bluuebunny/crossref_metadata_2025 huggingface dataset:
Sparse Nonnegative Matrix Factorization Strategy for Cochlear Implants
Authors: Hu Hongmei , Lutman Mark E. , Ewert Stephan D. , Li Guoping , Bleeck Stefan
Published: January 2016

Current cochlear implant (CI) strategies carry speech information via the waveform envelope in frequency subbands. CIs require efficient speech processing to maximize information transfer to the brain, especially in background noise, where the speech envelope is not robust to noise interference. In such conditions, the envelope, after decomposition into frequency bands, may be enhanced by sparse transformations, such as nonnegative matrix factorization (NMF). Here, a novel CI processing algorithm is described, which works by applying NMF to the envelope matrix ( envelopogram) of 22 frequency channels in order to improve performance in noisy environments. It is evaluated for speech in eight-talker babble noise. The critical sparsity constraint parameter was first tuned using objective measures and then evaluated with subjective speech perception experiments for both normal hearing and CI subjects. Results from vocoder simulations with 10 normal hearing subjects showed that the algorithm significantly enhances speech intelligibility with the selected sparsity constraints. Results from eight CI subjects showed no significant overall improvement compared with the standard advanced combination encoder algorithm, but a trend toward improvement of word identification of about 10 percentage points at +15 dB signal-to-noise ratio (SNR) was observed in the eight CI subjects. Additionally, a considerable reduction of the spread of speech perception performance from 40% to 93% for advanced combination encoder to 80% to 100% for the suggested NMF coding strategy was observed.
Comparing Binaural Pre-processing Strategies I
Authors: Baumgärtel Regina M. , Krawczyk-Becker Martin , Marquardt Daniel , Völker Christoph , Hu Hongmei , Herzke Tobias , Coleman Graham , Adiloğlu Kamil , Ernst Stephan M. A. , Gerkmann Timo , Doclo Simon , Kollmeier Birger , Hohmann Volker , Dietz Mathias
Published: January 2016

In a collaborative research project, several monaural and binaural noise reduction algorithms have been comprehensively evaluated. In this article, eight selected noise reduction algorithms were assessed using instrumental measures, with a focus on the instrumental evaluation of speech intelligibility. Four distinct, reverberant scenarios were created to reflect everyday listening situations: a stationary speech-shaped noise, a multitalker babble noise, a single interfering talker, and a realistic cafeteria noise. Three instrumental measures were employed to assess predicted speech intelligibility and predicted sound quality: the intelligibility-weighted signal-to-noise ratio, the short-time objective intelligibility measure, and the perceptual evaluation of speech quality. The results show substantial improvements in predicted speech intelligibility as well as sound quality for the proposed algorithms. The evaluated coherence-based noise reduction algorithm was able to provide improvements in predicted audio signal quality. For the tested single-channel noise reduction algorithm, improvements in intelligibility-weighted signal-to-noise ratio were observed in all but the nonstationary cafeteria ambient noise scenario. Binaural minimum variance distortionless response beamforming algorithms performed particularly well in all noise scenarios.
Comparing Binaural Pre-processing Strategies II
Authors: Baumgärtel Regina M. , Hu Hongmei , Krawczyk-Becker Martin , Marquardt Daniel , Herzke Tobias , Coleman Graham , Adiloğlu Kamil , Bomke Katrin , Plotz Karsten , Gerkmann Timo , Doclo Simon , Kollmeier Birger , Hohmann Volker , Dietz Mathias
Published: January 2016

Several binaural audio signal enhancement algorithms were evaluated with respect to their potential to improve speech intelligibility in noise for users of bilateral cochlear implants (CIs). 50% speech reception thresholds (SRT50) were assessed using an adaptive procedure in three distinct, realistic noise scenarios. All scenarios were highly nonstationary, complex, and included a significant amount of reverberation. Other aspects, such as the perfectly frontal target position, were idealized laboratory settings, allowing the algorithms to perform better than in corresponding real-world conditions. Eight bilaterally implanted CI users, wearing devices from three manufacturers, participated in the study. In all noise conditions, a substantial improvement in SRT50 compared to the unprocessed signal was observed for most of the algorithms tested, with the largest improvements generally provided by binaural minimum variance distortionless response (MVDR) beamforming algorithms. The largest overall improvement in speech intelligibility was achieved by an adaptive binaural MVDR in a spatially separated, single competing talker noise scenario. A no-pre-processing condition and adaptive differential microphones without a binaural link served as the two baseline conditions. SRT50 improvements provided by the binaural MVDR beamformers surpassed the performance of the adaptive differential microphones in most cases. Speech intelligibility improvements predicted by instrumental measures were shown to account for some but not all aspects of the perceptually obtained SRT50 improvements measured in bilaterally implanted CI users.
Comparing Binaural Pre-processing Strategies III
Authors: Völker Christoph , Warzybok Anna , Ernst Stephan M. A.
Published: January 2016

A comprehensive evaluation of eight signal pre-processing strategies, including directional microphones, coherence filters, single-channel noise reduction, binaural beamformers, and their combinations, was undertaken with normal-hearing (NH) and hearing-impaired (HI) listeners. Speech reception thresholds (SRTs) were measured in three noise scenarios (multitalker babble, cafeteria noise, and single competing talker). Predictions of three common instrumental measures were compared with the general perceptual benefit caused by the algorithms. The individual SRTs measured without pre-processing and individual benefits were objectively estimated using the binaural speech intelligibility model. Ten listeners with NH and 12 HI listeners participated. The participants varied in age and pure-tone threshold levels. Although HI listeners required a better signal-to-noise ratio to obtain 50% intelligibility than listeners with NH, no differences in SRT benefit from the different algorithms were found between the two groups. With the exception of single-channel noise reduction, all algorithms showed an improvement in SRT of between 2.1 dB (in cafeteria noise) and 4.8 dB (in single competing talker condition). Model predictions with binaural speech intelligibility model explained 83% of the measured variance of the individual SRTs in the no pre-processing condition. Regarding the benefit from the algorithms, the instrumental measures were not able to predict the perceptual data in all tested noise conditions. The comparable benefit observed for both groups suggests a possible application of noise reduction schemes for listeners with different hearing status. Although the model can predict the individual SRTs without pre-processing, further development is necessary to predict the benefits obtained from the algorithms at an individual level.
A Binaural CI Research Platform for Oticon Medical SP/XP Implants Enabling ITD/ILD and Variable Rate Processing
Authors: Backus B. , Adiloğlu K. , Herzke T.
Published: January 2016

We present the first portable, binaural, real-time research platform compatible with Oticon Medical SP and XP generation cochlear implants. The platform consists of (a) a pair of behind-the-ear devices, each containing front and rear calibrated microphones, (b) a four-channel USB analog-to-digital converter, (c) real-time PC-based sound processing software called the Master Hearing Aid, and (d) USB-connected hardware and output coils capable of driving two implants simultaneously. The platform is capable of processing signals from the four microphones simultaneously and producing synchronized binaural cochlear implant outputs that drive two (bilaterally implanted) SP or XP implants. Both audio signal preprocessing algorithms (such as binaural beamforming) and novel binaural stimulation strategies (within the implant limitations) can be programmed by researchers. When the whole research platform is combined with Oticon Medical SP implants, interaural electrode timing can be controlled on individual electrodes to within ±1 µs and interaural electrode energy differences can be controlled to within ±2%. Hence, this new platform is particularly well suited to performing experiments related to interaural time differences in combination with interaural level differences in real-time. The platform also supports instantaneously variable stimulation rates and thereby enables investigations such as the effect of changing the stimulation rate on pitch perception. Because the processing can be changed on the fly, researchers can use this platform to study perceptual changes resulting from different processing strategies acutely.
A Binaural Steering Beamformer System for Enhancing a Moving Speech Source
Authors: Adiloğlu Kamil , Kayser Hendrik , Baumgärtel Regina M. , Rennebeck Sanja , Dietz Mathias , Hohmann Volker
Published: January 2016

In many daily life communication situations, several sound sources are simultaneously active. While normal-hearing listeners can easily distinguish the target sound source from interfering sound sources—as long as target and interferers are spatially or spectrally separated—and concentrate on the target, hearing-impaired listeners and cochlear implant users have difficulties in making such a distinction. In this article, we propose a binaural approach composed of a spatial filter controlled by a direction-of-arrival estimator to track and enhance a moving target sound. This approach was implemented on a real-time signal processing platform enabling experiments with test subjects in situ. To evaluate the proposed method, a data set of sound signals with a single moving sound source in an anechoic diffuse noise environment was generated using virtual acoustics. The proposed steering method was compared with a fixed (nonsteering) method that enhances sound from the frontal direction in an objective evaluation and subjective experiments using this database. In both cases, the obtained results indicated a significant improvement in speech intelligibility and quality compared with the unprocessed signal. Furthermore, the proposed method outperformed the nonsteering method.
A Comparison of Two Objective Measures of Binaural Processing
Authors: Haywood Nicholas R. , Undurraga Jaime A. , Marquardt Torsten , McAlpine David
Published: January 2016

There has been continued interest in clinical objective measures of binaural processing. One commonly proposed measure is the binaural interaction component (BIC), which is obtained typically by recording auditory brainstem responses (ABRs)—the BIC reflects the difference between the binaural ABR and the sum of the monaural ABRs (i.e., binaural − (left + right)). We have recently developed an alternative, direct measure of sensitivity to interaural time differences, namely, a following response to modulations in interaural phase difference (the interaural phase modulation following response; IPM-FR). To obtain this measure, an ongoing diotically amplitude-modulated signal is presented, and the interaural phase difference of the carrier is switched periodically at minima in the modulation cycle. Such periodic modulations to interaural phase difference can evoke a steady state following response. BIC and IPM-FR measurements were compared from 10 normal-hearing subjects using a 16-channel electroencephalographic system. Both ABRs and IPM-FRs were observed most clearly from similar electrode locations—differential recordings taken from electrodes near the ear (e.g., mastoid) in reference to a vertex electrode (Cz). Although all subjects displayed clear ABRs, the BIC was not reliably observed. In contrast, the IPM-FR typically elicited a robust and significant response. In addition, the IPM-FR measure required a considerably shorter recording session. As the IPM-FR magnitude varied with interaural phase difference modulation depth, it could potentially serve as a correlate of perceptual salience. Overall, the IPM-FR appears a more suitable clinical measure than the BIC.
Sensitivity to Envelope Interaural Time Differences at High Modulation Rates
Authors: Monaghan Jessica J. M. , Bleeck Stefan , McAlpine David
Published: January 2016

Sensitivity to interaural time differences (ITDs) conveyed in the temporal fine structure of low-frequency tones and the modulated envelopes of high-frequency sounds are considered comparable, particularly for envelopes shaped to transmit similar fidelity of temporal information normally present for low-frequency sounds. Nevertheless, discrimination performance for envelope modulation rates above a few hundred Hertz is reported to be poor—to the point of discrimination thresholds being unattainable—compared with the much higher (>1,000 Hz) limit for low-frequency ITD sensitivity, suggesting the presence of a low-pass filter in the envelope domain. Further, performance for identical modulation rates appears to decline with increasing carrier frequency, supporting the view that the low-pass characteristics observed for envelope ITD processing is carrier-frequency dependent. Here, we assessed listeners’ sensitivity to ITDs conveyed in pure tones and in the modulated envelopes of high-frequency tones. ITD discrimination for the modulated high-frequency tones was measured as a function of both modulation rate and carrier frequency. Some well-trained listeners appear able to discriminate ITDs extremely well, even at modulation rates well beyond 500 Hz, for 4-kHz carriers. For one listener, thresholds were even obtained for a modulation rate of 800 Hz. The highest modulation rate for which thresholds could be obtained declined with increasing carrier frequency for all listeners. At 10 kHz, the highest modulation rate at which thresholds could be obtained was 600 Hz. The upper limit of sensitivity to ITDs conveyed in the envelope of high-frequency modulated sounds appears to be higher than previously considered.
Simultaneous Assessment of Speech Identification and Spatial Discrimination
Authors: Bizley Jennifer K. , Elliott Naomi , Wood Katherine C. , Vickers Deborah A.
Published: January 2016

With increasing numbers of children and adults receiving bilateral cochlear implants, there is an urgent need for assessment tools that enable testing of binaural hearing abilities. Current test batteries are either limited in scope or are of an impractical duration for routine testing. Here, we report a behavioral test that enables combined testing of speech identification and spatial discrimination in noise. In this task, multitalker babble was presented from all speakers, and pairs of speech tokens were sequentially presented from two adjacent speakers. Listeners were required to identify both words from a closed set of four possibilities and to determine whether the second token was presented to the left or right of the first. In Experiment 1, normal-hearing adult listeners were tested at 15° intervals throughout the frontal hemifield. Listeners showed highest spatial discrimination performance in and around the frontal midline, with a decline at more eccentric locations. In contrast, speech identification abilities were least accurate near the midline and showed an improvement in performance at more lateral locations. In Experiment 2, normal-hearing listeners were assessed using a restricted range of speaker locations designed to match those found in clinical testing environments. Here, speakers were separated by 15° around the midline and 30° at more lateral locations. This resulted in a similar pattern of behavioral results as in Experiment 1. We conclude, this test offers the potential to assess both spatial discrimination and the ability to use spatial information for unmasking in clinical populations.
Reducing Current Spread by Use of a Novel Pulse Shape for Electrical Stimulation of the Auditory Nerve
Authors: Ballestero Jimena , Recugnat Matthieu , Laudanski Jonathan , Smith Katie E. , Jagger Daniel J. , Gnansia Daniel , McAlpine David
Published: January 2016

Improving the electrode-neuron interface to reduce current spread between individual electrodes has been identified as one of the main objectives in the search for future improvements in cochlear-implant performance. Here, we address this problem by presenting a novel stimulation strategy that takes account of the biophysical properties of the auditory neurons (spiral ganglion neurons, SGNs) stimulated in electrical hearing. This new strategy employs a ramped pulse shape, where the maximum amplitude is achieved through a linear slope in the injected current. We present the theoretical framework that supports this new strategy and that suggests it will improve the modulation of SGNs’ activity by exploiting their sensitivity to the rising slope of current pulses. The theoretical consequence of this sensitivity to the slope is a reduction in the spread of excitation within the cochlea and, consequently, an increase in the neural dynamic range. To explore the impact of the novel stimulation method on neural activity, we performed in vitro recordings of SGNs in culture. We show that the stimulus efficacy required to evoke action potentials in SGNs falls as the stimulus slope decreases. This work lays the foundation for a novel, and more biomimetic, stimulation strategy with considerable potential for implementation in cochlear-implant technology.
Advancing Binaural Cochlear Implant Technology
Authors: Dietz Mathias , McAlpine David
Published: January 2016

This special issue contains a collection of 13 papers highlighting the collaborative research and engineering project entitled Advancing Binaural Cochlear Implant Technology—ABCIT—as well as research spin-offs from the project. In this introductory editorial, a brief history of the project is provided, alongside an overview of the studies.
Effective supervision of inland capture fisheries of Bangladesh and its hurdles in managing the resources
Authors: Firoz Khan A. K. M. , Mustafa M. G. , Niamul Naser M.
Published: January 2016

Community-based approaches have gained significant attention in inland open water fisheries management in Bangladesh. This article focuses on the challenges and opportunities of the inland open water fishery resources under community-based management approaches. The present study employed management information of waterbodies between 1991 and 2014 across a range of geographical locations and habitats. The study reveals that coordinated management of water bodies is essential given common management issues of waterbodies. Present study also reveals that complexity of different property rights and the diversity of users within individual clusters have had cumulatively adverse effects on fisheries. The study shows that different fisheries management policies promoted by the government of Bangladesh over time to have varied in strength and appropriateness. This study concludes that open water fisheries management through fishers’ community involvement is promising approach in Bangladesh but a variety of socio-economic factors that affect the governance in its implementation.
'Shhh! Please don't tell…’ Confidentiality in child and adolescent mental health
Authors: Vallance Aaron K.
Published: January 2016

Confidentiality in child and adolescent mental health is a complex and often challenging matter. Not only do young people frequently present to services in situations of risk, they often prefer to keep information confidential from parents and/or other professionals. This article explores confidentiality in the context of child and adolescent mental health services (CAMHS), particularly when the clinician is having to make decisions on whether to maintain or to breach it. Ethical principles (both deontological and consequentialist) and legal and regulatory frameworks (relating to human rights, case law and General Medical Council guidance) are outlined. Four hypothetical case scenarios are used to illustrate how to apply such principles: when a young person seeks confidential access to treatment, and when he or she discloses information that could signify a risk to self, to others or from others. Finally, practical suggestions on how to share information are explored.
Therapeutic applications of mindfulness in paediatric settings
Authors: Carona Carlos , Moreira Helena , Silva Neuza
Published: January 2016

Mindfulness is a meditation practice defined as a specific way of paying attention. It has been adapted from Buddhist traditions to Western secular use (e.g. in stress reduction, health promotion, treatment of psychological disorders). Despite its widespread application in adult populations, mindfulness remains a neglected topic in the psychological interventions designed for children and adolescents with psychological disorders and/or chronic physical conditions. In paediatric settings, a parent-child perspective may be useful in facilitating processes of adaptation and in improving paediatric outcomes. However, the delivery of mindfulness interventions in paediatric settings raises a number of issues and challenges, which include the developmental appropriateness of mindfulness exercises, the introduction of a parent-child perspective, and specific considerations to condition, treatment and caregiving.
Villification in the mouse: Bmp signals control intestinal villus patterning
Authors: Walton Katherine D. , Whidden Mark , Kolterud Åsa , Shoffner Suzanne , Czerwinski Michael J. , Kushwaha Juhi , Parmar Nishita , Chandhrasekhar Deepa , Freddo Andrew M. , Schnell Santiago , Gumucio Deborah L.
Published: January 2016

In the intestine, finger-like villi provide abundant surface area for nutrient absorption. During murine villus development, epithelial Hedgehog signals promote aggregation of sub-epithelial mesenchymal clusters that drive villus emergence. Clusters arise first dorsally and proximally and spread over the entire intestine within 24-hours, but the mechanism driving this pattern in the murine intestine is unknown. In the chick, the driver of cluster pattern is tensile force from developing smooth muscle, which generates deep longitudinal epithelial folds that locally concentrate the Hh signal, promoting localized expression of cluster genes. In contrast, we show that in the mouse, muscle-induced epithelial folding does not occur and artificial deformation of the epithelium does not determine the pattern of clusters or villi. In intestinal explants, modulation of Bmp signaling alters the spatial distribution of clusters and changes the pattern of emerging villi. Increasing Bmp signaling abolishes cluster formation while inhibiting Bmp signaling leads to merged clusters. These dynamic changes in cluster pattern are faithfully simulated by a mathematical model of a Turing field in which an inhibitor of Bmp signaling acts as the Turing activator. In vivo, genetic interruption of Bmp signal reception in either epithelium or mesenchyme reveals that Bmp signaling in Hh-responsive mesenchymal cells controls cluster pattern. Thus, unlike the chick, the murine villus patterning system is independent of muscle-induced epithelial deformation. Rather, a complex cocktail of Bmps and Bmp signal modulators secreted from mesenchymal clusters determines the pattern of villi in a manner that mimics the spread of a self-organizing Turing field.
Use of a genetically engineered mouse model as a preclinical tool for HER2 breast cancer
Authors: Creedon Helen , Balderstone Lucy A , Muir Morwenna , Balla Jozef , Gomez-Cuadrado Laura , Tracey Natasha , Loane Joseph , Klinowska Teresa , Muller William J , Brunton Valerie G
Published: January 2016

Resistance to HER2 targeted therapies presents a major clinical problem. Although preclinical studies have identified a number of possible mechanisms clinical validation has been difficult. This most likely reflects the reliance on cell line models that do not recapitulate the complexity and heterogeneity seen in human tumours. Here we show the utility of a genetically engineered mouse model of HER2 driven breast cancer (MMTV-NIC) to define mechanisms of resistance to the pan-HER family inhibitor AZD8931. Genetic manipulation of MMTV-NIC mice demonstrated that loss of PTEN conferred de novo resistance to AZD8931, while a tumour fragment transplantation model was established to assess mechanisms of acquired resistance. Using this approach 50% of tumours developed resistance to AZD8931. Analysis of the resistant tumours showed two distinct patterns of resistance: tumours in which reduced membranous HER2 expression was associated with an epithelial-to-mesenchymal transition (EMT) and resistant tumours that retained HER2 expression and an epithelial morphology. The plasticity of the EMT phenotype was demonstrated upon re-implantation of resistant tumours that then showed a mixed epithelial and mesenchymal phenotype. Further AZD8931 treatment resulted in the generation of secondary resistant tumours that again had either undergone EMT or had retained their original epithelial morphology. The data provide a strong rationale for basing therapeutic decisions on the biology of the individual resistant tumour, which may be very different from that of the primary tumour and will be specific to individual patients.
Machine learning models identify molecules active against the Ebola virus in vitro
Authors: Ekins Sean , Freundlich Joel S. , Clark Alex M. , Anantpadma Manu , Davey Robert A. , Madrid Peter
Published: January 2016

The search for small molecule inhibitors of Ebola virus (EBOV) has led to several high throughput screens over the past 3 years. These have identified a range of FDA-approved active pharmaceutical ingredients (APIs) with anti-EBOV activity in vitro and several of which are also active in a mouse infection model. There are millions of additional commercially-available molecules that could be screened for potential activities as anti-EBOV compounds. One way to prioritize compounds for testing is to generate computational models based on the high throughput screening data and then virtually screen compound libraries. In the current study, we have generated Bayesian machine learning models with viral pseudotype entry assay and the EBOV replication assay data. We have validated the models internally and externally. We have also used these models to computationally score the MicroSource library of drugs to select those likely to be potential inhibitors. Three of the highest scoring molecules that were not in the model training sets, quinacrine, pyronaridine and tilorone, were tested in vitro and had EC50 values of 350, 420 and 230 nM, respectively. Pyronaridine is a component of a combination therapy for malaria that was recently approved by the European Medicines Agency, which may make it more readily accessible for clinical testing. Like other known antimalarial drugs active against EBOV, it shares the 4-aminoquinoline scaffold. Tilorone, is an investigational antiviral agent that has shown a broad array of biological activities including cell growth inhibition in cancer cells, antifibrotic properties, α7 nicotinic receptor agonist activity, radioprotective activity and activation of hypoxia inducible factor-1. Quinacrine is an antimalarial but also has use as an anthelmintic. Our results suggest data sets with less than 1,000 molecules can produce validated machine learning models that can in turn be utilized to identify novel EBOV inhibitors in vitro.
A pocket guide to electronic laboratory notebooks in the academic life sciences
Authors: Dirnagl Ulrich , Przesdzing Ingo
Published: January 2016

Every professional doing active research in the life sciences is required to keep a laboratory notebook. However, while science has changed dramatically over the last centuries, laboratory notebooks have remained essentially unchanged since pre-modern science. We argue that the implementation of electronic laboratory notebooks (eLN) in academic research is overdue, and we provide researchers and their institutions with the background and practical knowledge to select and initiate the implementation of an eLN in their laboratories. In addition, we present data from surveying biomedical researchers and technicians regarding which hypothetical features and functionalities they hope to see implemented in an eLN, and which ones they regard as less important. We also present data on acceptance and satisfaction of those who have recently switched from paper laboratory notebook to an eLN.  We thus provide answers to the following questions: What does an electronic laboratory notebook afford a biomedical researcher, what does it require, and how should one go about implementing it?
Prosthodontic Management of Children with Hypohidrotic Ectodermal Dysplasia: Case Reports and a Review of the Literature
Authors: Maatouk Fethi , Afia Imene Ben , Masmoudi Fatma , Laribi Wafa , Ghedira Hichem
Published: January 2016

Hypohidrotic Ectodermal Dysplasia (HED) is a hereditary syndrome characterized by congenital defects in ectodermally derived structures as teeth, hair, skin and nails. Dental manifestations include abnormalities of form and number (hypodontia or anodontia) with subsequent aesthetic, psychological and functional consequences.
Objectives: The purpose of this paper was to show through cases report that dental management help to improve the patient’s quality of life and to optimize their social integration.
Methods: Two clinical cases about a boy and a girl, 8 and 6 years old respectively, with HED were exposed. They had a senile facial expression and presented a hypodontia with smooth dry skin, a hypotrichosis and an onychodystrophy.
Management: After clinical and radiographic examination, a prosthetic rehabilitation was planned. Instructions on denture wear, hygiene and maintenance were given.
Conclusion: In children with HED, an early oral management is essential because it gives a psychological boost and enhances conditions for normal growth and orofacial development. A close medical and psychological follow-up is needed.
A Complication of the Use of Fiber-Reinforced Ribbon-Composite Provisional Fixed Partial Denture in an Adolescent Patient
Authors: Tuncer Duygu , Arhun Neslihan , Halacoglu Derya Merve , Oglakci Burcu
Published: January 2016

Treatment of adolescent patients with a missing incisor may be compromising because implants cannot be placed until craniofacial growth is complete. Fiber reinforced ribbon-composite fixed provisional partial dentures can be used for the replacement of the missing teeth. Since the craniofacial growth continues transverse, sagittal and vertical directions, regular control appointments must be managed to check the alveolar ridge/gingival level in the pontic area. This case report describes a clinical complication fiber reinforced ribbon-composite fixed provisional partial denture of an adolescent patient with a trauma originated missing incisor. A 14 years old male patient who had attended to Baskent University in 2010, had a traumatic dental injury in #21 tooth which was extracted. The missing tooth was replaced with a fiber reinforced ribbon-composite fixed provisional partial denture with patient’s tooth as pontic until the definitive implant supported single-tooth prosthetic rehabilitation and the family was asked to visit regularly every six months. The patient didn’t attend to the control appointments until the provisional denture’s failure and the harmony between pontic tooth and the alveolar ridge/gingiva was severely compromised after 4 years. If the goals of treatment planning favors fiber reinforced ribbon-composite fixed provisional partial denture use before skeletal maturation, attention must be given to prosthesis design. Regular control appointments of alveolar ridge and pontic design must be managed and pontic tooth must be re-shaped to accommodate physiological soft and hard tissues in accordance with the skeletal growth to ensure esthetic future single implant supported prosthetic rehabilitation without any need for further augmentation surgeries.
Bone Density Evaluation In Vivo after Installation of Implants Using an Osteotome Technique: Case Report
Authors: Santagata Mario , Rienzo Domenico , D’Amato Salvatore , Tartaro Gianpaolo , Tozzi Umberto
Published: January 2016

The aim of our study was to evaluate bone density before and after implant placement by the osteotome technique in vivo and human posterior maxilla.
Patient treated with implants placement in position of right upper canine and right first upper premolar by osteotome technique. Radiological evaluation by CBCT was performed before and 4 months after surgery.
The results showed that osteotome technique achieved a significant increase in bone density in area of right upper canine but there was not increase in area right first upper premolar. According to our results, the osteotome technique is the best choice for implant placement in posterior maxilla but only when a low bone density is present.
A Systematic Review of Bone Anti-Resorptive Treatment Toxicity in Innate and Adaptive Immunity Cells: Osteonecrosis of the Jaws and Future Implications
Authors: Kyrgidis Athanassios , Yavropoulou Maria , Tilaveridis Ioannis , Andreadis Charalambos , Antoniades Konstantinos , Kouvelas Dimitrios
Published: January 2016

Introduction: Bone anti-resorptive agents, namely bisphosphonates and denosumab are widely prescribed for the prevention of osteoporosis fractures and of cancer-related skeletal events. Osteonecrosis of the jaws (ONJ) has been reported for both drug categories. These agents have anti-proliferative effects in osteoclasts. We argue that because osteoclasts share their progenitor cells with macrophages, ONJ could be the result of reduced numbers and function of macrophages.
Methods: We systematically searched MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) from inception through September 2014, for studies reporting the effects of bone-antiresorptive agents in the innate and adapted immunity. No limitations pertaining to study type were set.
Results: Periosteal and endosteal tissues contain a discrete population of resident tissue macrophages. BPs cause apoptosis of macrophages in a dose and agent dependent manner. Increased cytotoxic activity by the γδ T cell population, could induce macrophage cell death causing local immune deficiency. Upon apoptotic stimuli, zoledronatepre-treated macrophages exhibit a significantly greater apoptotic rate. Long term BP exposed monocytes and macrophages may lead to functional impairment and reduced numbers of monocytic cells.
Conclusions: Bone-anti-resorptive agents have the capacity of both functionally impairing and reducing the macrophage population. The currently available limited evidence suggests a plausible role of these agents in the pathogenesis of ONJ. Future studies both clinical and experimental should focus on the effects of these drugs in immune homeostasis.
Bioindicator beetles and plants in desertified and eroded lands in Turkey
Authors: Korotyaev Boris A. , Gültekin Levent , Volkovitsh Mark G. , Dorofeyev Vladimir I. , Konstantinov Alexander S.
Published: January 2016

The xerophilous vegetation with characteristic insect assemblages is described in the main agricultural regions and native landscapes of Turkey. Long term intensive investigations documented vast biotic degradation of soil and vegetation (commonly referred to as desertification) by overgrazing, construction, recreation etc. Two main types of xeric landscape are under investigation: 1) natural highly specific deserts, semi-deserts, dry mountain slopes and screes; and 2) anthropogenic, newly emerged, floristically impoverished desertified areas. The presence of a multi-species insect assemblage on a xerophilous plant in certain area testifies its indigenous nature, whereas the absence of the specific consortium suggests recent plant invasion. The examples of the first case are the consortia of 3–6 species of Coleoptera, mainly Buprestidae, Chrysomelidae, and Curculionoidea, on some Apiaceae, Asteraceae, Brassicaceae, Chenopodiaceae, Ephedraceae (Ephedra spp.) and Polygonaceae (Calligonum polygonoides L.). Extreme examples of anthropogenic vegetation are overgrazed wormwood steppe and semidesert which lack usually diversified coleopterous consortia, including the most characteristic of this landscape, e.g., tenebrionids, and orthopterans. Rapid disappearance of the xerophilous complexes from the extraordinarily diversified and largely uninventoried Turkish biota makes preservation of the endangered plant and animal assemblages in different climatic zones of Turkey an urgent task.
Increased Baseline C-Reactive Protein Concentrations Are Associated with Increased Risk of Infections: Results from 2 Large Danish Population Cohorts
Authors: Zacho Jeppe , Benfield Thomas , Tybjærg-Hansen Anne , Nordestgaard Børge G
Published: January 2016

BACKGROUND

The acute-phase reactant C-reactive protein (CRP) increases rapidly during an infection. We tested the hypothesis that chronic low-level increases in CRP are associated with an increased risk of infectious disease.

METHODS

We studied 9660 individuals from a prospective general population cohort, including 3592 in whom infectious disease developed, and another 60 896 individuals from a cross-sectional general population study, of whom 13 332 developed infectious disease; 55% were women, and the mean age was 57 years. Hospital diagnoses of infections in 1977–2010 were based on International Classification of Diseases–coded discharge records from the national Danish Patient Registry. We measured CRP concentrations and conducted genotyping for 4 CRP polymorphisms that increase CRP. Individuals with CRP >10 mg/L were excluded because of possible ongoing infection at the time of testing.

RESULTS

Individuals with CRP >3 mg/L had 1.2 and 1.7 times increased risk of infectious disease, in the prospective general population cohort and the cross-sectional general population study, respectively, compared with individuals with CRP <1 mg/L. In the combined populations, individuals in the highest CRP tertile (compared with the lowest) had an increased risk of bacterial diseases (hazard ratio 1.7, 95% CI 1.6–1.8), but not viral, mycosis, and parasitic diseases. The increased risk was mainly carried by pneumonia, sepsis, and particularly gram-negative infections. None of the genotype combinations examined conferred an increased risk of infectious disease.

CONCLUSIONS

Chronic low-level CRP increases were associated with increased risk of bacterial infections, gram-negative infections in particular. Genotypes associated with increases in CRP were not associated with increased risk of infection.
Empty Architecture and Empty Urbanism: the Remaking and Reframing on Contemporary Beijing
Authors: Ho-yin Fong Ian
Published: January 2016

The paper discusses a collage and montage understanding of modernity and argues that Beijing offers a contemporary simulacrum of the global system of sign values that is epitomized by the new CCTV headquarters and more directly mirrored in the Beijing World Park. In reading Beijing this way, the paper suggests that the city, as well as the global audience to which its spectacle architecture is addressed, is suffering an identity crisis in which our built environment has been reduced to series of signs. It discusses the architecture of the CCTV headquarters, then Beijing World Park as the miniature of Beijing, and finally how the slogan of Beijing Olympics 2008, “One World! One Dream!”, helps to read the contemporary architecture in Beijing as a symbol of the city’s – and through the city, the government’s – view of itself as a new world leader. It begins by placing this argument in a particular social, political, and economic framework – the attempts of the current Chinese authorities to position the Chinese economy, and its major cities, at the heart of the contemporary capitalist economy. These attempts, it is suggested, involve a more or less literal attempt to outstrip the city which throughout the twentieth century epitomized that system, New York.
The value of patient-reported outcomes in patients with type 2 diabetes mellitus receiving insulin therapy: assessment of quality of life and hypoglycemia problems
Authors: Ionova Tat'yana Ivanovna , Odin Vitaliy Ivanovich , Nikitina Tat'yana Pavlovna , Kurbatova Kira Aleksandrovna
Published: January 2016

Aim. To study quality of life (QoL) and hypoglycaemic symptoms in patients with type 2 diabetes receiving intensive insulin therapy.Materials and methods. One thousand patients with type 2 diabetes receiving intensive insulin therapy for at least 6 months were enrolled in this multicenter observational study. The mean age of patients was 61.1 years (range, 29–84 years) and the male/female ratio was 265/735. All patients completed the SF-36® questionnaire and the Comprehensive Symptom Profile-Diabetes Mellitus Hypoglycemia Module. For group comparisons, we used unpaired t-tests or Mann–Whitney tests and general linear models. To compare categorical variables, the χ2 test and Fisher’s exact test were used.Results. The patients with type 2 diabetes receiving intensive insulin therapy demonstrated heterogeneity in terms of QoL. More than half of the patients had mild QoL impartment while nearly one third experienced significant QoL impairment. The following factors had the most pronounced negative impact on QoL: late diabetic complications, concomitant diseases, poor glycemic control and type of hypoglycaemia. QoL parameters were lower in patients with hypoglycaemic episodes than in those without (p 0.01), but in patients with mild hypoglycaemia it was similar to those without. The most pronounced disturbances in QoL occurred in patients with severe and nocturnal hypoglycaemia (p 0.05). The hypoglycaemic symptoms with the greatest burden on QoL were dizziness, morning weakness, eye problems, nightmares or crying out during sleep, distress, loss of energy and sleep disturbances. Correlation between the severity of fear of hypoglycaemia and QoL was also demonstrated. Higher the fear of hypoglycaemia, the more impaired was social functioning, mental health, vitality and general health.Conclusion. Assessment of QoL and hypoglycaemic symptoms in patients with type 2 diabetes receiving intensive insulin therapy reveals the need for a patient-centred approach in treatment and for a comprehensive evaluation of treatment outcomes.
A review of mortality in type 2 diabetes mellitus
Authors: Asfandiyarova Nailya Sayfullaevna
Published: January 2016

The morbidity and mortality associated with type 2 diabetes have increased over recent years. The causes of death include cardiovascular disease, cancer, infection, kidney disease and diabetic coma. Risk factors for death are a sedentary lifestyle, obesity, smoking, sex, age, duration and severity of diabetes, macro- and microvascular complications and hyper- and hypoglycaemic states. Adequate glycemic control and moderate exercise along with the use of antiplatelet agents (e.g. aspirin), statins, antihypertensives and metformin can reduce mortality. Intensive glucose control was associated with an increased risk of severe hypoglycaemia and death, and surgical intervention increased the risk of death.
The works of professor N.P. Kravkov in the area of endocrinology
Authors: Uzbekova Dinora Galievna
Published: January 2016

This article describes the academic works of the N.P. Kravkov (1865–1924), a prominent Russian pharmacologist, on the study of the endocrine glands.In N.P. Kravkov’s laboratory, via experiments on rabbits and dogs, a method of isolating the pancreas and extracting its perfusate was developed based on passing Ringer-Locke’s solution through the vessels of the isolated gland. It was discovered that the perfusate contains a substance that reduces the level of glucose in the blood of healthy animals and, in large doses, causes hypoglycaemic coma. N.P. Kravkov called this substance pancreotoxin.The experiments of N.P. Kravkov’s followers on the isolated hearts of animals showed that, for a heart in the normal condition, pancreotoxin decelerates the heartbeat and reduces the amplitude of contractions, whereas for the heart tired above a certain threshold, the opposite effect is observed.The study of the blood vessels in isolated ears of rabbits and the eyes of frogs revealed antagonism between pancreotoxin and adrenalin: pancreotoxin weakens the vasoconstrictive effect of adrenalin and reduces its influence on the size of the pupil in frogs. It was also shown that passing the perfusate containing pancreotoxin through the adrenal gland increases the secretion of adrenalin.Later, pancreotoxin was obtained in the dried form and used to prepare a drug prescribed to patients with diabetes in hospitals.From its properties, pancreotoxin turned out to be insulin. It should be noted that the news that insulin had been isolated from the pancreas by the Canadian researchers F. Banting and C. Best reached Russia only after the researchers in N.P. Kravkov’s laboratory had extracted and studied pancreotoxin from isolated pancreases. Thus, N.P. Kravkov and foreign researchers discovered this hormone independently.In experiments on the isolated adrenal glands of cattle, N.P. Kravkov and his collaborators obtained the perfusate containing an adrenalin-like substance produced in the medulla of the adrenal gland and a muscarine-like substance produced by the suprarenal cortex.The research by N.P. Kravkov and his followers on the physiology, pathology and pharmacology of the glands of internal secretion at the beginning of the 20th century has proved to be of great importance for the development of endocrinology in Russia.
Analysis of the central zone of the retina in patients with diabetic macular edema
Authors: Bikbov Mukharram Muhtaramovich , Fayzrakhmanov Rinat Rustamovich , Yarmuhametova Alia Linarovna , Zainullin Rinat Mukhametovich
Published: January 2016

Aim. To assess morphological changes of retinal layers and optical density of macular pigment in patients with diabetic macular edema (DME) for the diagnostic criterion of pathological process.Materials and methods. 31 patients were divided in two groups. The first group (A) included 19 patients with DME (20 eyes), the second group (B) – 12 patients (20 eyes) without retinal pathology. Both groups were comparable with regard to age. Parameter estimation was conducted with the use of following methods: optical coherence tomography (OCT) of the macular area of the retina; fundus photography with the measurement of macular pigment optical density (MPOD); microperimetry.Results. OCT analysis showed that the inner nuclear and plexiform layers of retina were the most involved in pathological process and revealed significant differences in increase of mean retinal thickness in comparison with the control group. Analysis of MPOD revealed a significant reduction of all parameters in group A compared with the control group. On the basis of microperimetry of the central area of retina in group A light sensitivity indicators were reduced by an average of 9 dB and equaled 9.85 ± 0.09 dB. The analysis showed gross violations of retinal structure and distribution of optical density of macular pigment in patients with DME. Correlation analysis of retinal thickness, functional light sensitivity and optical density of macular pigment traced a strong connection (r = -0.93; p 0.05) between the indices of retinal thickness and MPOD.Conclusions. Diabetic macular edema showed a sharp decrease in optical density of macular pigment determined by deficiency of lutein and zeaxantin. A correlation between quantitative indicator of optical density of macular pigment and area of edema was established. Light sensitivity was significantly reduced in the central part of the retina.