bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative expression profiling of miRNA during anther development in genetic male sterile and wild type cotton
Authors: Wei Mingming , Wei Hengling , Wu Man , Song Meizhen , Zhang Jinfa , Yu Jiwen , Fan Shuli , Yu Shuxun
Published: April 2013

Background

Genetic male sterility (GMS) in cotton (Gossypium hirsutum) plays an important role in the utilization of hybrid vigor. However, the molecular mechanism of the GMS is still unclear. While numerous studies have demonstrated that microRNAs (miRNA) regulate flower and anther development, whether different small RNA regulations exist in GMS and its wild type is unclear. A deep sequencing approach was used to investigate the global expression and complexity of small RNAs during cotton anther development in this study.

Results

Three small RNA libraries were constructed from the anthers of three development stages each from fertile wild type (WT) and its GMS mutant cotton, resulting in nearly 80 million sequence reads. The total number of miRNAs and short interfering RNAs in the three WT libraries was significantly greater than that in the corresponding three mutant libraries. Sixteen conserved miRNA families were identified, four of which comprised the vast majority of the expressed miRNAs during anther development. In addition, six conserved miRNA families were significantly differentially expressed during anther development between the GMS mutant and its WT.

Conclusions

The present study is the first to deep sequence the small RNA population in G. hirsutum GMS mutant and its WT anthers. Our results reveal that the small RNA regulations in cotton GMS mutant anther development are distinct from those of the WT. Further results indicated that the differently expressed miRNAs regulated transcripts that were distinctly involved in anther development. Identification of a different set of miRNAs between the cotton GMS mutant and its WT will facilitate our understanding of the molecular mechanisms for male sterility.
Assessment of maternal anemia in rural Western China between 2001 and 2005: a two-level logistic regression approach
Authors: Pei Leilei , Ren Lin , Wang Duolao , Yan Hong
Published: April 2013

Background

There are multiple adverse effects of anemia on human function, particularly on women. However, few researches are conducted on women anemia in rural Western China. This study mainly aims to investigate the levels and associated factors of maternal anemia between 2001 and 2005 in this region.

Methods

6172 and 5372 mothers with children under three years old were selected from 8 provinces in 2001 and from 9 provinces in 2005 respectively in Western China by means of a multi-stage probability proportion to size sampling method (PPS). The blood samples were tested and related socio-demographic information was obtained through questionnaires. A two-level logistic regression model was employed to identify the determinants and provincial variations of women anemia in 2001 and 2005.

Results

The results indicated that the crude prevalence of women anemia in 2005 was higher than the rate in 2001(45.7% vs 33.6%). Based on the nationwide census data in 2000, the age-standardized prevalence of women anemia in the study were obtained as 38.0% in 2001 and 50.0% in 2005 respectively. Two-level logistic model analysis showed that compared to the average, women were more likely to be anemic in Guangxi and Qinghai in 2001 as well as in Chongqing and Qinghai in 2005; that women from Minority groups had higher odds of anemia in contrast with Han; that women with higher parity, longer breastfeeding duration and higher socioeconomic level had a lower rate of anemia, while age of women was positively associated with anemia. The positive correlation between women anemia and altitude was also observed.

Conclusions

The study demonstrated that the burden of maternal anemia in rural Western China increased considerably between 2001 and 2005. The Chinese government should conduct integrated interventions on anemia of mothers in this region.
Factors influencing research engagement: research interest, confidence and experience in an Australian speech-language pathology workforce
Authors: Finch Emma , Cornwell Petrea , Ward Elizabeth C , McPhail Steven M
Published: April 2013

Background

Recent initiatives within an Australia public healthcare service have seen a focus on increasing the research capacity of their workforce. One of the key initiatives involves encouraging clinicians to be research generators rather than solely research consumers. As a result, baseline data of current research capacity are essential to determine whether initiatives encouraging clinicians to undertake research have been effective. Speech pathologists have previously been shown to be interested in conducting research within their clinical role; therefore they are well positioned to benefit from such initiatives. The present study examined the current research interest, confidence and experience of speech language pathologists (SLPs) in a public healthcare workforce, as well as factors that predicted clinician research engagement.

Methods

Data were collected via an online survey emailed to an estimated 330 SLPs working within Queensland, Australia. The survey consisted of 30 questions relating to current levels of interest, confidence and experience performing specific research tasks, as well as how frequently SLPs had performed these tasks in the last 5 years.

Results

Although 158 SLPs responded to the survey, complete data were available for only 137. Respondents were more confident and experienced with basic research tasks (e.g., finding literature) and less confident and experienced with complex research tasks (e.g., analysing and interpreting results, publishing results). For most tasks, SLPs displayed higher levels of interest in the task than confidence and experience. Research engagement was predicted by highest qualification obtained, current job classification level and overall interest in research.

Conclusions

Respondents generally reported levels of interest in research higher than their confidence and experience, with many respondents reporting limited experience in most research tasks. Therefore SLPs have potential to benefit from research capacity building activities to increase their research skills in order to meet organisational research engagement objectives. However, these findings must be interpreted with the caveats that a relatively low response rate occurred and participants were recruited from a single state-wide health service, and therefore may not be representative of the wider SLP workforce.
Maternal diabetes causes abnormal dynamic changes of endoplasmic reticulum during mouse oocyte maturation and early embryo development
Authors: Zhang Chun-Hui , Qian Wei-Ping , Qi Shu-Tao , Ge Zhao-Jia , Min Ling-Jiang , Zhu Xiu-Lang , Huang Xin , Liu Jing-Ping , Ouyang Ying-Chun , Hou Yi , Schatten Heide , Sun Qing-Yuan
Published: April 2013

Background

The adverse effects of maternal diabetes on oocyte maturation and embryo development have been reported.

Methods

In this study, we used time-lapse live cell imaging confocal microscopy to investigate the dynamic changes of ER and the effects of diabetes on the ER’s structural dynamics during oocyte maturation, fertilization and early embryo development.

Results

We report that the ER first became remodeled into a dense ring around the developing MI spindle, and then surrounded the spindle during migration to the cortex. ER reorganization during mouse early embryo development was characterized by striking localization around the pronuclei in the equatorial section, in addition to larger areas of fluorescence deeper within the cytoplasm. In contrast, in diabetic mice, the ER displayed a significantly higher percentage of homogeneous distribution patterns throughout the entire ooplasm during oocyte maturation and early embryo development. In addition, a higher frequency of large ER aggregations was detected in GV oocytes and two cell embryos from diabetic mice.

Conclusions

These results suggest that the diabetic condition adversely affects the ER distribution pattern during mouse oocyte maturation and early embryo development.
Joint source and relay design for two-hop amplify-and-forward relay networks with QoS constraints
Authors: Mohammadi Jafar , Gao Feifei , Rong Yue , Chen Wen
Published: April 2013

In this paper, we consider the joint design of source precoding matrix and the relay precoding matrix in a two-hop multiple-input multiple-output relay network. The goal is to find a pair of matrices in order to minimize the power consumption and at the same time meet pre-selected quality of service constraints that are defined as the mean square error of each data stream. Using majorization theory, we simplify the matrix-valued optimization problem into a scalar-valued one. We then propose a lower bound and an upper bound of the original problem, both in convex forms. Specifically, the latter is solved by a multi-level water-filling algorithm that is much efficient than directly applying the interior point method. Numerical examples corroborate the proposed studies and also demonstrate the tightness of both bounds to the original problem.
Existence results for classes of infinite semipositone problems
Authors: Goddard Jerome , Lee Eun Kyoung , Sankar Lakshmi , Shivaji R
Published: April 2013

We consider the problem

{

−

Δ
p

u
=

a

u

p
−
1

−
b

u

γ
−
1

−
c

u
α

,

x
∈
Ω
,

u
=
0
,

x
∈
∂
Ω
,

where

Δ
p

u
=
div
(

|
∇
u
|

p
−
2

∇
u
)

,

p
>
1

, Ω is a smooth bounded domain in

R
n

,

a
>
0

,

b
>
0

,

c
≥
0

,

γ
>
p

and

α
∈
(
0
,
1
)

. Given a, b, γ and α, we establish the existence of a positive solution for small values of c. These results are also extended to corresponding exterior domain problems. Also, a bifurcation result for the case

c
=
0

is presented.
FPGA based wireless sensor node with customizable event-driven architecture
Authors: Liao Junsong , Singh Brajendra K , Khalid Mohammed AS , Tepe Kemal E
Published: April 2013

This article presents the design and implementation of modular customizable event-driven architecture with parallel execution capability for the first time with wireless sensor nodes using stand alone FPGA. This customizable event-driven architecture is based on modular generic event dispatchers and autonomous event handlers, which will help WSN application developers to quickly develop their applications by adding the required number of event dispatchers and event handlers as per the need of a WSN application. This architecture can handle multiple events in parallel, including high priority ones. Additionally, it provides non-preemptive operation which removes the timing uncertainty and overhead involved with interrupt-driven processor-based sensor node implementation, which is required in real-time wireless sensor networks (WSNs). Thus, higher computation power of FPGAs combined with the non-preemptive modular event-driven architecture with parallel execution capability enables a variety of new WSN applications and facilitates rapid prototyping of WSN applications. In this article, the performance of FPGA-based sensor device is compared with general purpose processor-based implementations of sensor devices. Results show that our FPGA-based implementation provides significant improvement in system efficiency measured in terms of clock cycle counts required for typical sensor network tasks such as packet transmission, relay and reception.
Characteristics of Japanese Duchenne and Becker muscular dystrophy patients in a novel Japanese national registry of muscular dystrophy (Remudy)
Authors: Nakamura Harumasa , Kimura En , Mori-Yoshimura Madoka , Komaki Hirofumi , Matsuda Yu , Goto Kanako , Hayashi Yukiko K , Nishino Ichizo , Takeda Shin‘ichi , Kawai Mitsuru
Published: April 2013

Background

Currently, clinical trials for new therapeutic strategies are being planned for Duchenne and Becker muscular dystrophies (DMD/BMD). However, it is difficult to obtain adequate numbers of patients in clinical trials. As solutions to these problems, patient registries are an important resource worldwide, especially in rare diseases such as DMD/BMD.

Methods

We developed a national registry of Japanese DMD/BMD patients in collaboration with TREAT-NMD. The registry includes male Japanese DMD/BMD patients whose genetic status has been confirmed by genetic analysis. The registry includes patients throughout Japan.

Results

As of February 2012, 583 DMD and 105 BMD patients were registered. Most individuals aged less than 20 years. In terms of genetic mutations of registrants of DMD and BMD, deletion of exons was the most frequent (61.4% and 79.0%) followed by point mutations (24.5% and 14.3%) and duplications (13.6% and 4.8%), respectively. 43.6% of DMD are capable of walking, and 76.2% of BMD registrants are able to walk. 41.1% of DMD registrants in the database were treated using steroids. 29.5% of DMD and 23.8% of BMD registrants were prescribed one cardiac medicine at least. 22% of DMD used ventilator support, and non-invasive support was common. Small numbers of DMD and BMD registrants, only 3.9% and 1.0% of them, have received scoliosis surgery. 57 (9.8%) patients were eligible to clinical trial focused on ‘skipping’ exon 51.

Conclusions

The Remudy has already demonstrated utility in clinical researches and standardization of patients care for DMD/BMD. This new DMD/BMD patient registry facilitates the synchronization of clinical drug development in Japan with that in other countries.
In vivo measurement of apolipoprotein E from the brain interstitial fluid using microdialysis
Authors: Ulrich Jason D , Burchett Jack M , Restivo Jessica L , Schuler Dorothy R , Verghese Philip B , Mahan Thomas E , Landreth Gary E , Castellano Joseph M , Jiang Hong , Cirrito John R , Holtzman David M
Published: April 2013

Background

The APOE4 allele variant is the strongest known genetic risk factor for developing late-onset Alzheimer’s disease. The link between apolipoprotein E (apoE) and Alzheimer’s disease is likely due in large part to the impact of apoE on the metabolism of amyloid β (Aβ) within the brain. Manipulation of apoE levels and lipidation within the brain has been proposed as a therapeutic target for the treatment of Alzheimer’s disease. However, we know little about the dynamic regulation of apoE levels and lipidation within the central nervous system. We have developed an assay to measure apoE levels in the brain interstitial fluid of awake and freely moving mice using large molecular weight cut-off microdialysis probes.

Results

We were able to recover apoE using microdialysis from human cerebrospinal fluid (CSF) in vitro and mouse brain parenchyma in vivo. Microdialysis probes were inserted into the hippocampus of wild-type mice and interstitial fluid was collected for 36 hours. Levels of apoE within the microdialysis samples were determined by ELISA. The levels of apoE were found to be relatively stable over 36 hours. No apoE was detected in microdialysis samples from apoE KO mice. Administration of the RXR agonist bexarotene increased ISF apoE levels while ISF Aβ levels were decreased. Extrapolation to zero-flow analysis allowed us to determine the absolute recoverable concentration of apoE3 in the brain ISF of apoE3 KI mice. Furthermore, analysis of microdialysis samples by non-denaturing gel electrophoresis determined lipidated apoE particles in microdialysis samples were consistent in size with apoE particles from CSF. Finally, we found that the concentration of apoE in the brain ISF was dependent upon apoE isoform in human apoE KI mice, following the pattern apoE2>apoE3>apoE4.

Conclusions

We are able to collect lipidated apoE from the brain of awake and freely moving mice and monitor apoE levels over the course of several hours from a single mouse. Our technique enables assessment of brain apoE dynamics under physiological and pathophysiological conditions and in response to therapeutic interventions designed to affect apoE levels and lipidation within the brain.
Survival outcomes of patients with advanced oral cavity squamous cell carcinoma treated with multimodal therapy: A multi-institutional analysis
Authors: Zhang Han , Dziegielewski Peter T , Biron Vince L , Szudek Jacek , Al-Qahatani Khaled H , O'Connell Daniel A , Harris Jeffrey R , Seikaly Hadi
Published: April 2013

Background

The oral cavity is the most common site for head and neck squamous cell carcinoma. Treatment of advanced stage oral cavity squamous cell carcinoma (OCSCC) has classically involved surgical resection with postoperative adjuvant radiotherapy (S-RT).Despite this aggressive dual modality therapy, the disease outcomes have remained poor. The treatment options expanded in 2004 when two international trials showed the addition of postoperative chemotherapy to radiation improved outcomes. These trials were, however not oral cavity site specific.

Objective

To assess survival outcomes of advanced OCSCC treated by differing modalities. The primary goal was to determine if the addition of postoperative chemotherapy (S-CRT) improves survival compared to other treatment regimens.

Methods

Demographic, pathologic, treatment, and survival data was obtained from patients diagnosed with OCSCC from 1998–2010 in Alberta, Canada. 222 patients were included in the final analysis from 895 OCSCC patients. Actuarial overall, disease-specific, disease-free, and metastasis-free survivals were estimated with Kaplan-Meier and Cox regression analyses. Patients were grouped by treatment.

Results

Patients receiving S-CRT had improved overall, disease-specific, disease-free, and metastasis-free survival compared to S-RT, CRT or RT(p < 0.05). Two and five year estimated overall survival was significantly higher in the S-CRT group at 77 and 58% (p < 0.05), versus S-RT with 55 and 40% rates(p < 0.05). Results were similar for disease-specific, disease-free, and metastasis free survival with S-CRT being favoured. Patients with extracapsular spread (ECS) treated with S-CRT versus S-RT had 55% survival advantage at 5 years (p < 0.05).

Conclusion

This study shows that adding adjuvant chemotherapy to S-RT improves survival outcomes in advanced OCSCC, especially in patients with ECS.
In –silico molecular docking analysis of prodigiosin and cycloprodigiosin as COX-2 inhibitors
Authors: Krishna Pabba Shiva , Vani Kompally , Prasad Metuku Ram , Samatha Burra , Bindu Nidadavolu Shesha Venkata Sathya Si , Charya Maringanti Alaha Singara , Reddy Shetty Prakasham
Published: April 2013

Prodigiosin and cycloprodigiosin are tripyrrole red pigmented compounds with medical importance for their anticancer property. In the present investigation, molecular docking studies were performed for both prodigiosin and cycloprodigiosins to evaluate the in- silico anti-inflammatory activity against Cycloxigenase-2 (COX-2) protein as model compound and the data compared with rofecoxib and celcoxid. Cycloprodigiosin showed higher initial potential, initial RMS gradient and potential energy values compared to prodigiosin. Analysis of COX-2 protein and ligand binding revealed that cyclprodigiosin interacted with COX-2 protein amino acid residues of Tyr324, Phe487 and Arg89 while prodigiosin interaction was observed with two amino acids i.e. Leu321 and Tyr324. The computational ligand binding interaction suggested > 45% higher fitness score value for prodigiosin to that of cycloprodigiosin with COX-2 protein while the standard compounds rofecoxib and celecoxid revealed fitness score of 44 and 62, respectively. The prodigiosin ligand revealed the best fitness score compared with the standard drug rofecoxib suggesting the prodigiosin could be effective as the potential inhibitor compound against COX-2 protein and can be evaluated as anti-inflammatory drug molecule using clinical trials.
Rugby-ball-shaped Na0.5La0.5MoO4:Eu3+ 3D architectures: synthesis, characterization, and their luminescence behavior
Authors: Krishnan Rajagopalan , Thirumalai Jagannathan , Banu Ithrees Basha Shameem , Peter Anthuvan John
Published: April 2013

Three-dimensional self-assembled rugby-ball-shaped microarchitectures of tetragonal Na0.5La0.5MoO4:Eu3+ crystal structure were synthesized by facile hydrothermal method at 200°C for 8 h using ethylenediaminetetraacetic acid (EDTA) as surfactant. Structure and morphology of Na0.5La0.5MoO4:Eu3+ were investigated by X-ray diffraction and scanning electron microscopy. In the hydrothermal process, EDTA not only acts as a chelating reagent to facilitate the formation of Na0.5La0.5MoO4:Eu3+ but also acts as a surface capping agent to adhere to the newly created surface and to promote crystal splitting. The molar concentration of EDTA plays an important role and can effectively tune the size of the particles. Photoluminescence study reveals that hierarchical structures of Na0.5La0.5MoO4:Eu3+ show a strong emission in the red region under 395-nm UV excitation.
Management of bleeding and coagulopathy following major trauma: an updated European guideline
Authors: Spahn Donat R , Bouillon Bertil , Cerny Vladimir , Coats Timothy J , Duranteau Jacques , Fernández-Mondéjar Enrique , Filipescu Daniela , Hunt Beverley J , Komadina Radko , Nardi Giuseppe , Neugebauer Edmund , Ozier Yves , Riddez Louis , Schultz Arthur , Vincent Jean-Louis , Rossaint Rolf
Published: April 2013

Introduction

Evidence-based recommendations are needed to guide the acute management of the bleeding trauma patient. When these recommendations are implemented patient outcomes may be improved.

Methods

The multidisciplinary Task Force for Advanced Bleeding Care in Trauma was formed in 2005 with the aim of developing a guideline for the management of bleeding following severe injury. This document represents an updated version of the guideline published by the group in 2007 and updated in 2010. Recommendations were formulated using a nominal group process, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) hierarchy of evidence and based on a systematic review of published literature.

Results

Key changes encompassed in this version of the guideline include new recommendations on the appropriate use of vasopressors and inotropic agents, and reflect an awareness of the growing number of patients in the population at large treated with antiplatelet agents and/or oral anticoagulants. The current guideline also includes recommendations and a discussion of thromboprophylactic strategies for all patients following traumatic injury. The most significant addition is a new section that discusses the need for every institution to develop, implement and adhere to an evidence-based clinical protocol to manage traumatically injured patients. The remaining recommendations have been re-evaluated and graded based on literature published since the last edition of the guideline. Consideration was also given to changes in clinical practice that have taken place during this time period as a result of both new evidence and changes in the general availability of relevant agents and technologies.

Conclusions

A comprehensive, multidisciplinary approach to trauma care and mechanisms with which to ensure that established protocols are consistently implemented will ensure a uniform and high standard of care across Europe and beyond.http://ccforum.com/content/17/4/442
Quantitative single cell analysis of cell population dynamics during submandibular salivary gland development and differentiation
Authors: Nelson Deirdre A. , Manhardt Charles , Kamath Vidya , Sui Yunxia , Santamaria-Pang Alberto , Can Ali , Bello Musodiq , Corwin Alex , Dinn Sean R. , Lazare Michael , Gervais Elise M. , Sequeira Sharon J. , Peters Sarah B. , Ginty Fiona , Gerdes Michael J. , Larsen Melinda
Published: April 2013

Epithelial organ morphogenesis involves reciprocal interactions between epithelial and mesenchymal cell types to balance progenitor cell retention and expansion with cell differentiation for evolution of tissue architecture. Underlying submandibular salivary gland branching morphogenesis is the regulated proliferation and differentiation of perhaps several progenitor cell populations, which have not been characterized throughout development, and yet are critical for understanding organ development, regeneration, and disease. Here we applied a serial multiplexed fluorescent immunohistochemistry technology to map the progressive refinement of the epithelial and mesenchymal cell populations throughout development from embryonic day 14 through postnatal day 20. Using computational single cell analysis methods, we simultaneously mapped the evolving temporal and spatial location of epithelial cells expressing subsets of differentiation and progenitor markers throughout salivary gland development. We mapped epithelial cell differentiation markers, including aquaporin 5, PSP, SABPA, and mucin 10 (acinar cells); cytokeratin 7 (ductal cells); and smooth muscle α-actin (myoepithelial cells) and epithelial progenitor cell markers, cytokeratin 5 and c-kit. We used pairwise correlation and visual mapping of the cells in multiplexed images to quantify the number of single- and double-positive cells expressing these differentiation and progenitor markers at each developmental stage. We identified smooth muscle α-actin as a putative early myoepithelial progenitor marker that is expressed in cytokeratin 5-negative cells. Additionally, our results reveal dynamic expansion and redistributions of c-kit- and K5-positive progenitor cell populations throughout development and in postnatal glands. The data suggest that there are temporally and spatially discreet progenitor populations that contribute to salivary gland development and homeostasis.
Primary ciliogenesis requires the distal appendage component Cep123
Authors: Sillibourne James E. , Hurbain Ilse , Grand-Perret Thierry , Goud Bruno , Tran Phong , Bornens Michel
Published: April 2013

Primary cilium formation is initiated at the distal end of the mother centriole in a highly co-ordinated manner. This requires the capping of the distal end of the mother centriole with a ciliary vesicle and the anchoring of the basal body (mother centriole) to the cell cortex, both of which are mediated by the distal appendages. Here, we show that the distal appendage protein Cep123 (Cep89/CCDC123) is required for the assembly, but not the maintenance, of a primary cilium. In the absence of Cep123 ciliary vesicle formation fails, suggesting that it functions in the early stages of primary ciliogenesis. Consistent with such a role, Cep123 interacts with the centriolar satellite proteins PCM-1, Cep290 and OFD1, all of which play a role in primary ciliogenesis. These interactions are mediated by a domain in the C-terminus of Cep123 (400–783) that overlaps the distal appendage-targeting domain (500–600). Together, the data implicate Cep123 as a new player in the primary ciliogenesis pathway and expand upon the role of the distal appendages in this process.
PSiP-Pincer Type Palladium-Catalyzed Dehydrogenative Borylation of Alkenes and 1,3-Dienes
Authors: Kirai Naohiro , Iguchi Shoichiro , Ito Tatsuyoshi , Takaya Jun , Iwasawa Nobuharu
Published: April 2013

Dehydrogenative borylation of alkenes and 1,3-dienes was realized by carrying out the reaction in the presence of bis(pinacolato)diboron (B2pin2) and a catalytic amount of PSiP-pincer palladium complex. This protocol has the following notable features. 1) Monoanionic nature of the PSiP-pincer ligand prevents the formation of boryl(hydrido)- or dihydridopalladium species, enabling synthesis of various vinyl- or dienylboronic esters in good yield from a 1:1 mixture of B2pin2 and alkenes or 1,3-dienes without forming hydroboration or hydrogenation products. 2) Due to the strong trans influence of the silicon atom, PSiP-pincer palladium complex showed high activity toward migratory insertion. 3) Suppression of these side-reactions and the high reactivity of the PSiP-pincer palladium complex enabled an efficient, successive dehydrogenative borylation to give 1,1- or 1,2-diborylated products depending on the kind of substituent on alkenes by using more than 2 equivalents of B2pin2. Mechanistic study revealed that PSiP-pincer borylpalladium complex was generated from hydridopalladium complex and B2pin2, and this complex underwent alkene insertion followed by β-hydride elimination to give alkenylboronic ester with regeneration of the hydridopalladium complex.
Post-orgasmic illness syndrome: a case report
Authors: Attia Abdalla M , Yasien Hossam A , Al-Ziny Magda H
Published: April 2013

Post orgasmic illness syndrome (POIS) is a newly described syndrome. Manifestations of this syndrome may be physical, cognitive or both. Many theories have been proposed to explain the causes of this syndrome including allergy to seminal components, allergy to unknown proteins released during ejaculation or a psychosomatic etiology. We present a case of POIS with a manifestation of atopy that may be consistent with the allergy hypothesis.
Comparison of arterial and venous blood biomarker levels in chronic obstructive pulmonary disease
Authors: Kelly Emer , Owen Caroline A , Abraham Amadeus , Knowlton David L , Celli Bartolome R , Pinto-Plata Victor
Published: April 2013

Purpose: The development of novel biomarkers is an unmet need in chronic obstructive pulmonary disease (COPD). Arterial blood comes directly from the lung and venous blood drains capillary beds of the organ or tissue supplied. We hypothesized that there would be a difference in levels of the biomarkers metalloproteinase 9 (MMP-9), vascular endothelial growth factor A (VEGF-A) and interleukin 6 (IL-6) in arterial compared with venous blood. 

Methods: Radial artery and brachial vein blood samples were taken simultaneously in each of 12 patients with COPD and seven controls with normal lung function. Circulating immunoreactive MMP-9, VEGF-A and IL-6 levels in serum were measured using quantitative enzyme-linked immunosorbent assays. Results were compared using a Student’s paired t test. The study was powered to determine whether significant differences in cytokine levels were present between paired arterial and venous blood samples.  

Results: In the 12 patients with COPD, four were female, and age ranged 53-85 years, mean age 69 years. Three patients in the control group were female, with age range 46-84 years, mean age 64.7 years. In the COPD group, three patients had mild, five moderate and four severe COPD. No significant difference was found between arterial and venous levels of MMP-9, VEGF-A or IL-6. 

Conclusions: In this pilot study, levels of the measured biomarkers in arterial compared with venous blood in both COPD patients and healthy controls did not differ. This suggests that as we continue to chase the elusive biomarker in COPD as a potential tool to measure disease activity, we should focus on venous blood for this purpose.
Crystal structure of trans-diacetonitritrile(diaqua)(N,N,N',N'-tetramethylethylenediamine) nickel(II)dibromide tetrahydrate, [Ni(tmen)(CH3CN)2(H2O)2]2+·2Br–·4H2O, C10H34Br2N4NiO6
Authors: Ishikawa Yuki , Miyamoto Keiko , Horn Ernst
Published: April 2013

C10H34Br2N4NiO6, monoclinic, C2/c (no. 15), a = 19.062(4) Å, b = 8.106(2) Å, c = 15.484(3) Å, β = 112.96(3)°, V = 2203.0(9) Å3, Z = 4, Rgt(F) = 0.0348, wRref(F2) = 0.0405, T = 273.2 K.
Crystal structure of dichlorido-(6-methyl-1H-benzo[d]imidazole-2-thiolo κS)-(triphenylphosphine-κP)palladium(II)-methanol monosolvate (1:1), [PdCl2(C8H8N2S)(C18H15P)]·CH3OH, C27H27Cl2N2OPPdS
Authors: Qiu Qi-Ming , Yu Yue , Liu Min , Jin Qiong-Hua , Zhang Cun-Lin
Published: April 2013

C27H27Cl2N2OPPdS, triclinic, P1¯ (no. 2), a = 9.0350(8) Å, b = 9.9180(9) Å, c = 15.823(1) Å, α = 89.477(2)°, β = 80.435(1)°, γ = 78.123(1)°, V = 1367.8 Å3, Z = 2, Rgt(F) = 0.0686, wRref(F2) = 0.1901, T = 298 K.
Crystal structure of 1-(propan-2-ylidene)-2-(thiazolo[5,4-b]pyridin-2-yl)- hydrazine, C9H10N4S
Authors: Ma Ning , Guo Wen-Bo , Miao Shao-Bin
Published: April 2013

C9H10N4S, monoclinic, P21/c (no. 14), a = 13.076(3) Å, b = 6.654(2) Å, c = 11.230(3) Å, β = 92.740(3)°, V = 976.0 Å3, Z = 4, Rgt(F) = 0.0330, wRref(F2) = 0.0876, T = 296 K.
Atomic-Level Control during Film Growth under Highly Kinetically Constrained Conditions: H Mediation and Ultrahigh Doping during Si1–X Gex Gas-Source Epitaxy
Authors: Greene J.E.
Published: April 2013

We are living in the golden era of materials science. To cite but one example, consider the field of thin-film physics. Crystal growers have been moving inexorably closer to being able to deposit layers and hence to control film properties on an atom-by-atom basis. We are nearing an era in which it will be possible to deposit “designer” materials with a specified set of properties.
Bright infrared LEDs based on colloidal quantum-dots
Authors: Sun Liangfeng , Choi Joshua J. , Stachnik David , Bartnik Adam C. , Hyun Byung-Ryool , Malliaras George G. , Hanrath Tobias , Wise Frank W.
Published: April 2013

Record-brightness infrared LEDs based on colloidal quantum-dots have been achieved through control of the spacing between adjacent quantum-dots. By tuning the size of quantum-dots, the emission wavelengths can be tuned between 900nm and 1650nm.
New Atomic Force Microscopy Based Astrocyte Cell Shape Index
Authors: Tiryaki Volkan Mujdat , Adia-Nimuwa Usienemfon , Hartz Steven Allen , Xie Kan , Ayres Virginia M. , Ahmed Ijaz , Shreiber David I.
Published: April 2013

A new three-dimensional cell shape index using the AFM height images of cells cultured on cell substrates was defined. The new cell shape index revealed quantitative cell spreading information of cells that is not included in the conventional cell shape index. The quantitative morphometry of rat cerebral cortical astrocytes cultured on four different kinds of cell substrates were investigated using the conventional and the new cell shape index, and the results were compared. The new cell shape index showed the quantitative astrocyte spreading and stellation behavior that agrees with the AFM height images of astrocytes.
The role of the micro-porous layer (MPL) in fuel cells: neutron imaging and advanced electrochemical analysis study.
Authors: Boillat Pierre , Oberholzer Pierre , Lehmann Eberhard H. , Scherer Günther G. , Wokaun Alexander
Published: April 2013

The effect of the micro-porous layer (MPL) in polymer electrolyte fuel cells (PEFCs) was studied by a combination of in situ visualization of the liquid water distribution and advanced electrochemical analysis using helox and O2 pulses. Four cells with and without MPLs on the anode and cathode side were tested. Visualization studies showed that the significant changes in performance observed when using an MPL on the cathode side cannot be related to a reduction of the water content in the cathode side diffusion layer (GDL). The helox/O2 pulse analysis indicated that two different mechanisms are responsible for the performance loss without an MPL.
GISAXS study on the annealing behavior of sputtered HfO2 thin films
Authors: Belo G. S. , Nakagomi F. , de Souza P. E. N. , da Silva S. W. , Buchanan D. A.
Published: April 2013

Grazing Incidence Small-Angle X-ray Scattering (GISAXS) is a versatile technique for the analysis of nano and micro thin films surfaces. The scattering data depend strongly on the form and distribution of the scattering objects. In the present work GISAXS is used to study hafnium dioxide (HfO2) thin films deposited by magnetron sputtering using different deposition processes and post-deposition annealing conditions. Two distinct types of 15 nm thick samples were produced using different sputtering targets and different gas mixtures. The GISAXS results show that the ellipsoids that compose the thin films present a reduction in their size for both samples sets. For the sputtered Hf metal target samples, the ellipsoid diameter value shifted from 9 nm (as-deposited) to 6 nm following a 800 °C thermal treatment. For the sputtered HfO2 target samples the diameter value shifts from 19 nm (as-deposited) to 3 nm after a 800 °C anneal in oxygen. The size distribution, for both sets of samples, follows a Gaussian distribution function.
Influence of oxygen impurity on containerless solidification of quasicrystalline-forming Zr80Pt20 alloy
Authors: Harada Takeshi , Mizuno Akitoshi , Watanabe Masahito
Published: April 2013

The influence of oxygen content on containerless solidification of Zr80Pt20 alloy has been studied by using conical nozzle levitation (CNL) technique. The doping level of oxygen from 41 to 5450 ppm mass oxygen (PMO) affects the undercooling of the liquid Zr80Pt20 alloy. Time-resolved synchrotron x-ray diffraction revealed that the quasicrystalline (QC) phase precipitated as a primary phase during solidification of the Zr80Pt20 alloy. The amount of the QC phase depends on the oxygen content in the alloy. This indicates that the doping level of oxygen in Zr80Pt20 alloy can be related to the metastable phase formation as well as the glass-formation ability.
Enhancement of Corrosion Resistance AISI 304 Steel by Plasma Polymerized Thin Films
Authors: Santos Nazir M. , Amorim Jayr , Nascente Pedro A.P. , Freire Célia M.A. , Cruz Nilson C. , Rangel Elidiane C.
Published: April 2013

The purpose of this work is the deposition of films in order to increase the corrosion resistance of AISI 304 steel, which is a material used to construct the reactors for bioethanol production. This deposition inhibits the permeation of corrosive species to the film-metal interface. Thin films were prepared by radio-frequency plasma enhanced chemical vapor deposition (RF-PECVD) method using plasmas of hexamethyldisiloxane/argon/oxygen mixtures excited by signals of different powers. The plasma was generated by the application of RF power of 13.56 MHz to the sample holder while keeping grounded the topmost electrode and the chamber walls. The effect of the RF power on the properties of the samples was investigated by perfilometry, X-ray photoelectron spectroscopy (XPS), contact angle, and electrochemical impedance spectroscopy (EIS). The results of the corrosion resistance tests of the AISI 304 steel were interpreted in terms of the energy delivered to the growing layer by plasma excitation power.
Nanostructure and Strain Field in Vertically Aligned Nano-Islands for Si/Ge 2D Photonic Nanocrystals.
Authors: Kiguchi Takanori , Hoshi Yusuke , Tayagaki Takeshi , Usami Noritaka
Published: April 2013

The local strain field and the intermixing of a Ge nano-islands (NIs)/Si spacer stacked structure in a novel solar cell with a p-i-n type Si single crystal with two-dimensional photonic nanocrystals connecting to the vertically aligned NIs were analyzed using electron microscopy. High-angle annular dark field-scanning transmission electron microscope (HAADF-STEM) images show intermixing between Ge and Si clearly and reveal that the surface segregation of Ge becomes advanced. The average composition of the NIs is Ge0.42Si0.58, which is almost constant in a row of vertically aligned NIs. The local strain analysis results obtained from the high-resolution transmission electron microscope (HRTEM) images show that the strain state is partially relaxed after the elastic relaxation of NIs.
An attempt to handle the nanopatterning of materials created under ion beam mixing
Authors: Simeone D. , Baldinozzi G. , Gosset D. , Demange G. , Zhang Y. , Luneville L.
Published: April 2013

In the past fifty years, experimental works based on TEM or grazing incidence X ray diffraction have clearly shown that alloys and ceramics exhibit a nano pattering under irradiation [1,2,3]. Many works were devoted to study the nano patterning induced by ion beam mixing in solids [17,18,19]. Understanding the nano patterning will provide scientific bases to tailor materials with well-defined microstructures at the nanometric scale. The slowing down of impinging particles in solids leads to a complex distribution of subcascades. Each subcascade will give rise to an athermal diffusion of atoms in the medium. In this work, we focused on this point. Based on the well-known Cahn Hilliard Cook (CHC) equation, we analytically calculate the structure factor describing the nano patterning within the mean field approximation. It has shown that this analytical structure factor mimics the structure factor extracted from direct numerical simulations of the time dependent CHC equation. It appears that this structure factor exhibits a universal feature under irradiation.
Bandgap Engineering of Double Perovskites for One- and Two-photon Water Splitting
Authors: Castelli Ivano E. , Thygesen Kristian S. , Jacobsen Karsten W.
Published: April 2013

Computational screening is becoming increasingly useful in the search for new materials. We are interested in the design of new semiconductors to be used for light harvesting in a photoelectrochemical cell. In the present paper, we study the double perovskite structures obtained by combining 46 stable cubic perovskites which was found to have a finite bandgap in a previous screening-study.1 The four-metal double perovskite space is too large to be investigated completely. For this reason we propose a method for combining different metals to obtain a desired bandgap. We derive some bandgap design rules on how to combine two cubic perovskites to generate a new combination with a larger or smaller bandgap compared with the constituent structures. Those rules are based on the type of orbitals involved in the conduction bands and on the size of the two cubic bandgaps. We also see that a change in the volume has an effect on the size of the bandgap. In addition, we suggest some new candidate materials that can be used as photocatalysts in one- and two-photon water splitting devices.
The Microscopic Effect of Filler on Rubber Reinforcement: A Coarse-grained Molecular Dynamics Study
Authors: Kimura Yosuke , Sato Masatoshi
Published: April 2013

In this paper, we developed a microscopic approach to understand rubber reinforcement using coarse-grained molecular dynamics simulations. We investigated static uniaxial tensile behavior of filled and unfilled rubber models, and found two reinforcement mechanisms. One of these is the same as the mechanism predicted by Guth, which depends only on the volume content of fillers. We have confirmed this mechanism at small strain region. The other is caused by filler-filler network created by the advantage of chemical bond at large strain. In this region, some polymers linked fillers and were stretched, that is, these polymers generated tension. Additionally, we investigated the effect of filler distribution on rubber reinforcement.
Dynamics and Kinetics of Dislocations in Metals and Alloys Under Dynamic Loading
Authors: Ilnitski Denis , Krasnikov Vasily , Kuksin Alexey , Mayer Alexander , Yanilkin Alexey
Published: April 2013

The work presented is devoted to study the mechanisms and kinetics of plastic deformation of bcc and fcc metals and alloys under shock-wave loading (strain rates > 105 s-1). To study the behavior of metals under conditions described the two scale approach is developed. It comprises molecular dynamics (MD) calculations of dislocation mobility and dislocations nucleation rate and continuum mechanics model with equations for description of elastoplastic deformation, kinetics and dynamics of dislocations.

Dislocation velocities as functions of applied shear stress are calculated from MD in a wide temperature range up to the melting point. Velocity-dependent drag coefficient is introduced to approximate the data obtained.

The influence of Guinier–Preston (GP) zones on dislocation motion is analyzed. The results obtained are used to evaluate temperature dependence of dynamic flow stress and the evolution of dislocations subsystem under shock loading. Data on the attenuation of the elastic precursor and rare surface velocity profiles calculated for Al are in good agreement with the experiments. Simulation of the free surface velocity profiles during shock-wave loading of AlCu alloys is carried out.
Exploring amyloid aggregates with coarse-grained protein simulations
Authors: Derreumaux Philippe
Published: April 2013

Proteins are complex, yet elegant, machines fine-tuned by evolution to properly fulfill a variety of tasks in the crowded cellular environment. These are, however, very challenging numerically due to their dimension, number of degrees of freedom and the wide range of relevant time scales. With aging, some proteins misfold and form harmful amyloid aggregates associated with multiple neurodegenerative diseases, and in particular Alzheimer’s, which challenge our society today. Here, I present the coarse-grained OPEP (Optimized Potential for Efficient peptide structure Prediction) force field and what we can learn from OPEP simulations to get insights into the self-assembly of amyloid peptides.
Microstructure simulations within the Lattice Statics formalism: elasticity and morphologies at the atomic scale
Authors: Varvenne C. , Le Bouar Y. , Finel A. , Fèvre M.
Published: April 2013

In this paper, the Lattice Statics formalism is used to perform Monte Carlo simulations of alloy microstructures when elastic effects are present. It provides sets of long-range effective pair interactions (EPIs), defined in a rigid average reference state, that allow us to compute microstructural evolutions on diffusion time scale. A wide composition range is investigated in order to characterize the different precipitation processes with elasticity (nucleation and growth, spinodal decomposition). An advantage of the approach is to include the concentration dependence of both the effective chemical interactions and the elastic properties of the reference state. The importance of this point is illustrated by comparing the precipitation sequences in two alloys with symmetric average concentrations.
Atomistic Modeling of Shock Loading in SiC Ceramics
Authors: Branicio Paulo S. , Zhang Jingyun
Published: April 2013

Large scale molecular-dynamics simulations of plane shock loading in SiC are performed to reveal the interplay between shock-induced compaction, structural phase transformation (SPT) and plastic deformation. The shock profile is calculated for a wide range of particle velocity from 0.1 km/s to 6.0 km/s. Single crystalline models indicate no induced plasticity or SPT for shock loading below 2.0 km/s. For intermediate particle velocity, between 2.0 km/s and 4.5 km/s the generated shock wave splits into an elastic precursor and a zinc blende to rocksalt structural transformation wave. That is induced by the increase in shock pressure to over 90 GPa and results in a steep increase of density from 3.21 g/cm3 to ∼4.65 g/cm3. For particle velocity greater than 4.5 km/s a single overdriven transformation shock wave is generated. These simulation results provide an atomistic view of the dynamic effects of shock impact on single crystal high-strength ceramics.