bluuebunny/crossref_metadata_2025 huggingface dataset:
Compliant treatment with anti‐copper agents prevents clinically overt Wilson's disease in pre‐symptomatic patients
Authors: Dzieżyc K. , Karliński M. , Litwin T. , Członkowska A.
Published: December 2013

Background and purpose

Wilson's disease (WD) is an inherited copper metabolism disorder that leads to dysfunction of affected tissues, mostly in the liver and brain. Anti‐copper treatment should prevent clinically overt WD in pre‐symptomatic patients but this has not been supported by strong evidence. Our aim was to evaluate the long‐term effectiveness of treatment in clinically pre‐symptomatic patients, with particular emphasis on patient compliance with treatment.

Methods

Data were analyzed for 87 consecutive patients with no clinical symptoms of WD who were identified between 1957 and 2009 by family screening. All of them since diagnosis were treated with either zinc sulphate (Zn) (66.7%) or D‐penicillamine (DPA) (33.3%).

Results

During a median follow‐up of 12 years (range 3–52), 55 (63%) patients remained without clinical symptoms, 13 (15%) developed neuropsychiatric symptoms and 21 (24%) developed hepatic dysfunction, including five deaths from hepatic failure. Non‐compliance for at least three consecutive months was observed in 39 patients, and in 29 cases this extended for more than 12 months. Multivariate analysis showed that the odds of developing symptomatic WD were independently increased by non‐compliance (odds ratio 24.0, 95% confidence interval 6.0–99.0). According to Kaplan–Meier analysis patients who were compliant to treatment had a significantly higher likelihood of remaining symptom‐free, and their overall survival was similar to the survival rate observed in the general population.

Conclusion

The use of anti‐copper agents in clinically pre‐symptomatic patients diagnosed with WD allows clinically overt disease to be effectively prevented. However, compliance with therapy is extremely important.
Greater occipital nerve blocks in chronic cluster headache: a prospective open‐label study
Authors: Lambru G. , Abu Bakar N. , Stahlhut L. , McCulloch S. , Miller S. , Shanahan P. , Matharu M. S.
Published: December 2013

Background and purpose

Greater occipital nerve blockade (GONB) has been shown to be effective in episodic cluster headache. However, its use in chronic cluster headache (CCH) is less certain. The study aims to prospectively assess the efficacy and consistency of response to GONB in a large series of CCH patients.

Methods

CCH patients who had a unilateral GONB and were referred to the National Hospital for Neurology and Neurosurgery were studied prospectively. Headache characteristics were collected using headache diaries. Responders were considered to be patients with a complete or partial response lasting at least 7 days. In a subgroup of responders the outcomes of serial GONB performed at 3‐monthly intervals were also analysed.

Results

Eighty‐three CCH patients were studied. After the first GONB, a positive response was observed in 47 (57%) patients: 35 (42%) were rendered pain free, 12 (15%) had a partial benefit and one patient obtained <50% improvement. The duration of a positive response lasted a median of 21 days (range 7–504 days). There was a transient worsening of condition in 6% of patients. The overall rate and average duration of response remained consistent after the second [n = 37; 31 responders (84%); median duration 21 days], third [n = 28; 20 responders (71%); median duration 25 days] and fourth [n = 14; 10 responders (71%); median duration 23 days] injections.

Conclusion

GONB seems to be an efficacious treatment with reproducible effects in CCH patients. Performed three monthly, GONB may have a useful role in the management of CCH.
Temporal lobe surgery in Germany from 1988 to 2008: diverse trends in etiological subgroups
Authors: Helmstaedter C. , May T. W. , von Lehe M. , Pfaefflin M. , Ebner A. , Pannek H. W. , Elger C. E. , Stefan H. , Schramm J.
Published: December 2013

Background and purpose

In the epilepsy community, there is talk that the number of classical patients with early onset temporal lobe epilepsy (TLE) and Ammon's horn sclerosis (AHS) is decreasing. This is counterintuitive, considering the success story of epilepsy surgery, improved diagnostic methods and the current recommendation of early admission to surgery. In order to recognize trends, the development of temporal lobe surgery over 20 years in three major German epilepsy centers was reviewed.

Methods

Age at surgery and duration of epilepsy, which was differentiated according to histopathology (AHS, developmental, tumor, vascular), year of surgery and center, were evaluated in a cohort of 2812 patients from three German epilepsy centers who underwent temporal lobe surgery between 1988 and 2008. The analysis was carried out for the pooled cohort as well as for each center separately.

Results

Of all patients, 52% showed AHS. Compared with other pathologies, the AHS group had the earliest epilepsy onset and the longest duration of epilepsy. Across five time epochs, the diagnosis of AHS increased in the first epoch, remaining constant thereafter. Contrary to the trends in other pathologies, in the AHS group the mean age of patients at surgery increased by 7 years and the duration of epilepsy until surgery increased by 5 years. This trend could be replicated in all three centers. As initially hypothesized for all groups, age and duration of epilepsy in other pathology groups remained constant or indicated earlier submission to surgery.

Conclusions

During the first few years studied, most probably due to progress in brain imaging, the proportion of patients with AHS increased. However, despite stable numbers over time, and contrary to the trends in other pathology groups, age and duration of epilepsy in mesial TLE with AHS (mTLE + AHS) increased over time. This supports the hypothesis of a decreasing incidence of AHS. This trend is discussed with respect to disease‐modifying factors which have changed the incidence of classical mTLE + AHS or, alternatively, to recent developments in antiepileptic drug treatment, the appraisal of surgery and economic incentives for treatment options other than surgery.
Dysarthria plus dysphagia is associated with severe sleep‐disordered breathing in patients with acute intracerebral hemorrhage
Authors: Shibazaki K. , Kimura K. , Aoki J. , Uemura J. , Fujii S. , Sakai K.
Published: December 2013

Background and purpose

Sleep‐disordered breathing (SDB) is a risk factor for stroke. The frequency of SDB in Japanese patients with acute intracerebral hemorrhage (ICH) was investigated, as well as factors associated with SDB severity.

Methods

Between April 2010 and April 2013, patients with ICH within 24 h of onset were prospectively enrolled to participate in a sleep study within 7 days of admission. SDB was defined as a respiratory disturbance index (RDI: apnea or hypopnea events per hour) of ≥5. Patients were assigned to groups based on RDI values of ≥30 (severe SDB) and <30 (absent or not severe SDB). The frequency of SDB and factors associated with its severity were investigated using multivariate logistic regression analysis.

Results

Of 97 patients (55 males; mean age 68.1 years) enrolled in the study, 91 (94%) had SDB. Severe SDB was evident in 29 (30%) patients. Compared with the RDI< 30 group, the RDI≥ 30 group had a higher frequency of dysarthria plus dysphagia (76% vs. 47%, P = 0.008), larger waist circumference [86 (84–92) vs. 84 (78–88) cm, P = 0.019] and a greater body mass index [23.8 (21.1–26.8) vs. 21.5 (19.4–25.0) kg/m2, P = 0.046]. Multivariate logistic regression analysis showed that dysarthria plus dysphagia was independently associated with severe SDB (odds ratio 3.4; 95% confidence interval 1.250–9.252, P = 0.017).

Conclusion

Most Japanese patients with acute ICH had SDB, and dysarthria plus dysphagia was associated with severe SDB.
Gene‐expression profile and localization of Na+/K+‐ATPase in rat enamel organ cells
Authors: Wen Xin , Lacruz Rodrigo S. , Smith Charles E. , Paine Michael L.
Published: December 2013

The sodium pump Na+/K+‐ATPase, expressed in virtually all cells of higher organisms, is involved in establishing a resting membrane potential and in creating a sodium gradient to facilitate a number of membrane‐associated transport activities. Na+/K+‐ATPase is an oligomer of α, β, and γ subunits. Four unique genes encode each of the α and β subunits. In dental enamel cells, the spatiotemporal expression of Na+/K+‐ATPase is poorly characterized. Using the rat incisor as a model, this study provides a comprehensive expression profile of all four α and all four β Na+/K+‐ATPase subunits throughout all stages of amelogenesis. Real‐time PCR, western blot analysis, and immunolocalization revealed that α1, β1, and β3 are expressed in the enamel organ and that all three are most highly expressed during late‐maturation‐stage amelogenesis. Expression of β3 was significantly higher than expression of β1, suggesting that the dominant Na+/K+‐ATPase consists of an α1β3 dimer. Localization of α1, β1, and β3 subunits in ameloblasts was primarily to the cytoplasm and occasionally along the basolateral membranes. Weaker expression was also noted in papillary layer cells during early maturation. Our data support that Na+/K+‐ATPase is functional in maturation‐stage ameloblasts.
Dynamic interplay between autophagic flux and Akt during melanoma progression in vitro
Authors: Maes Hannelore , Martin Shaun , Verfaillie Tom , Agostinis Patrizia
Published: December 2013

Despite advances in cancer diagnosis and therapy, metastatic melanoma remains untreatable, due to its notorious resistance to apoptosis, deeming traditional therapies obsolete. Deregulated PI3K/Akt signalling is a common oncogenic event enabling melanocyte transformation and represents a significant and ‘druggable’ pathway in melanoma. Emerging data show that the ability of cancer cells to survive is also facilitated by alteration of vital homoeostatic mechanisms, such as autophagy. Although the role of autophagy in melanoma is still controversial, recent studies suggest that basal autophagy is down‐modulated in primary melanomas. However, the dynamic connection between pro‐tumorigenic PI3K/Akt and autophagy during melanoma progression has not been systematically studied. By using human primary melanocytes, incipient melanoma and metastatic melanoma cell lines, we show that early in melanomagenesis, increased Akt activity is associated with a low baseline autophagic flux. However, during melanoma progression, metastatic melanoma cells regain the ability to stimulate autophagic flux, supporting survival. Heightened autophagy is associated with an attenuated Akt activation status and can be suppressed by overexpressing a constitutive active mutant of Akt. On the other hand, blocking the higher Akt activity of primary melanoma is sufficient to incite autophagy. Interestingly, we found that although Akt supports survival of melanocytes and all melanoma cell lines, autophagy inhibition specifically targeted the metastatic melanoma cells, thus indicating a stage‐specific requirement for Akt and autophagic flux, throughout melanoma progression. Therefore, this study highlights a dynamic interplay between Akt signalling and autophagic rescue in melanoma, which should be considered in the design of therapeutic strategies targeting these pathways.
Lack of expression of an alternative CD20 transcript variant in circulating B cells from patients with pemphigus
Authors: Gamonet Clémentine , Ferrand Christophe , Colliou Natacha , Musette Philippe , Joly Pascal , Girardin Marie , Humbert Philippe , Aubin François
Published: December 2013

We have identified a spliced mRNA transcript of CD20 (named D393‐CD20) which was associated with resistance to RTX in primary B cell from patients with lymphoma and leukaemia. In the present work, we wished to investigate whether D393‐CD20 variant was expressed by B cells from patients with pemphigus. Ten patients with bullous pemphigoid and twenty‐five patients with pemphigus were included. All patients were responder to conventional immunosuppressive agents or rituximab (n = 11). Efficacy of B‐cell activation by pokeweed mitogen was assessed by CD86 expression using a FACS Canto II flow cytometer. mRNA CD20 expression study was then performed using RT‐PCR assay allowing first to discriminate wild‐type (wt)‐CD20 and D393‐CD20 transcript. Although wt‐CD20 expression was always detected, we were unable to detect D393‐CD20, even after B‐cell activation or RTX treatment. Our results suggest that D393‐CD20 transcript may be a molecular marker of B‐cell malignancies rather than autoimmune disease like pemphigus. Further study of RTX non‐responders or non‐escaping PV patients is thus still required to appreciate whether D393‐CD20 expression may be detected under the pressure of RTX therapy.
Origin of Langerhans cells in normal skin and chronic GVHD after hematopoietic stem‐cell transplantation
Authors: Andani Rafiq , Robertson Ivan , MacDonald Kelli P. A. , Durrant Simon , Hill Geoffrey R. , Khosrotehrani Kiarash
Published: December 2013

Chronic graft‐versus‐host disease (cGVHD) is a common complication following allogeneic stem‐cell transplantation (SCT). Past studies have implicated the persistence of host antigen‐presenting cells (APCs) in GVHD. Our objective was to determine the frequency of host Langerhans cells (LCs) in normal skin post‐SCT and ask if their persistence could predict cGVHD. Biopsies of normal skin from 124 sex‐mismatched T‐cell‐replete allogenic SCT recipients were taken 100 days post‐transplant. Patients with acute GVHD and those with <9 months of follow‐up were excluded and prospective follow‐up information was collected from remaining 22 patients. CD1a staining and X and Y chromosome in‐situ hybridization were performed to label LCs and to identify their host or donor origin. At 3 months, 59 ± 5% of LCs were host derived. The density of LCs and the proportion of host‐derived LCs were similar between patients that did or did not develop cGVHD. Most LCs in the skin remained of host origin 3 months after SCT regardless of cGVHD status. This finding is in line with the redundant role of LCs in acute GVHD initiation uncovered in recent experimental models.
AML1–ETO triggers epigenetic activation of early growth response gene l, inducing apoptosis in t(8;21) acute myeloid leukemia
Authors: Fu Lin , Huang Wenrong , Jing Yu , Jiang Mengmeng , Zhao Yu , Shi Jinglong , Huang Sai , Xue Xue , Zhang Qingyi , Tang Juying , Dou Liping , Wang Lili , Nervi Clara , Li Yonghui , Yu Li
Published: December 2013

The t(8;21)(q22;q22) translocation is the most common chromosomal translocation in acute myeloid leukemia (AML), and it gives rise to acute myeloid gene 1 (AML1)–myeloid transforming gene 8 (ETO)‐positive AML, which has a relatively favorable prognosis. However, the molecular mechanism related to a favorable prognosis in AML1–ETO‐positive AML is still not fully understood. Our results show that the AML1–ETO fusion protein triggered activation of early growth response gene l (EGR1) by binding at AML1‐binding sites on the EGR1 promoter and, subsequently, recruiting acetyltransferase P300, which is known to acetylate histones. However, AML1–ETO could not recruit DNA methyltransferases and histone deacetylases; therefore, EGR1 expression was affected by histone acetylation but not by DNA methylation. Both transcription and translation of EGR1 were higher in AML1–ETO‐positive AML cell lines than in AML1–ETO‐negative AML cell lines, owing to acetylation. Furthermore, when AML1–ETO‐positive AML cell lines were treated with C646 (P300 inhibitor) and trichostatin A (histone deacetylase inhibitor), EGR1 expression was significantly decreased and increased, respectively. In addition, treatment with 5‐azacytidine (methyltransferase inhibitor) did not cause any significant change in EGR1 expression. Overexpression of EGR1 inhibited cell proliferation and promoted apoptosis, and EGR1 knockout promoted cell proliferation. Thus, EGR1 could be a novel prognostic factor for a favorable outcome in AML1–ETO‐positive AML. The results of our study may explain the molecular mechanisms underlying the favorable prognosis in AML1–ETO‐positive AML.
Near‐threshold behaviour of shear‐mode fatigue cracks in metallic materials
Authors: Pokluda J. , Pippan R. , Vojtek T. , Hohenwarter A.
Published: December 2013

This review paper presents a brief state‐of‐the art of the research on long fatigue shear‐mode cracks and describes some recent results on effective crack growth thresholds and mode I branching conditions achieved by the authors for ARMCO iron, titanium with two different microstructures, nickel and stainless steel. A special technique for preparation of fatigue precracks enabled us to substantially suppress the crack closure (friction) effects at the beginning of the experiment, and the measured threshold values could be considered to be very close to the effective ones. In all investigated materials, the effective thresholds under the remote mode II loading were found to be about 1.7 times lower than those under the remote mode III loading. Effective thresholds under mode II loading of investigated materials were found to follow a simple formula assembled by the shear modulus G, the magnitude of Burgers vector b and a goniometrical function nα of the mean deflection angle that depends on the number of available crystallographic slip systems. These quantities determine the intrinsic material resistance to mode II crack propagation at the threshold. A simple criterion for mode I branching in terms of effective threshold values well reflects a transition from the shear‐mode to the opening‐mode controlled crack propagation at the threshold. The associated transition deflection angle of 40° is a material independent constant.
Dynamic fracture behaviour of Fe78Si9B13 metallic glass ribbon under laser shock loading
Authors: Zheng C. , Sun S. , Ji Z. , Song L. , Zhang G. , Zhang J.
Published: December 2013

The fracture behaviour of Fe78Si9B13 metallic glass under laser shock loading was investigated. Morphologies of the fracture surface and laser irradiated surface were characterized using scanning electron microscope. The results show that the fracture surface consists of sliding region and final fracture region with crack propagation. Liquid droplets and melted belts are scattered on the fracture surface as the notable features compared with fracture surface morphology under quasistatic loading, indicating the significant temperature increase in shear bands during dynamic loading. The primary and secondary shear bands are distributed on the specimen surface resulting from the simultaneous operation of multiple shear bands at high strain rates. Ripples with the characteristic spacing of about 1 µm are generated on the laser irradiated surface because of the interaction of laser pulse with solid surface.
The potential impact of second‐generation biofuel landscapes on at‐risk species in the US
Authors: Evans Samuel G. , Kelley Lisa C. , Potts Matthew D.
Published: December 2013

The recent increase in corn ethanol production has drawn attention to the environmental sustainability of biofuel production. Environmental assessments of second‐generation biofuel crops (SGBC) have focused primarily on greenhouse gas emissions and water quality. However, expanding the production of cellulosic biomass resources, especially those that require dedicated agricultural land, is also likely to have impacts on biodiversity. We developed an optimization framework for projecting the spatial pattern ofSGBCexpansion in the United States and intersected these predictions with occurrence data for at‐risk species. In particular, we focused on two candidate perennial grass feedstocks,Panicum virgatum(switchgrass), andMiscanthus × giganteus(Miscanthus). Tradeoffs between biodiversity and economic profitability are assessed using county level data sets ofSGBCyield, agricultural land availability, land rents, and at‐risk species occurrences. Results show that futureSGBCexpansion is likely to occur outside of the Corn Belt, where conventional biofuel feedstocks are currently grown. The set of at‐risk species that could potentially be impacted is therefore likely to be different from the at‐risk species prevalent in the agroecological landscapes of the Upper Midwest that are dominated by corn and soy production. The total number and type of potentially impacted taxa is influenced by several factors, including the total demand for cellulosic biomass, the type of agricultural land used for production, and the method for defining at‐risk species.SGBCproduction is also concentrated in fewer counties when a national species conservation constraint is combined with a biofuel production mandate. This analysis provides a foundation for future research on species conservation in bioenergy production landscapes and highlights the importance of incorporating biodiversity into broader environmental assessments of biofuel sustainability.
Effect of two additives on the fermentation, in vitro digestibility and aerobic security of Sorghum–sudangrass hybrid silages
Authors: Han L. Y. , Li J. , Na R. S. , Yu Z. , Zhou H.
Published: December 2013

Two additives (Silo Guard (SG) and propionic acid (PA)) were tested for their effects on the quality and aerobic security of sorghum–sudangrass hybrid silages (JC‐1 and WC‐2). Two sorghum–sudangrass hybrid varieties were harvested for ensiling without additives (CK) or after the following treatments: SG at 0·5% of fresh forage or PA at 0·5% of fresh forage, with three replicates per treatment. The addition of SG and PA both affected the fermentation quality and chemical composition of the silages by lowering pH and NH3‐N/TN and increasing lactic acid, the LA/TA ratio, WSC and CP concentrations compared with the untreated silages. In vitro DM digestibility (IVDMD), in vitro NDF digestibility (IVNDFD) and in vitro CP digestibility (IVCPD) were increased by SG in the JC‐1 silages and WC‐2 silages. Both additives improved the aerobic stability of sorghum–sudangrass hybrid silages. Furthermore, the additives reduced the mould counts and the aflatoxin and zearalenone levels compared with the untreated silages following aerobic exposure. Therefore, ensiling two sorghum–sudangrass hybrid varieties resulted in high‐quality silages. The addition of SG and PA improved silage quality, in vitro digestibility and aerobic security.
Regrowth patterns of elephant grass (Pennisetum purpureum Schum) subjected to strategies of intermittent stocking management
Authors: Pereira L. E. T. , Paiva A. J. , Geremia E. V. , da Silva S. C.
Published: December 2013

The morphogenetic responses of individual tillers and the composition of tiller populations throughout regrowth in response to all combinations of two post‐grazing heights (35 and 45 cm) and two pre‐grazing conditions (95% and maximum canopy light interception during regrowth – LI95% and LIMax) were studied in swards of elephant grass (Pennisetum purpureum Schum. cv. Napier) from November 2011 to April 2012. Swards were subjected to the same treatments from January 2011 until measurements began, to enable them to adapt to the defoliation regimes. Treatments were allocated to experimental units (850 m2 paddocks) according to a 2 × 2 factorial arrangement in a randomized complete block design, with four replications. The total number of tillers (basal + aerial) was similar for both LI pre‐grazing targets. However, there was a change in the preferential growth pathway used by plants characterized by modification in the proportion of tiller classes in plant population. Swards managed with the LIMax target had a smaller population density of basal tillers and used the recruitment of aerial tillers as the main growth pathway. Although effective for maintaining stable rates of leaf elongation and senescence, such a strategy resulted in greater tiller death. Additionally, stem elongation, a consequence of the competition for light under those circumstances, resulted in differences in sward herbage mass and morphological composition with potential implications for herbage feeding value.
Comparison of feed intake, body weight gain, enteric methane emission and relative abundance of rumen microbes in steers fed sainfoin and lucerne silages under western Canadian conditions
Authors: Bouchard K. , Wittenberg K. M. , Legesse G. , Krause D. O. , Khafipour E. , Buckley K. E. , Ominski K. H.
Published: December 2013

Beef cattle are major contributors of enteric methane (CH4) emissions in Canada. Feeding forages containing condensed tannins (CT) has been suggested as a means of reducing enteric CH4 emissions and improving production efficiency. Sainfoin (Onobrychis viciifolia) is one of the CT‐containing legumes, which has also been recognized to have several additional beneficial properties. This study compared sainfoin silage (SS) and lucerne (Medicago sativa) silage (LS) with respect to animal performance, enteric CH4 production, abundance of selected rumen microbes and selected serum parameters in yearling steers during a Canadian winter. Sainfoin silage in our study contained approximately 12 g CT kg−1 dry matter (DM), a level which did not adversely affect silage palatability as steers fed SS experienced higher DM intake. However, animals fed LS and SS had similar body weight gain over the course of the trial. Feeding SS resulted in lower blood urea nitrogen concentrations and relative abundance of methanogenic archaea in rumen fluid. Yet, microbial population shifts fell short of exerting significant influence on enteric CH4 emissions. This study suggests that under western Canadian growing and animal‐rearing conditions, sainfoin is not yet competitive with lucerne forage with respect to enteric CH4 emissions or animal productivity warranting further research and development.
Oral prophylaxis and its effects on halitosis‐associated and inflammatory parameters in patients with chronic periodontitis
Authors: Guentsch A , Pfister W , Cachovan G , Raschke G , Kuepper H , Schaefer O , Eick S
Published: December 2013

Objective

A controlled clinical trial was conducted to evaluate the effects of oral prophylaxis on halitosis‐associated, immunological and microbiological parameters.

Methods

Thirty subjects were included in this controlled clinical trial (patients with generalized chronic periodontitis and controls without clinical attachment loss; each n = 15). Before oral prophylaxis and 14 days after (including tongue cleaning) volatile sulphur compounds (VSC), organoleptic scores and a tongue coating index were evaluated. The levels of IL‐1β, IL‐8, IL‐10 and MMP‐8 were measured in GCF, and also major periodontal pathogens were detected. Data were statistically analysed using anova and paired t‐test.

Results

Supragingival plaque and calculus removal with combined tongue cleaning was able to reduce significantly (P < 0.05) the VSC values in both groups (no significant differences between both groups). Two weeks after periodontal debridement, the VSC values were observed in the periodontitis group, but not in the control group, similar to the baseline values. The difference between the groups was statistically significant (P < 0.05). Only a repeated prophylaxis session in the periodontitis group was able to reduce VSC values significantly in comparison with baseline (P < 0.05). Organoleptic scores (10 and 30 cm) were significantly different (P < 0.05) between both groups before and after the treatment. Periodontal pathogens and host‐derived markers were not significantly affected by a single prophylaxis session.

Conclusions

Oral prophylaxis may result in a significant decrease in VSC values. However, in periodontal diseases, a more complex treatment seems to be necessary.
Chitosan/tripolyphosphate‐nanoliposomes core‐shell nanocomplexes as vitamin E carriers: shelf‐life and thermal properties
Authors: Xia Shuqin , Tan Chen , Xue Jin , Lou Xiaowei , Zhang Xiaoming , Feng Biao
Published: December 2013

The aim of this study was to prepare the new core‐shell nanocomplexes as vitamin E (VE) carriers through chitosan (CS) coating onto the liposomal membrane surface in combination with sodium tripolyphosphate (TPP) cross‐linking, and investigated their storage and thermal properties by dynamic light scattering, ζ potential and fluorescence. Results showed that no obvious aggregation of nanocomplexes particles appeared and the VE retention rate was over 80% during the 30‐day storage. Thermal experiments demonstrated that the modification of polymers enhanced the stability of liposomes against temperature, including suppressing particle aggregation, ζ potential inversion and membrane fluidity. Compared with the great leakage of VE from uncovered liposomes, the retention rate of VE loaded into nanocomplexes remained around 92% and 97% after heated at 65 °C for 30 min and 80 °C for 16 s, respectively. The findings proved that these nanocomplexes can be employed to protect VE for extending shelf‐life and enhancing thermostability, and provide feasibility for commercial usage.
Effects of A1/A2‐Sites Occupancy upon Ferroelectric Transition in (SrxBa1−x)Nb2O6 Tungsten Bronze Ceramics
Authors: Huang C. J. , Li K. , Liu X. Q. , Zhu X. L. , Chen X. M.
Published: December 2013

The dielectric and ferroelectric characteristics of (SrxBa1−x)Nb2O6 unfilled tungsten bronze ceramics have been investigated together with the structure. The dielectric and ferroelectric characteristics of the present ceramics vary significantly with x, and the A1/A2‐sites occupancy has been determined as the primary parameter governing this variation tendency. Ba ions tend to occupy A2‐sites, Sr ions tend to occupy A1‐sites, and one A1‐site is empty. When the ratio of Sr/Ba is close to 1:4 (where four A2‐sites are just occupied by Ba ions, and one A1‐site is occupied by Sr ion while another A1‐site is empty), the normal ferroelectric transition is observed with one anomaly in the tanδ–T curve (x = 0.25). When the ratio of Sr/Ba is far away from 1:4, the typical relaxor behavior is indicated together with three anomalies in the tanδ–T curve (x = 0.75). The incommensurate oxygen octahedral tilting and A‐site random distribution are considered to be the structure origins for the relaxor ferroelectricity and low temperature dielectric relaxations.
Novel Visible Emission and Mechanism Investigation from PbS Nanoclusters‐Doped Borosilicate Glasses
Authors: Fan Shaohua , Wu Guobo , Zhang Yuanhao , Chai Guanqi , Ma Zhijun , Qiu Jianrong , Dong Guoping
Published: December 2013

Borosilicate glasses doped with PbO, ZnS, or PbS were fabricated to investigate the visible emissions (one located at 370 nm and another at 550 nm) observed in the PbO and ZnS codoped glass. Several series of glassy systems were designed to investigate the mechanism of above visible emissions. The absorption, photoluminescence (PL), photoluminescence excitation (PLE) spectra, and lifetime measurements were used to characterize all the emissions. The nanosecond level lifetimes for all the samples' 370 nm emissions ascribed the 370 nm emission to the glass defects. Measured lifetimes for the PbS quantum dots (QDs) in the glasses with an emission in the near‐infrared region which was about 8 μs was close to the values for the yellow emission, which confirmed the formation of PbS nanoclusters in the codoped glass was responsible for the yellow emission.
Kinetics and Activation Energy of Magnesium Oxide Hydration
Authors: Thomas Jeffrey J. , Musso Simone , Prestini Ivan
Published: December 2013

The kinetics of hydration of magnesium oxide (MgO) powder to form magnesium hydroxide (Mg(OH)2) were measured using isothermal calorimetry at different temperatures, and the morphology of the powders before and after hydration were examined. The hydration kinetics of light‐burned MgO exhibit a hydration rate peak similar to that of portland cement hydration, whereas the hydration kinetics of hard‐burned MgO are comparatively slower at the same temperature, and exhibit a continuously declining hydration rate after the first several minutes of reaction. The hydration kinetics of both light‐burned and hard‐burned MgO can be fit using a boundary nucleation and growth model that has previously been applied to the hydration of portland cement and tricalcium silicate. Activation energy values for MgO hydration were determined from the fitted rate constants and were also measured directly using small temperature excursions according to a recently proposed method. For light‐burned MgO the resulting values are in good agreement and indicate a value of 77 kJ/mol. For the hard‐burned MgO the activation energy values vary considerably depending on temperature and how the activation energy is measured, but are always lower than the value obtained for the light‐burned MgO.
Phase Evolution and Microstructural Studies in CaZrTi2O7–Nd2Ti2O7 System
Authors: Jafar Mohsin , Sengupta Pranesh , Achary Srungarpu N. , Tyagi Avesh K.
Published: December 2013

A series of compositions with general stoichiometry Ca1−xZr1−xNd2xTi2O7 has been prepared by high‐temperature solid‐state reaction of component oxides and characterized by powder X‐ray diffraction and electron probe for microanalyses (EPMA). The phase fields in CaZrTi2O7–Nd2Ti2O7 system and distribution of ions in different phases have been determined. Four different phase fields, namely monoclinic zirconolite, cubic perovskite, cubic pyrochlore, and monoclinic Nd2Ti2O7 structure types are observed in this system. The 4M‐polytype of zirconolite structure is stabilized by substitution of Nd3+ ion. The addition of Nd3+ ions form a cubic perovskite structure‐type phase and thus observed in all the compositions with 0.05 ≤ x ≤ 0.80. Cubic pyrochlore structure‐type phase is observed as a coexisting phase in the nominal composition with 0.20 ≤ x ≤ 0.90. Only a subtle amounts of Ca2+ and Zr4+ are incorporated into the perovskite‐type Nd2Ti2O7 structure. EPMA analyses on different coexisting phases revealed that the pyrochlore and perovskite phases have Nd3+‐rich compositions.
In Situ Observation of the Dissolution of SiO2 Particles in CaO–Al2O3–SiO2 Slags and Mathematical Analysis of its Dissolution Pattern
Authors: Feichtinger Stefan , Michelic Susanne K. , Kang Youn‐Bae , Bernhard Christian
Published: December 2013

The dissolution of amorphous SiO2 particles in CaO–Al2O3–SiO2 slags was investigated at 1450°C by high‐temperature confocal scanning laser microscopy (HT‐CSLM) and thermodynamic/kinetic analyses. The SiO2 particles used in this experimental study had a spherical form so that any rotation of the particle did not cause errors in the determination of the particle size during the dissolution. Moreover, a wide composition range of the slag could be chosen without forming any solid reaction layer which could distort the evaluation of the dissolution mechanism. The evolution of the diameter of the spherical SiO2 particle was measured by image analysis of pictures obtained from the HT‐CSLM. It was found that the dissolution curve of the SiO2 particle (size as a function of time) exhibited either a parabolic‐like curve or an S‐shaped curve depending on the slag composition. The patterns were compared with a well‐known shrinking core model (SCM), and it was shown that the SCM could not represent the dissolution behavior of the SiO2 particle observed in this study. It was experimentally found that the shape of the dissolution curves varies as a function of the slag composition. The curve exhibited a parabolic‐like shape for low SiO2‐containing slags and changed to an S‐type shape with increasing SiO2 concentration in the slag. To elucidate the dissolution mechanism, a model based on approximations for the diffusion near the particle was proposed by modifying the previously available model [M. J. Whelan, Met. Sci. J., 3, 95–97 (1969)]. From the experimental data and the model calculations, the viscosity of the slag was shown to be the major factor affecting both dissolution rate and mechanism. Effective binary diffusion coefficients were estimated using the model and experimental data. Those were shown to be in the range of literature data.
Atomic Structure of ZnO Σ13 [0001]/{130} Symmetric Tilt Grain Boundary
Authors: Roh Ji‐Young , Sato Yukio , Ikuhara Yuichi
Published: December 2013

Zinc oxide (ZnO) is used for a wide range of electrical applications, where its grain boundaries (GBs) possibly influence the physical properties. It is important to determine the GB structure in atomic scale to understand GB effects on the electrical properties. In this study, the atomic structure of a ZnO GB is investigated in detail by scanning transmission electron microscopy and theoretical calculations. It is shown that the atomic structure of ZnO Σ13 [0001]/{130} 32.2° symmetric tilt GB is constructed as an array of structural units (SUs) of six‐ and eight‐membered rings. The GB has two different SU alignments. The dominant structure of the GB is the zig‐zag SU alignment and the secondary one is the straight SU alignment. The relation between the SU alignment and the rotation angle has been determined.
Improving the High‐Temperature Oxidation Resistance of Nb4AlC3 by Silicon Pack Cementation
Authors: Zheng Liya , Wang Jingyang , Zhou Yanchun
Published: December 2013

Niobium aluminum carbide (Nb4AlC3), as a member of the MAX phases, can retain its stiffness and strength up to over 1400°C. However, its applications are limited due to its poor oxidation resistance at high temperatures. In this work, silicon pack cementation has been applied to improve the oxidation resistance of Nb4AlC3. After Si pack cementation at 1200°C for 6 h, a dense and uniform silicide coating which was mainly composed of NbSi2 and SiC and well bonded to the matrix was successfully formed on the surface of Nb4AlC3. The Si pack cemented Nb4AlC3 shows excellent oxidation resistance up to 1200°C due to the formation of protective Al2O3 layer. The oxidation kinetics of the cemented Nb4AlC3 obey parabolic law all the way to up to 1200°C, and the parabolic rate constants of cemented Nb4AlC3 are in the same order of magnitude as those of Ti3AlC2 in the temperature range 1000°C–1200°C. However, the oxidation of the cemented Nb4AlC3 was accelerated after oxidation at 1300°C for about 15 h due to the formation of NbAlO4.
Al Surface Modification by a Facile Route
Authors: Fang Chun‐Sheng , Gai Wei‐Zhuo , Deng Zhen‐Yan
Published: December 2013

A facile route was used to modify Al particle surfaces by putting Al particles into an Al(OH)3 suspension, which was produced by the reaction of Al powder with water under vacuum at a mild temperature, then drying and heat‐treating under vacuum at elevated temperature. The modified Al powder has a good reaction activity with water to generate hydrogen, and its reaction rate depends on the sizes of Al particles used to produce Al(OH)3 suspension. The reaction induction time of the modified Al powder prepared using the Al(OH)3 suspension produced by the reaction of Al with water is obviously shorter than that prepared using the Al(OH)3 suspension formed by the direct addition of a commercial Al(OH)3 powder, because the in situ formed Al(OH)3 has a finer microstructure. As the present method has no complicated processing procedure and the Al‐water reaction byproduct can be reused to modify Al, it is an economically viable way to fabricate the activated Al powder for commercial applications.
Influence of Y and La Additions on Grain Growth and the Grain‐Boundary Character Distribution of Alumina
Authors: Bojarski Stephanie A. , Stuer Michael , Zhao Zhe , Bowen Paul , Rohrer Gregory S.
Published: December 2013

Grain‐boundary character distributions (GBCDs) were determined for spark plasma sintered Y‐ and La‐doped aluminas prepared at temperatures between 1450°C and 1600°C. La doping leads to grain boundaries that adopt (0001) orientations 3.7 times more frequently than expected in a random distribution, whereas the Y‐doped microstructures are more equiaxed. At 1500°C, some of the boundaries in the Y‐doped samples transform to a higher mobility complexion; in this microstructure, the grain‐boundary plane is 1.3 times more likely to occur than expected in a random distribution. After the fast‐growing grains impinge, the dominant plane becomes and these boundaries have areas that are 1.2 times more likely to occur than expected in a random distribution. The grain‐boundary planes in the Y‐ and La‐codoped samples preferred (0001) and orientations, combining the characteristics of the singly doped samples. Grain boundaries with a 60° misorientation about [0001] were up to six times more common than random in the Y‐doped samples. The preference for (0001) oriented grain‐boundary planes in the La‐doped sample persisted at all specific misorientations.
Ball Impact Response of Unstrengthened and Chemically Strengthened Glass Bars
Authors: Jannotti Phillip , Subhash Ghatu , Varshneya Arun K.
Published: December 2013

Ball impact experiments were conducted at impact velocities of 52–345 m/s on unstrengthened and chemically strengthened lithium aluminosilicate glass bars to assess the damage propagation characteristics. The damage was captured by high‐speed imaging at frame rates up to 500 000 frames per second (fps). Upon impact, the damage front in the unstrengthened glass reached a maximum velocity of 1626–2135 m/s, and rapidly fell to zero within a short distance. On the contrary, the damage front in the strengthened glass reached an initial velocity of 1791–2275 m/s, but then stabilized to a constant velocity of 1920 m/s until the entire glass bar was consumed. In addition, the cascading release of stored energy due to strengthening led to self‐sustained damage propagation preferentially within the outer layers of the glass bar (predominantly within the compressive zones) at a higher rate than in the interior region (dominated by residual tension). This is counter to what has been traditionally reported in the literature. Stress wave reflection from the rear of the unstrengthened bar caused tensile cracking (i.e., spallation), but the ultrahigh residual compression in the strengthened bar prevented similar damage initiation. Finally, it is suggested that strengthened glasses are most suitable as intermediate layers in laminate window panels for impact applications.
An Exploration of the Self‐Advocacy Support Role Through Collaborative Research: ‘There Should Never be a Them and Us’
Authors: Chapman Rohhss
Published: December 2013

Background

The role of the support worker in self‐advocacy groups for people with intellectual disability is pivotal in setting the scene for empowerment. However, despite the growing importance of the role, it has attracted very little scrutiny.

Method

The study developed an inclusive team approach working alongside researchers labelled with learning difficulties. Emphasis was placed on making all aspects of the research cycle accessible to the team. A variety of qualitative methods were used.

Results

Despite supporters’ allegiances to disability equality and their emphasis on reflexivity, many crucial aspects of organizational practice and support remained hidden. However, an emerging shared narrative about the potential of people first implied the possibility of increased collaboration. This was evidenced in some of the groups.

Conclusions

Where problematic practice was discussed, supporters were open to developing alternative approaches. Acknowledging members contributions alongside the work of their supporters helped nurture more collaborative relationships.

Accessible Abstract

A lot of accessible methods were used to find out what was happening. Much support work is hidden away and not listed by organisations. The supporter role is very complex where supporters are managed by members. Supporters may find ways to hold on to power even when they say they try not to. There were some good ways seen for members and supporters to work together fairly. The writer talks about working in a team with researchers with learning difficulties. The study concludes that we can all learn from each other.
Supply Chain Disruption Management: Severe Events, Recovery, and Performance
Authors: Macdonald John R. , Corsi Thomas M.
Published: December 2013

Given their proclivity to occur despite managers' best efforts, disruptions often result in lost sales, lead to large financial losses, and have a negative impact on shareholder wealth and operating performance. Less attention, however, has been paid to improving the process of managing a disruption from its discovery through to complete recovery. This entire process is not, in fact, fully understood. Clearer insights are needed surrounding the following issues: factors influencing the recovery process, how those factors interact to play a role in managerial decision making, and the company's actual ability to recover. While it is possible to determine basic recovery process factors, a more complete picture of disruption management can be built from analysis of data collected through qualitative in‐depth interviews. This research delivers insights around the interactions and relationships among factors, providing the foundation for a set of propositions useful for further investigation in the following areas: discovery of the disruption event, causes of the event, and recovery performance. One finding indicates that while internal disruptions are faster to recover from, they more likely lead to negative perceptions about the recovery performance outcome.
The Case of the C‐TPAT Border Security Initiative: Assessing the Adoption/Persistence Decisions When Dealing With a Novel, Institutionally Driven Administrative Innovation
Authors: Melnyk Steven A. , Ritchie William J. , Calantone Roger J.
Published: December 2013

The current study examines attributes of a diffusion process associated with an institutionally driven administrative innovation (IDAI) that was designed to mitigate international supply chain logistic risk. Using a sample of firms who adopted this type of administrative innovation (AI), we find that managers' adoption and persistence decisions differed from observed behaviors associated with economically driven AIs. For example, with IDAIs, large firms are the characteristic early adopters and the innovation persists in spite of a lack of a clearly compelling economic rationale for its continued support. These findings are drawn from an analysis of respondent data pertaining to Customs‐Trade Partnership Against Terrorism—an AI that has been previously identified as being an example of such a development. The results prompt us to rethink on the mechanisms governing AI adoption and persistence decisions and enhance the theoretical richness surrounding research into not only IDAIs but also other related areas such as certified management standards.
Public–Private Partnerships and Supply Chain Security: C‐TPAT as an Indicator of Relational Security
Authors: Voss M. Douglas , Williams Zachary
Published: December 2013

Following the attacks of September 11th, public and private entities recognized a need to protect the global supply chain from terrorist disruption. In response to this need, the U.S. Government partnered with industry to create the Customs‐Trade Partnership Against Terrorism (C‐TPAT) program. This research investigates the public–private partnership (PPP) relational aspects of C‐TPAT. C‐TPAT encourages firms to voluntarily improve their security competence and that of their supply chain partners. We introduce the concept of relational security in the context of PPPs. We define relational security as all activities that establish, cultivate, and maintain successful security exchanges between parties. We establish C‐TPAT as one indicator of relational security by demonstrating its ability to establish, cultivate, and maintain successful security exchanges between parties. Results indicate certified firms outperform noncertified firms in security performance, firm performance, and resilience.