bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative evaluation of the role of cysteine and methionine residues in the antioxidant activity of human serum albumin using recombinant mutants
Authors: Iwao Yasunori , Ishima Yu , Yamada Junji , Noguchi Taishi , Kragh‐Hansen Ulrich , Mera Katsumi , Honda Daisuke , Suenaga Ayaka , Maruyama Toru , Otagiri Masaki
Published: February 2012

The importance of cysteine (Cys) and methionine (Met) residues for the antioxidant activity of human serum albumin (HSA) was investigated using recombinant HSA mutants, in which Cys34 and/or the six Met residues had been mutated to Ala. The scavenging activities of the mutants against five reactive oxygen and nitrogen species were evaluated by a chemiluminescence assay, electron paramagnetic resonance spectroscopy, or a HPLC‐flow reactor assay. Our results showed that the contributions of Cys34 and the Met residues to the antioxidant activity of HSA were 61% and 29% against O2
•−, 68% and 61% against H2O2, 38% and 6% against HO•, 36% and 13% against HOCl, and 51% and 1% against •NO, respectively. Thus, the findings propose in a direct way that Cys34 plays a more important role than the Met residues in the antioxidant activity of HSA. © 2012 IUBMB Life, 2012
Hyperbaric oxygen therapy attenuates neuropathic hyperalgesia in rats and idiopathic trigeminal neuralgia in patients
Authors: Gu N. , Niu J.‐Y. , Liu W.‐T. , Sun Y.‐Y. , Liu S. , Lv Y. , Dong H.‐L. , Song X.‐J. , Xiong L.‐Z.
Published: February 2012

Background:

Neuropathic pain after nerve injury is severe and intractable, and current drug and non‐drug therapies offer very limited pain relief. Hyperbaric oxygen (HBO
2) has been clinically used for protection of the nervous system after acute injury. We investigated whether HBO
2 treatment could prevent and/or attenuate neuropathic pain in animals and in patients.

Methods:

Mechanical allodynia and thermal hyperalgesia and neurochemical alterations of neuropathic pain were analysed in male, adult, Sprague‐Dawley rats with sciatic nerve injury. Clinical trials were conducted in patients with idiopathic trigeminal neuralgia.

Results:

Repetitive HBO
2 treatment [a combination of pressure at 3 atmosphere absolute (ATA) and pure oxygen] greatly inhibited behavioural signs of neuropathic pain manifested as thermal hyperalgesia and mechanical allodynia. Such an HBO
2 treatment also inhibited nerve injury‐induced induction of c‐Fos and activation of astrocytes and increased phosphorylation of NR2B receptor and the subsequent Ca
2+‐dependent signals in rats. Neither high pressure (up to 3 ATA) nor pure oxygen alone resulted in analgesic effect. In clinical trials, one course of HBO
2 therapy (10 consecutive days) produced a rapid‐onset, dose‐dependent and long‐lasting analgesic effects evidenced by the decreased doses of carbamazepine required for keeping patient pain at a minimum and decreased scores of visual analogue scales, which was used for patient's self‐evaluation.

Conclusions:

These findings support that HBO
2 therapy is an effective approach for treating neuropathic pain in both animals and human beings and suggest that neural protection, anti‐inflammation and inhibition of nerve injury‐induced altered neural activity may contribute to the analgesic effect of HBO
2 therapy.
Cannabinoids and muscular pain. Effectiveness of the local administration in rat
Authors: Sánchez Robles E. Ma , Bagües Arias A. , Martín Fontelles Ma I.
Published: February 2012

Background:

Pain associated with musculoskeletal disorders can be difficult to control and the incorporation of new approaches for its treatment is an interesting challenge. Activation of cannabinoid (CB) receptors decreases nociceptive transmission in acute, inflammatory and neuropathic pain states; however, although the use of cannabis derivatives has been recently accepted as a useful alternative for the treatment of spasticity and pain in patients with multiple sclerosis, the effects of CB receptor agonists in muscular pain have hardly been studied.

Methods:

Here, we characterized the antinociceptive effect of non selective and selective CB agonists by systemic and local administration, in two muscular models of pain, masseter and gastrocnemius, induced by hypertonic saline (HS) injection. Drugs used were: the non‐selective agonist WIN 55,212‐2 and two selective agonists, ACEA (CB
1) and JWH 015 (CB
2); AM 251 (CB
1) and AM 630 (CB
2) were used as selective antagonists.

Results:

In the masseter pain model, both systemic (intraperitoneal) and local (intramuscular) administration of CB
1 and CB
2 agonists reduced the nociceptive behaviour induced by HS, whereas in the gastrocnemius model the local administration was more effective than systemic.

Conclusions:

Our results provide evidence that both, CB
1 and CB
2 receptors can contribute to muscular antinociception and, interestingly, suggest that the local administration of CB agonists could be a new and useful pharmacological strategy in the treatment of muscular pain, avoiding adverse effects induced by systemic administration.
Distinctiveness of long‐term pain that does not interfere with life: An observational cohort study
Authors: Jordan K.P. , Sim J. , Moore A. , Bernard M. , Richardson J.
Published: February 2012

Background

Reporting of pain that does not interfere with life is common in the older population but little is known about people with such long‐term non‐interfering pain.

Objectives

To assess whether non‐interfering pain can be a long‐term state, and to compare this group with those who continuously report no pain, and with those with chronic pain that interferes with life.

Methods

This was a prospective general population cohort study set within the North Staffordshire Osteoarthritis Project (NorStOP). People aged 50 plus were sent baseline, 3‐year and 6‐year questionnaires. Those who reported the same pain status (no pain, non‐interfering pain, interfering pain) at each time point were compared on pain intensity, widespread pain and medication, and on sociodemographic and co‐morbid characteristics at 6 years.

Results

Forty percent of responders reported the same pain status at each time point; 12% reported long‐term non‐interfering pain. Fifty‐nine percent of those with non‐interfering pain reported at least one site of high pain intensity, 33% reported widespread pain, and 90% had used pain medication in the past 4 weeks. This group was similar to the no‐pain group but distinct on sociodemographic and co‐morbid measures from those with pain that interfered.

Conclusions

Long‐term non‐interfering pain is common, but despite often suffering from high pain intensity and widespread pain, those within this group seem to be able to control their pain without allowing it to affect their everyday lives. Future work is needed to assess how people with long‐term pain ensure it does not cause interference with life.
Empathy for pain: The effects of prior experience and sex
Authors: Preis M.A. , Kroener‐Herwig B.
Published: February 2012

Background:

Empathy is considered as both a characteristic trait and a variable state. The present experiment examined whether or not prior exposure to pain, perceived similarity, sex and attributed pain intensity are associated with state empathy for pain.

Methods:

The state empathy of students (38 female, 42 male) in response to pictures displaying exposure to pressure pain was measured via self‐reports, using a newly developed state empathy scale with the two subscales of ‘emotional response’ and ‘perspective taking’. Physiological responses were also recorded. Half of the participants were exposed to pressure pain prior to the experiment. Perceived similarity to the person being exposed to pain and their estimated pain intensity were assessed.

Results:

The results revealed that perceived similarity and sex were significantly related to the emotional dimension of empathy. This sex difference was partially mediated by the estimated intensity of pain. Women rated the intensity of pain more highly and achieved higher scores on the emotional response subscale. Exposure to pain predicted empathy on the perspective‐taking subscale, resulting in higher scores when the subject had been exposed to the same pain stimulus. The physiological recordings did not correlate with any of the empathy scores.

Conclusions:

Greater degrees of perceived similarity, being female and higher estimated pain were linked to a stronger ‘emotional reaction’, whereas previous exposure to pain facilitated ‘perspective taking’. Pointing out similarities between people and their past experiences, as well as focusing on the imagined discomfort being felt by another person, may modulate empathy for pain.
Osteocyte RANKL: New insights into the control of bone remodeling
Authors: Xiong Jinhu , O'Brien Charles A
Published: February 2012

The idea that osteoblasts, or their progenitors, support osteoclast formation by expressing the cytokine receptor activator of NFkB ligand (RANKL) is a widely held tenet of skeletal biology. Two recent studies provide evidence that osteocytes, and not osteoblasts or their progenitors, are the major source of RANKL driving osteoclast formation in cancellous bone. The goal of this review is to highlight the results of these new studies and discuss their implications for our understanding of bone remodeling. © 2012 American Society for Bone and Mineral Research
Digital storage cost savings: Three key areas
Authors: Fanning Kurt , Drogt Emily , Grant Rita
Published: February 2012

Storing documents in digital form—as opposed to using paper documents—has long been touted as a way to save money. But the cost in time and labor to scan paper documents into digital format has often been a problem. So what's the most practical way to save money by using digital storage? The authors discuss three areas that are ripe for cost savings: e‐discovery compliance, website content management, and collaborative document storage. © 2012 Wiley Periodicals, Inc.
Integrating sustainability into corporate DNA
Authors: Bell Jan , Soybel Virginia E. , Turner Robert M.
Published: February 2012

The term sustainability covers a broad set of issues. As a result, each organization has to identify specific issues that it can effectively address and that are relevant to its industries, markets, geographic locations, and stakeholders. But if an organization fails to focus on a reasonable number of organization‐wide commitments, resources will be scattered and fail to yield significant value to the company. This article provides advice on how to deploy sustainability using change management techniques and examples from industry. © 2012 Wiley Periodicals, Inc.
MINING FDI AND INFRASTRUCTURE DEVELOPMENT ON AFRICA'S EAST COAST: EXAMINING THE RECENT EXPERIENCE OF TANZANIA AND MOZAMBIQUE
Authors: Robbins Glen , Perkins David
Published: February 2012

Since the turn of the century, Tanzania and Mozambique have emerged in Africa's foreign direct investment stakes as leading performers. In both countries, the demands placed on infrastructure to enable these investments have presented some significant challenges. Caught amid high debt, low state revenue and weak capacity, the performance of infrastructure has been widely reported as a constraint to growth. Lessons learned from how these countries have responded to these challenges provide some insight as to the degree to which potential synergies can be crafted around inflows of mining‐related foreign direct investment and enhancements to the infrastructure networks. Copyright © 2012 John Wiley & Sons, Ltd.
Serum microRNA‐21 is a novel biomarker in patients with esophageal squamous cell carcinoma
Authors: Kurashige Junji , Kamohara Hidenobu , Watanabe Masayuki , Tanaka Youhei , Kinoshita Koichi , Saito Seiya , Hiyoshi Yukiharu , Iwatsuki Masaaki , Baba Yoshifumi , Baba Hideo
Published: February 2012

Background

It was recently revealed that microRNAs (miRNAs) can stably exist in serum and may affect the pathogenesis of several diseases. However, there are few reports that have demonstrated the significance of miRNAs in the serum of patients with esophageal squamous cell carcinoma (ESCC). Thus, the aims of this study were to clarify the status of miRNA‐21 in serum of ESCC patients and to reveal the usefulness of this molecule as a biomarker.

Methods

We measured the miRNA‐21 levels in serum samples from 71 ESCC patients and 39 healthy controls by using real‐time RT‐PCR. We also evaluated the changes in the miRNA‐21 level during operation and chemotherapy.

Results

We found that serum concentration of miRNA‐21 in ESCC patients was significantly higher than that in healthy controls (P < 0.001). A significant reduction in the serum miR‐21 levels was observed in the postoperative samples versus the preoperative samples (P = 0.003). Furthermore, miRNA‐21 levels were significantly reduced in ESCC patients who responded to chemotherapy (P = 0.003), whereas no significant change was observed in the non‐responders.

Conclusion

Serum miRNA‐21 is considered to be a novel biomarker for diagnosing ESCC, and it can also be used as a response marker during chemotherapy for ESCC patients. J. Surg. Oncol. 2012; 106:188–192. © 2012 Wiley Periodicals, Inc.
Does non‐curative gastrectomy improve survival in patients with metastatic gastric cancer?
Authors: Kokkola Arto , Louhimo Johanna , Puolakkainen Pauli
Published: February 2012

Background

The role of non‐curative or palliative gastrectomy remains controversial. Our aim was to compare retrospective patients who have undergone non‐curative gastrectomy to the patients with surgical exploration only.

Methods

Between years 2000 and 2009, 488 patients with gastric adenocarcinoma were treated at the Department of Surgery, Helsinki University Central Hospital. Fifty‐five patients had metastatic disease but their symptoms were not severe enough to require palliative surgery. Thirty‐two of them underwent operative exploration (Group A), and 23 non‐curative gastrectomy (Group B). All operations were initiated with curative intent.

Results

The difference in median survival between Groups A and B was insignificant (5.7 months in Group A and 10.8 months in Group B, P = 0.152). However, 33 patients with postoperative chemotherapy had significantly better median survival than the others (14.2 months vs. 1.9 months, P < 0.001). No significant differences were observed between Groups A and B in the rate of late postoperative gastrointestinal obstruction or bleeding.

Conclusions

Non‐curative gastrectomy does not improve survival in patients with metastatic gastric cancer, nor reduces the rate of late occlusions. There is no need for prophylactic palliative gastrectomy in patients with gastric cancer who do not have bleeding or obstruction preoperatively. Among those patients, postoperative chemotherapy seems to improve survival. J. Surg. Oncol. 2012; 106:193–196. © 2012 Wiley Periodicals, Inc.
Analysis of p16INK4A expression of oral squamous cell carcinomas in Taiwan: Prognostic correlation without relevance to betel quid consumption
Authors: Chen Ya‐Wei , Kao Shou‐Yen , Yang Muh‐Hwa
Published: February 2012

Objectives

In this study, we examined the role of p16INK4A, a surrogate biomarker of HPV‐related head and neck cancers with better prognosis, in an endemic area of betel quid (BQ)‐related oral squamous cell carcinoma (OSCC).

Methods

p16INK4A immunohistochemistry was examined in 165 OSCCs, statistical analyses were performed to elucidate the correlation between p16INK4A expression and BQ habits/pathologic features, and the prognostic impact of p16INK4A and different parameters were analyzed.

Results

The incidence of p16INK4A expression was similar between BQ chewers and non‐chewers. p16INK4A expression was significantly associated with nodal metastasis (P = 0.005). There was a trend suggesting that the loss of p16INK4A expression was more frequent in higher T stages, however, this was found only in patients without lymph node metastasis (P = 0.059). A poorer prognosis and a higher risk of tumor recurrence were found in OSCCs without p16INK4A expression. (The HR for cancer‐specific mortality and cancer recurrence was 3.55 and 1.89, respectively.)

Conclusion

Although it has been suggested that BQ chewers had a greater tendency toward tumor recurrence and poor outcome, our data demonstrated that p16INK4A expression is unrelated to BQ habit and that p16INK4A downregulation is a strong predictor for OSCC progression, recurrence and survival in Taiwan. J. Surg. Oncol. 2012; 106:149–154. © 2012 Wiley Periodicals, Inc.
Teachers' experiences supporting children after traumatic exposure
Authors: Alisic Eva , Bus Marissa , Dulack Wendel , Pennings Lenneke , Splinter Jessica
Published: February 2012

Teachers can be instrumental in supporting children's recovery after trauma, but some work suggests that elementary school teachers are uncertain about their role and about what to do to assist children effectively after their students have been exposed to traumatic stressors. This study examined the extent to which teachers working with children from ages 8 to 12 years report similar concerns. A random sample of teachers in the Netherlands (N = 765) completed a questionnaire that included 9 items measuring difficulties on a 6‐point Likert scale (potential range of total scores: 9–54). The mean total difficulty score was 29.8 (ranging from 10 to 50; SD = 7.37). On individual items, the fraction of teachers scoring 4 or more varied between 25 and 63%. A multiple regression analysis showed that teachers' total scores depended on amount of teaching experience, attendance at trauma‐focused training, and the number of traumatized children they had worked with. The model explained 4% of the variance, a small effect. Because traumatic exposure in children is rather common, the findings point to a need to better understand what influences teachers' difficulties and develop trauma‐informed practice in elementary schools.
Multiple traumas, postelection violence, and posttraumatic stress among impoverished Kenyan youth
Authors: Harder Valerie S. , Mutiso Victoria N. , Khasakhala Lincoln I. , Burke Heather M. , Ndetei David M.
Published: February 2012

Research on posttraumatic stress disorder (PTSD) among youth has focused on specific subgroups from developed countries. Most of the world's youth and war‐like violence, however, is concentrated in developing countries, yet there is limited mental health data within affected countries. This study focused on a random community‐based sample of 552 impoverished youth ages 6–18 within an informal settlement in Nairobi, Kenya, which experienced war‐like violence for a month following the contested presidential election of 2007. Six months after the violence ended, 99 (18%) had PTSD according to the UCLA PTSD Reaction Index (Steinberg, Brymer, Decker, & Pynoos, 2004), and an additional 18 (3%) were found to have partial PTSD due to high overall scores. Kenyan psychologists conducted diagnostic interviews and found the positive predictive value of the assessment tool to be 72% in this sample; the confirmed prevalence was 12%. Similar to other studies worldwide, Criterion C (avoidance) was the limiting factor for diagnosing PTSD according to the DSM‐IV‐TR, and parent–child agreement was at best fair. The number of traumatic experiences was strongly associated with PTSD outcomes. Differences due to age or sex were not found. The findings indicate the need for universal mental health services for trauma‐exposed youth and their families in the impoverished informal settlements of Nairobi, Kenya.
Folate‐Conjugated Poly(N‐(2‐hydroxypropyl) methacrylamide)‐block‐Poly(benzyl methacrylate): Synthesis, Self‐Assembly, and Drug Release
Authors: Wei Chuan , Wu Keyi , Li Jumei , Ma Wanfu , Guo Jia , Hu Jun , Wang Changchun
Published: February 2012

Well‐defined amphiphilic diblock copolymers of poly(N‐(2‐hydroxypropyl)methacrylamide)‐block‐poly(benzyl methacrylate) (PHPMA‐b‐PBnMA) are synthesized using reversible addition–fragmentation chain transfer polymerization. The terminal dithiobenzoate groups are converted into carboxylic acids. The copolymers self‐assemble into micelles with a PBnMA core and PHPMA shell. Their mean size is <30 nm, and can be regulated by the length of the hydrophilic chain. The compatibility between the hydrophobic segment and the drug doxorubicin (DOX) affords more interaction of the cores with DOX. Fluorescence spectra are used to determine the critical micelle concentration of the folate‐conjugated amphiphilic block copolymer. Dynamic light scattering measurements reveal the stability of the micelles with or without DOX. Drug release experiments show that the DOX‐loaded micelles are stable under simulated circulation conditions and the DOX can be quickly released under acidic endosome pH.
New limiting real interpolation methods and their connection with the methods associated to the unit square
Authors: Cobos Fernando , Fernández‐Cabrera Luz M. , Silvestre Pilar
Published: February 2012

We study limit K‐spaces for general Banach couples, not necessarily ordered. They correspond to the extreme choice θ = 0, 1 in the realization of the real method as a K‐space. We also show the connection of these limit spaces with interpolation methods defined by the unit square.
Singularities of slice regular functions
Authors: Stoppato Caterina
Published: February 2012

Beginning in 2006, G. Gentili and D. C. Struppa developed a theory of regular quaternionic functions with properties that recall classical results in complex analysis. For instance, in each Euclidean ball B(0, R) centered at 0 the set of regular functions coincides with that of quaternionic power series converging in B(0, R). In 2009 the author proposed a classification of singularities of regular functions as removable, essential or as poles and studied poles by constructing the ring of quotients. In that article, not only the statements, but also the proving techniques were confined to the special case of balls B(0, R). Quite recently, F. Colombo, G. Gentili and I. Sabadini (2010) and the same authors in collaboration with D. C. Struppa (2009) identified a larger class of domains, on which the theory of regular functions is natural and not limited to quaternionic power series. The present article studies singularities in this new context, beginning with the construction of the ring of quotients and of Laurent‐type expansions at points p other than the origin. These expansions, which differ significantly from their complex analogs, allow a classification of singularities that is consistent with the one given in 2009. Poles are studied, as well as essential singularities, for which a version of the Casorati‐Weierstrass Theorem is proven.
The benefits of the Met Office variable resolution NWP model for forecasting convection
Authors: Tang Yongming , Lean Humphrey W. , Bornemann Jorge
Published: February 2012

High‐resolution NWP models which can explicitly allow convection (albeit poorly resolved) are usually run in limited‐area domains, and are nested inside coarser resolution models with parametrized convection. The mismatch of the grids and model physics at the boundaries of the limited‐area fine resolution model can be a major source of model error. Two major issues are the change in the representation of convection (parameterized to explicit) as air enters the fine resolution model and the limited boundary updating frequency. In this paper, a variable‐grid, fine‐resolution, limited‐area version of the Met Office's Unified Model (UM), developed with the aim of addressing this and related problems with nested models is described. In this variable resolution model, the grid size varies smoothly from coarser (but still convection permitting) resolution at the outer boundaries to a uniform fine resolution in the interior of the domain. In this paper we present results from a comparison of this variable grid model with the analogous results from an equivalent nested model set with uniform high‐resolution model nested inside a lower resolution one. The comparison is carried out for a number of convective cases. It is found that the variable resolution model gives very similar results to the nested model system in the inner fixed resolution part of the domain away from the boundaries, both in individual case studies and when statistics are aggregated over cases. This gives confidence in the validity of the variable resolution approach. It is shown that the variable resolution model also gives the hoped for benefits of reducing artefacts at the boundaries.
A improved F‐expansion method and its application to the Zhiber–Shabat equation
Authors: Ding Yumin , He Bin , Li Wei
Published: February 2012

Based on the F‐expansion method and Exp‐function method, an improved F‐expansion method is introduced. As illustrative examples, the exact solutions expressed by exponential function, hyperbolic functions, logarithmic function, and other type of functions for the Zhiber–Shabat equation are derived. Some previous results are extended. Copyright © 2012 John Wiley & Sons, Ltd.
Some exact solutions for Toda type lattice differential equations using the improved (G′/G)‐expansion method
Authors: Aslan İsmail
Published: February 2012

Nonlinear lattice differential equations (also known as differential‐difference equations) appear in many applications. They can be thought of as hybrid systems for the inclusion of both discrete and continuous variables. On the basis of an improved version of the basic (G′/G)‐expansion method, we focus our attention towards some Toda type lattice differential systems for constructing further exact traveling wave solutions. Our method provides not only solitary and periodic wave profiles but also rational solutions with more arbitrary parameters. Copyright © 2012 John Wiley & Sons, Ltd.
Are Personal Characteristics Associated with Exercise Participation in Patients with Rheumatoid Arthritis? A Cross‐Sectional Explorative Survey
Authors: Vervloesem Nele , Van Gils Nele , Ovaere L. , Westhovens René , Van Assche Dieter
Published: February 2012

Background

Organized exercise programs for patients with rheumatoid arthritis (RA) are useful to enhance physical activity and fitness. However, participation and adherence rates of these programs are low. This study aimed to identify demographic, personal and disease‐related factors interfering with implementing an exercise program for RA.

Methods

A random sample of ambulatory RA patients from a single centre was divided into two groups, depending on their willingness to participate in an exercise program. Subsequently, demographic data (gender, age, disease duration and educational level) and disease‐related and personal factors were obtained (Disease Activity Score; Short Form 36 [SF‐36]; Health Assessment Questionnaire; Global Disease Activity; and also the Utrecht Coping List [UCL], Illness Cognition Questionnaire; TAMPA scale and modified Baecke questionnaire).

Results

Of the 154 people completing the survey, 113 (73%) indicated that they were willing to participate in an exercise program. These positive responders (PR) were more often female (p < 0.05), and had a higher educational level (p < 0.05). In the negative responders (NR), higher scores were found in the general health perception (54.7; [SD 18.3] versus 47.4; [SD 20.8]) and vitality (61.6 [SD 19.8] versus 53.7 [SD 20.1] sections of the SF‐36, and a lower score was found on the reassuring thoughts subscale of the UCL (11.9 [SD 2.7] versus 12.9 [SD 2.7]) compared with the PR (all p < 0.05).

Conclusions

Although few differences were found between the groups, some insights regarding pitfalls in implementing an exercise program were highlighted. Further insights into external and personal motivators for patients are needed. Copyright © 2012 John Wiley & Sons, Ltd.
Real‐time monitoring of undirected networks: Articulation points, bridges, and connected and biconnected components
Authors: Ausiello Giorgio , Firmani Donatella , Laura and Luigi
Published: February 2012

In this article, we present the first algorithm in the streaming model to characterize completely the biconnectivity properties of undirected networks: articulation points, bridges, and connected and biconnected components. The motivation of our work was the development of a real‐time algorithm to monitor the connectivity of the autonomous systems (AS) network, but the solution provided is general enough to be applied to any network. The network structure is represented by a graph, and the algorithm is analyzed in the datastream framework. Here, as in the on‐line model, the input graph is revealed one item (i.e., graph edge) after the other, in an on‐line fashion; but, if compared to traditional on‐line computation, there are stricter requirements for both memory occupation and per item processing time. Our algorithm works by properly updating a forest over the graph nodes. All the graph (bi)connectivity properties are stored in this forest. We prove the correctness of the algorithm, together with its space (O(nlog n), with n being the number of nodes in the graph) and time bounds. We also present the results of a brief experimental evaluation against real‐world graphs, including many samples of the AS network, ranging from medium to massive size. These preliminary experimental results confirm the effectiveness of our approach. © 2012 Wiley Periodicals, Inc. NETWORKS, Vol. 2012
Property Pd,m and efficient design of reliable networks
Authors: Faudree Ralph J. , Gould Ronald J. , Powell Jeffrey S.
Published: February 2012

For d ≥ 1 and m ≥ 1, a graph has property Pd,m if there exist at least m vertex‐disjoint paths of length at most d between each pair of vertices. Property Pd,m, which has a strong connection to wide diameter, is one way of measuring the reliability of a network. In this article, we first examine the relationship of Pd,m to other similar properties and then we prove several results regarding the extremal number for property Pd,m (the minimum number of edges needed for a graph to have the property). In particular, we find (i) the extremal number for graphs of certain orders when d = 2, (ii) several extremal graphs when d ≥ 3, (iii) a new lower bound on the extremal number when d ≥ 3, m ≥ 3, and (iv) a new upper bound on the extremal number when d,m are even with d = 4k + 2(k ≥ 1) and m ≥ 4. © 2012 Wiley Periodicals, Inc. NETWORKS, 2012
Dye‐sensitized TiO2 solar cells based on nanocomposite photoanode containing plasma‐modified multi‐walled carbon nanotubes
Authors: Chan Yen‐Fong , Wang Cheng‐Chien , Chen Bing‐Hung , Chen Chuh‐Yung
Published: February 2012

A series of anatase TiO2‐based nanocomposite incorporated with plasma‐modified multi‐walled carbon nanotubes (MWNTs) was prepared by physical blending and shows its capability for efficient electron transport when used as photoanode in dye‐sensitized solar cells (DSSCs). These MWNTs characterized with good dispersal performance were obtained by functionalization technique via in situ plasma treatment and subsequent grafting with maleic anhydride (MA) onto the external walls reported previously. Compared with the conventional DSSCs, the TiO2 film with 1D carbon nanotubes possesses more outstanding ability to transport electrons injected from the excited dye within the device under illumination. As a result, at an optimum addition of 0.3 wt% MWNTs‐MA in TiO2 matrix, the photocurrent–voltage (J–V) characteristics showed a significant increase in the short‐circuit photocurrent (Jsc) of 50%, leading to an increase in overall solar conversion efficiency by a factor of 1.5. Electrochemical impedance spectroscopy analyses reveal that the MWNTs‐MA/TiO2 incur smaller resistances at the photoanode in assembled DSSCs when compared with those in the anatase titania DSSCs. These features suggest that the conducting properties of the MWNTs‐MA within the anodes are crucial for achieving a higher transport rate for photo‐induced electrons in TiO2 layer by exhibiting lower resistance in the porous network and hence retard charge recombination that could result in poor conversion efficiency. Copyright © 2012 John Wiley & Sons, Ltd.
Polyfluorene derivatives pending iridium complexes: Improved optoelectronic properties by introducing D‐A units and altering pendent mode
Authors: Tan Hua , Yu Junting , Chen Jianhua , Nie Kaixuan , Chen Qing , Huang Ying , Zhang Zhiyong , Wang Yafei , Liu Yu , Lei Gangtie , Zhu Weiguo
Published: February 2012

To study influence of the donor(D)‐acceptor(A) units and pendent mode of phosphorescent moiety on the opto‐electronic properties for its resulting copolymers, two D‐A‐based polyfluorene derivatives (P1 and P2) pending the red‐emitting iridium bi(phenylisoquilonato) (picolinato) [Ir(Piq)2(pic)] unit and a polyfluorene derivative (P3) only pending Ir(Piq)2(pic) unit were synthesized and characterized, in which the donor of carbazole, the acceptor of oxadiazole are grafted into the C‐9 position of fluorene, the Ir(Piq)2(pic) unit is pended into either the C‐9 position for P1 and P3 or the end for P2 of fluorene by unconjugated linkage, respectively. Their opto‐electronic properties were significantly influenced by the D‐A units and pendent mode of the Ir(Piq)2(pic) unit. In the polymer light‐emitting devices with a configuration of ITO/PEDOT/polymers/LiF/Al, the P1 showed best electroluminescent properties than the P2 and P3. The maximum current efficiency of 0.72 cd/A and the highest luminance of 1398 cd/m2 were obtained in the P1‐based device, which are 1.3 and 1.5 times higher than those in the P2‐based device, respectively. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Micro reflectance difference techniques: Optical probes for surface exploration
Authors: Lastras‐Martínez L. F. , del Pozo‐Zamudio O. , Herrera‐Jasso R. , Ulloa‐Castillo N.A. , Balderas‐Navarro R.E. , Ortega‐Gallegos J. , Lastras‐Martínez A.
Published: February 2012

Micro reflectance difference spectroscopy (µ‐RDS) is a promising tool for the in‐situ and ex‐situ characterization of semiconductors surfaces and interfaces. We discuss and compare two different approaches used to measure µ‐RD spectra. One is based on a charge‐coupled device (CCD) camera, while the other uses a laser and a XY translation stage. To show the performance of these systems, we have measured surface optical anisotropies of GaSb(001) sample on which anisotropic strains have been generated by preferential mechanical polishing along [110] and $[1{\bar {1}}0]$ directions. The spectrometers are complementary and the selection of one of them depends on the sample to be investigated and on experimental conditions.
Plasmonic antennas, positioning, and coupling of individual quantum systems
Authors: Dregely Daniel , Lindfors Klas , Dorfmüller Jens , Hentschel Mario , Becker Merle , Wrachtrup Jörg , Lippitz Markus , Vogelgesang Ralf , Giessen Harald
Published: February 2012

Plasmonic nanoantennas can enhance the radiative decay rate of quantum emitters via the Purcell‐effect. Similar to their radiofrequency equivalents, they can also direct the emitted light into preferential directions. In this paper we first investigate plasmonic Yagi‐Uda antennas that are able to confine light to and direct light from subwavelength size volumes. Hence, enhanced transition rates and directed emission are expected when near‐field coupling between quantum emitters and the antennas is achieved. Second, we present suitable techniques to couple different quantum systems to plasmonic antennas. We use top‐down fabrication techniques to achieve positioning of individual quantum emitters relative to plasmonic nanostructures with an accuracy better than 10 nm. We assure a sufficiently small distance for an efficient near‐field coupling of the transition dipole to the plasmonic nanoantenna, which is, however, large enough not to quench the transition. The hybrid system using quantum dots, molecules, or nitrogen‐vacancy (NV)‐centers in diamond can serve as an efficient single photon source. It is suitable for high‐speed information transfer at optical frequencies on the nanoscale for future applications.
The role of oxygen‐induced processes on the emission characteristics of single molecule emitters
Authors: Nothaft Maximilian , Höhla Steffen , Jelezko Fedor , Pflaum Jens , Wrachtrup Jörg
Published: February 2012

Single molecule studies are limited to a defined class of organic dye molecules inserted into respective host materials. Basic requirements for suited material combinations include high photon emission rates and long term photostability. A majority of known aromatic host–guest systems employ crystalline organic matrices to prevent dye molecules from uncontrolled reactions with contaminants. However, in terms of device fabrication and technological potentials it is often desirable to use polymers as room temperature host matrices. Unfortunately, single dye molecule investigations in polymers at room temperature usually report orders of magnitude lower photostabilities compared to their crystalline molecular counterparts, leading to a reduced interest in organic thin film applications. In this report, we exemplary demonstrate the feasibility of engineering a host–guest system based on dibenzoterrylene dye molecules which were diluted into the polymer poly‐(p‐phenylene‐vinylene) (PPV) possessing very low photobleaching probabilities at room temperature. By controlling the oxygen exposure during manufacturing the number of emitted photons prior to photobleaching was significantly increased from 106 up to 1011 photons. Employing suited encapsulation techniques to prevent oxygen penetration after host–guest preparation, photostable devices over prolonged time periods on the order of months to years could be achieved. Therefore, this approach grants access to a variety of new polymer based combinations of host–guest systems for studying single molecular quantum emitters inside organic electronic devices and nanostructured polymer films with sufficient count rates and long‐term stability at room temperature.
Effect of defects in ferromagnetic C doped ZnO thin films
Authors: Subramanian Munisamy , Akaike Yuhei , Hayashi Yasuhiko , Tanemura Masaki , Ebisu Hiroshi , Ping Daniel Lau Shu
Published: February 2012

The present work investigates the relation between ferromagnetism and intrinsic defects of C‐doped ZnO thin films. The room‐temperature ferromagnetism (RTFM) in C‐doped ZnO is due to the charge transfer between Zn 4s and C 2p orbitals. The long‐range magnetic interaction in C‐doped ZnO is due to carbon–carbon interaction mediated by oxygen. The oxygen‐ and zinc‐related defects in C‐doped ZnO affect the mediation of ferromagnetic interaction and the existence of hybridization between Zn and C, respectively.
Determination of levamisole in feeds by liquid chromatography coupled to electrospray mass spectrometry on an ion trap
Authors: Gallo Pasquale , Fabbrocino Serena , Serpe Luigi
Published: February 2012

Test methods have to be developed by laboratories for official control to monitor possible misuse of veterinary drugs in animal productions, also through feeding stuff. A novel method for identification and quantification of levamisole in feeds by liquid chromatography coupled to electrospray mass spectrometry in an ion trap (LC/ESI‐MS/MS) is herein described; after a single‐step cleanup by liquid‐liquid extraction from the feed and separation by reversed‐phase liquid chromatography, levamisole was determined and unambiguously confirmed by tandem mass spectrometry, on the basis of two product ions. The method was in‐house validated, according to the Regulation 882/2004/EC, evaluating trueness, repeatability, within‐laboratory reproducibility, ruggedness, specificity, and the limit of quantification (LOQ). The method is reliable and specific for complete and complementary feeds for pigs, cattle, rabbits and poultry; very good mean recoveries (higher than 92 %) and precision (RSD values < 15.2%) were attained. The LOQ at 2.0 mg/kg was verified. Moreover, we describe how the method was developed to support Italian Police investigations regarding illegal treatments of pigs; in this case, since the drug(s) added to the feed were unknown, a preliminary untargeted analysis was performed by full scan mass spectrometry on an ion trap, from 50 up to 2000 m/z; the presence of levamisole was hypothesised, on the basis of the most abundant ion and its fragmentation pattern. Then, levamisole was unambiguously confirmed by the ion trap LC/ESI‐MS/MS method. Copyright © 2012 John Wiley & Sons, Ltd.
Screening of glycoside isomers in P. scrophulariiflora using ionic liquid‐based ultrasonic‐assisted extraction and ultra‐performance liquid chromatography/electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry
Authors: Cao Xiaoji , Qiao Jingfang , Wang Liping , Ye Xuemin , Zheng Lebin , Jiang Nan , Mo Weimin
Published: February 2012

A powerful ionic liquid‐based ultrasonic‐assisted extraction (ILUAE) method combined with ultra‐performance liquid chromatography coupled to electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry (UPLC/ESI‐QTOFMSn) was employed in the rapid simultaneous screening of iridoid glycosides, phenylethanoid glycosides, and cucurbitacin glycosides from P. scrophulariiflora. The ILUAE procedure was optimized over several ultrasonic parameters, including the ultrasonic power, concentration of the ionic liquid, and solid–liquid ratio. A comparison with conventional heat‐reflux extraction and regular UAE demonstrated that the optimized approach yielded a high extraction efficiency (Picroside I, 2.84%; Picroside II, 3.57%; 6‐O‐E‐feruloyl catalpol, 2.20%) within a short extraction time of 30 min. Negative ion mode ESI‐QTOFMS2 analysis of the fragmentation reactions of the [M–H]– ions was conducted to characterize the diagnostic ions related to the glycosyl moieties, aglycone units, and the type and substituted position of the ester groups. Interestingly, the positional isomers of the iridoid glycosides could be easily discriminated based on the characteristic ions. A total of 15 glycosides, including three groups of iridoid glycoside isomers and two groups of phenylethanoid glycoside isomers, were conveniently identified within 13.5 min. Moreover, 6'‐O‐vanilloyl catalpol was identified in P. scrophulariiflora for the first time. The method developed here was further validated by measuring the recovery, correlation coefficient (R2), and reproducibility (RSD, n = 5) of three iridoid glycosides: 89.60%–109.02%, 0.9991–0.9998, and 0.93%–1.44%, respectively. This study demonstrated the capabilities of ILUAE combined with UPLC/ESI‐QTOFMSn for the rapid screening of glycosides in P. scrophulariiflora. This method offers an approach to similar studies on other natural plants. Copyright © 2012 John Wiley & Sons, Ltd.
Building a disease risk model of osteoporosis based on traditional Chinese medicine symptoms and western medicine risk factors
Authors: Zhou X. H. , Li S. L. , Tian F. , Cai B. J. , Xie Y. M. , Pei Y. , Kang S. , Fan M. , Li J. P.
Published: February 2012

In the Traditional Chinese Medicine (TCM) cross‐sectional survey conducted by our team, we were interested in determining the risk factors of osteoporosis. To analyze this TCM study, we had to deal with three statistical problems: (1) a very large number of potential risk factors, (2) interactions among potential risk factors, and (3) nonlinear effects of some continuous‐scale risk factors. To address these analytic issues, we used two data mining methods, support vector machine recursive feature elimination and random forest; to deal with the curse of high‐dimensional risk factors, we applied another data mining technique of association rule learning to discover the potential associations among risk factors. Finally, we employed the generalized partial linear model (GPLM) to determine nonlinear effects of an important continuous‐scale risk factor. The final GPLM model shows that TCM symptoms play an important role in assessing the risk of osteoporosis. The GPLM also reveals a nonlinear effect of the important risk factor, menopause years, which might be missed by the generalized linear model. Copyright © 2012 John Wiley & Sons, Ltd.
The value of reusing prior nested case–control data in new studies with different outcome
Authors: Salim Agus , Yang Qian , Reilly Marie
Published: February 2012

Many epidemiological studies use a nested case–control (NCC) design to reduce cost while maintaining study power. However, because of the incidence density sampling used, reusing data from NCC studies for analysis of secondary outcomes is not straightforward. Recent methodological developments have opened the possibility for prior NCC data to be used to complement controls in a current study, thereby improving study efficiency. However, practical guidelines on the effectiveness of prior data relative to newly sampled subjects and the potential power gains are still lacking. Using simulated cohorts, we show in this paper how the efficiency of NCC studies that use a mixture of prior and newly sampled subjects depends on the number of newly sampled controls and prior subjects as well as the overlap in the distributions of the matching variables. We explore the feasibility and efficiency of a current study that gathers no controls, relying instead on prior data. Using the concept of effective number of controls, we show how researchers can assess the potential power gains from reusing prior data. We apply the method to analyses of anorexia and contralateral breast cancer in the Swedish population and show how power calculations can be done using publicly available software. This work has important applications in genetic and molecular epidemiology to make optimal use of costly exposure measurements. Copyright © 2012 John Wiley & Sons, Ltd.
Entrepreneurial orientation, social capital, and the internationalization of SMES: Evidence from China
Authors: Zhang Xiao , Ma Xufei , Wang Yue
Published: February 2012

This article combines arguments from entrepreneurship literature and social capital theory to examine the antecedents to the internationalization of small and medium‐sized enterprises (SMEs) from China. Our quantitative study of 117 Chinese SMEs demonstrates the overall importance of entrepreneurial orientation and social capital of entrepreneurs in facilitating their internationalization efforts, and also reveals that different dimensions of entrepreneurial orientation and different types of social capital exert different levels of independent influence on Chinese SMEs' internationalization. Complementary data from multiple case studies explains the variation between our quantitative findings and the findings of previous research. By highlighting the value of the entrepreneurial attributes of Chinese SMEs and the social capital embedded in their networks in the pursuit of their internationalization, the article adds to the scant literature on the internationalization behavior of the rapidly emerging Chinese SMEs. © 2012 Wiley Periodicals, Inc.
Interpreting LHC SUSY searches in the phenomenological MSSM
Authors: Sekmen S. , Kraml S. , Lykken J. , Moortgat F. , Padhi S. , Pape L. , Pierini M. , Prosper H. B. , Spiropulu M.
Published: February 2012

Abstract

We interpret within the phenomenological MSSM (pMSSM) the results of SUSY searches published by the CMS collaboration based on the first ~1 fb−1 of data taken during the 2011 LHC run at 7 TeV. The pMSSM is a 19-dimensional parametrization of the MSSM that captures most of its phenomenological features. It encompasses, and goes beyond, a broad range of more constrained SUSY models. Performing a global Bayesian analysis, we obtain posterior probability densities of parameters, masses and derived observables. In contrast to constraints derived for particular SUSY breaking schemes, such as the CMSSM, our results provide more generic conclusions on how the current data constrain the MSSM.