Correlation of Dental Plaque Acidogenicity and Acidurance with Caries Activity – Perspectives of the Ecological Plaque Hypothesis

The ecological plaque hypothesis for the aetiopathogenesis of caries implies a microbial shift towards a more acidogenic and aciduric dental plaque microflora, due to a frequent carbohydrate intake. Certain plaque bacteria exhibit metabolic activity, at a low pH. A correlation exists between the increased numbers of some aciduric bacterial species, e.g. mutans streptococci and lactobacilli, and caries activity. The aim of this study was to study the acidogenic (lactate production / mg plaque x min., at pH 7.0) and aciduric potential (lactate production at pH 5.5 / lactate production at pH 7.0) of dental plaque in relation to the caries activity. Samples of dental plaque were collected from fifteen caries free and fifteen caries active children. Plaque suspensions in Ringer’s solution containing 1% sucrose and buffered with 0.5 M MOPS (pH 7.0) or MES (pH 5.5) were incubated aerobically at 37 ºC for 10-20 min. The production of lactic acid in the suspensions was determined by an enzymatic assay. In caries free children, significantly lower acidogenic potential at both pHs were recorded than in caries active children. The highest difference between the groups was in the acidogenic activity at neutral pH. On the contrary, the aciduric potential was lower in the caries active group than in the caries free. Caries activity correlated with the acidogenic potentials of dental plaque at both pH 7.0 and 5.5. A new perspective of the ecological plaque hypothesis based on the increased catabolic ability of plaque is proposed

Transition technologies towards 6G networks

[EN] The sixth generation (6G) mobile systems will create new markets, services, and industries making possible a plethora of new opportunities and solutions. Commercially successful rollouts will involve scaling enabling technologies, such as cloud radio access networks, virtualization, and artificial intelligence. This paper addresses the principal technologies in the transition towards next generation mobile networks. The convergence of 6G key-performance indicators along with evaluation methodologies and use cases are also addressed. Free-space optics, Terahertz systems, photonic integrated circuits, softwarization, massive multiple-input multiple-output signaling, and multi-core fibers, are among the technologies identified and discussed. Finally, some of these technologies are showcased in an experimental demonstration of a mobile fronthaul system based on millimeter 5G NR OFDM signaling compliant with 3GPP Rel. 15. The signals are generated by a bespoke 5G baseband unit and transmitted through both a 10 km prototype multi-core fiber and 4 m wireless V-band link using a pair of directional 60 GHz antennas with 10 degrees beamwidth. Results shown that the 5G and beyond fronthaul system can successfully transmit signals with both wide bandwidth (up to 800 MHz) and fully centralized signal processing. As a result, this system can support large capacity and accommodate several simultaneous users as a key candidate for next generation mobile networks. Thus, these technologies will be needed for fully integrated, heterogeneous solutions to benefit from hardware commoditization and softwarization. They will ensure the ultimate user experience, while also anticipating the quality-of-service demands that future applications and services will put on 6G networks.This work was partially funded by the blueSPACE and 5G-PHOS 5G-PPP phase 2 projects, which have received funding from the European Union's Horizon 2020 programme under Grant Agreements Number 762055 and 761989. D. PerezGalacho acknowledges the funding of the Spanish Science Ministry through the Juan de la Cierva programme.Raddo, TR.; Rommel, S.; Cimoli, B.; Vagionas, C.; Pérez-Galacho, D.; Pikasis, E.; Grivas, E.... (2021). Transition technologies towards 6G networks. EURASIP Journal on Wireless Communications and Networking. 2021(1):1-22. https://doi.org/10.1186/s13638-021-01973-91222021

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Tooth Wear Epidemiology and Its Associated Periodontal Health and Sociodemographic Factors in a Cluster of Senior Citizens in Northern Greece

Tooth wear (TW) is an irreversible and cumulative phenomenon causing aesthetic and functional compromise. Increasing wear has been associated with age, and various other factors have been reported to influence its type and/or severity both in individuals and groups. Increased TW may constitute a major future problem for the elderly. The present cross-sectional study aims at determining the prevalence of TW in senior citizens from Northern Greece and evaluating the patient-level associations between TW, periodontal condition, and sociodemographic factors. A sample of 363 dentate individuals, aged between 65 and 74 years, was considered according to the WHO guidelines for national pathfinder surveys and three different dentists examined the representative population groups from different urban and rural areas in Northern Greece. The examiners were calibrated prior to the survey, with an interexaminer agreement of over 85%. The simplified TWI, community periodontal index (CPI), attachment loss (AL), plaque index (DI), calculus index (CI), and sociodemographic factors were detected and measured. TW is very prevalent among senior citizens in Northern Greece, with males having been found to experience more wear. Age and oral health status, when measured by the periodontal indices AL, DI, and CI, are significantly combined with TW in both urban and rural areas

Tooth Wear and Periodontal Status in a Cluster of Middle-Aged Adults in Northern Greece

The present observational study aims to investigate the prevalence of tooth wear (TW) in a cluster of Northern Greek adults aged 35–44 years and, additionally, to assess any probable associations and interrelationships between TW and periodontal condition and sociodemographic factors. A cross-sectional design was embraced identically to our previous study on senior citizens. A sample of 531 individuals was considered, and they were examined according to WHO guidelines for national pathfinder surveys by three calibrated dentists-examiners in different urban and rural areas of Northern Greece. Simplified Tooth Wear Index (TWI), Community Periodontal Index (CPI), Attachment Loss (AL) and simplified Oral Hygiene Index (OHI-S) were screened and calculated in a patient-level approach. TW is quite prevalent among middle-aged adults in Northern Greece, although it remains lower compared to older age groups. All the aforementioned periodontal indices were correlated significantly with TW; moreover, a tendency was detected for there to be more tooth wear in older age participants within the specific age group, in men as compared with women, in persons with lower educational levels and in those residing in rural areas

Water Stress Effects on the Morphological, Physiological Characteristics of Maize (Zea mays L.), and on Environmental Cost

Water stress is one of the most important yield constraints on crop productivity for many crops, and especially for maize, worldwide. In addition, climate change creates new challenges for crop adaptation as water stress appears even in areas where, until recently, there was an adequate water supply. The objective of the present study was to determine the effect of water availability on the morphological and physiological characteristics of maize, and also on the environmental cost under field conditions. The lowest water treatment (ET50) reduced leaf area index, plant height, chlorophyll content, assimilation rate and gas exchange parameters, photosynthetic efficiency, and silage yield. Furthermore, mild water stress (ΕΤ70) affected the characteristics that were studied but maintained a high crop yield. Moreover, the outputs/inputs ratio and energy efficiency showed similar trends, with the highest values under ΕΤ100 treatment and the lowest under ΕΤ50 treatment in two consecutive years. Therefore, the results of this study can be used by farmers in the Mediterranean area, who can maintain or improve their crop yield using a lower amount of water when the water supply is limited, thereby contributing to reducing the impact of global climate change and maintaining crop productivity

Network planning for 802.11ad and MT-MAC 60 GHz fiber-wireless gigabit wireless local area networks over passive optical networks

© 2016 [2016 Optical Society of America.]. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited.We present a study concerning the network planning of 60 GHz gigabit wireless local area networks (WLANs) over existing passive optical network (PON) infrastructures. Two fiber-wireless configurations for gigabit WLAN network formations are investigated: i) the Radio & Fiber (R&F) approach that considers several 802.11ad access points connected to conventional gigabit passive optical network (GPON) optical network units, henceforth termed as the GPON-plus-802.11ad approach; and ii) the Radio-over-Fiber (RoF) paradigm that employs several remote access units operating under the medium-transparent MAC (MT-MAC) protocol, hence termed as the MT-MA-Cover-PON approach. Simulation-based throughput and delay results are obtained for both network scenarios, revealing the dependence of the 60 GHz enterprise network performance on several network-planning parameters such as load, traffic shape, number of optical wavelengths in the backhaul, and optical backhaul fiber length, highlighting in each case the prevailing architecture. Based on the respective findings we also study a hybrid multitier architecture, termed the GPON-plus-MT-MAC approach, that fuses the abilities of both the RoF and R&F architectures in order to optimally combine their properties and set a framework for next-generation 60 Ghz fiber-wireless networks.Peer ReviewedPostprint (author's final draft

Network planning for 802.11ad and MT-MAC 60 GHz fiber-wireless gigabit wireless local area networks over passive optical networks

© 2016 [2016 Optical Society of America.]. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited.We present a study concerning the network planning of 60 GHz gigabit wireless local area networks (WLANs) over existing passive optical network (PON) infrastructures. Two fiber-wireless configurations for gigabit WLAN network formations are investigated: i) the Radio & Fiber (R&F) approach that considers several 802.11ad access points connected to conventional gigabit passive optical network (GPON) optical network units, henceforth termed as the GPON-plus-802.11ad approach; and ii) the Radio-over-Fiber (RoF) paradigm that employs several remote access units operating under the medium-transparent MAC (MT-MAC) protocol, hence termed as the MT-MA-Cover-PON approach. Simulation-based throughput and delay results are obtained for both network scenarios, revealing the dependence of the 60 GHz enterprise network performance on several network-planning parameters such as load, traffic shape, number of optical wavelengths in the backhaul, and optical backhaul fiber length, highlighting in each case the prevailing architecture. Based on the respective findings we also study a hybrid multitier architecture, termed the GPON-plus-MT-MAC approach, that fuses the abilities of both the RoF and R&F architectures in order to optimally combine their properties and set a framework for next-generation 60 Ghz fiber-wireless networks.Peer Reviewe

Complex permittivity measurements by multi-mode microwave resonant cavity

A new method has been developed which uses a multiply resonant TE_1_0_p rectangular waveguide cavity coupled by inductive irises at each end and operating in the transmission mode to measure the complex permittivity of medium to low loss dielectric materials at all its resonant frequencies. The main advantage here is that, for e.g. in the 7GHz to 13GHz range, a cavity of length 220mm is long enough to resonate at a number of fairly evenly spaced frequencies over the dominant mode frequency range for a given waveguide size, corresponding to different p values, e.g. for p = 4 to 16, giving 13 resonant frequencies f_r_p. Insertion of a sample completely filling the cross-section of the waveguide in an appropriate position near the centre can shift the f_r_p and decrease the Q_p of all of these modes without their f_r_p becoming confused. With a pair of measurements over the frequency range by network analyzer, one on the empty cavity and one on the cavity plus sample, #epsilon#_r* can be determined at these 13 frequencies. A further practical advantage is that, for materials that have to be ground, the sample cutting and fitting in a rectangular waveguide is much easier than for circular disc samples. A fully rigorous calculation of the f_r and Q values of such a resonator with real metal walls and practical circuit coupling has not appeared in the literature, and such an analysis has not been made here, because it represents too large a step in too many aspects of the theory simultaneously. However, the differences between measured f_r and Q values of empty cavities and those calculated by the simplest standard analysis are easily detected with modem equipment, and were found to be sufficient to cause considerable uncertainty in final #epsilon#_r* values. Therefore, an approach of increasing in steps the sophistication of experiment and analysis until the differences were reduced, enough to give acceptable confidence in the #epsilon#_r* values was taken. In the course of this, new results were attained relevant to the extension of the standard theory of empty cavities to sample filled cavities, the effects of circuit coupling on wall loss or higher mode interaction on iris to iris or iris to samples and the calculation of Q_E by stored energy/external circuit dissipation. Experiments made and the results achieved over the frequency range 7GHz-13GHz on a range of medium and low loss materials characterised to varying degrees by other workers by other methods are presented and compared to those characterisations. Conclusions are drawn on the accuracy and utility of the new method compared to previous ones for various purposes. (author)SIGLEAvailable from British Library Document Supply Centre-DSC:DX208598 / BLDSC - British Library Document Supply CentreGBUnited Kingdo