bluuebunny/crossref_metadata_2025 huggingface dataset:
The density gradient effect on quantum Weibel instability
Authors: Mahdavi M. , Khodadadi Azadboni F.
Published: March 2015

The Weibel instability plays an important role in stopping the hot electrons and energy deposition mechanism in the fast ignition of inertial fusion process. In this paper, the effects of the density gradient and degeneracy on Weibel instability growth rate are investigated. Calculations show that decreasing the density degenerate in the plasma corona, near the relativistic electron beam emitting region by 8.5% leads to a 92% reduction in the degeneracy parameter and about 90% reduction in Weibel instability growth rate. Also, decreasing the degenerate density near the fuel core by 8.5% leads to 1% reduction in the degeneracy parameter and about 8.5% reduction in Weibel instability growth rate. The Weibel instability growth rate shrinks to zero and the deposition condition of relativistic electron beam energy can be shifted to the fuel core for a suitable ignition by increasing the degeneracy parameter in the first layer of plasma corona.
Intrinsic synchronization of an array of spin-torque oscillators driven by the spin-Hall effect
Authors: Siracusano G. , Tomasello R. , Puliafito V. , Giordano A. , Azzerboni B. , La Corte A. , Carpentieri M. , Finocchio G.
Published: March 2015

This paper micromagnetically studies the magnetization dynamics driven by the spin-Hall effect in a Platinum/Permalloy bi-layer. For a certain field and current range, the excitation of a uniform mode, characterized by a power with a spatial distribution in the whole ferromagnetic cross section, is observed. We suggest to use the ferromagnet of the bi-layer as basis for the realization of an array of spin-torque oscillators (STOs): the Permalloy ferromagnet will act as shared free layer, whereas the spacers and the polarizers are built on top of it. Following this strategy, the frequency of the uniform mode will be the same for the whole device, creating an intrinsic synchronization. The synchronization of an array of parallely connected STOs will allow to increase the output power, as necessary for technological applications.
Memory operation mechanism of fullerene-containing polymer memory
Authors: Nakajima Anri , Fujii Daiki
Published: March 2015

The memory operation mechanism in fullerene-containing nanocomposite gate insulators was investigated while varying the kind of fullerene in a polymer gate insulator. It was cleared what kind of traps and which positions in the nanocomposite the injected electrons or holes are stored in. The reason for the difference in the easiness of programming was clarified taking the role of the charging energy of an injected electron into account. The dependence of the carrier dynamics on the kind of fullerene molecule was investigated. A nonuniform distribution of injected carriers occurred after application of a large magnitude programming voltage due to the width distribution of the polystyrene barrier between adjacent fullerene molecules. Through the investigations, we demonstrated a nanocomposite gate with fullerene molecules having excellent retention characteristics and a programming capability. This will lead to the realization of practical organic memories with fullerene-containing polymer nanocomposites.
Improved GaSb-based quantum well laser performance through metamorphic growth on GaAs substrates
Authors: Richardson Christopher J. K. , He Lei , Apiratikul Paveen , Siwak Nathan P. , Leavitt Richard P.
Published: March 2015

The promise of the metamorphic growth paradigm is to enable design freedom of the substrate selection criteria beyond current choices that are limited by lattice matching requirements. A demonstration of this emerging degree of freedom is reported here by directly comparing identical laser structures grown both pseudomorphically on a GaSb substrate and metamorphically on a GaAs substrate. Improved thermal performance of the metamorphic laser material enables a higher output power before thermal roll-over begins. These performance gains are demonstrated in minimally processed gain-guided broad-area type-I lasers emitting close to 2-μm wavelengths and mounted p-side up. Continuous wave measurements at room temperature yield a T0 of 145 K and peak output power of 192 mW from metamorphic lasers, compared to a T0 of 96 K and peak output power of 164 mW from identical lasers grown pseudomorphically on GaSb.
Suppression of boron-oxygen defects in Czochralski silicon by carbon co-doping
Authors: Wu Yichao , Yu Xuegong , He Hang , Chen Peng , Yang Deren
Published: March 2015

We have investigated the influence of carbon co-doping on the formation of boron-oxygen defects in Czochralski silicon. It is found that carbon can effectively suppress the formation of boron-oxygen defects. Based on our experiments and first-principle theoretical calculations, it is believed that this effect is attributed to the formation of more energetically favorable carbon-oxygen complexes. Moreover, the diffusion of oxygen dimers in carbon co-doped silicon also becomes more difficult. All these phenomena should be associated with the tensile stress field induced by carbon doping in silicon.
Hybrid type-I InAs/GaAs and type-II GaSb/GaAs quantum dot structure with enhanced photoluminescence
Authors: Ji Hai-Ming , Liang Baolai , Simmonds Paul J. , Juang Bor-Chau , Yang Tao , Young Robert J. , Huffaker Diana L.
Published: March 2015

We investigate the photoluminescence (PL) properties of a hybrid type-I InAs/GaAs and type-II GaSb/GaAs quantum dot (QD) structure grown in a GaAs matrix by molecular beam epitaxy. This hybrid QD structure exhibits more intense PL with a broader spectral range, compared with control samples that contain only InAs or GaSb QDs. This enhanced PL performance is attributed to additional electron and hole injection from the type-I InAs QDs into the adjacent type-II GaSb QDs. We confirm this mechanism using time-resolved and power-dependent PL. These hybrid QD structures show potential for high efficiency QD solar cell applications.
The multiferroic properties of BiFe0.5Mn0.5O3 and BiFeO3/BiMnO3 superlattice films
Authors: Xu Qingyu , Sheng Yan , He Maocheng , Qiu Xiangbiao , Du Jun
Published: March 2015

BiFe0.5Mn0.5O3 (BFMO) and BiFeO3/BiMnO3 superlattice (BFO/BMO) films were epitaxially grown on (111) SrTiO3 substrates by pulsed laser deposition. The ferroelectricity of both BFMO and BFO/BMO has been confirmed by piezoresponse force microscopy. Weak ferromagnetism was observed for both samples. The magnetization of BFO/BMO is smaller than that of BFMO, confirming the antiferromagnetic Fe3+-O2−-Mn3+ interaction. Two anomalies at low temperature, T1 = 235 K and T2 = 42 K for BFMO and T1 = 198 K and T2 = 77 K for BFO/BMO, were observed in temperature dependent magnetization (M-T) curves. The peaks at T1 in zero field cooled (ZFC) M-T curves for both samples can be understood by the onset of Fe3+-O2−-Mn3+ interaction. The peak at T2 for BFMO can be understood by the blocking of ferromagnetic Mn-rich clusters due to the inhomogeneous distribution of Mn. The peak at T2 for BFO/BMO observed in both field cooled and ZFC M-T curves has been ascribed to the enhanced single-ion magnetocrystalline anisotropy due to the highly distorted oxygen octahedra in the ordered structure of Fe3+ and Mn3+ ions along (111) orientation.
Double-loop hysteresis in tetragonal KTa0.58Nb0.42O3 correlated to recoverable reorientations of the asymmetric polar domains
Authors: Tian Hao , Yao Bo , Tan Peng , Zhou Zhongxiang , Shi Guang , Gong Dewei , Zhang Rui
Published: March 2015

KTa1−xNbxO3 single crystals are typically regarded as normal ferroelectrics. Such crystals are thought to undergo a paraelectric-ferroelectric phase transition from the cubic to the tetragonal phase where generally a single hysteresis loop is expected. Nevertheless, a double-loop hysteresis is clearly observed in the tetragonal phase of KTa0.58Nb0.42O3. Our investigations reveal further that the double loop exhibits good ergodicity during changes in temperature under various applied electric fields. The origin of this unusual double-loop hysteresis in tetragonal KTa0.58Nb0.42O3 is revealed with the recoverable reorientation of the asymmetric polar domains.
Independently controlling permittivity and diamagnetism in broadband, low-loss, isotropic metamaterials at microwave frequencies
Authors: Parke L. , Hooper I. R. , Edwards E. , Cole N. , Youngs I. J. , Hibbins A. P. , Sambles J. R.
Published: March 2015

A metamaterial based on the design of Shin et al. [Phys. Rev. Lett. 102, 093903 (2009)] that allows independent control of its permeability and permittivity has been fabricated and experimentally characterised. It is comprised of an array of metallic cubic-shaped elements with faces that are connected only through six orthogonal spokes emanating from the centre. The permeability is tailored through appropriate patterning of the faces, thereby controlling the propagation of eddy currents around the cubic elements while permittivity may be controlled by the thickness and dielectric constant of the inter-cube spacers.
On the impact of indium distribution on the electronic properties in InGaN nanodisks
Authors: Benaissa M. , Sigle W. , Ng T. K. , El Bouayadi R. , van Aken P. A. , Jahangir S. , Bhattacharya P. , Ooi B. S.
Published: March 2015

We analyze an epitaxially grown heterostructure composed of InGaN nanodisks inserted in GaN nanowires in order to relate indium concentration to the electronic properties. This study was achieved with spatially resolved low-loss electron energy-loss spectroscopy using monochromated electrons to probe optical excitations—plasmons—at nanometer scale. Our findings show that each nanowire has its own indium fluctuation and therefore its own average composition. Due to this indium distribution, a scatter is obtained in plasmon energies, and therefore in the optical dielectric function, of the nanowire ensemble. We suppose that these inhomogeneous electronic properties significantly alter band-to-band transitions and consequently induce emission broadening. In addition, the observation of tailing indium composition into the GaN barrier suggests a graded well-barrier interface leading to further inhomogeneous broadening of the electro-optical properties. An improvement in the indium incorporation during growth is therefore needed to narrow the emission linewidth of the presently studied heterostructures.
Spectral behavior of second harmonic signals from organic and non-organic materials in multiphoton microscopy
Authors: Ehmke Tobias , Knebl Andreas , Reiss Stephan , Fischinger Isaak R. , Seiler Theo G. , Stachs Oliver , Heisterkamp Alexander
Published: March 2015

Multimodal nonlinear microscopy allows imaging of highly ordered biological tissue due to spectral separation of nonlinear signals. This requires certain knowledge about the spectral distribution of the different nonlinear signals. In contrast to several publications we demonstrate a factor of 122 relating the full width at half maximum of a gaussian laser pulse spectrum to the corresponding second harmonic pulse spectrum in the spatial domain by using a simple theoretical model. Experiments on monopotassium phosphate crystals (KDP-crystals) and on porcine corneal tissue support our theoretical predictions. Furthermore, no differences in spectral width were found for epi- and trans-detection of the second harmonic signal. Overall, these results may help to build an optimized multiphoton setup for spectral separation of nonlinear signals.
Developmental competence of 8–16-cell stage bison embryos produced by interspecies somatic cell nuclear transfer
Authors: González-Grajales L. Antonio , Favetta Laura A. , King W. Allan , Mastromonaco Gabriela F.
Published: March 2015

Altered communication between nuclear and cytoplasmic components has been linked to impaired development in interspecies somatic cell nuclear transfer (iSCNT) embryos as a result of genetic divergence between the two species. This study investigated the developmental potential and mitochondrial function of cattle (Bos taurus), plains bison (Bison bison bison) and wood bison (Bison bison athabascae) embryos produced by iSCNT using domestic cattle oocytes as cytoplasts. Embryos in all groups were analysed for development, accumulation of ATP, apoptosis and gene expression of nuclear- and mitochondrial-encoded genes at the 8–16-cell stage. The results of this study showed no significant differences in the proportion of developed embryos at the 2-, 4- and 8–16-cell stages between groups. However, significantly higher ATP levels were observed in cattle SCNT embryos compared with bison iSCNT embryos. Significantly more condensed and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL)-positive nuclei were found in plains bison iSCNT embryos. No significant differences in the expression levels of nuclear respiratory factor 2 (NRF2) or mitochondrial subunit 2 of cytochrome c oxidase (mt-COX2) were found in any of the groups. However, mitochondrial transcription factor A (TFAM) expression significantly differed between groups. The results of this study provide insights into the potential causes that might lead to embryonic arrest in bison iSCNT embryos, including mitochondrial dysfunction, increased apoptosis and abnormal gene expression.
Relationship between sperm apoptosis and bull fertility: in vivo and in vitro studies
Authors: Erickson Lauren , Kroetsch Tom , Anzar Muhammad
Published: March 2015

The objectives of this study were to confirm the relationship of apoptosis-associated membrane and nuclear changes in bull spermatozoa with field fertility, to predict the fertility of beef bulls used for natural breeding and to study the role of DNA-nicked spermatozoa in early embryonic development. In Experiment 1, the relationship between fertility and different sperm populations identified by the Annexin V/propidium iodide (PI) and terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) assays was determined. Bull fertility was related to live (P < 0.05) and necrotic (P < 0.01) and DNA-nicked (P < 0.001) spermatozoa. In Experiment 2, the percentage of DNA-nicked spermatozoa was determined in 15 beef bulls used for natural breeding and their fertility potential was determined using a regression model developed in Experiment 1.The predicted fertility deviation of beef bulls ranged from –7.3 to 2.4. In Experiment 3, the effect of DNA-nicked spermatozoa on in vitro cleavage and blastocyst rates was evaluated, using 30 000 or 300 000 spermatozoa per droplet. Cleavage rate was adversely affected (P < 0.05) by DNA-nicked spermatozoa, regardless of sperm concentration. Blastocyst rate was lower (P < 0.05) in high DNA-nicked spermatozoa at the lower sperm concentration. In conclusion, the incidence of DNA-nicked spermatozoa is a useful marker to predict a bull’s fertility potential. DNA-nicked spermatozoa showed adverse effects on early embryonic development.
Cryptic haplotypes of “CandidatusLiberibacter africanus”
Authors: Nelson Warrick R , Eveillard Sandrine , Dubrana Marie-Pierre , Bové Joseph M
Published: March 2015

“CandidatusLiberibacter africanus” (Laf) has long been recognised as a causal agent of the devastating citrus disease huanglongbing (HLB) or citrus greening. This species is currently restricted to Africa, the Arabian Peninsula and some Indian Ocean islands and vectored by the African citrus psyllid,Trioza erytreae. Blotchy mottle on citrus leaves is characteristic of the disease.

Somewhat similar symptoms in the Rutaceous treeCalodendrum capensis(Cape Chestnut) resulted in the discovery of Laf outside commercial citrus crops in South Africa. This was classed as a subspecies of Laf (capensis, hence LafC). In subsequent surveys of both commercial citrus crops andCalodendrum, both natural and ornamental specimens, LafC was not found in the citrus crop, nor has Laf been found inC. capensis. HLB was reported from Madagascar in 1968 but no sequences from this source have so far been published.

Until fairly recently, only the reference 16S rRNA gene sequences of Laf (L22533) and LafC (AF137368) had been deposited in GenBank. Both of these reference sequences contain a number of unresolved nucleotides. Resolving these nucleotide positions by aligning against more recently available sequences, it becomes evident that these unresolved positions represent one percentage point difference in similarity between Laf and LafC. The originally reported 97.4% similarity is therefore incorrect based on this new information. Recalculating the similarity on the full length 16S rDNA sequence results in 99.54% similarity, a value too high to justify a subspecies status. LafC should therefore be reduced to that of a haplotype of Laf.

Further, the six 16S rRNA gene sequences currently available in GenBank identified as the species Laf separate into 2 haplotype groups. The 3 haplotypes of Laf are therefore LafA designated as the first accession sequenced (L22533), LafC for the former capensis subspecies and to recognise the prior use of this term, and LafB for the third haplotype not previously recognised. Thus the cryptic presence of 3 haplotypes is revealed by this review of the Laf 16S rDNA sequences.
Active prey mixing as an explanation for polyphagy in predatory arthropods: synergistic dietary effects on egg production despite a behavioural cost
Authors: Marques Renata Vieira , Sarmento Renato Almeida , Lemos Felipe , Pedro‐Neto Marçal , Sabelis Maurice W. , Venzon Madelaine , Pallini Angelo , Janssen Arne
Published: March 2015

Mixing of prey that differ in nutrient content or toxic compounds (dietary mixing) may allow synovigenic predatory arthropods to balance their diet or dilute toxins of different prey items to maximize performance: dietary mixing may therefore explain the prevalence of polyphagy in this functional group.

Several predatory arthropods can redress nutritional imbalances in their diet by actively mixing different diets, based on experiments with artificial diets or with prey that were manipulated to contain different nutrients.

Evidence is also accumulating that predator species perform better on a mixed diet of several different prey species, but evidence that they actively forage for different prey species is scarce.

Thus, evidence that predators actively forage for a mixed diet consisting of natural, non‐manipulated prey to increase their performance is still rare. Here, we investigate whether arthropod predators invest in achieving an optimal diet by active mixing of different prey species or by simply eating what they encounter.

Females of two species of plant‐inhabiting predatory mites produced significantly more eggs when feeding on a prey mixture of co‐occurring phytophagous mites than when feeding on either of the two prey species separately.

When the two prey species were offered on two separate, connected patches at some distance from each other, predators commuted significantly more between the two patches to obtain a mixed diet and had a significantly increased egg production than predators that were offered a single prey species on two patches.

Thus, predators actively commuted between patches to balance their diet. We propose that active dietary mixing can have synergistic effects on predator fitness and has the potential to explain polyphagy in this functional group.
Multi‐block finite‐difference method for 3D elastodynamic simulations in anisotropic subhorizontally layered media
Authors: Sofronov Ivan , Zaitsev Nikolai , Dovgilovich Leonid
Published: March 2015

Prediction of elastic full wavefields is required for reverse time migration, full waveform inversion, borehole seismology, seismic modelling, etc. We propose a novel algorithm to solve the Navier wave equation, which is based on multi‐block methodology for high‐order finite‐difference schemes on curvilinear grids. In the current implementation, the blocks are subhorizontal layers. Smooth anisotropic heterogeneous media in each layer can have strong discontinuities at the interfaces. A curvilinear adaptive hexahedral grid in blocks is generated by mapping the original 3D physical domain onto a parametric cube with horizontal layers and interfaces. These interfaces correspond to the main curvilinear physical contrast interfaces of a subhorizontally layered formation. The top boundary of the parametric cube handles the land surface with smooth topography. Free‐surface and solid–solid transmission boundary conditions at interfaces are approximated with the second‐order accuracy. Smooth media in the layers are approximated up to sixth‐order spatial schemes. All expected properties of the developed algorithm are demonstrated in numerical tests using corresponding parallel message passing interface code.
Levator hiatal area as a risk factor for cystocele recurrence after surgery: a prospective study
Authors: Vergeldt TFM , Notten KJB , Weemhoff M , van Kuijk SMJ , Mulder FEM , Beets‐Tan RG , Vliegen RFA , Gondrie ETCM , Bergmans MGM , Roovers JPWR , Kluivers KB
Published: March 2015

Objective

To investigate whether increased levator hiatal area, measured preoperatively, was independently associated with anatom‐ical cystocele recurrence 12 months after anterior colporrhaphy.

Design

Multicentre prospective cohort study.

Setting

Nine teaching hospitals in the Netherlands.

Population

Women planned for conventional anterior colporrhaphy without mesh.

Methods

Women underwent physical examination, translabial three‐dimensional (3D) ultrasound and magnetic resonance imaging (MRI) prior to surgery. At 12 months after surgery the physical examination was repeated.

Main outcome measures

Women with and without anatomical cystocele recurrence were compared to assess the association with levator hiatal area on 3D ultrasound, levator hiatal area on MRI, and potential confounding factors. The receiver operating characteristic (ROC) curve was created to quantify the discriminative ability of using levator hiatal area to predict anatomical cystocele recurrence.

Results

Of 139 included women, 76 (54.7%) had anatomical cystocele recurrence. Preoperative stage 3 or 4 and increased levator hiatal area during Valsalva on ultrasound were significantly associated with cystocele recurrence, with odds ratios of 3.47 (95% confidence interval, 95% CI 1.66–7.28) and 1.06 (95% CI 1.01–1.11) respectively. The area under the ROC curve was 0.60 (95% CI 0.51–0.70) for levator hiatal area during Valsalva on ultrasound, and 0.65 (95% CI 0.55–0.71) for preoperative Pelvic Organ Prolapse Quantification (POP–Q) stage.

Conclusions

Increased levator hiatal area during Valsalva on ultrasound prior to surgery and preoperative stage 3 or 4 are independent risk factors for anatomical cystocele recurrence after anterior colporrhaphy; however, increased levator hiatal area as the sole factor for predicting anatomical cystocele recurrence after surgery shows poor test characteristics.
Association between individual response to food taste and gastroesophageal symptoms
Authors: Shibata Tomoyuki , Nakamura Masahiko , Omori Takafumi , Tahara Tomomitsu , Ichikawa Yuichiro , Okubo Masaaki , Ishizuka Takamitsu , Nakagawa Yoshihito , Nagasaka Mitsuo , Nakamura Masakatsu , Arisawa Tomiyasu , Hirata Ichiro
Published: March 2015

Objective

Taste is an important element in food preferences. Gastroesophageal reflux disease (GERD) is related to lifestyles including eating habits. We aimed to investigate the relationship between responses to specific tastes and GERD.

Methods

Altogether 280 patients including 170 men with a mean age of 58.6 years were included in the study to determine the relationship between their liking for specific tastes and GERD using a new self‐administered questionnaire (responses to various tastes and participants' sensitivity to taste and hot food and on the frequency of stomatitis). Another self‐administrated questionnaire was administrated for a diagnosis of GERD (the frequency scale for the symptoms of GERD cut‐off score of 10). Furthermore, 142 of 280 patients who had received esophagogastroduodenoscopy (EGD) were investigated on the association between endoscopic esophagitis and their favorite tastes.

Results

In the association analyses between responses to specific tastes and GERD, the group liking salty food and the group with a high frequency of stomatitis had a significantly higher incidence of GERD (salty food: odds ratio [OR] 2.059, 95% confidence interval [CI] 1.215–3.488, P = 0.0073; stomatitis: OR 2.861, 95% CI 1.558–5.253, P = 0.0007, respectively). In association analyses with endoscopic esophagitis, the groups liking salty and sour food had a significantly higher incidence rate of endoscopic esophagitis (salty: OR 2.718, 95% CI 1.330–5.555, P = 0.0061; sour: OR 3.267, 95% CI 1.491–7.160, P = 0.0031, respectively).

Conclusions

Sensitivity and response to specific food taste were associated with GERD. The results of a preference to hot or salty food and endoscopic esophagitis suggest that physical stimuli are important for esophageal injuries.
Endodontics and the ageing patient
Authors: Johnstone M , Parashos P
Published: March 2015

Patients are living longer and the rate of edentulism is decreasing. Endodontic treatment is an essential part of maintaining the health and well‐being of the elderly. Retention of natural teeth improves the quality of life and the overall health and longevity of ageing patients. Also, teeth that might be otherwise extracted may be strategically valuable to retain a prosthesis, and elderly patients are more likely to have medical complications that may prevent dental extractions from being safely performed. The technical goals of endodontic treatment in the elderly are the same as those for younger patients. However, the pulpo‐dentinal complex undergoes calcific changes over time, which may pose challenges for the clinician. The purposes of this review are to discuss age changes in the pulp and the challenges posed by diagnosing, treatment planning and treating the elderly endodontic patient.
Treatment planning concepts for the ageing patient
Authors: Ettinger RL
Published: March 2015

There is an ageing imperative in Australia as in many other industrialized nations, and these populations are extremely heterogeneous. In young adults, the factors which influence decision making for oral health care are whether the patient has the will, the time or the finances to pay for care, while for clinicians, the decisions are whether they have the skill and the resources to carry out the treatment plan. For older adults, the decision making includes all of the previous identified factors, but they are now complicated by the patient's medical and medication problems, the side effects of the medications they are taking, their cognitive status as well as the cumulative effects of a lifetime of physiological, traumatic and iatrogenic effects on the dentition and the oral cavity.

The decision‐making process which has evolved has been called many names, from cost‐effective care to minimal invasive dentistry to rational dental care. Fundamentally, they are similar. Rational dental care has been defined as the process of decision making, which develops a treatment plan that is in the best interest of the patient after evaluating all of the modifying factors. This article will discuss the various concepts, and the strengths and weaknesses of some of these systems. It will also illustrate some of the clinical problems as there is very little evidence‐based data to support any of these concepts. However, treatment planning is still an art, which can only be carried out for an individual and not a group, and the result must serve the needs of the patient and enhance the quality of his or her life.
Advanced restorative dentistry – a problem for the elderly? An ethical dilemma
Authors: Murray CG
Published: March 2015

The type of dental restorations taken into old age may have an adverse effect on the quality of life of the elderly. Root caries and dry mouth increase in prevalence with age and may precipitate the breakdown of remaining natural and restored teeth. At present the availability of dental personnel and facilities in residential aged care facilities (RACFs) is limited, often non‐existent, and the elderly living at home may be unable to easily gain access to dental care. Thus, the provision of appropriate and timely dental treatment may not occur, resulting in prolonged pain and suffering. It is important that, as our elderly population increasingly retain natural teeth into advanced old age, appropriate funds are made available to ensure their dental health is maintained. A lack of early intervention to arrest dental disease may result in life‐threatening medical consequences in the elderly, such as ventilator assisted pneumonia or the need for a general anaesthetic and possible associated medical risks. Significant local disease, such as osteonecrosis, may also result from a lack of appropriate dental intervention. The necessity to remove questionable teeth prior to irradiation for neoplastic disease or bisphosphonate prescription for neoplastic disease or severe osteoporosis emphasizes the need for regular dental care.

In contrast, extensive dental restorative treatment for younger people may have benefits, such as optimal dental aesthetics and oral function, but in older individuals careful consideration should be given to select the most appropriate treatment modality so that adverse situations can be avoided or their resolution simplified should they occur later when the individual is compromised or in a RACF. This may mean the use of conservative dental restorative materials and an avoidance of complex restorative options which may be difficult for the individual or RACF staff to maintain. Some years after receipt of their complex restorations they may be unable to cope with the operative demands and financial burden of resolving their deteriorating dental situation and so complex implant‐born structures and precision removable prostheses should probably be avoided for those individuals contemplating entering a care situation. Therefore, the timing of the provision of complex dentistry poses an ethical dilemma.
Social implications and workforce issues in the oral health of an ageing population
Authors: Wright FAC
Published: March 2015

A functional and socially acceptable level of oral health is an integral part of healthy ageing! More teeth, more sophisticated dental technology and increasing co‐morbidities of an ageing Australian society will have significant impacts on oral health professionals and their capacities to work within expanded teams of health, education and social organizations. Society is adapting its perspective on the social role of older citizens; replacing its perception of the elderly as an economic social burden, to one of senior citizens as being a respected and active source of social and economic benefit.

Maintaining general and oral health for older Australians will bring into sharp focus the need for recognizing and managing not only the biological markers associated with ageing and frailty, but also the potential mediators on health outcomes associated with changing health and social behaviours. Increasing social capital of older Australians through national policy initiatives such as the Living Longer Living Better reforms, and greater involvement of allied health and carers’ organizations in oral health education and health promotion will set a new scene for the roles of dental professionals. Issues of equity will drive the service delivery agenda, and a socio‐cultural shift to ‘consumer‐directed’ health outcomes will shape the range of services, quality of care and support required by an older Australian population. Formal education and training modules for aged care workers, allied health practitioners and geriatricians will develop. The challenge for the dental profession is the coordination and integration of these changes into new models of dental and general health care.
A Constrained Helical Peptide Against S100A4 Inhibits Cell Motility in Tumor Cells
Authors: Naiya Gitashri , Kaypee Stephanie , Kundu Tapas K. , Roy Siddhartha
Published: March 2015

S100A4, a member of a calcium‐regulated protein family, is involved in various cellular signaling pathways. From many studies over the last decade or so, it has become clear that it is involved in tumor metastasis, probably playing a determinative role. However, except the phenothiazine group of drugs, no significant inhibitor of S100A4 has been reported. Even the phenothiazines are very weak inhibitors of S100A4 action. In this study, we report design and development of a conformationally constrained helical peptide modeled on the non‐muscle myosin peptide that binds to S100A4. This conformationally constrained peptide binds to S100A4 with a dissociation constant in the nanomolar range. We also synthesized a peptide for experimental control that bears several alanine mutations in the peptide–protein interface. We demonstrate that the former peptide specifically inhibits motility of H1299 and MCF‐7 cells in a wound‐healing assay. Structures of several S100A4–ligand complexes suggest that it may be possible to develop a smaller peptide–small molecule conjugate having high affinity for S100A4. Peptide–drug conjugates of this kind may play an important role in developing drug leads against this antimetastasis target.
MicroRNA-155 may be involved in the pathogenesis of atopic dermatitis by modulating the differentiation and function of T helper type 17 (Th17) cells
Authors: Ma L , Xue H-B , Wang F , Shu C-M , Zhang J-H
Published: March 2015

Our aims were to identify the differential expression of microRNA (miR)-155, as well as to explore the possible regulatory effects of miR-155 on the differentiation and function of T helper type 17 (Th17) cells in atopic dermatitis (AD). The Th17 cell percentage and expression levels of miR-155, retinoic acid-related orphan receptor (ROR)γt, interleukin (IL)-17 and suppressor of cytokine signalling-1 (SOCS1) in peripheral CD4+ T cells, plasma and skin specimens were detected and compared in AD patients and healthy subjects. A miR-155 mimic and an inhibitor were transfected separately into AD CD4+ T cells to confirm the in-vivo data. The Th17 cell percentage, miR-155 expression, RORγt mRNA expression, IL-17 mRNA expression and plasma concentration were increased significantly in AD patients compared with healthy subjects. Conversely, SOCS1 mRNA expression and plasma concentration were decreased significantly. Similar results were detected in cultured CD4+ T cells transfected with the miR-155 mimic compared with a miR-155 inhibitor or a negative control. Additionally, there was a sequential decrease in miR-155 expression, as well as RORγt and IL-17 mRNA expression, but an increase in SOCS1 mRNA expression, from AD lesional skin and perilesional skin to normal skin. Positive correlations were found between miR-155 expression and AD severity, Th17 cell percentage, RORγt mRNA expression and IL-17 mRNA expression and plasma concentration, while negative correlations were observed between miR-155 expression and SOCS1 mRNA expression and plasma concentration in AD peripheral circulation and skin lesions. In conclusion, miR-155 is over-expressed and may be involved in AD pathogenesis by modulating the differentiation and function of Th17 cells.
The most frequent cause of 90‐day unplanned hospital readmission following colorectal cancer resection is chemotherapy complications
Authors: Ang C. W. , Seretis C. , Wanigasooriya K. , Mahadik Y. , Singh J. , Chapman M. A. S.
Published: March 2015

Aim

NHS England deems 90‐day readmission rates as a marker of quality of care. The causes of readmission have not been previously reported in the UK. The aim of this study was to examine the factors associated with 90‐day readmission following colorectal cancer surgery at a hospital trust with a catchment population 1.2 million.

Method

A retrospective review was performed of all patients undergoing resection for colorectal cancer between January 2012 and December 2013. Unplanned readmission was defined as an emergency admission to the trust for any cause within 90 days of surgery. Readmission analyses were restricted to patients discharged from hospital within 28 days of resection.

Results

A total of 570 patients underwent surgery, of whom 522 were discharged within 28 days and are included for readmission analysis. The readmission rate was 24.3% (127 patients with a total of 163 episodes of hospital readmissions) within 90 days following surgery. The most frequent cause for readmission was complications related to adjuvant chemotherapy (18.4%) followed by wound‐related complications (14.1%). Most patients presenting with wound‐related complications were admitted within 60 days and patients with chemotherapy‐related complications after 61 days; 13/127 (10.2%) patients who were readmitted underwent emergency surgery, and one patient died following readmission. Multivariate analysis demonstrated that comorbidity was the only independent risk factor.

Conclusion

Ninety‐day readmissions include a high number of readmissions secondary to chemotherapy‐related complications, whereas most surgical‐related readmission present within 60 days.
Early vs late tracheostomy in critically ill patients: a systematic review and meta‐analysis
Authors: Meng Liang , Wang Chunmei , Li Jianxin , Zhang Jian
Published: March 2015

Background and Aims

This study aims to compare the outcomes of early tracheostomy (ET) (≤10 days after translaryngeal intubation) with late tracheostomy (LT) (>10 days after translaryngeal intubation) in critically ill patients with prolonged mechanical ventilation (MV).

Methods

We searched PubMed, EMBASE and the Cochrane Library from inception to April 2014. We included all randomized controlled trials (RCTs), which compared ET with LT in critically ill patients. There was no language restriction. Two authors extracted data and conducted a quality assessment. Meta‐analyses using the fixed‐effects or random‐effects model were conducted for mortality, incidence of ventilator‐associated pneumonia (VAP), duration of MV and sedation, length of intensive care unit (ICU) stay.

Results

We enrolled 9 studies, in which a total of 2040 patients were randomized to either ET group (N = 1018) or LT group (N = 1022). ET might reduce the duration of sedation [weighted mean difference (WMD) = −5.99 days; 95% confidence intervals (CI) = −11.41 to −0.57 days; P = 0.03]. ET did not significantly alter the mortality [relative risk (RR) = 0.88; 95% CI = 0.76–1.00; P = 0.06], incidence of VAP (RR = 0.84; 95% CI = 0.66–1.08; P = 0.17), duration of MV (WMD = −4.46 days; 95% CI = −12.61 to 3.69 days; P = 0.28) and length of ICU stay (WMD = −7.57 days; 95% CI = −15.42 to 0.29 days; P = 0.06).

Conclusions

Our meta‐analysis suggested that ET might be able to reduce the duration of sedation but did not significantly alter the mortality, incidence of VAP, duration of MV and length of ICU stay.
Correlation between the Wells score and the Quanadli index in patients with pulmonary embolism
Authors: Obradović Dušanka , Joveš Biljana , Pena Karan Slobodanka , Stefanović Srdjan , Ivanov Igor , Vukoja Marija
Published: March 2015

Background and Aims

Determining clinical probability of pulmonary embolism (PE) with Wells scoring system is the first step towards diagnosis of PE. Definitive diagnosis of PE is confirmed by computed tomography pulmonary angiography (CTPA).

Methods

This was a prospective study on 80 patients referred to the Institute for Pulmonary Diseases of Vojvodina with suspected PE between April 2010 and August 2012. Clinical probability of PE was determined according to the Wells and modified Wells scoring system. CTPA was performed in 60 patients. The degree of pulmonary vascular obstruction was quantified by the Qanadli index.

Results

Low clinical probability of PE was present in one patient (1.6%), moderate in 43 (71.6%) and high in 16 (26.6%) patients. PE was confirmed in 50 (83.3%) patients. There were 21 patients (42%) whose Quanadli index was <25%, 18 (36%) between 25%–50%, while Quanadli index was ≥50 in 11 patients (22%). When compared to CTPA findings, modified Wells scoring system showed 90% sensitivity [95% confidence interval (CI) 78.2%–96.6%], and 20% specificity (95% CI 3.11%–55.6%), positive predictive value (PPV) 84.9% (95% CI 72.4%–93.2%) and negative predictive value (NPV) 28.6% (95% CI 4.5%–70.7%). There was weak positive correlation between Wells score and Quanadli index (r = 0.14; P = 0.29), without statistical significance. Wells score was significantly higher in haemodynamically unstable than in haemodynamically stable patients (6.8 vs 5.6, P = 0.014). There was no statistically significant difference between the values of Quanadli index in these two groups (31.33% vs 26.64%, P = 0.062).

Conclusion

Modified Wells criteria have high sensitivity but low specificity in PE diagnostics. The Wells score does not correlate well with the Quanadli index.
Clinical outcomes of adult inpatients treated with continuous subcutaneous insulin infusion for diabetes mellitus: a systematic review
Authors: Anstey J. , Yassaee A. , Solomon A.
Published: March 2015

Aims

To provide a systematic review of the current evidence concerning the diabetes‐related outcomes of patients provided with continuous subcutaneous insulin infusion for treating diabetes mellitus while a hospital inpatient.

Methods

Relevant publications were obtained from MEDLINE and EMBASE databases concerning hospital inpatients with diabetes being treated with continuous subcutaneous insulin infusion. Studies were assessed independently by two reviewers, and data on the following outcomes were extracted: inpatient mortality; clinical complications, e.g. diabetic ketoacidosis; hyperglycaemia; hypoglycaemia; length of hospital stay; mean bedside glucose level; and glucose level on discharge. Obstetric cases were examined separately to look at maternal and neonatal glycaemic outcomes.

Results

A total of 11 studies met the required criteria and were analysed in detail, 5 of which were predominantly obstetric. No significant complications were reported, with no incidences of death, ketoacidosis or severe hypoglycaemia. Length of hospital stay appeared to be shorter in those patients who remained on continuous subcutaneous insulin infusion, while data on mild hyperglycaemia and hypoglycaemia were inconclusive.

Conclusions

There are limited data available to form a significant conclusion about the safety of continuous subcutaneous insulin infusion continuation in hospital; however, its use can be justified with the presence of a specialized inpatient diabetes team for advice and support and an alternative treatment regime (e.g. subcutaneous basal bolus) should be accessible if the need were to arise.
Reduction of hypoglycaemic events with a behavioural intervention: a randomized clinical trial for paediatric patients with Type 1 diabetes mellitus
Authors: Gee B. T. , Nansel T. R. , Liu A.
Published: March 2015

Aims

To determine if a low‐intensity, clinic‐integrated behavioural intervention reduced the incidence of hypoglycaemic events in children with Type 1 diabetes.

Methods

A total of 390 families with children with Type 1 diabetes were enrolled in a 2‐year, randomized clinical trial of a behavioural intervention. The intervention was designed to improve diabetes management practices by targeting the family's diabetes problem‐solving skills. Hypoglycaemic events were categorized in two groups: those treated by oral ingestion and those treated by parenteral therapy. Events were self‐reported by participants at each clinic visit, which occurred approximately every 3–4 months. Analyses included two‐sample t‐tests, the mean cumulative function test, and the Cox proportional hazards model for recurrent events to compare the incidence between groups.

Results

Across the entire 2‐year study period, the incidence of hypoglycaemic events treated by oral ingestion of glucose‐rich foods and events requiring parenteral therapy did not significantly differ between study conditions; however, during the second year of participant enrolment, the incidence of events treated by oral ingestion in the intervention group was 13.6 per 100 person‐years compared with 27.3 per 100 patient‐years in the control group (P = 0.02). The hazard ratio of these events during the second year was 0.49 (95% CI 0.27–0.90; P = 0.02).

Conclusions

Our findings suggest the need for a long‐term (> 1 year) focus on the implementation of interventions targeting diabetes management in young people. Behavioural interventions targeting problem‐solving skills could be considered as practical, non‐pharmacological strategies to reduce hypoglycaemia in adolescents with Type 1 diabetes.
Challenges in diagnosing infection in the diabetic foot
Authors: Glaudemans A. W. J. M. , Uçkay I. , Lipsky B. A.
Published: March 2015

Diagnosing the presence of infection in the foot of a patient with diabetes can sometimes be a difficult task. Because open wounds are always colonized with microorganisms, most agree that infection should be diagnosed by the presence of systemic or local signs of inflammation. Determining whether or not infection is present in bone can be especially difficult. Diagnosis begins with a history and physical examination in which both classic and ‘secondary’ findings suggesting invasion of microorganisms or a host response are sought. Serological tests may be helpful, especially measurement of the erythrocyte sedimentation rate in osteomyelitis, but all (including bone biomarkers and procalcitonin) are relatively non‐specific. Cultures of properly obtained soft tissue and bone specimens can diagnose and define the causative pathogens in diabetic foot infections. Newer molecular microbial techniques, which may not only identify more organisms but also virulence factors and antibiotic resistance, look very promising. Imaging tests generally begin with plain X‐rays; when these are inconclusive or when more detail of bone or soft tissue abnormalities is required, more advanced studies are needed. Among these, magnetic resonance imaging is generally superior to standard radionuclide studies, but newer hybrid imaging techniques (single‐photon emission computed tomography/computed tomography, positron emission tomography/computed tomography and positron emission tomography/magnetic resonance imaging) look to be useful techniques, and new radiopharmaceuticals are on the horizon. In some cases, ultrasonography, photographic and thermographic methods may also be diagnostically useful. Improved methods developed and tested over the past decade have clearly increased our accuracy in diagnosing diabetic foot infections.
Use of a Baerveldt gonioimplant for secondary glaucoma in a horse
Authors: Wilson R. , Dees D. D. , Wagner L. , Monheit B. E. , O'Gan D.
Published: March 2015

This case report describes the surgical placement of a Baerveldt glaucoma shunt in the right eye of a 14‐year‐old Arabian gelding. The glaucomatous right eye was refractory to aggressive medical and repeated surgical therapies yet maintained functional vision. Despite the need for intensive post operative management and continued daily topical therapy, shunt placement surgery was successful at maintaining normotension and vision for a period of 402 days. This is the first report of long‐term successful glaucoma filtration surgery in this species. Further studies are warranted to evaluate long‐term success of glaucoma shunt placement in equine glaucoma cases.