Exploring the Perspective of Oral Microbiome Studies in PubMed Database: A Bibliometric Appraisal

This research aims to postulate an exhaustive sketch of the current research background on the oral microbiome to emphasize prevailing research trends. On November 25, 2023, a digital exploration was conducted on the PubMed platform. The search strategy employed was- '(Microbiome, Microbiota, Microorganisms, Bacteria, Virus, Fungi) AND (Oral, Dental, Saliva, Plaque, Gingival Crevicular Fluid)'. Inclusive criteria comprised review articles, clinical trials, and meta-analyses. The Biblioshiny app and VOSviewer software were used to create and visualize bibliometric maps for network, thematic, and factorial analyses. The PubMed database search unveiled 215,068 published research studies on the oral microbiome, indicating a fluctuating publication pattern with an all-embracing mounting trajectory. Notably, there was a substantial increase in publications in 2020 and 2021, succeeded by a marked decline in 2022 and 2023. Sichuan University and the International Journal of Molecular Sciences emerged as the most prolific contributors among organizations and relevant sources. Keyword analysis revealed a research emphasis on the COVID-19 pandemic and the SARS-CoV-2 virus since 2019. Thematic mapping categorized key terms into motor, primary, niche, and emerging themes. The emerging terms identified are viral immunogenicity, antibodies, and vaccines, which support the revelation that COVID-19 and related terms will be the most pertinent subjects in oral microbiome studies in the future. Factorial analysis delineated the relationships between topics and subtopics in this domain.

Adequacy of the WHOQoL-BREF to Assess the Quality of Life of Victims of Armed Conflicts

There is a deterioration in the quality of life (QoL) of survivor victims of warlike conflicts. Because there is a need to guarantee the effectiveness of assessment tools for these populations, we studied the adequacy of the World Health Organization Quality of Life Questionnaire (WHOQoL-BREF) to assess the QoL of 1,136 surviving victims of the armed conflict in Colombia. Although this questionnaire has yielded promising results, questions remain about its psychometric suitability for specific populations. We used model modification at the item level, comparisons of models with different factor structures, and dimensionality analysis to address the psychometric problems encountered. Dimensionality analysis using a bifactor model suggests that WHOQoL-BREF total scores might be a more appropriate way of reporting results when model fit adequacy is not reached. Conclusions are offered on the psychometric properties of the WHOQoL-BREF, the evaluation of special populations, and possible strategies to address future questionnaire modifications.

Toward a new model of human resource management practices: construction and validation of the High Wellbeing and Performance Work System Scale

Introduction

The integrated mutual gains model suggests five provisional sets of human resource management (HRM) practices that should benefit both employees and organizations and, as such, be explicitly designed to have a positive impact on wellbeing, which, in turn, can affect performance.

Methods

An extensive review of the literature on scales that used a high-performance work system to assess HRM practices, as well as an extraction of items related to the theoretical dimensions of the integrated mutual gains model, were performed. Based on these preliminary steps, an initial scale with the 66 items found most relevant in the literature was developed and assessed regarding its factorial structure, internal consistency, and reliability over a two-week period.

Results

Exploratory factorial analysis following test -retest resulted in a 42-item scale for measuring 11 HRM practices. Confirmatory factor analyses resulted in a 36-item instrument for measuring 10 HRM practices and showed adequate validity and reliability.

Discussion

Even though the five provisional sets of practices were not validated, the practices that emerged from them were assembled into alternative sets of practices. These sets of practices reflect HRM activities that are considered conducive to employees' wellbeing and, consequently, their job performance. Consequently, the "High Wellbeing and Performance Work System Scale" was created. Nonetheless, future research is necessary to evaluate the predictive capacity of this new scale.

Brief COPE Short Version (Mini-COPE): A Proposal of Item and Factorial Reduction in Mexican Population

The factorial reduction of Brief COPE has not been successfully replicated by independent studies, and few have been performed in Spanish-speaking populations; therefore, the objective of this study was to perform a factorial reduction of the instrument in a large sample of the Mexican population and perform a convergent and divergent validity of the factors obtained. We distributed a questionnaire via social networks with sociodemographic and psychological variables, including the Brief COPE and the scales of the CPSS, GAD-7, and CES-D to measure stress, anxiety, and depression. A total of 1283 persons were included, most of whom (64.8%) were women and had a bachelor's degree (55.2%). After performing the exploratory factorial analysis, we did not find a model with an adequate fit and a reduced number of factors; therefore, we decided to reduce the number of items according to the most representative ones of adaptive, maladaptive, and emotional coping strategies. The resulting model with three factors showed good fit parameters and good internal consistency of the factors. In addition, the nature and naming of the factors were confirmed by convergent and divergent validity, with significant negative correlations between factor 1 (active/adaptive) and stress, depression, and anxiety, significant positive correlations between factor 2 (avoidant/maladaptive) and these three variables, and no significant correlation between factor 3 (emotional/neutral) and stress or depression. This shortened version of the brief COPE (Mini-COPE) is a good option to evaluate adaptive and maladaptive coping strategies in Spanish-speaking populations.

Larger-diameter trunnions and bolt-reinforced taper junctions are associated with less tribocorrosion in reverse total shoulder arthroplasty

BACKGROUND

Morse taper junction tribocorrosion is recognized as an important failure mode in total hip arthroplasty. Although taper junctions are used in almost all shoulder arthroplasty systems currently available in the United States, with large variation in design, limited literature has described comparable analyses of taper damage in these implants. In this study, taper junction damage in retrieved reverse total shoulder arthroplasty (RTSA) implants was assessed and analyzed.

METHODS

Fifty-seven retrieved RTSAs with paired baseplate and glenosphere components with Morse taper junctions were identified via database query; 19 of these also included paired humeral stems and trays or spacers with taper junctions. Components were graded for standard damage modes and for fretting and corrosion with a modified Goldberg-Cusick classification system. Medical records and preoperative radiographs were reviewed. Comparative analyses were performed assessing the impact of various implant, radiographic, and patient factors on taper damage.

RESULTS

Standard damage modes were commonly found at the evaluated trunnion junctions, with scratching and edge deformation damage on 76% and 46% of all components, respectively. Fretting and corrosion damage was also common, observed on 86% and 72% of baseplates, respectively, and 23% and 40% of glenospheres, respectively. Baseplates showed greater moderate to severe (grade ≥ 3) fretting (43%) and corrosion (27%) damage than matched glenospheres (fretting, 9%; corrosion, 13%). Humeral stems showed moderate to severe fretting and corrosion on 28% and 30% of implants, respectively; matched humeral trays or spacers showed both less fretting (14%) and less corrosion (17%). On subgroup analysis, large-tapered implants had significantly lower summed fretting and corrosion grades than small-tapered implants (P < .001 for both) on glenospheres; paired baseplate corrosion grades were also significantly lower (P = .031) on large-tapered implants. Factorial analysis showed that bolt reinforcement of the taper junction was also associated with less fretting and corrosion damage on both baseplates and glenospheres. Summed fretting and corrosion grades on glenospheres with trunnions (male) were significantly greater than on glenospheres with bores (female) (P < .001 for both).

CONCLUSIONS

Damage to the taper junction is commonly found in retrieved RTSAs and can occur after only months of being implanted. In this study, tribocorrosion predominantly occurred on the taper surface of the baseplate (vs. glenosphere) and on the humeral stem (vs. tray or spacer), which may relate to the flexural rigidity difference between the titanium and cobalt-chrome components. Bolt reinforcement and the use of large-diameter trunnions led to less tribocorrosion of the taper junction. The findings of this study provide evidence for the improved design of RTSA prostheses to decrease tribocorrosion.

Application of Laser-Induced Breakdown Spectroscopy in the Quantitative Analysis of Elements-K, Na, Ca, and Mg in Liquid Solutions

Results of laser-induced breakdown spectroscopy measurements of K, Na, Ca, and Mg content in liquid media are discussed in the paper. Calibration results show correct parameters—linearity and R² coefficients of determination at the levels of 0.94–0.99. Obtained regression equations have been used to determine K, Na, Ca, and Mg concentrations in biological samples with known element content. Measurement results showed acceptable, within the expanded standard uncertainty, conformity with their content in the certified materials. Results have been supported by multivariate factorial analysis, which was especially effective for Ca and Mg samples. For these elements, factorial analysis allows the application of the whole spectra to obtain quantitative data on the tested samples, in contrast to a common method based on the selection of a particular spectral line for the calibration.

Control Strategies of Plastic Biodegradation through Adjusting Additives Ratios Using In Silico Approaches Associated with Proportional Factorial Experimental Design

Plastics, as a polymer material, have long been a source of environmental concern. This paper uses polystyrene plastics as the research object, and the relative contribution of each component of plastic additives to plastic degradation is screened using the molecular dynamics method. The factorial experimental design method is combined with molecular dynamics simulation to adjust the additive composition scheme, analyze the mechanism of interaction between the additive components, and select the plastic additive combination that is most readily absorbed and degraded by microorganisms. Seven different types of plastic additives, including plasticizers, antioxidants, light and heat stabilizers, flame retardants, lubricants, and fillers, are chosen as external stimuli affecting the biodegradability of plastics. Using molecular dynamics simulation technology, it is demonstrated that plastic additives can promote the biodegradability of plastics. The factorial experimental design analysis revealed that all plastic additives can promote plastic biodegradation and plasticizer is the most favorable factor affecting plastic degradation, that hydrophobicity interactions are the primary reason for enhancing plastic degradation, and that screening No. 116–45 (plasticizer A, light stabilizer C, flame retardant E) is the most advantageous combination of biodegradable plastic additives. The plastic biodegradation effect regulation scheme proposed in this study is based on optimizing the proportion of additive components. To continue research on aquatic biodegradable plastics, the optimal combination of plastic components that can be absorbed and degraded by microorganisms is recommended.

Apolipoprotein A-V is a potential target for treating coronary artery disease: evidence from genetic and metabolomic analyses

Triglyceride (TG)-lowering LPL variants in combination with genetic LDL-C-lowering variants are associated with reduced risk of coronary artery disease (CAD). Genetic variation in the APOA5 gene encoding apolipoprotein A-V also strongly affects TG levels, but the potential clinical impact and underlying mechanisms are yet to be resolved. Here, we aimed to study the effects of APOA5 genetic variation on CAD risk and plasma lipoproteins through factorial genetic association analyses. Using data from 309,780 European-ancestry participants from the UK Biobank, we evaluated the effects of lower TG levels as a result of genetic variation in APOA5 and/or LPL on CAD risk with or without a background of reduced LDL-C. Next, we compared lower TG levels via APOA5 and LPL variation with over 100 lipoprotein measurements in a combined sample from the Netherlands Epidemiology of Obesity study (N = 4,838) and the Oxford Biobank (N = 6,999). We found that lower TG levels due to combined APOA5 and LPL variation and genetically-influenced lower LDL-C levels afforded the largest reduction in CAD risk (odds ratio: 0.78 (0.73-0.82)). Compared to patients with genetically-influenced lower TG via LPL, genetically-influenced lower TG via APOA5 had similar and independent, but notably larger, effects on the lipoprotein profile. Our results suggest that lower TG levels as a result of APOA5 variation have strong beneficial effects on CAD risk and the lipoprotein profile, which suggest apo A-V may be a potential novel therapeutic target for CAD prevention.

The Tongue and Mouth Imagery Questionnaire (TMIQ) for Assessing Motor Imagery vividness of the temporomandibular region: a reliability and validity case-control study

Background

To date, no validated assessment of motor imagery (MI) ability with temporomandibular disorders (TMD) exists preventing identification of good imagers and appropriate MI use during TMD rehabilitation.

Objective

To assess the reliability and construct validity of the previously developed Tongue and Mouth Imagery Questionnaire (TMIQ) compared with the gold‐standard Kinaesthetic and Visual Imagery Questionnaire (KVIQ‐10).

Methods

Both KVIQ‐10 and TMIQ assess MI ability using vividness (i.e. clarity/brightness for visual MI, _VMI; or intensity for kinesthetic MI, _KMI) of MI using a 5‐point Likert scale (1: no image/sensation, 5: clear/intense image/sensation). The KVIQ‐10 was administered once (test) and the TMIQ twice (test–retest) to heathy participants and patients with TMD. Questionnaire validity was investigated using concurrent validity (Pearson correlation and paired t test); TMIQ‐test–retest reliability (intraclass correlation coefficients, ICCs); internal consistency (Cronbach ⍺) and the factorial structure (principal factor extraction).

Results

A total of 94 participants were included (n = 47 per group). The mean vividness scores of the KVIQ‐10 and the TMIQ were significantly correlated, and not significantly different for both groups indicating concurrent validity. ICCs in the control group (range: 0.82‐0.90), and in the TMD group (range: 0.75‐0.82) indicated good reproducibility. The Cronbach ⍺ values were all above 0.94, indicating excellent reliability. Two factors were extracted corresponding to _VMI and _KMI, and explained 66% of total variance.

Conclusion

The TMIQ is a valid and reproducible MI questionnaire showing excellent internal consistency and, therefore, can be used to assess imagined movements of the TM region in healthy individuals and patients with TMD.

Family Sense of Coherence Scale: A Confirmatory Factor Analysis in a Portuguese Sample

Background: Family sense of coherence (FSOC) can be defined as the cognitive map of a family that enables the family to deal with stress during their lifetime. FSOC is the degree to which a family perceives family life as comprehensible, manageable, and meaningful. To the best of our knowledge, few studies have used this scale, and very few have evaluated FSOC Scale psychometric properties.

Objective: This study aimed to evaluate the psychometric properties of the original FSOC Scale in a sample of Portuguese caregivers of children aged between 10 and 15 years.

Methods: A total of 329 caregivers completed a sociodemographic questionnaire and the FSOC Scale. Analyses were performed to evaluate the factor structure of the FSOC Scale with 26 items as well as composite reliability, internal consistency, convergent-related validity, and discriminant-related validity of the scale scores.

Results: The findings supported a three-factor solution for a 13-item version that maintains the original FSOC Scale structure. The three FSOC dimensions presented a good fit to the data. Cronbach’s alpha, composite reliability, and convergent-related validity were considered very good for the FSOC Scale (α = 0.956; CR = 0.974; AVE = 0.689). No evidence of discriminant-related validity was found for the dimensions of FSOC.

Conclusion: The findings support the use of the Portuguese FSOC Scale for research and clinical purposes with Portuguese caregivers. Future research is necessary to further develop a European Portuguese version of the FSOC Scale.

Implications: This study provides a psychometric evaluation of FSOC Scale characteristics in a Portuguese sample. The results are helpful for clinicians and family therapists who work with families since it could help them to assess the resources of families and their ability to cope with adversity and enhance their strengths.

Testing the Factorial Validity of the Classroom Engagement Inventory with Spanish Students

Introduction

The purpose of the study was to test the factorial validity of Classroom Engagement Inventory of Wang, Bergin and Bergin with Spanish high school students.

Methods

In this study, 546 students participated (mean = 13.27, standard deviation = 0.629), from several high schools in Andalusia. To analyze the psychometric properties of the scale, several analyses were carried out.

Results

The results offered support for the five-factor structure. The analysis of invariance with respect to gender showed that the factor structure of the questionnaire was invariant. The Cronbach alpha values were higher than 0.70 in the subscales.

Discussion

The results of this study demonstrated the reliability and validity of the Spanish version of the Classroom Engagement Inventory with high school students.

Factorial Structure of the EOCL-1 Scale to Assess Executive Functions

The process of assessing executive functions through behavioral observation scales is still under theoretical and empirical construction. This article reports on the analysis of the factorial structure of the EOCL-1 scale that assesses executive functions, as proposed by the theory developed by Luria, which has not been previously considered in this type of evaluation. In this scale, the executive functions taken into account are error correction, internal behavioral and cognition regulatory language, limbic system conscious regulation, decision making, future consideration of consequences of actions, goal-directed behavior, inhibitory control of automatic responses, creation of new behavioral repertoires, and cognitive–behavioral activity verification. A variety of validity and reliability analyses were carried out, with the following results: (a) an adequate internal consistency level of executive functions between α = 0.70 and α = 0.83, (b) significant convergent validity with a scale that assesses frontal deficits between r = −0.07 and r = 0.28, and (c) the scale’s construct validity that proposes a model with an executive central factor comparative fit index (CFI) = 0.93, root mean square error of approximation (RMSEA) = 0.04 (LO.04 and HI.04), standardized root mean square residual (SRMR) = 0.04, and x²₍₃₁₂₎ = 789.29, p = 0.001. The findings are discussed based on previous literature reports and in terms of the benefits of using a scale to assess the proposed executive functions.

Factor analysis of the Resilience Scale for Brazilian caregivers of people with Alzheimer's disease

Introduction

Resilience is a dynamic process that acts to modify the effects of an adverse life event. In this study, we aimed to test the construct validity of the Resilience Scale by employing exploratory and confirmatory procedures, and to investigate the relationship between caregiver’s resilience and clinical status of people with Alzheimer’s disease.

Methods

A sample of 143 dyads of people with Alzheimer’s disease and their primary caregivers were included.

Results

The total Resilience Scale mean score was 140.3 (standard deviation [SD] = 16.289), ranging from 25 to 175, indicating a high level of resilience. Cronbach’s alpha was high (α = 0.77), indicating excellent internal consistency. The mean of corrected item-total correlation coefficients was moderate. The Resilience Scale presented a four-factor solution with a well-defined structure: sense of life and self-sufficiency, perseverance, self-confidence and equanimity, and meaningfulness.

Conclusion

The findings indicate excellent internal consistency of the Resilience Scale when used to evaluate psychological and emotional difficulties of caregivers, even though the correlations observed between the Resilience Scale and clinical variables were not significant for functionality, mood, awareness, neuropsychiatric symptoms, or burden.

Validation and Adaptation of the Brief Self-Control Scale With Spanish Adolescents: Factorial Structure and Evidences of Reliability, Validity, and Factor Invariance Across Gender and Age

During adolescence, the difficulty to control impulses is especially notable. The Brief Self-Control Scale has been used in different countries for years to study associations between self-control and other variables. However, its factor structure is not completely clear, and it is necessary to have a scale with psychometric assurances that evaluates self-control in adolescents. The aim of this study was to examine the factorial structure of the Brief Self-Control Scale and to provide evidences of reliability, validity, and factor invariance across gender and age in a sample of Spanish adolescents. Participants were 693 adolescents from Southeastern Spain, aged 13 to 18 years. Data supported an excellent fit to a two-dimensional model and evidences of reliability, validity and factor invariance across gender and age were obtained. This study provides new data on the two-dimensionality of self-control. The need of this tool becomes increasingly relevant to the susceptibility of new emerging addictions, such as mobile phones or internet.

Validation of the Lasher and Faulkender Anxiety about Aging Scale (AAS) for the Spanish Context

Increased longevity has led to concerns and fears among the population about the inexorable process of ageing. This process causes individuals to become more anxious about the physical and psychosocial changes caused by the passage of time. However, there are currently no scales in the Spanish context that analyse ageing. Therefore, the aim of the present study is to validate the Anxiety about Aging scale to the Spanish context. In the present study, 594 subjects between 25 and 64 years old participated. Both exploratory and confirmatory factor analyses were used. The results revealed that the factor structure of the questionnaire shows adequate psychometric properties, showing a four-factor factor structure.

Validation of the Index for Inclusion Questionnaire for Parents of Non-University Education Students

The perspective from the parents of non-university students is essential in determining inclusive education in a school. The Index of Inclusion is one of the most widely used self-assessment tools and strategies to help teaching teams self-assess their political cultures and practices from the perspective of the values and principles of educational inclusion worldwide. For this reason, the present study intends to show evidence of validity of the Index for Inclusion questionnaire for parents of non-university education students, in a quantitative way, through a confirmatory factor analysis (CFA). In this study, 108 fathers and 500 mothers took part, aged between 21 and 62 years (M = 43.59; SD = 6.64), whose children belonged to educational institutions throughout Spain. The results revealed adequate adjustment rates, showing invariant structure with respect to sex. The Index for Inclusion for families of non-university education students was shown to be a robust and adequate psychometric instrument to assess the degree of development of inclusive education in educational institutions from the perspective of the parents of said student body. The family is a basic pillar in the education of children and a reference for them. In addition, parents of non-university education students are configured as fundamental participatory elements of the child's educational institution thus; making the family a fundamental element that favors inclusive education. Precisely because of all this, the future administration of this questionnaire (to the parents of these students) is recommended.

Influence of Glucose Availability and CRP Acetylation on the Genome-Wide Transcriptional Response of Escherichia coli: Assessment by an Optimized Factorial Microarray Analysis

Background: While in eukaryotes acetylation/deacetylation regulation exerts multiple pleiotropic effects, in Escherichia coli it seems to be more limited and less known. Hence, we aimed to progress in the characterization of this regulation by dealing with three convergent aspects: the effector enzymes involved, the master regulator CRP, and the dependence on glucose availability.

Methods: The transcriptional response of E. coli BW25113 was analyzed across 14 relevant scenarios. These conditions arise when the wild type and four isogenic mutants (defective in deacetylase CobB, defective in N(ε)-lysine acetyl transferase PatZ, Q- and R-type mutants of protein CRP) are studied under three levels of glucose availability (glucose-limited chemostat and glucose-excess or glucose-exhausted in batch culture). The Q-type emulates a permanent stage of CRP^acetylated, whereas the R-type emulates a permanent stage of CRP^deacetylated. The data were analyzed by an optimized factorial microarray method (Q-GDEMAR).

Results: (a) By analyzing one mutant against the other, we were able to unravel the true genes that participate in the interaction between ΔcobB/ΔpatZ mutations and glucose availability; (b) Increasing stages of glucose limitation appear to be associated with the up-regulation of specific sets of target genes rather than with the loss of genes present when glucose is in excess; (c) Both CRP^deacetylated and CRP^acetylated produce extensive changes in specific subsets of genes, but their number and identity depend on the glucose availability; (d) In other sub-sets of genes, the transcriptional effect of CRP seems to be independent of its acetylation or deacetylation; (e) Some specific ontology functions can be associated with each of the different sets of genes detected herein.

Conclusions: CRP cannot be thought of only as an effector of catabolite repression, because it acts along all the glucose conditions tested (excess, limited, and exhausted), exerting both positive and negative effects through different sets of genes. Acetylation of CRP does not seem to be a binary form of regulation, as there is not a univocal relationship between its activation/inhibitory effect and its acetylation/deacetylation stage. All the combinatorial possibilities are observed. During the exponential growth phase, CRP also exerts a very significant transcriptional effect, mainly on flagellar assembly and chemotaxis (FDR = 7.2 × 10⁻⁴⁴).

Exploring visuospatial abilities and their contribution to constructional abilities and nonverbal intelligence

The present study aimed at exploring relationships among the visuospatial tasks included in the Battery for Visuospatial Abilities (BVA), and at assessing the relative contribution of different facets of visuospatial processing on tests tapping constructional abilities and nonverbal abstract reasoning. One hundred forty-four healthy subjects with a normal score on Mini Mental State Examination completed the BVA plus Raven's Coloured Progressive Matrices and Constructional Apraxia test. We used Principal Axis Factoring and Parallel Analysis to investigate relationships among the BVA visuospatial tasks, and performed regression analyses to assess the visuospatial contribution to constructional abilities and nonverbal abstract reasoning. Principal Axis Factoring and Parallel Analysis revealed two eigenvalues exceeding 1, accounting for about 60% of the variance. A 2-factor model provided the best fit. Factor 1 included sub-tests exploring "complex" visuospatial skills, whereas Factor 2 included two subtests tapping "simple" visuospatial skills. Regression analyses revealed that both Factor 1 and Factor 2 significantly affected performance on Raven's Coloured Progressive Matrices, whereas only the Factor 1 affected performance on Constructional Apraxia test. Our results supported functional segregation proposed by De Renzi, suggesting clinical caution to utilize a single test to assess visuospatial domain, and qualified the visuospatial contribution in drawing and non-verbal intelligence test.

Factorial analysis of the binding properties of acetylated ginger starch in metronidazole tablet formulations

INTRODUCTION

The delivery of drug is often affected by formulation processes and the excipients used in the formulation.

MATERIALS AND METHODS

A 2³ factorial analysis was used in this study to evaluate the effect of acetylated ginger starch (AGS) (Zingiber officinale) as a binder in metronidazole tablets, in comparison to corn starch (CS) BP. The individual and interacting effects of variables (binder type X₁, binder concentration X₂, and compression pressure X₃) used on tablet properties such as friability, crushing strength, crushing strength friability ratio (CSFR), disintegration and crushing strength friability/disintegration time ratio (CSFR/DT) were determined. The effect of these binders on the granule properties using Hausner's ratio, Carr's index (CI), angle of repose, and densities as response parameters was also determined.

RESULTS

Granules prepared with AGS had high densities and small granule sizes when compared with those containing CS. Granules containing CS have better flow properties. X₁ (binder type) has a significant effect on the crushing strength of the tablet. It also had the highest effects on CSFR and CSFR/DT. The combination of X_IX₃ had the highest effect on crushing strength and DT.

CONCLUSION

This study shows that, in formulations, care must be taken in choosing the excipients and the process parameters required for the formulation since these can affect the delivery of the drug individually or in combination. AGS could be useful as a binder when a tablet with low crushing strength and fast disintegration is desired.

Defining a typology of primary care practices: a novel approach

Objective

To define a typology of primary care (PC) practices based on a mixed inductive/deductive approach that uses a large number of variables describing organizational and demographic characteristics of practices and a priori hierarchical structuring of the data.

Design

Secondary analysis of the Swiss part of the QUALICOPC study using a multiple factor analysis approach incorporating 74 variables hierarchically structured and including information on infrastructures, clinical care, workforces, accessibility and geographic location of PC practices.

Setting

Switzerland.

Participants

Two hundred randomly selected PC practices.

Main Outcome Measures

Typology of PC practices based on axes identified through the multiple factorial approach.

Results

The factorial analysis extracted two uncorrelated axes summarizing 17% of the global variance. The first axis is mainly associated with two dimensions related to the comprehensiveness of services, namely 'clinical care provided' (Pearson's r = 0.73) and 'available infrastructures' (r = 0.78). The second axis is mainly associated with the workforce in the practice such as the number of general practitioners or other health workers (r = 0.69). Swiss PC practices were mapped using these two axes.

Conclusions

This innovative approach allows defining a global typology of PC practices. Based upon Swiss data, two axes were identified to globally describe PC organization: comprehensiveness of services and workforces development. This exploratory study demonstrates a promising way, first to characterize globally one or several PC models that emerge from complex features, second to compare more accurately PC organization between countries and finally to assess how these models might be associated with patients' outcomes.

Non-factorial analyses of two-by-two factorial trial designs

BACKGROUND/AIMS

Factorial analyses of 2 × 2 trial designs are known to be problematic unless one can be sure that there is no interaction between the treatments (A and B). Instead, we consider non-factorial analyses of a factorial trial design that addresses clinically relevant questions of interest without any assumptions on the interaction. Primary questions of interest are as follows: (1) is A better than the control treatment C, (2) is B better than C, (3) is the combination of A and B (AB) better than C, and (4) is AB better than A, B, and C.

METHODS

A simple three-step procedure that tests the first three primary questions of interest using a Bonferroni adjustment at the first step is proposed. A Hochberg procedure on the four primary questions is also considered. The two procedures are evaluated and compared in limited simulations. Published results from three completed trials with factorial designs are re-evaluated using the two procedures.

RESULTS

Both suggested procedures (that answer multiple questions) require a 50%-60% increase in per arm sample size over a two-arm design asking a single question. The simulations suggest a slight advantage to the three-step procedure in terms of power (for the primary and secondary questions). The proposed procedures would have formally addressed the questions arising in the highlighted published trials arguably more simply than the pre-specified factorial analyses used.

CONCLUSION

Factorial trial designs are an efficient way to evaluate two treatments, alone and in combination. In situations where a statistical interaction between the treatment effects cannot be assumed to be 0, simple non-factorial analyses are possible that directly assess the questions of interest without the zero interaction assumption.

Design of antimicrobial peptides conjugated biodegradable citric acid derived hydrogels for wound healing

Wound healing is usually facilitated by the use of a wound dressing that can be easily applied to cover the wound bed, maintain moisture, and avoid bacterial infection. In order to meet all of these requirements, we developed an in situ forming biodegradable hydrogel (iFBH) system composed of a newly developed combination of biodegradable poly(ethylene glycol) maleate citrate (PEGMC) and poly(ethylene glycol) diacrylate (PEGDA). The in situ forming hydrogel systems are able to conform to the wound shape in order to cover the wound completely and prevent bacterial invasion. A 2(k) factorial analysis was performed to examine the effects of polymer composition on specific properties, including the curing time, Young's modulus, swelling ratio, and degradation rate. An optimized iFBH formulation was achieved from the systematic factorial analysis. Further, in vitro biocompatibility studies using adult human dermal fibroblasts (HDFs) confirmed that the hydrogels and degradation products are not cytotoxic. The iFBH wound dressing was conjugated and functionalized with antimicrobial peptides as well. Evaluation against bacteria both in vitro and in vivo in rats demonstrated that the peptide-incorporated iFBH wound dressing offered excellent bacteria inhibition and promoted wound healing. These studies indicated that our in situ forming antimicrobial biodegradable hydrogel system is a promising candidate for wound treatment.

Nanosizing of a poorly soluble drug: technique optimization, factorial analysis, and pharmacokinetic study in healthy human volunteers

CONTEXT

Diacerein (DCN) has low aqueous solubility (3.197 mg/L) and, consequently, low oral bioavailability (35%-56%). To increase both the solubility and dissolution rate of DCN while maintaining its crystalline nature, high pressure homogenization was used but with only a few homogenization cycles preceded by a simple bottom-up technique.

METHODS

The nanosuspensions of DCN were prepared using a combined bottom-up/top-down technique. Different surfactants - polyvinyl alcohol, sodium deoxycholate, and sodium dodecyl sulfate - with different concentrations were used for the stabilization of the nanosuspensions. Full factorial experimental design was employed to investigate the influence of formulation variables on nanosuspension characteristics using Design-Expert(®) Software. Particle size (PS), zeta potential, saturation solubility, in vitro dissolution, and drug crystallinity were studied. Moreover, the in vivo performance of the optimized formula was assessed by bioavailability determination in healthy human volunteers.

RESULTS

The concentration of surfactant had a significant effect on both the PS and polydispersity index values. The 1% surfactant concentration showed the lowest PS and polydispersity index values compared with other concentrations. Both type and concentration of surfactant had significant effects on the zeta potential. Formula F8 (containing 1% sodium deoxycholate) and Formula F12 (containing 1% sodium dodecyl sulfate) had the highest desirability values (0.952 and 0.927, respectively). Hence, they were selected for further characterization. The saturated solubility and mean dissolution time, in the case of F8 and F12, were significantly higher than the coarse drug powder. Techniques utilized in the nanocrystals' preparation had no effect on DCN crystalline state. The selected formula (F12) showed a higher bioavailability compared to the reference market product with relative bioavailability of 131.4%.

CONCLUSION

The saturation solubility, in vitro dissolution rate and relative bioavailability of DCN were significantly increased after nanocrystallization. Less time and power consumption were applied by the combination of bottom-up and top-down techniques.

[Factorial analysis of root canal irrigants and cements on coronal microleakage after cementing metal post-cores]

OBJECTIVE

To evaluate the effect of different root canal irrigants and cements on coronal microleakage and the interaction effects after cementing metal post-cores.

METHODS

Ninety newly extracted single-rooted mandibular human premolars were endodontically treated. Post spaces were prepared in the root canals, and Co-Cr post-cores were cast routinely. The specimens were randomly divided into six groups (n = 15) via a two-way factorial design method. The irrigant factors (A) included A1: no irrigant (75% alcohol wiping), A2: 3% H2O2 + 0.9% NaCl, and A3: 15% ethylenediamine tetraacetic acid (EDTA) + 5.25% NaClO. The cement factors (B) included B1: zinc polycarboxylate cement, and B2: glass ionomer cement. The specimens received treatments based on the grouping of A1B1, A1B2, A2B1, A2B2, A3B1, and A3B2. All samples were sectioned longitudinally after being immersed in India ink for three weeks. The microleakages were observed using a stereomicroscope. The SPSS 13.0 software package was used for factorial analysis.

RESULTS

The mean microleakage scores and standard deviations were as follows: Group A1BI: (1,192.59 +/- 417.84) microm, Group A1B2: (1,317.38 +/- 527.35) microm, Group A2B1: (1,429.33 +/- 482.68) microm, Group A2B2: (1,026.79 +/- 459.49) microm, Group A3B1: (1,448.29 +/- 561.02) microm, and Group A3B2: (1,922.47 +/- 678.86) microm. The A2B2 group showed minimum microleakage, whereas the A3B2 group showed maximum microleakage. The microleakage degrees among different irrigants presented significant statistical difference (P < 0.05), but the two cements showed no significant difference (P > 0.05). An interactive effect on the microleakage existed between the irrigants and the cements after cementing the metal post-cores (P < 0.05).

CONCLUSION

When cementing metal post-cores, the coronal microleakage following 3% H2O2 + 0.9% NaCl irrigation combined with glass ionomer cement can be reduced. The combined application of 15% EDTA + 5.25% NaClO and glass ionomer cement significantly aggravates microleakage.

Inhibition/activation in bipolar disorder: validation of the Multidimensional Assessment of Thymic States scale (MAThyS)

BACKGROUND

One of the major issues in clinical practice is the accurate differential diagnosis between mixed states and depression, often leading to inappropriate prescriptions of antidepressants in mixed states, and as a consequence, increasing the risk of manic switch and suicide. In order to better define the spectrum of mixed states, it may be useful to develop a dimensional approach. In this context, the MAThyS (Multidimensional Assessment of Thymic States) scale was built to assess activation/inhibition levels in all bipolar mood episodes, and to determine whether a clinical description in terms of activation/inhibition can help better define bipolar states with which both manic and depressive symptoms are associated. The aim of this paper is the validation of the MAThyS scale in 141 bipolar patients in acute states (manic, hypomanic, mixed, or depressive).

METHODS

The validation of the MAThyS scale was the primary outcome of this 24-week, phase III, open-label, olanzapine single-arm clinical trial. Principal component, factorial analysis, and Cronbach's coefficient calculation (internal consistency) were performed. Concurrent validity (correlations with 17-item Hamilton Depression Rating Scale [HAMD-17], Hamilton Anxiety Rating Scale [HAMA], and Young Mania Rating Scale [YMRS]) and responsiveness to the clinical intervention were assessed (change in MAThyS scale and effect size) at 6 and 24 weeks.

RESULTS

Scree plot of eigenvalues identified a 2-dimension structure ("activation/inhibition level" and "emotional component"). Psychometric properties were good: Cronbach's coefficient was >0.9. Concurrent validity was good with low correlation (-0.19) with the HAMA scale and a higher correlation at baseline with the YMRS (0.72) and HAMD-17(-0.43). As expected, the activation state was predominant in manic, hypomanic, and mixed states while inhibition was predominant in depressive states. MAThyS score improvement was observed (effect size: -0.3 at 6 and 24 weeks).

CONCLUSIONS

The MAThyS demonstrated good psychometric properties. The MAThyS scale may help clinicians to better discriminate and follow bipolar episodes, especially the broad spectrum of mixed episodes.