Mean Retention Research Articles

Rhodojaponin III-Loaded Chitosan Derivatives-Modified Solid Lipid Nanoparticles for Multimodal Antinociceptive Effects in vivo.

BackgroundRhodojaponin III (RJ-III) is a bioactive diterpenoid, which is mainly found in Rhododendron molle G. Don (Ericaceae), a potent analgesia in traditional Chinese medicine with several years of clinical applications in the country. However, its clinical use is limited by its acute toxicity and poor pharmacokinetic profiles. To reduce such limitations, the current study incorporated RJ-III into the colloidal drug delivery system of hydroxypropyl trimethyl ammonium chloride chitosan (HACC)-modified solid lipid nanoparticles (SLNs) to improve its sustained release and antinociceptive effects in vivo for oral delivery.ResultsThe optimized RJ-III@HACC-SLNs were close to spherical, approximately 134 nm in size, and with a positive zeta potential. In vitro experiments showed that RJ-III@HACC-SLNs were stable in the simulated gastric fluid and had a prolonged release in PBS (pH = 6.8). Pharmacokinetic results showed that after intragastric administration in mice, the relative bioavailability of RJ-III@HACC-SLNs was 87.9%. Further, it was evident that the peak time, half-time, and mean retention time of RJ-III@HACC-SLNs were improved than RJ-III after the administration. In addition, pharmacodynamic studies revealed that RJ-III@HACC-SLNs markedly reduced the acetic acid, hot, and formalin-induced nociceptive responses in mice (P < 0.001), and notably increased the analgesic time (P < 0.01). Moreover, RJ-III@HACC-SLNs not only showed good biocompatibility with Caco-2 cells in vitro but its LD50 value was also increased by 1.8-fold as compared with that of RJ-III in vivo.ConclusionThese results demonstrated that RJ-III@HACC-SLNs improved the pharmacokinetic characteristics of the RJ-III, thereby exhibiting toxicity-attenuating potential and antinociceptive enhancing properties. Consequently, HACC-SLNs loaded with RJ-III could become a promising oral formulation for pain management that deserves further investigation in the future.

No size-dependent net particle retention in the hindgut of horses.

Sieve analyses of hindgut contents of horses as well as observations in horses where plastic markers had been applied to a caecal cannula suggested that there may be a discrimination by particle size in the passage or retention of digesta. Here, we performed a similar experiment with five caecum-cannulated horses (562 ± 31 kg) fed a constant amount (6.81 kg dry matter/day) of grass hay. Passage markers representing the liquid (Co-EDTA) as well as the particulate digesta phase (Yb-undefined; Cr mordanted fibre 1-2 mm; Ce-mordanted fibre 8 mm) were given as a pulse-dose into the cannula to measure their mean retention times (MRT). The MRTs were compared by repeated-measurements analysis of variance. The MRT in the hindgut was 22.2 ± 2.4 h for Co, 25.0 ± 3.4 h for Yb, 26.2 ± 1.6 h for Cr and 26.3 ± 1.5 h for Ce. Whereas differences between the particle marker MRTs were not significant (padj. > 0.05), significant differences were observed between the solute marker Co and each of the particle markers Cr and Ce (padj. < 0.009). The results confirm the well-known significant, albeit small, difference in MRT in horses between the fluid and the particle digesta phase, and corroborate another recent study that used a combination of whole, marked hay and individual marker analysis in different particle size fractions of the faeces, which also did not detect a selective retention of any particle size class.

Therapeutic potential of human serum albumin nanoparticles encapsulated actinonin in murine model of lung adenocarcinoma

Non-small cell lung cancer comprises 85% of the global lung cancer cases. Conventional chemotherapeutics possess certain limitations like systemic toxicity and drug resistance that requires the development of new therapeutic agents for successful treatment of lung cancer. Actinonin, a human peptide deformylase inhibitor, has demonstrated anti-cancerous properties in various leukemias and solid cancer types. However, it has limited therapeutic application because of its low bioavailability and systemic toxicity if administered in free form. This limitation can be overcome by using nano-delivery systems that will increase the therapeutic efficacy of actinonin. In the present study, human serum albumin actinonin nanoparticles were prepared using a desolvation technique and folic acid was conjugated to lysine residues of albumin for effective delivery to the lung. The lung adenocarcinoma model was established 24 weeks after intraperitoneal administration of urethane and chemotherapeutic efficacy of free as well as nanoencapsulated actinonin was evaluated. This study demonstrated anti-proliferative potential of folic acid conjugated human serum albumin nanoparticles encapsulating actinonin. The intraperitoneally administered nanoformulation exhibited sustain release profile of actinonin with longer half-life and mean retention time. The reduced dose frequency resulted in therapeutic efficacy comparable to free drug in vivo in terms of 100% survival and reduced tumor burden along with downregulation of epidermal growth factor receptor, folate receptor α and peptide deformylase expression in lung adenocarcinoma mice model. Therefore, actinonin encapsulated albumin nanoparticles-based therapy holds great potential as an alternative strategy to improve its anti-cancerous activity against lung adenocarcinoma.

Effects of Gamification and Mastery Learning Strategies On Student’s Performance and Retention in Mathematics in Oju Local Government Area of Benue State

This study is aimed at finding effects of gamification and mastery learning strategies on students’ performance and retention in mathematics. The study was Quasi-Experimental Non-Randomized Pretest-Posttest Control Group Design. The population for this study consisted of all the 3, 524 Upper Basic II mathematics in Oju Local Government Area of Benue State, Nigeria in 2021/2022 academic session in Benue State, Nigeria. Purposive sampling technique was used to obtain a sample of six schools. The sample for the study was 74 Upper Basic II students from the selected schools. The instrument used for data collection was mathematics. Achievement and Retention Test” (MART). The researcher trained the teachers in the experimental group on the technique of GLS and MLS before the treatment. The instrument was pilot tested to asserted the reliability. The reliability co-efficient alpha was 0.85. Data was analyzed using mean and standard deviation to answer the research question while Analysis of Covariance (ANCOVA) was used to test the null hypotheses at 0.05 significant level. The result of the study show that there is significant difference in the mean performance scores of students in mathematics using gamification, mastery learning and conventional Strategies and there is significant difference in the student’s mean retention scores in mathematics taught using gamification,and mastery learning than conventional Strategies. The research concluded that MLS is an effective teaching method, which teachers should be encouraged to use and should be implemented in the teachers’ education programmes in Nigeria and other African nations.

Pharmacokinetics Study of Jin-Gu-Lian Prescription and Its Core Drug Pair (Sargentodoxa cuneata (Oliv.) Rehd. et W and Alangium chinense (Lour.) Harms) by UPLC-MS/MS.

Jin-Gu-Lian (JGL) is traditionally used by Miao for the treatment of rheumatism arthralgia. At the same time, the combination of Sargentodoxa cuneata (Oliv.) Rehd. et W (SC) and Alangium chinense (Lour.) Harms (AC), the core drug pair (CDP) in the formula of JGL, is used at high frequencies in many Miao medicine prescriptions for rheumatic diseases. However, previous research lacks the pharmacokinetic study of JGL, and study on the compatibility of its CDP with other medicinal herbs in the formula is needed. This study aims to establish a simple, rapid, and sensitive Ultra Performance Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS/MS) method for the simultaneous determination of four main bioactive components of JGL in rat plasma, including Salidroside (Sal), Anabasine (Ana), Chlorogenic Acid (CA), and Protocatechuic Acid (PCA), and compare the pharmacokinetic properties of two groups of rats after being orally administrated with JGL and its CDP extracts, respectively. The results showed that area under the plasma concentration-time curve (AUC), mean retention time (MRT), and clearance rate (CL), of Sal, Ana, CA and PCA in the two groups of rats were changed in different degrees. The CDP combined with other drugs could significantly increase the absorption of Sal and Ana, prolong its retention time in vivo, and may accelerate the absorption rate of CA and PCA. This indicated that the combination of CDP and other herbs may affect the pharmacokinetics process of active components in vivo, increase the exposure and bioavailability of compounds in the JGL group, and prolong the retention time, which may be the reason why JGL has a better inhibitory effect on inflammatory cytokines, providing a viable orientation for the compatibility investigation of herb medicines.

Supervised Exercise Interventions in Childhood Cancer Survivors: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Background: Childhood cancer survivors (CCSs) may suffer from a multitude of health impairments, resulting in a compromised quality of life (QoL). This review’s objective was to examine CCSs’ adherence to supervised exercise training interventions and the impact of these interventions on health outcomes. Methods: The following databases were searched in May 2022: PubMed, Embase, Cochrane Library, and Web of Science. The included studies were limited to randomized controlled trials (RCTs), published in English involving CCSs aged 18 years and below. Results: Nine RCTs (n = 642 participants) were included in the systematic review, and seven of them (n = 551 participants) were included in the meta-analysis. Both the mean retention rate and adherence to the supervised exercise interventions were 87%. Supervised exercise interventions significantly improved muscle strength (standardized mean difference (SMD) = 1.42, p = 0.03), level of daily physical activity (SMD = 1.05, p < 0.001), body mass index (BMI) (mean difference (MD) = 1.06, p = 0.03), and fatigue (SMD = −0.44, p < 0.001), while there was no statistical significance in the quality of life (QoL) (SMD = 0.21, p = 0.20). Conclusions: The adherence of CCSs to supervised exercise interventions is high, and supervised exercise interventions are safe and effective.

Frugivory and seed dispersal by the Red-footed Tortoise Chelonoidis carbonaria

Seed dispersal by frugivores is essential in plant life cycles, with birds and mammals the principal and well-studied dispersal agents. However, there is an increasing recognition that terrestrial tortoises could also be considered important seed dispersers in many ecosystems. The red-footed tortoise (Chelonoidis carbonaria) is one of the largest terrestrial tortoises in South America and is thought to disperse large seeds. However, little is known about their role as seed dispersers, and their potential use as restorers of defaunated areas. Here, we assessed the maximum width of seeds this species could ingest, the mean gut retention time (GRT), and the post-consumption germination capacity for tropical fruit species. Forty different fruit species were offered to eight captive individuals, obtaining a maximum seed width swallowed of 23 mm. We used four native plant species to measure the GRT within four tortoises, and we found a mean retention time of 18.92 ± 4.81 days. We also found that sex is an important indicator of GRT, with females presenting longer retention periods. This novel finding may be due to the higher metabolic defecating and dispersing rates of males. Although germination proportions varied between the four plant species used in the experiment, overall defecated seeds germinated faster than control seeds. We conclude that red-footed tortoises are potentially important seed dispersers due to their ability to swallow a large quantity and size of seeds while accelerating seed germination rates. This species should be considered a viable ecological substitute for large frugivores in rewilding projects, as C. carbonaria performs similar functions to large dispersers that have been extirpated due to defaunation processes.

Synthesis of an Organotin Specific Molecularly Imprinted Polymer for Organotin Passive Sampling in Seawater

Environmental contaminations can sometimes be difficult to measure, particularly in complex matrices such as seawater. This is the case of organotin compounds (OSn) such as the monobutyltin (MBT), dibutyltin (DBT), and tributyltin (TBT), whose range of polarity is wide. These compounds, mostly coming from antifouling paints used on ship shell, can be found in water and sediments where they are stable and can persist for years. Passive sampling is gaining in interest to offer solutions to monitor these kinds of compounds even in low concentrations. However, due to the diversity of pollutants present in the environment nowadays, it is important to propose solutions that allow a specific sampling. This work aims to highlight the usability of molecularly imprinted polymers (MIPs) in passive sampling for the monitoring of OSn. MIPs were synthetized using three synthesis ways (bulk, suspension, and mini-emulsion processes) and kinetics were realized in order to estimate the retention of OSn by the solid MIP phase. Results highlighted a good retention of OSn with mean retention kinetic constants near 10−5, 10−6 and 10−7 L·ng·s−1 for DBT, TBT and MBT respectively. The synthesis mode showed no impact on retention kinetics, therefore, bulk synthesis is recommended because of its simplicity. If the elimination of OSn from MIPs is to be optimized, the retention of OSn on MIPs has been demonstrated, and is very promising for their use in specific passive samplers.

Transient Retention of Floating Particles Captured by Emergent Vegetation Through Capillarity

AbstractThis work presents and discusses a series of experiments focusing on the transport of floating particles, mimicking seeds and propagules, within an array of randomly arranged cylinders mimicking emergent vegetation stems. The focus is on the temporary capture process by which particles colliding with a cylinder are trapped by surface tension for finite but relatively long retention times, thus promoting a large mechanical dispersion. Video analysis of the particle paths within the array shows that the probability of particles being captured, either temporarily or permanently, as well as the mean retention time, vary with flow velocity while being weakly affected by stem density. On the contrary, stem density plays a significant role in determining the frequency of the temporary captures; in particular, the probability of having temporary, rather than permanent, captures increases with vegetation density. We also propose some relationships to predict the probability of having temporary capture events and their mean duration based on experimental results.

Pharmacokinetic Parameters of Oral Pegylated IFN-λ1.

We studied the pharmacokinetics of a pegylated IFN-λ1 (PEG IFN-λ1) after its oral administration to rats in different therapeutic doses. The hypothesis on linear pharmacokinetics of PEG IFN-λ1 within the dose range of 2.6-7.8 μg/kg was confirmed, high for protein molecules bioavailability from 17.5 to 21%, the absence of intravascular deposition, and effective elimination with feces and urine (85 and 15% of the administered dose, respectively) were demonstrated. At the same time, the mean retention time for PEG IFN-λ1 in the circulation is 6.46-6.65 h and half-life is 3 h. These findings give ground for continuing experimental studies of PEG IFN-λ1 pharmacokinetics, in particular, tissue distribution of the drug.

The Influence of Seed Characteristics on Seed Dispersal Early Stages by Tibetan Macaques.

Simple SummarySeed dispersal by frugivores is critical to forest regeneration. However, the Tibetan macaque’s seed dispersal function and the effect of seed physical characteristics on seed dispersal effectiveness need to be confirmed. We not only demonstrated that Tibetan macaques could act as seed dispersers, but we also investigated the effect of seed physical characteristics on gut passage time and seed damage rates. Smaller seeds are less likely to be damaged and remain for longer periods of time, whereas larger and heavier seeds are defecated more quickly. In our experiments, the seed-to-shell investment rate had no effect on the damage rate. Understanding the role of seed dispersal in primates can aid in the understanding of seed dispersal symbiosis.There are numerous ecological and evolutionary implications for the ability of frugivores to predate on fruits and consume or disperse their seeds. Tibetan macaques, which are considered important seed predators, typically feed on fruits or seeds. However, systematic research into whether they have a seed dispersal function is still lacking. Endozoochory allows seeds to disperse over greater distances by allowing them to remain in the animal’s digestive tract. Consumption of fruit may not imply effective seed dispersal, and the physical characteristics of seeds (e.g., size, weight, specific gravity, etc.) may influence the dispersal phase’s outcome. We conducted feeding experiments with three captive Tibetan macaques (Macaca thibetana) and nine plant seeds to determine the influence of seed characteristics on Tibetan macaques’ early stages of seed dispersal. The results revealed that the percentage of seed destruction (PSD) after ingestion was 81.45% (range: 15.67–100%), with the PSD varying between plant species. Among the three passage time parameters, the transit time (TT) (mean: 18.8 h and range: 4–24 h) and the time of seed last appearance (TLA) (mean: 100.4 h and range: 48–168 h) differed significantly between seed species, whereas the mean retention time (MRT) (mean: 47.0 h and range: 32–70.3 h) did not. In terms of model selection, PSD was influenced by seed size, weight, volume, and specific gravity; TT was influenced by seed-to-shell investment rate, weight, volume, and specific gravity; and TLA was influenced only by seed size. These findings imply that seeds with a smaller size, specific gravity, volume, and greater weight pass more easily through the monkeys’ digestive tracts. Particularly, seeds with a mean cubic diameter (MCD) of <3 mm had a higher rate of expulsion, larger volume, and weight seeds pass faster, while smaller remained longer. Tibetan macaques, as potential seed dispersers, require specific passage time and passage rates of small or medium-sized seeds. Larger and heavier seeds may be more reliant on endozoochory. Tibetan macaques have the ability to disperse seeds over long distances, allowing for gene flow within the plant community.

Individual differences in digesta retention and their relation to chewing in cattle-A pilot investigation.

While information on individual differences in digesta mean retention time (MRT) might be interesting when selecting phenotypes for digestive efficiency, MRT measurements are prohibitively labour-intensive for large-scale application. Therefore, more easily measured proxies of MRT might be helpful. We used the opportunity of an experiment applying saliva stimulant in cattle to investigate the effect of different individual chewing behaviour on fluid and particle MRT with a consistent diet. Four non-lactating cattle (670-850 kg body mass [BM]) were used in a 4 × 4 Latin square design, treated with the saliva stimulant pilocarpine in dosages of 0, 1, 2.5and 5 mg/kg BM per day. The cattle were fed hay with dry matter intake (DMI) assigned according to their metabolic body weight. MRT in the whole gastrointestinal tract (GIT), the reticulorumen (RR) and the distal tract were measured using Co-EDTA, Cr-mordanted fibre and La-mordanted fibre as markers representing fluid, small particles (2 mm) and large particles (1 cm), respectively. The chewing behaviour was measured via noseband pressure sensor and expressed as chewing frequency (chews per time) and chewing intensity (chews per DMI), both for total chewing (ingestion plus rumination) and rumination chewing alone. The animals differed considerably in chewing behaviour and MRT measures. BM did not show a significant effect on chewing behaviour and MRT measures, though it tended to negatively correlated to total chewing intensity. Chewing intensity exerted a significant negative influence on MRT of fluid and particles in the RR, which was not the case for chewing frequency. Chewing frequency showed a significant relationship with MRT of large particles in the GIT. We suggest that chewing behaviour could influence MRT in two ways: (i) by affecting saliva production via the masticatory-salivary reflex and subsequently, the fluid inflow to the RR; (ii) by contributing to particle size reduction. Should the link between chewing behaviour and MRT be corroborated in larger studies, chewing measures, with their large interindividual variation, could emerge as an easy-to-measure proxy for MRT characteristics.

Incising and Double Impregnation of Beech Sleepers—Investigation of an Alternative Preservation System for Wooden Railway Sleepers

For nearly 200 years wooden railway sleepers are impregnated with creosote. After initially using vacuum pressure processes for impregnation, empty-cell processes have been developed quickly and are used until today. Because of political developments and its alarming properties against human health and environment the use of creosote is already restricted to certain industrial and commercially used products and will probably be banned on the European market and elsewhere in the near future. Today, most of the sleepers in track are concrete sleepers, but wooden sleepers are still essential for particular applications such as tracks with narrow curve radii, mountain tracks with uneven underground conditions and low ballast bed thicknesses, for switches, for railway bridges and for shunting stations. Without a successor product, wooden sleepers have to be installed either again without adequate protection against wood destroying organisms or will possibly be replaced by sleepers made from alternative materials like concrete, steel or polymers. The Fürstenberg-System-Sleeper, which combines a mechanical pre-treatment (incising), a double impregnation of sleepers including an alternative oily wood preservative and a water-borne copper salt as well as a modernized quality control shall on the one hand serve as an alternative to creosoted sleepers and on the other hand ensure future use of wooden sleepers in track superstructure. Incising reduced the formation of checks regarding their length, width, and depth in sleepers made from European beech (Fagus sylvatica L.) until they are sufficiently seasoned for impregnation. A decrease of the seasoning speed was not observed. During seasoning, the average global moisture content (MC) as well as the local MC showed hardly any differences between incised and not incised sleepers. Additionally, incising showed no influence on the dimensional stability, which would have reduced the number of sleepers being culled based on excessive deformation. Furthermore, positive effects on preservative retention and penetration were observed, where incising doubled the penetration depth up to over 30 mm and increased the mean retention from 46.5 to 72.0 kg/m3. During double impregnation with the water-borne preservative first and the oily preservative afterward, it became evident, that a gross weight of at least 950 kg/m3 was needed for penetrating the peripheral area of the sleepers to achieve an additional homogenous envelope treatment during the second impregnation with an average retention of approximately 30 kg/m3.

Retention Capacity of Original Denture Adhesives and White Brands for Conventional Complete Dentures: An In Vitro Study.

(1) Introduction: Denture adhesives (DAs) promote stability, chewing ability, and quality of life. The objective of this study was to compare the effectiveness of original brand DAs and white brands in their retention of conventional complete dentures. (2) Methods: This study followed the recommendations of the international standard ISO 10873. Three original brands of DA (Corega® Fixação 3D, GlaxoSmithKline®, Stafford Miller Ltd., Dungarvan Co. Waterford, Ireland), KuKident® Pro Procter & Gamble Technical Centres®, Ltd., Whitehal Lane, Germany and Elgydium® Fix, Laboratórios URGO® SL, Florida, Spain) were compared to three white brands (Fixação Extra Forte Pingo Doce®, Laboratórios Cosmodent®, Cantabria, Spain), Fixador de Próteses (Continente®, Propack®,Gmbh, Ladenburg, Germany) and Creme Fixador de Próteses (Auchan®, Ellipse®, Roubaix, France). Their retention capacities were analyzed using a mechanical test device. (3) Results: The mean retentive ability of original brand adhesives (M = 11.16, SD = 5.27) was significantly higher (t(298) = 11.88; p < 0.001) than that of the white brands (M = 5.92, SD = 1.18). When comparing all brands, statistically significant differences were also observed, F(5.294) = 707.68 (p < 0.001). The generic adhesive results were more homogeneous. The generic brands from Continente® (M = 5.24, SD = 0.94) and Auchan® (M = 5.80, SD = 0.79) were not significantly different, while the Pingo Doce® brand obtained significantly higher mean retention results (M = 6.71, SD = 1.28). (4) Conclusions: The original brands of DA have a significantly higher retentive ability than the white brands. Elygidim® Fix had the worst result of the three original brands, and the product from Pingo Doce® had the best result among the three white brands.

Dietary neutral detergent fibre and lignin contents affect intake, digestibility and digesta retention in captive sloths (Bradypus variegatus).

We evaluated food intake, digestibility, digesta retention and digestible energy (DE) intake in four three-toed sloths (Bradypus variegatus, body mass 2.86 ± 0.10 kg) fed two leaf-based diets containing different neutral detergent fibre (NDF) and lignin contents. Total dry matter intake (DMI), and intake in relation to body mass and metabolic body weight were higher for the mixed diet with lower NDF content based on Pterondon sp. + Inga sp. (47 g day-1 , 16 g kg-1 day-1 and 21 g kg-0.75 day-1 ) compared to the treatment with higher content of NDF from only Cecropia pachystachya leaves (37 g day-1 , 14 g kg-1 day-1 and 18 g kg-0.75 day-1 ). The digestibility of dry matter (dDM) and neutral detergent fibre (dNDF) were higher in the mixed diet (60% and 61%respectively). There was a higher supply of DEand metabolisable energy (ME) on the mixed diet, at 221 and 199 kJ kg-0.75 day-1 , meeting the average energy requirement of 185 kJ ME kg-0.75 day-1 ME estimated for sloths in this study. In contrast, the diet with C. pachystachya generated a deficit of 31 kJ ME kg-0.75 day-1 . There was a correlation between DMI and dNDF (r2 = 0.89), and between dNDF and dDM (r2 = 0.98) across treatments. The mean retention times for a liquid and a particle marker were lower on the mixed diet with the higher intake at 133 h (passage rate = 0.75% h-1 ) and 181 h (0.55% h-1 ), and longer on the single-species diet with lower intake at 204 h (0.49% h-1 ) and 261 h (0.38% h-1 ). The results suggest that it may be beneficial for sloths to be offered a variety of browse from which they can choose low-NDF components. Further, we suggest that these sloths perform 'digesta washing'to increase the microbial yield in the stomach to maximise the digestion of NDF and dry matter.

Impact of Manipulation of Symbols by Upper Basic Education Students in Performance and Retention of Algebraic Processes

The study focused on the use of instructional materials for effective teaching and learning of mathematics at upper Basic Education Level. The use of shapes was employed to introduce the teaching of algebra to upper Basic Education Junior Secondary School One (JSSI) students. Quasi-experimental (Pre-test Post-test Non-equivalent control group design) was used for the study. The instrument use for the study was Algebraic Performance and Retention Test (APRT). The Performance Test was used as Pre-test, Pre-test and Retention-test. Researchers self-constructed two-dimensional shapes were used as manipulative skills for the teaching and learning of algebra. Two intact classrooms of JSSI were randomly selected out of the private schools in Gusau metropolis. Mode of instruction was randomly assigned to the classes using simple random technique of balloting. A sample size of 180 students were involved in the study comprising of 90 for experimental and 90 for control groups. The teaching and scoring were made by the researchers while the items, lesson plan and marking guide were all validated by the experts in mathematics education from the Federal University, Gusau. The findings of the study show that students taught algebra using manipulating skill performed better than those taught using conventional method. Also, students in the manipulative group retained the algebra contents more than those in the conventional group. More so, there was no significant difference in the mean achievement scores of male and female student’s algebra for both teaching methods. Similarly, there was no significant difference in the mean retention scores of male and female students in algebra for both teaching methods.

Determination of Menbutone: Development and Validation of a Sensitive HPLC Assay according to the European Medicines Agency Guideline

Menbutone is often used to stimulate the hepato-digestive activity in case of digestive disorders and hepatic insufficiency in different species (cattle, sheep, goats, pigs, horses, dogs) because it has choleretic and cholagogue effects and increases gastric and pancreatic juices. The objective was to develop and validate an HPLC method to quantify menbutone in sheep plasma using sparfloxacin as internal standard. The HPLC mobile phase consisted of acetonitrile:monopotassium phosphate solution. The method was validated according to EMA guideline (EMEA/CHMP/EWP/192217/2009). Mean retention times of menbutone and sparfloxacin were 4.5 and 2.2 min, respectively. The method met all specifications of the EMA guideline, being selective and linear in the range of 0.2–100 µg/mL (R2 ≥ 0.99). The within-run precision range was 0.19–8.21%, with an accuracy of 102.99–119.52% for the lower limit of quantitation (LLOQ). For the other values (LOW, MED, HIGH) the precision range was 0.01–4.77%, with an accuracy of 85.17–109.67%. The LLOQ was 0.2 µg/mL, and no interference from the biological matrix was found. Stability of menbutone in the biological matrix at different storage conditions was also demonstrated. Thus, the method can be used to determine menbutone concentrations in plasma sheep in different types of studies.

Effect of dietary fiber on fecal androgens levels: An experimental analysis in brown brocket deer (Mazama gouazoubira)

Non-invasive endocrinology is an important tool for animal conservation, but its success depends on many factors (e.g. adequate hormonal extraction, diet, antibody used in the assay). Dietary fiber is one of the main sources that can lead to erroneous interpretation of the endocrine status provided by EIA analysis. This study aimed to evaluate the dietary fiber effect on the fecal androgen metabolites (FAM) detection, on the daily defecation rate and fecal production, as well as to analyze the gastrointestinal passage and retention time of the experimental diets. Eight brown brocket deer (Mazama gouazoubira) males were randomly assigned to two groups and submitted to both isocaloric and isoproteic experimental diets for 10 days, in a crossover system: low fiber percentage feed (LF, 7% fiber) and high fiber percentage feed (HF, 19% fiber). Such groups were alternated in the middle of this period, with an interval of 10 days between them. In addition, there was a five-day adaptation phase at the beginning of each diet. Fecal collection for FAM measurement was performed during 10 days of treatment, whereas,the defecation rate and fecal production were performed every two hours, for 6 days. The mean FAM level in the HF group was 5038.0 ± 1529.1 ng/g, while for LF, 2178.7 ± 824.9 ng/g (p < 0.05). The mean HF fecal production was 182.6 ± 36.2 g DM/day and 117.5 ± 12.6 g DM/day for LF (p < 0.05). There were no differences in terms of mean defecation rate, passage, and retention times between groups. The results suggest that dietary fiber affects the FAM detection, and this should be taken into consideration before conducting experiments using fecal samples as a source of reproductive hormones profiling.

Retention Forces of Implant-Supported Single Crowns and Fixed Dental Prostheses after Cementation: An In-Vitro Study

The aim of this in vitro study was to investigate three different cements for their suitability to provide semi-permanent cementation, and to compare the retention forces of implant-supported single crowns (SC) and three-unit fixed dental prostheses (FDP) luted with these cements. Twenty-four methacrylate models were supplied with three implants/abutments each to simulate the condition of SCs/FDPs. Cobalt-chromium frameworks were fabricated, sandblasted (Al2O3/50 µm/0.2 MPa) then cemented with glass-ionomer (KTC), polycarboxylate (DUR) or self-adhesive resin cement (RXU). Specimens were stored in a saline-solution (NaCl/37 °C/24 h) or subjected to thermocycling. A universal testing machine and a pull-off device were used to remove the copings. The multi-factor ANOVA showed that the retention force differed significantly among all cements for the SCs after NaCl storage (p &lt; 0.05). Mean retention forces (in Newtons) after NaCl storage were (SCs/FDPs): KTC 170/352, DUR 409/406, RXU 265/426, and after thermocycling (SCs/FDPs): KTC 156/262, DUR 306/380, RXU 494/508. FDPs showed higher retention values in comparison to SCs. For SCs, artificial aging with thermocycling resulted in a significant retention increase for RXU, whereas the retention of KTC and DUR was decreased. Glass ionomer can be used as a semi-permanent cement for both SCs and FDPs. Polycarboxylate cement is considered semi-permanent after one year of aging.

Engagement Strategies to Improve Adherence and Retention in Web-Based Mindfulness Programs: Systematic Review.

BackgroundWeb-based mindfulness programs may be beneficial in improving the well-being outcomes of those living with chronic illnesses. Adherence to programs is a key indicator in improving outcomes; however, with the digitization of programs, it is necessary to enhance engagement and encourage people to return to digital health platforms. More information is needed on how engagement strategies have been used in web-based mindfulness programs to encourage adherence.ObjectiveThe aim of this study is to develop a list of engagement strategies for web-based mindfulness programs and evaluate the impact of engagement strategies on adherence.MethodsA narrative systematic review was conducted across the MEDLINE Complete, CINAHL Complete, APA PsycINFO, and Embase databases and followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines. Articles were screened using the population, intervention, comparator, and outcome framework. Adults aged >18 years with chronic health conditions were included in the study. Mindfulness interventions, including those in combination with mindfulness-based cognitive therapy, delivered on the web through the internet or smartphone technology were included. Interventions lasted at least 2 weeks. Studies with a randomized controlled trial design or a pilot randomized controlled trial design were included. Engagement strategies, including web-based program features and facilitator-led strategies, adherence, and retention, were included.ResultsA total of 1265 articles were screened, of which 19 were relevant and were included in the review. On average, 70.98% (2258/3181) of the study participants were women with a mean age of 46 (SD 13) years. Most commonly, mindfulness programs were delivered to people living with mental health conditions (8/19, 42%). Of the 19 studies, 8 (42%) used only program features to encourage adherence, 5 (26%) used facilitator-led strategies, and 6 (32%) used a combination of the two. Encouraging program adherence was the most common engagement strategy used, which was used in 77% (10/13) of the facilitator-led studies and 57% (8/14) of the program feature studies. Nearly two-thirds (63%) of the studies provided a definition of adherence, which varied between 50% and 100% completion across studies. The overall mean participant compliance to the mindfulness programs was 56% (SD 15%). Most studies (10/19, 53%) had a long-term follow-up, with the most common follow-up period being 12 weeks after intervention (3/10, 30%). After the intervention, the mean retention was 78% (SD 15%).ConclusionsEngagement strategies in web-based mindfulness programs comprise reminders to use the program. Other features may be suitable for encouraging adherence to interventions, and a facilitator-led component may result in higher retention. There is variance in the way adherence is measured, and intervention lengths and follow-up periods are inconsistent. More thorough reporting and a standardized framework for measuring adherence are needed to more accurately assess adherence and engagement strategies.