reconstruction of solution chemistry evolution based on the sedimentary record of salt lakes in the Olkhon region
Authors: Gaskova O.L. , Solotchina E.P. , Sklyarova O.A.
Published: April 2011

Using data on the chemical composition of lake waters in the Olkhon region, we calculated the under- and oversaturation of modern chloride solutions of Lake Tsagan-Tyrm. These data are a basis for the determination of the composition of suspension and bottom sediments. The thermodynamically calculated solubility of carbonates (inverse problem) discovered in the evaporite lacustrine sediments gave an insight into the main regularities of the chemical evolution of ancient brines and the formation conditions of various magnesian calcites. The calculations confirmed that an increase in solution mineralization leads to the deposition of high-Mg calcites, which is also observed in the bottom sediments of other lakes under climate aridization and temperature decrease.
Seismic quality factor of the lithosphere of the southwestern flank of the Baikal rift system
Authors: Dobrynina A.A. , Chechel’nitskii V.V. , San’kov V.A.
Published: April 2011

The seismic quality factor (Qc), the frequency parameter (n), and the attenuation coefficient (δ) of seismic waves in the lithosphere of the southwestern flank of the Baikal rift system are obtained from records of S coda waves from regional earthquakes. There is a strong dependence of the quality factor on the frequency and coda window length: for central frequencies of 0.3 and 12.0 Hz and a coda window length W = 20 s, Qc varies from 47 ± 51 to 1036 ± 190, and for the same frequencies and W = 60 s, it varies from 83 ± 46 to 1596 ± 573. The values of the quality factor and the attenuation coefficient are calculated for the whole southwestern flank of the Baikal rift system and for individual tectonic blocks: the stable Siberian Platform, Khamar-Daban and East Sayan uplifts, and South Baikal and Tunka basins. A comparison of the obtained values of Qc with data on the age, tectonics, and seismic activity level of the structures shows that the quality factor depends on the recent tectonic activity of the structures, and to a lesser extent, on the age of the crust.
Amplitude-dependent effects in a transmitted wave in cemented sandstone under pressure
Authors: Mashinskii E.I. , Egorov G.V.
Published: April 2011

This paper presents the results of experiments on the effect of variable amplitude and pressure on the P-wave velocity and attenuation in cemented sandstone sample. The measurements were performed in transmitted waves at a predominant pulse frequency of 6.8 kHz in the range of strain amplitudes Aε ≈ (0.2−2.4) × 10−6 at an axial static pressure of 0.25 MPa to 1.0 MPa. The wave velocity depends weakly on the amplitude and decreases only slightly with its increase. With increasing pressure the velocity Ve nonlinearly increases (to 6%) at all amplitudes. The attenuation Qe−1 increases linearly (to 2.5%) with increasing amplitude and decreases nonlinearly with increasing pressure. There is an anomalous change in the attenuation in the pressure range (0.5–0.75) MPa, where it decreases to 30% at all amplitudes. These results may be useful for improving acoustic and seismic methods of diagnostics.
Temperature and vital effect controls on bamboo coral (Isididae) isotope geochemistry: A test of the “lines method”
Authors: Hill T. M. , Spero H. J. , Guilderson T. , LaVigne M. , Clague D. , Macalello S. , Jang N.
Published: April 2011

Deep‐sea bamboo corals hold promise as long‐term climatic archives, yet little information exists linking bamboo coral geochemistry to measured environmental parameters. This study focuses on a suite of 10 bamboo corals collected from the Pacific and Atlantic basins (250–2136 m water depth) to investigate coral longevity, growth rates, and isotopic signatures. Calcite samples for stable isotopes and radiocarbon were collected from the base the corals, where the entire history of growth is recorded. In three of the coral specimens, samples were also taken from an upper branch for comparison. Radiocarbon and growth band width analyses indicate that the skeletal calcite precipitates from ambient dissolved inorganic carbon and that the corals live for 150–300 years, with extension rates of 9–128 μm/yr. A linear relationship between coral calcite δ18O and δ13C indicates that the isotopic composition is influenced by vital effects (δ18O:δ13C slope of 0.17–0.47). As with scleractinian deep‐sea corals, the intercept from a linear regression of δ18O versus δ13C is a function of temperature, such that a reliable paleotemperature proxy can be obtained, using the “lines method.” Although the coral calcite δ18O:δ13C slope is maintained throughout the coral base ontogeny, the branches and central cores of the bases exhibit δ18O:δ13C values that are shifted far from equilibrium. We find that a reliable intercept value can be derived from the δ18O:δ13C regression of multiple samples distributed throughout one specimen or from multiple samples within individual growth bands.
The effect of convergence angle on the kinematic evolution of strain partitioning in transpressional brittle wedges: Insight from analog modeling and high‐resolution digital image analysis
Authors: Leever Karen A. , Gabrielsen Roy H. , Sokoutis Dimitrios , Willingshofer Ernst
Published: April 2011

Using analog modeling aided by digital image analysis (DPIV), we constrained the long‐term kinematic evolution of strain partitioning in transpressional brittle wedges as a function of convergence angle. We ran a series of dry quartz sand experiments representing highly oblique continent‐continent collision (convergence angles of 4° to 30°). The digital image analysis provided high‐resolution constraints on the long‐term kinematic evolution of these wedges, which could be subdivided in distinct kinematic stages, comprising (1) an initial “distributed strain” stage and (2) an “oblique wedge” stage before (3) the stage of strain partitioning is reached. Thus, we document the evolution of different deformation stages from a single plate tectonic boundary condition. In addition, the relationship between convergence angle, kinematic stages, and wedge geometry (including fault dips and fault hierarchy) was established. The modeling results show that smaller convergence angles lead to steeper faults. Besides, for a constant convergence angle, the proshears that evolved during the strain partitioning stage were less steep than those formed during the oblique wedge stage. The fault slip vector on individual fault segments was derived from the DPIV data set for each time increment, quantifying the magnitude and orientation of slip on fault segments during the different kinematic stages. In addition, in the 7.5° and 15° models, rotation of the slip vector by up to 40° was observed on a single proshear during the strain partitioning stage. These observations allow to some degree a validation of existing analytical models of strain partitioning, in particular the assumption of steady state.
In-situ measurements of the onset of bulk exothermicity in shock initiation of reactive powder mixtures
Authors: Jetté François-Xavier , Higgins Andrew J. , Goroshin Samuel , Frost David L. , Charron-Tousignant Yannick , Radulescu Matei I. , Lee Julian J.
Published: April 2011

The shock initiation process was directly observed in different powder mixtures that produce little or no gas upon reaction. The samples of reactive powder were contained in recovery capsules that permitted the samples to be analyzed after being shocked and that allowed the initiation of reaction to be monitored using three different methods. The microsecond time-scale processes were observed via a fast two-color pyrometer. Light intensity detected from the bottom of reactive samples was slightly greater compared to inert simulants in the first 10 μs after shock arrival. However, this light was much less intense than that which would correspond to the bulk of the material reacting. Thus it seemed that only small, localized zones, or hot spots, had begun to react on a time scale of less than 30 μs. Light emissions were then recorded over longer time scales, and intense light appeared at the bottom of samples a few milliseconds to a few hundreds of milliseconds after shock arrival at the bottom of the test samples. Thus it appeared that the bulk of the material reacted as the hot spots spread via convective/diffusive means. This bulk reaction was also observed using thermocouples for a large number of mixtures and incident shock pressures. The delay time for the onset of bulk reaction was found to be not strongly dependent upon shock pressure but seemed to correlate with the burning speed of the mixtures. The shock initiation process appeared to take place via the initiation and growth of hot spots, as in high explosives, except that burning speeds are much slower in reactive powders that produce little gas.
Net sputtering rate due to hot ions in a Ne-Xe discharge gas bombarding an MgO layer
Authors: Ho S. , Tamakoshi T. , Ikeda M. , Mikami Y. , Suzuki K.
Published: April 2011

An analytical method is developed for determining net sputtering rate for an MgO layer under hot ions with low energy (<100 eV) in a neon-xenon discharge gas at near-atmospheric pressure. The primary sputtering rate is analyzed according to spatial and energy distributions of the hot ions with average energy, Ehi, above a threshold energy of sputtering, Eth,i, multiplied by a yield coefficient. The threshold energy of sputtering is determined from dissociation energy required to remove an atom from MgO surface multiplied by an energy-transfer coefficient. The re-deposition rate of the sputtered atoms is calculated by a diffusion simulation using a hybridized probabilistic and analytical method. These calculation methods are combined to analyze the net sputtering rate. Maximum net sputtering rate due to the hot neon ions increases above the partial pressure of 4% xenon as EhNe becomes higher and decreases near the partial pressure of 20% xenon as ion flux of neon decreases. The dependence due to the hot neon ions on partial pressure and applied voltage agrees well with experimental results, but the dependence due to the hot xenon ions deviates considerably. This result shows that the net sputtering rate is dominated by the hot neon ions. Maximum EhNe (EhNe,max = 5.3 − 10.3 eV) is lower than Eth,Ne (19.5 eV) for the MgO layer; therefore, weak sputtering due to the hot neon ions takes place. One hot neon ion sputters each magnesium and each oxygen atom on the surface and distorts around a vacancy. The ratio of the maximum net sputtering rate is approximately determined by number of the ions at Ehi,max multiplied by an exponential factor of –Eth,i/Ehi,max.
Sharp Fe/MgO/Ge(001) epitaxial heterostructures for tunneling junctions
Authors: Petti D. , Cantoni M. , Rinaldi C. , Brivio S. , Bertacco R. , Gazquez J. , Varela M.
Published: April 2011

We report on the growth of epitaxial Fe/MgO/Ge(001) heterostructures by molecular beam epitaxy. The lowest oxidation and highest sharpness of the MgO/Ge interface, corresponding to a transition layer on the order of one Ge unit cell, is obtained for room temperature growth of the MgO layer followed by annealing in a vacuum at 500 °C. In these conditions, the MgO layer grows epitaxially on Ge(001) with the [110] direction parallel to the [100] direction of Ge, at variance with the cube-on-cube growth on Si(001) and GaAs(001). However, in some cases, the cube-on-cube growth mode of MgO on Ge competes with the mode involving a 45° rotation, as revealed by transmission electron microscopy and photoelectron diffraction data on MgO films grown at 300 °C without postannealing, and on p-doped Ge substrates. For the Fe overlayer, in all the cases reported, room temperature growth followed by annealing up to 200 °C gives rise to a sharp interface and the well-known 45° rotation of the Fe lattice with respect to the MgO lattice.