Random Group Research Articles

Friction of Laser-Textured Zirconia Coated with a Platelet-Rich Fibrin.

In the present in vitro study, we evaluated the adhesion of an injectable platelet-rich fibrin (i-PRF) to laser-textured zirconia surfaces and their resultant friction behavior against bone tissue. Three types of zirconia surfaces were compared regarding the i-PRF coating effects: 1) grit blasted with 250-μm spherical alumina particles and acid etched with 20% hydrofluoric acid (ZLA), 2) laser textured with a random (RD) surface pattern, or 3) laser textured with a designed pattern based on 16 lines and 8 passages (L16N8). The coefficient of friction (COF) of the specimens was assessed on a reciprocating sliding pin-on-plate tribometer at 1-N normal load, 1 Hz, and a 2-mm stroke length. Sliding wear tests were carried out against bovine femoral bone tissue in 0.9% sodium chloride solution at room temperature. Surfaces were then assessed by scanning electron microscopy. COF mean values for test groups (0.35, ZLA; 0.45, L16N8) were lower when compared with the control groups (0.52, ZLA; 0.60, L16N8), with the exception of the RD group (0.47, test; 0.43, control). Results did not show significant differences in COF mean values between RD and L16N8 surfaces after coating with i-PRF. The 3-dimensional fibrin network embedded with leukocytes, platelets, and red blood cells was responsible for decreasing COF mean values over the zirconia surfaces, thus providing a lubricant effect. Also, the morphologic aspects of the laser-treated zirconia surfaces increased the adhesion of the platelet-rich fibrin, which could speed up the osseointegration process of zirconia implants.

Effect of different acupuncture sequences of Huiyangjiuzhen acupoints on blood glucose and hemorheology in the anesthetized rabbits

Background and objectiveHemorheology and blood glucose are commonly used to estimate the risks of thrombosis and stress hyperglycemia after anaesthesia. The sequence of acupoint stimulation might influence the therapeutic effects of acupuncture. In the current study, we aimed at investigating the effect of different acupuncture sequences of “Huiyangjiuzhen” acupoints on the blood glucose and hemorheology in anesthetized rabbits. MethodsTwenty-five rabbits were randomly divided into five groups, including the control group (CG), the positive-sequence group (PSG), the reverse-sequence group (RSG), the disorder-sequence group (DSG), and the random group (RG). Except for the CG and RG, the rabbits in other groups were acupunctured with different sequences of “Huiyangjiuzhen"acupoints when the rabbits were anesthetized. The acupoints in rabbits of the RG were chosen randomly. The levels of blood glucose and hemorheology indexes before and after anaesthesia was detected. ResultsIn the PSG, Hηb 200/s, Mηb 30/s, Hηr 200/s, ERI, hematocrit and plasma viscosity levels were decreased, and the blood glucose level was not changed. In the DSG, the levels of Mηb 30/s and hematocrit were decreased, and the blood glucose was increased. In the CG, RSG and RG, no hemorheology indexes were changed and the blood glucose was increased. Conclusion“Huiyangjiuzhen” acupuncture could decrease the risks of post-operative thrombosis and stress hyperglycemia in anesthetized rabbits. This effectiveness depends on both acupuncture and acupuncture sequence at the “Huiyangjiuzhen” acupoints.

Evaluating Equating Methods for Varying Levels of Form Difference

Equating is a statistical procedure used to adjust for the difference in form difficulty such that scores on those forms can be used and interpreted comparably. In practice, however, equating methods are often implemented without considering the extent to which two forms differ in difficulty. The study aims to examine the effect of the magnitude of a form difficulty difference on equating results under random group (RG) and common-item nonequivalent group (CINEG) designs. Specifically, this study evaluates the performance of six equating methods under a set of simulation conditions including varying levels of form difference. Results revealed that, under the RG design, mean equating was proven to be the most accurate method when there is no or small form difference, whereas equipercentile is the most accurate method when the difficulty difference is medium or large. Under the CINEG design, Tucker Linear was found to be the most accurate method when the difficulty difference is medium or small, and either chained equipercentile or frequency estimation is preferred with a large difficulty level. This study would provide practitioners with research evidence–based guidance in the choice of equating methods with varying levels of form difference. As the condition of no form difficulty difference is also included, this study would inform testing companies of appropriate equating methods when two forms are similar in difficulty level.

Private Multi-Group Aggregation

We study the differentially private multi-group aggregation (PMGA) problem. This setting involves a single server and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$n$ </tex-math></inline-formula> users. Each user belongs to one of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$k$ </tex-math></inline-formula> distinct groups and holds a discrete value. The goal is to design schemes that allow the server to find the aggregate (sum) of the values in each group (with high accuracy) under communication and local differential privacy constraints. The privacy constraint guarantees that the user’s group remains private. This is motivated by applications where a user’s group can reveal sensitive information, such as his religious and political beliefs, health condition, or race. We propose a novel scheme, dubbed Query and Aggregate (Q&A) for PMGA. The novelty of Q&A is that it is an interactive aggregation scheme. In Q&A, each user is assigned a random query matrix, to which he sends the server an answer based on his group and value. We characterize the Q&A scheme’s performance in terms of accuracy (MSE), privacy, and communication. We compare Q&A to the Randomized Group (RG) scheme, which is non-interactive and adapts existing randomized response schemes to the PMGA setting. We observe that typically Q&A outperforms RG, in terms of privacy vs. utility, in the high privacy regime.

Service Differentiation in IEEE 802.11ah WLAN under Restricted Access Window based MAC protocol

The restricted access window (RAW) based channel access scheme proposed for IEEE 802.11ah wireless LAN (WLAN) divides the stations (STAs) in the network into groups and allocates RAW slots for each group of STAs. In this way, the STAs belonging to each group can attempt to access the medium during their designated RAW slot by invoking the enhanced distributed channel access (EDCA) protocol. This paper describes an analytical model to evaluate the saturation throughput of IEEE 802.11ah WLAN under the RAW based scheme, when STAs carry traffic of distinct access categories (ACs) and use the EDCA protocol for medium sharing. However, when groups are formed by randomly selecting the STAs, i.e., if random grouping (RG) scheme is employed, each group will contain STAs carrying traffic of distinct ACs. This will lead to starvation and degraded throughput performance for the low priority class STAs, since they have to contend with high priority class STAs within the same group during the RAW slot assigned. To resolve this issue, we propose an algorithm to realize priority class based grouping (PCG), in which the STAs belonging to the same ACs are grouped together. We also describe an analytical model to evaluate the saturation throughput of the network under the proposed PCG scheme. We establish that saturation throughput of the network and the relative service differentiation ratio of the lower priority class STAs can be significantly improved under the proposed PCG scheme compared to the conventional RG scheme.

A Brain Storm Optimization With Multi-Information Interactions for Global Optimization Problems

The original brain storm optimization (BSO) fails to consider some potential information interactions in its individual update pattern, causing the premature convergence for complex problems. To address this problem, we propose a BSO algorithm with multi-information interactions (MIIBSO). First, a multi-information interaction (MII) strategy is developed, thoroughly considering various information interactions among individuals. Specially, this strategy contains three new MII patterns. The first two patterns aim to reinforce information interaction capability between individuals. The third pattern provides interactions between the corresponding dimensions of different individuals. The collaboration of the above three patterns is established by an individual stagnation feedback mechanism, contributing to preserve the diversity of the population and enhance the global search capability for MIIBSO. Second, a random grouping (RG) strategy is introduced to replace both the K-means algorithm and cluster center disruption of the original BSO algorithm, further enhancing the information interaction capability and reducing the computational cost of MIIBSO. Finally, a dynamic difference step-size (DDS), which can offer individual feedback information and improve search range, is designed to achieve an effective balance between global and local search capability for MIIBSO. By combining the MII strategy, RG, and DDS, MIIBSO achieves the effective improvement in the global search ability, convergence speed, and computational cost. MIIBSO is compared with 11 BSO algorithms and five other algorithms on the CEC2013 test suit. The results confirm that MIIBSO obtains the best global search capability and convergence speed amongst the 17 algorithms.

Validation of a Questionnaire that Surveys Confidence in Sports among Korean Competitive Athletes

Background and Objective&#x0D; This study aimed to verify the validity of a questionnaire that surveys confidence in sports among athletes in combat sports. The questionnaire addresses the concepts of persistence, calmness, hesitation, and physical prime.&#x0D; Material and Methods&#x0D; Purposeful sampling using non-probability sampling was conducted in 367 players participating in university- and business-level athletics in the Republic of Korea. The data were analyzed using a multi-group confirmatory factor analysis, and a second confirmatory factor analysis with linear structural relations (LISREL) version 8.5. Concept reliability and average variance extracted (AVE) values were calculated using Excel 2010 (Microsoft Corporation, Redmond, WA, USA). Two-way (2×2) randomized group (RG) analysis of variance (ANOVA) was conducted using the SPSS 18.0 program (IBM Corp., Armonk, NY, USA).&#x0D; Results&#x0D; We proved that the sub-factors measured by the survey questions were relatively exact regarding self-confidence in combat-sport athletes. The questions relating to self-confidence in sports could be applied to both male and female athletes alike. The scores of the male athletes were higher than female athletes in factors such as fighting spirit, calmness, and performing under pressure. The scores of the national athletes were higher than those of the non-national athletes with respect to the body preparation factor.&#x0D; Conclusion&#x0D; These results suggest that the competitive sports questionnaire developed in a previous study could be utilized without difficulty in a confidence-related study of competitive sports athletes. The questionnaire is particularly effective in evaluating the confidence level of athletes.

Nasal Trauma in Neonates receiving CPAP And its Prevention in tertiary care hospital.

Objectives: This study was done to evaluate the frequency and severity of nasal trauma secondary to nasal continuous positive airway pressure (NCPAP) in neonates and different methods to reduce the nasal septum injury via CPAP&#x0D; Methods: This is a prospective study carried out in the Neonatal Care Unit (NCU) of LAL DED maternity hospital associated with department of pediatrics Government Medical College, Srinagar, Kashmir. The study included newborns that underwent NCPAP with prongs on admission and those receiving NCPAP after weaning from ventilator, from 1st January 2016 - 1st jan 2017. Neonates noses were monitored from the first day of NCPAP treatment until its weaning. Nasal trauma was reported into Three Grades: (I) Erythema/pressure indentation (II) superficial Erosion and (III) Septal necrosis.&#x0D; Results:-258 newborns were included in study, 136 males and 122 females. All enrolled newborn received CPAP. Babies were randomly allocated to different groups in which no barrier and different barriers were applied. Randomization ofgroup of infants who received no barrier(group 0) and different barriers( group 1,2,&amp;amp;3) was done by systematic allocation, in which first newborn was randomly designated to no barrier group 0 on particular day of admission ,and subsequently alternating with other three groups i.e group 1,group 2, group 3. The mean gestational age, birth weight and CPAP days in each group is 31wk (GA28-35 wks),1200 gms(0.7kg-1.8kg) &amp;amp; 5 days(3-10days) respectively. Incidence of Septal necrosis was 26.7% in the babies that had ‘No barrier applied at septal hudson prongs interface (Group0), which was significantly more (p&amp;lt;0.001) when compared with other three groups, within which its incidence was 2.8% in Cotton applied at septal and hudson prongs interface with glycerine (Group1), 7.1% in Danaplast applied at interface(Group2) and 0.0% in Cotton soaked with normal saline(Group3) respectively. In Group 0 nasal septal injury Grade 1 is (35%),grade 2 (35%),and grade 3(30.0%), in Group 1, grade 1 septal injury is (84%), grade 2(12.7%) &amp;amp; grade 3(2.8%),In Group 2 grade 1 is (65.7%),grade2(30.0%),grade3 (4.3%) and Group3 grade1(80.7%),grade2(19.3%) and Grade3 (0.0%)&#x0D; Conclusions: Nasal trauma is a frequent complication of NCPAP, especially in preterm babies and babies requiring nasal prongs for longer duration. And can be prevented by applying a barrier as in group 1,2 &amp;amp;3 in our study shows statistically significant decreased in severe nasal septal injury. JMS 2017;20(2):96-100&#x0D;

Light and feeding entrainment of the molecular circadian clock in a marine teleost (Sparus aurata)

Daily light and feeding cycles act as powerful synchronizers of circadian rhythmicity. Ultimately, these external cues entrain the expression of clock genes, which generate daily rhythmic behavioral and physiological responses in vertebrates. In the present study, we investigated clock genes in a marine teleost (gilthead sea bream). Partial cDNA sequences of key elements from both positive (Bmal1, Clock) and negative (Per2, Cry1) regulatory loops were cloned before studying how feeding time affects the daily rhythms of locomotor activity and clock gene expression in the central (brain) and peripheral (liver) oscillators. To this end, all fish were kept under a light-dark (LD) cycle and were divided into three experimental groups, depending on the time of their daily meal: mid-light (ML), mid-darkness (MD), or at random (RD) times. Finally, the existence of circadian control on gene expression was investigated in the absence of external cues (DD + RD). The behavioral results showed that seabream fed at ML or RD displayed a diurnal activity pattern (>91% of activity during the day), whereas fish fed at MD were nocturnal (89% of activity during the night). Moreover, seabream subjected to regular feeding cycles (ML and MD groups) showed food-anticipatory activity (FAA). Regardless of the mealtime, the daily rhythm of clock gene expression in the brain peaked close to the light-dark transition in the case of Bmal1 and Clock, and at the beginning of the light phase in the case of Per2 and Cry1, showing the existence of phase delay between the positive and negative elements of the molecular clock. In the liver, however, the acrophases of the daily rhythms differed depending on the feeding regime: the maximum expression of Bmal1 and Clock in the ML and RD groups was in antiphase to the expression pattern observed in the fish fed at MD. Under constant conditions (DD + RD), Per2 and Cry1 showed circadian rhythmicity in the brain, whereas Bmal1, Clock, and Per2 did in the liver. Our results indicate that the seabream clock gene expression is endogenously controlled and in liver it is strongly entrained by food signals, rather than by the LD cycle, and that scheduled feeding can shift the phase of the daily rhythm of clock gene expression in a peripheral organ (liver) without changing the phase of these rhythms in a central oscillator (brain), suggesting uncoupling of the light-entrainable oscillator (LEO) from the food-entrainable oscillator (FEO). These findings provide the basis and new tools for improving our knowledge of the circadian system and entraining pathways of this fish species, which is of great interest for the Mediterranean aquaculture. (Author correspondence: javisan@um.es).

Abstract P4-11-01: Cardiovascular Effects of Postmastectomy Irradiation Evident after 15 Years. Results from the South Sweden Breast Cancer Group's Randomised Studies SBII:1 with 25 Years of Follow-Up of Pre-and Postmenopausal Women with Stage II Breast Cancer

Abstract Background: The importance of radiotherapy for local control after mastectomy and breast conservation surgery is well established with a reduction in loco-regional recurrences by two thirds. In early radiotherapy trials the reduction of loco-regional failures did not result in a reduction of mortality due to increased late non-breast cancer mortality. The 2005 overview of radiotherapy by EBCTCG did however show a significantly improved survival with the addition of radiotherapy. Patients and methods: From 1978 to 1985 1100 patients with breast cancer stage II were included in two randomized trials of radiotherapy and adjuvant systemic treatment, SBII:1 pre (Cyclophosphamide per os one year) and SB II:1 post (Tamoxifen 10 mg x 3 one year). The radiotherapy technique and the outcome of these studies have been published previously (Arwidi Å et al. Acta Radiol Oncol 18:273, 1979, Killander F et al. Eur J Cancer 43:2100, 2007, Killander F et al. The Breast 18:309, 2009). An efficient reduction of loco-regional recurrences but no improvement in survival was reported at 25 years of follow-up. Linkage to the following population based Swedish registries was obtained: 1. National Population Registry 2. National Cause of Death Registry, and 3. Swedish Hospital Discharge Registry. Per protocol treatment was administered to 1044 patients, which form the basis for the analyses. We have included both underlying and contributing causes of death due to heart, cerebrovascular and lung disease. Results: After 15 years a significantly increased cardiac mortality was observed in irradiated patients compared to patients given systemic treatment only, and this effect prevailed at 25 years of follow-up. However not until 15 years after radiotherapy significantly higher cardiovascular mortality was observed. When analysing cerebro-vascular mortality the same pattern was seen. Cumulative incidence of non-breast cancer mortality after postmastectomy radiation in pre-and For lung diseases no increase in mortality was discernible. An interesting observation was that in premenopausal patients cardiovascular and cerebrovascular mortality were less pronounced, and that the latency period was longer than for postmenopausal patients. Analyses of all hospital admissions during follow-up showed neither increased overall morbidity nor increased cardiovascular morbidity. Discussion: The significant cardiovascular side effects of radiation observed with the radiotherapy technique used in these studies underlines the importance of careful dose planning and reduction in the volumes of the heart and large vessels, that are exposed to radiation. Extended follow-up is necessary for detection of these late effects. The longer latency and lower cardiovascular mortality in premenopausal patients may reflect lower sensitivity for radiation of normal tissue compared to postmenopausal women. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-11-01.

Psychotropic drug use in intellectually disabled group-home residents with behavioural problems.

Little is known about psychiatric and behavioural factors associated with psychotropic drug use and how appropriately these drugs are prescribed in settings for people with intellectual disabilities. The aim of this study was to measure the point prevalence of psychotropic drug use in a problem-behaviour group (PBG) consisting of intellectually disabled residents of group homes compared to a random group (RG), and to gain insight in possible factors that are associated with group membership. From all group homes in the Netherlands, 573 problematic residents were selected by the staff (one resident from each home) and 1479 residents were randomly sampled from all of the homes. Mental health problems were measured using the Reiss Screen for Maladaptive Behaviour and the Psychopathology Instrument for Mentally Retarded Adults. The response rate in the PBG was 68.9 % and in the RG 71.7 %. Psychotropics (excluding anticonvulsants) were used by 52.6 % of the PBG and by 22.8 % of the RG. Young age, psychotic, anxiety, and aggression symptoms were significantly associated with the PBG, as was the use of antipsychotics and antidepressants. The PBG more often used multiple (three or more) drugs (17.3 %) than the RG (7.3 %). A low prevalence of antidepressants or mood stabilisers, antipsychotics, and anxiolytics was found in residents with affective, psychotic, or anxiety symptoms. We conclude that psychotropic drug use in the PBG compared to the RG was high. It is likely that the group-home staff finds it difficult to deal with young people with socially disruptive behaviour, which is underlined by our finding of high prevalence of antipsychotics and multiple-drug therapy in the PBG. Finally, our findings suggest that a considerable number of residents with psychiatric or behavioural symptoms are undertreated.