Isolation, identification, and significance of salivary Veillonella spp., Prevotella spp., and Prevotella salivae in patients with inflammatory bowel disease.

The global prevalence of inflammatory bowel disease (IBD) is on the rise, prompting significant attention from researchers worldwide. IBD entails chronic inflammatory disorders of the intestinal tract, characterized by alternating flares and remissions. Through high-throughput sequencing, numerous studies have unveiled a potential microbial signature for IBD patients showing intestinal enrichment of oral-associated bacteria. Simultaneously, the oral microbiome can be perturbed by intestinal inflammation. Our prior investigation, based on 16S rRNA amplicon sequencing, underscored elevated abundance of Veillonella spp. and Prevotella spp. in the salivary microbiomes of IBD patients. Noteworthy, Prevotella salivae emerged as a distinct species significantly associated with IBD. P. salivae is an under-recognized pathogen that was found to play a role in both oral and systemic diseases. In this study, we delve deeper into the salivary microbiomes of both IBD patients and healthy controls. Employing diverse cultivation techniques and real-time quantitative polymerase chain reactions (RT-qPCR), we gauged the prevalence and abundance of Veillonella spp., Prevotella spp., and P. salivae. Our isolation efforts yielded 407 and 168 strains of Veillonella spp., as well as 173 and 90 strains of Prevotella spp., from the saliva samples of IBD patients and healthy controls, respectively. Veillonella-vancomycin agar emerged as the discerning choice for optimal Veillonella spp. cultivation, while Schaedler kanamycin-vancomycin agar proved to be the most suitable medium for cultivating Prevotella spp. strains. Comparing our RT-qPCR findings to the previous 16S rRNA amplicon sequencing data, the results corroborated the higher abundance of Veillonella spp., Prevotella spp., and P. salivae in the saliva of IBD patients compared to healthy controls. However, it's worth noting that in contrast to RT-qPCR, the 16S rRNA amplicon sequencing data revealed greater absolute abundance of all three bacterial groups in both IBD patients and controls.

Exploring the genetic and functional diversity of Porphyromonas gingivalis long fimbriae.

Porphyromonas gingivalis is a key pathobiont in periodontitis. Its long fimbriae consist of a single anchor (FimB), a varying number of stalk (FimA), and three accessory (tip-related) proteins (FimC, FimD, and FimE). Based on 133 strains/genomes available, it was our aim to investigate the diversity within FimA and FimB and explain the variety of long fimbriae (super-)structures. Combining the new forward primer fimAnewF with the established fimAunivR, we were able to amplify and sequence fimA including its leader region covering all genotypes and serotypes for phylogenetic analysis. We designed two primer pairs sensing the presence of an internal stop codon in fimB with an impact on fimbrial length. Finally, we examined fimbrial secondary structures by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The phylogeny of fimA/FimA revealed two new subtypes (IIa and IIb) with specific changes in functional domains and thus adding to the current classification scheme (I, Ib, and II-V). Regarding evolution, we confirm that Porphyromonas gulae fimA-type A is closely related to human P. gingivalis strains of cluster Ib and might be its ancestor genotype. A fimB internal stop codon is rare and was found in ATCC 33277 only. Comparing P. gingivalis TEM/SEM pictures of type I ATCC 33277 with type V OMI622 revealed a broad spectrum of fimbrial structures including bundling, cell-cell knotting, and brick-wall formation. In conclusion, FimA forms more distinct subtypes than previously known. The bundling of long fimbriae, a mechanism known from EPEC/EHEC and Salmonella, is proposed and supported by TEM/SEM pictures for the first time here. The role and variations of terminal accessory FimC-E in superstructure formation and/or (co-) adhesion should be investigated more closely next.

Cyclodextrins for Lithium Batteries Applications.

Due to their high energy and power density, lithium-ion batteries (LIBs) have gained popularity in response to the demand for effective energy storage solutions. The importance of the electrode architecture in determining battery performance highlights the demand for optimization. By developing useful organic polymers, cyclodextrin architectures have been investigated to improve the performance of Li-based batteries. The macrocyclic oligosaccharides known as cyclodextrins (CDs) have relatively hydrophobic cavities that can enclose other molecules. There are many industries where this "host-guest" relationship has been found useful. The hydrogen bonding and suitable inner cavity diameter of CD have led to its selection as a lithium-ion diffusion channel. CDs have also been used as solid electrolytes for solid-state batteries and as separators and binders to ensure adhesion between electrode components. This review gives a general overview of CD-based materials and how they are used in battery components, highlighting their advantages.

Modified Capsulorrhaphy Technique in Open Reduction of Developmental Dysplasia of the Hip.

BACKGROUND: Neglected patients with developmental dysplasia of the hip (DDH) are not uncommon. Various treatment modalities have been used. Capsulorrhaphy is one of the most critical steps during the process of open reduction of DDH. Inadequate capsulorrhaphy technique can increase the failure rate of open reduction procedures. This study presented the clinical and radiographic results of using a new capsulorrhaphy technique. METHODS: Between November 2005 and March 2018, 540 DDH in 462 patients were retrospectively reviewed. The mean age at surgery was 31 months. All patients underwent a modified capsulorrhaphy technique developed by the main author (with or without additional pelvic or femoral procedures). Postoperative patient assessment during the follow-up period was performed both clinically and radiologically. RESULTS: Follow-up period ranged between 36 months and 12 years. Based on the modified McKay score, good and excellent outcomes were obtained in 90.3%. Functional results were better in younger age (less than 39 mo). Both acetabular index and lateral center edge angle showed significant improvement at 3 years follow-ups. Proximal femoral growth disturbance (PFGD) was encountered in 92 hips. Classes 2 and 3 did not affect the functional results, whereas patients with PFGD classes 4 and 5 had fair to poor functional outcomes. There were 12 hips with redislocation. Revision was done using the same capsulorrhaphy technique. CONCLUSION: Using the index technique of capsulorrhaphy in DDH surgery is safe, reliable, and yields good functional and radiologic outcomes with a relatively low complication rate. LEVEL OF EVIDENCE: Level IV-therapeutic retrospective case series.

A Comparison between the Molecularly Imprinted and Non-Molecularly Imprinted Cyclodextrin-Based Nanosponges for the Transdermal Delivery of Melatonin.

Melatonin is a neurohormone that ameliorates many health conditions when it is administered as a drug, but its drawbacks are its oral and intravenous fast release. To overcome the limitations associated with melatonin release, cyclodextrin-based nanosponges (CD-based NSs) can be used. Under their attractive properties, CD-based NSs are well-known to provide the sustained release of the drug. Green cyclodextrin (CD)-based molecularly imprinted nanosponges (MIP-NSs) are successfully synthesized by reacting ß-Cyclodextrin (ß-CD) or Methyl-ß Cyclodextrin (M-ßCD) with citric acid as a cross-linking agent at a 1:8 molar ratio, and melatonin is introduced as a template molecule. In addition, CD-based non-molecularly imprinted nanosponges (NIP-NSs) are synthesized following the same procedure as MIP-NSs without the presence of melatonin. The resulting polymers are characterized by CHNS-O Elemental, Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric (TGA), Differential Scanning Calorimetry (DSC), Zeta Potential, and High-Performance Liquid Chromatography (HPLC-UV) analyses, etc. The encapsulation efficiencies are 60-90% for MIP-NSs and 20-40% for NIP-NSs, whereas melatonin loading capacities are 1-1.5% for MIP-NSs and 4-7% for NIP-NSs. A better-controlled drug release performance (pH = 7.4) for 24 h is displayed by the in vitro release study of MIP-NSs (30-50% released melatonin) than NIP-NSs (50-70% released melatonin) due to the different associations within the polymeric structure. Furthermore, a computational study, through the static simulations in the gas phase at a Geometry Frequency Non-covalent interactions (GFN2 level), is performed to support the inclusion complex between ßCD and melatonin with the automatic energy exploration performed by Conformer-Rotamer Ensemble Sampling Tool (CREST). A total of 58% of the CD/melatonin interactions are dominated by weak forces. CD-based MIP-NSs and CD-based NIP-NSs are mixed with cream formulations for enhancing and sustaining the melatonin delivery into the skin. The efficiency of cream formulations is determined by stability, spreadability, viscosity, and pH. This development of a new skin formulation, based on an imprinting approach, will be of the utmost importance in future research at improving skin permeation through transdermal delivery, associated with narrow therapeutic windows or low bioavailability of drugs with various health benefits.

Carbon Dioxide-Mediated Desalination.

Conventional desalination membrane technologies, although offer portable drinking water, are still energy-intensive processes. This paper proposes a potentially new approach for performing water desalination and purification by utilizing the reversible interaction of carbon dioxide (CO2) with nucleophilic amines─reminiscent of the Solvay process. Based on our model studies with small molecules, CO2-responsive amphiphilic insoluble diamines were prepared, characterized, and applied in the formation of soda and ammonium chloride upon exposure to ambient CO2 (1 atm), thus removing chloride ions from model and real seawater. This ion-exchange process and separation of chloride from the aqueous phase are spontaneous in the presence of CO2 without the need for external energy sources. We demonstrate a flow system to envisage energy-efficient CO2-mediated desalination and simultaneous carbon capture and sequestration.

Evaluation of hydrocortisone as a strain-dependent growth-regulator of Porphyromonasgingivalis.

OBJECTIVE: Porphyromonas gingivalis is an oral key pathogen and known to be very diverse in geno- and phenotypes. It is a fastidious bacterium with low O2-tolerance and 3-7 days of incubation are necessary. With growing interest in the field of microbial endocrinology we explored the potential growth-stimulating effect of hydrocortisone (HC, synonym cortisol) on P. gingivalis cultures. MATERIAL AND METHODS: Six different P. gingivalis strains were pre-incubated in supplemented Brain-Heart-Infusion broth under appropriate conditions for 24 h, diluted and transferred into microplates. A newly developed and semi-automated spectrophotometric measurement in triplicate, applying a SpectraMax i3x microplate reader at an optical density of 600 nm, was conducted to test growth differences between test group (exposed to a supplement of either 1.25, 2.5, 5, 10, or 20 µg/ml of hydrocortisone) and control group over 48 h of anaerobic incubation (O2 ≤ 1%). Furthermore, strains were also incubated on HC-supplemented blood agar to test for a possible growth-stimulating effect on solid media. RESULTS: HC significantly stimulated the lag-phase growth of four out of six P. gingivalis strains. Our data suggest a concentration-dependent growth stimulatory effect of HC between 2.5 and 5 µg/ml, while below 1.25 µg/ml and above 10 µg/ml HC either did not stimulate or inhibited growth. CONCLUSIONS: HC could reduce the incubation time when isolating P. gingivalis from clinical samples and could boost low biomass cultivations especially during their lag-phase. The growth-modulating effect might be via modulation of virulence factors/quorum sensing gene expression or by reactive oxygen species(ROS)-capturing during early stages of bacterial growth. Further experiments are necessary to explain the mechanism behind our observations.

Antimicrobial efficiency and cytocompatibility of different decontamination methods on titanium and zirconium surfaces.

OBJECTIVES: The purpose of this study was to investigate the efficiency of different implant-decontamination methods regarding biofilm modification and potential cytotoxic effects. Therefore, the amount of biofilm reduction, cytocompatibility, and elementary surface alterations were evaluated after decontamination of titanium and zirconium surfaces. MATERIAL AND METHODS: Titanium and zirconium disks were contaminated with a newly developed high-adherence biofilm consisting of six microbial species. Decontaminations were performed using titanium curette, stainless steel ultrasonic scaler (US), glycine (GPAP) and erythritol (EPAP) powder air-polishing, Er:YAG laser, 1% chlorhexidine (CHX), 10% povidone-iodine (PVI), 14% doxycycline (doxy), and 0.95% NaOCl solution. Microbiologic analysis was done using real-time qPCR. For assessment of cytocompatibility, a multiplex assay for the detection of cytotoxicity, viability, and apoptosis on human gingival fibroblasts was performed. X-ray photoelectron spectroscopy (XPS) was used to evaluate chemical alterations on implant surfaces. RESULTS: Compared with untreated control disks, only GPAP, EPAP, US, and Er:YAG laser significantly reduced rRNA counts (activity) on titanium and zirconium (p < .01), whereas NaOCl decreased rRNA count on titanium (p < .01). Genome count (bacterial presence) was significantly reduced by GPAP, EPAP, and US on zirconium only (p < .05). X-ray photoelectron spectroscopy analyses revealed relevant re-exposure of implant surface elements after GPAP, EPAP, and US treatment on both materials, however, not after Er:YAG laser application. Cytocompatibility was impaired by CHX, PVI, doxy, and NaOCl. CHX and PVI resulted in the lowest viability and doxy in the highest apoptosis. CONCLUSIONS: Within the limits of this in vitro study, air-polishing methods and ultrasonic device resulted in effective biofilm inactivation with surface re-exposure and favorable cytocompatibility on titanium and zirconium. Chemical agents, when applied on implant surfaces, may cause potential cytotoxic effects.

The oral-gut axis: Salivary and fecal microbiome dysbiosis in patients with inflammatory bowel disease.

Inflammatory bowel disease (IBD) is a group of chronic inflammatory disorders that fall into two main categories: Crohn's disease (CD) and ulcerative colitis (UC). The gastrointestinal tract extends from the mouth to the anus and harbors diverse bacterial communities. Several sequencing-based studies have identified an intestinal enrichment of oral-associated bacteria and demonstrated their ability to induce intestinal inflammation in mice, suggesting that intestinal pathobionts originate from the oral cavity, particularly members of the genus Streptococcus. This study aimed to investigate the composition of the salivary and fecal microbiome of IBD patients (n = 14) compared to healthy controls (n = 12) and to determine the abundance of common bacterial taxa in both niches. Metagenomic DNA was extracted from saliva and fecal samples, and the 16S rRNA gene was targeted for sequencing. Our results revealed that the overall microbial composition of saliva was significantly altered in the IBD patients compared to the control subjects (p = 0.038). At the genus level, Veillonella and Prevotella were highly abundant in IBD (median: 25.4% and 22.2%, respectively) compared to the control group (17.9% and 13.4%, respectively). In contrast, Neisseria, Streptococcus, Haemophilus, and Fusobacterium were associated with a healthy gut state. Regarding the fecal microbiome, the IBD group had a significantly higher abundance of Clostridium sensu stricto 1 and Escherichia-Shigella (both comprising pathogenic bacteria) compared with the control group. Members of both bacterial groups have previously been shown to positively correlate with intestinal inflammation and high expression of pro-inflammatory cytokines that disrupt intestinal barrier integrity. In addition, we demonstrate that the increased abundance of Clostridium sensu stricto 1 and Escherichia-Shigella has also been associated with significant upregulation of certain metabolic pathways in the feces of the IBD group, including bacterial invasion of epithelial cells. Streptococcus was the only common genus detected in both the salivary and fecal microbiome and represented the oral-gut axis in our study. Using culture-based methods, we isolated 57 and 91 Streptococcus strains from saliva as well as 40 and 31 strains from fecal samples of the controls and IBD patients, respectively. The phylogenetic tree of streptococci based on sodA sequences revealed several patient-specific clusters comprising salivary and fecal streptococcal isolates from the same patient and belonging to the same species, suggesting that the oral cavity is an endogenous reservoir for intestinal strains.

Impact of sucroferric oxyhydroxide on the oral and intestinal microbiome in hemodialysis patients.

Hyperphosphatemia is a consequence of chronic kidney disease associated with mineral/bone impairment, increased cardiovascular events and mortality. Therapeutically, most dialysis patients have to take phosphate binders. Here, we investigated effects of the Fe(3+)-based phosphate binder sucroferric oxyhydroxide (SFOH) on the oral and gastrointestinal microbiome of 11 hemodialysis patients. Saliva, dental plaque and stool were collected at baseline, one and four weeks of SFOH intake and subjected to 16S rRNA gene (V3-V4 region) directed Illumina MiSeq-based analysis. Total Fe, Fe(2+) and Fe(3+) were determined in stool and saliva. Overall, the microbiome did not change significantly. However, some patient-, sample- and taxon-specific differences were noted, which allowed patients to be divided into those with a shift in their microbiome (6/11) and those without a shift (5/11). Total Fe and Fe(2+) were highest after one week of SFOH, particularly in patients who exhibited a shift in microbiome composition. Eight bacterial taxa showed significant unidirectional changes during treatment. In-depth microbiome analysis revealed that taxa that significantly benefited from iron plethora had no iron-binding siderophores or alternatives, which was in contrast to taxa that significantly declined under iron plethora. Patients with microbiome-shift were significantly younger and had higher serum phosphate concentrations. In conclusion, this study sheds light on the impact of iron on the microbiome of hemodialysis patients.

Impact of Three Nonsurgical, Full-Mouth Periodontal Treatments on Total Bacterial Load and Selected Pathobionts.

For the treatment of periodontitis stage III/IV, a quadrant/week-wise debridement (Q-SRP) was compared with three full-mouth approaches: full-mouth scaling (FMS, accelerated Q-SRP within 24 h), full-mouth scaling with chlorhexidine-based disinfection (FMD), and FMD with adjuvant erythritol air polishing (FMDAP). The objective of this prospective, randomized study (a substudy of ClinicalTrials.gov, identifier: NCT03509233) was to compare the clinical and microbiological effects of the treatments. In total, 105 patients were randomized to one of the four aforementioned treatment groups, with n = 25, 28, 27, and 25 patients allocated to each group, respectively. At baseline and 3 and 6 months after treatment, the clinical parameters, including the pocket probing depths, clinical attachment level, and bleeding on probing, were recorded, and the prevalence of the total bacteria and four periodontal pathobionts (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, and Tannerella forsythia) was determined using real-time quantitative PCR. Concerning the clinical outcomes, all the treatment modalities were effective, but the full-mouth approaches, especially FMDAP, were slightly superior to Q-SRP. Using the FMD approach, the reduction in the bacterial load and the number of pathobionts was significantly greater than for FMS, followed by Q-SRP. FMDAP was the least effective protocol for microbial reduction. However, after a temporary increase 3 months after therapy using FMDAP, a significant decrease in the key pathogen, P. gingivalis, was observed. These findings were not consistent with the clinical results from the FMDAP group. In conclusion, the dynamics of bacterial colonization do not necessarily correlate with clinical outcomes after full-mouth treatments for periodontitis stage III/IV.

Isoeugenol-functionalized nanogels inhibit peri-implantitis associated bacteria in vitro.

OBJECTIVES: Obligate and facultative anaerobic bacteria adhering to dental implants are a major cause for peri-implant inflammation, which, if left untreated, can lead to implant loss. Previously, our group developed a new route for the synthesis of isoeugenol-functionalized aqueous nanogels for implant coatings. METHODS: Here, the antimicrobial activity of several new nanogels differing in spacer length (n = 6, 9, 44), radius (60-200 nm), and amount of isoeugenol functional substance (1-20 mol%) was tested against the following peri-implantitis-associated species: Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Aggregatibacter actinomycetemcomitans, Escherichia coli, Actinomyces viscosus, Enterococcus faecalis, Staphylococcus aureus, Streptococcus oralis, S. parasanguinis, and the yeast Candida albicans. The minimal bactericidal concentration (MBC) and fungicidal concentration (MFC) were determined for each combination. In addition, transmission electron microscopy (TEM) and fluorescence microscopy after live-dead-staining (LD-S) were performed to visualize nanogel-microbe interactions. RESULTS: Two nanogels, NG9-3 and NG9-4 (colloids of 80-150 nm, with a spacer length of n = 9 and feeding between 5 and 10 mol% isoeugenol), had an inhibitory effect on all Gram-positive species and on P. gingivalis and P. intermedia with MBC ≥31.25 µg/ml. TEM and LD-S images showed that cellular adhesion and uptake of nanogels resulted in swelling, shedding, or even complete detachment of the cell wall and then to bursting (see graphical abstract). CONCLUSIONS: Functional nanogels can be used as building blocks in the design of bioactive coatings on implants to prevent infection and accelerate tissue regeneration, but the concentrations required are higher than for antibiotics.

Urethral complex thickness and thickness index are the independent risk factors for urethroplasty complications after tubularized incised plate hypospadias repair.

INTRODUCTION: In tubularized incised plate urethroplasty, the depth of the mid-line relaxing incision is the key factor for urethral plate tubularization without tension. The incision depths will be different from one case to the other even if they have been done by the same surgeon. This difference in depths resulted from the different thicknesses of the urethral plate and the underlying corpus spongiosum (urethral complex). OBJECTIVES: To evaluate the urethral complex thickness and thickness index as risk factors for the complications of TIPU in penile shaft hypospadias repair. STUDY DESIGN: All primary penile shaft (distal and mid-penile) hypospadias (with or without mild penile chordee) were operated with TIPU between March 2018 and February 2021. We measured the urethral complex thickness in the hypospadiac and proximal normal parts of urethra pre-operatively with superficial U/S probe. Intraoperative, we measured the urethral plate width before and after the midline relaxing incision, calculate the relative increase in urethral plate width (RIUPW). Stepwise logistic regression assessed the effect of different variables on the complication rate. These variables include; urethral plate width before and after incision, urethral complex thickness, thickness index, RIUPW, site of hypospadiac meatus and patients ages. RESULTS: 10 cases had 11 complications (12.7%). Fistulae were the commonest complication (8.9%). Complication rate has significant negative correlations with many variables on Univariate analysis. Stepwise logistic regression shows that urethral plate thickness and thickness index are the independent risk factors for complications after TIPU in penile shaft hypospadias. DISCUSSION: Urethral plate width was suggested to be a risk factor for TIPU complications. In our study, Univariate analysis shows that complications were more with plate width ˂8 mm but without significant difference (P = 0.487). Also it shows that post incision width and RIUPW have significant negative correlation with complications rate. Multivariate analysis showed that the urethral complex thickness and thickness index are the independent risk factors for complications after TIPU hypospadias repair (AUC 0.94 95% CI 0.894-0.972 P Ë‚ 0.001 and 0.965 95% CI 0.921-0.996, respectively). CONCLUSION: The thickness of the urethral plate and the underlying spongiosum is the determining factor for TIPU success. We can use it as an objective reproducible assessment tool for urethral plate quality and to predict TIPU complications.

Lessons Learned from Peer Learning Conference in Cardiothoracic Radiology.

Medical errors may lead to patient harm and may also have a devastating effect on medical providers, who may suffer from guilt and the personal impact of a given error (second victim experience). While it is important to recognize and remedy errors, it should be done in a way that leads to long-standing practice improvement and focuses on systems-level opportunities rather than in a punitive fashion. Traditional peer review systems are score based and have some undesirable attributes. The authors discuss the differences between traditional peer review systems and peer learning approaches and offer practical suggestions for transitioning to peer learning conferences. Peer learning conferences focus on learning opportunities and embrace errors as an opportunity to learn. The authors also discuss various types and sources of errors relevant to the practice of radiology and how discussions in peer learning conferences can lead to widespread system improvement. In the authors' experience, these strategies have resulted in practice improvement not only at a division level in radiology but in a broader multidisciplinary setting as well. The online slide presentation from the RSNA Annual Meeting is available for this article. ©RSNA, 2022.

The Antimicrobial Susceptibility of Porphyromonas gingivalis: Genetic Repertoire, Global Phenotype, and Review of the Literature.

The in vitro antimicrobial susceptibility of 29 strains of the major periodontal pathogen Porphyromonas gingivalis and three P. gulae (as an ancestor) to nine antibiotics (amoxicillin, amoxicillin/clavulanate, clindamycin, metronidazole, moxifloxacin, doxycycline, azithromycin, imipenem, and cefoxitin) was evaluated by E-testing of minimal inhibitory concentration (MIC) according to international standards. The results were compared with 16 international studies reporting MICs from 1993 until recently. In addition, 77 currently available P. gingivalis genomes were screened for antimicrobial resistance genes. E-testing revealed a 100% sensitivity of P. gingivalis and P. gulae to all antibiotics. This was independent of the isolation year (1970 until 2021) or region, including rural areas in Indonesia and Africa. Regarding studies worldwide (675 strains), several method varieties regarding medium, McFarland inoculation standards (0.5-2) and incubation time (48-168 h) were used for MIC-testing. Overall, no resistances have been reported for amoxicillin + clavulanate, cefoxitin, and imipenem. Few strains showed intermediate susceptibility or resistance to amoxicillin and metronidazole, with the latter needing both confirmation and attention. The only antibiotics which might fail in the treatment of P. gingivalis-associated mixed anaerobic infections are clindamycin, macrolides, and tetracyclines, corresponding to the resistance genes erm(B), erm(F), and tet(Q) detected in our study here, as well as fluoroquinolones. Periodical antibiotic susceptibility testing is necessary to determine the efficacy of antimicrobial agents and to optimize antibiotic stewardship.

Durability Assessment and Microstructure of High-Strength Performance Bricks Produced from PET Waste and Foundry Sand.

Fired clay brickwork in buildings is prone to cracks and deterioration upon exposure to long-time acidic contamination and water absorption, hence decreasing the bearing capacity of masonry walls. As its contribution toward resolving this challenge, this study assessed the durability and morphological characteristics of high-strength performance bricks produced from a mixture of PET waste (PW) and foundry sand (FS). The PET waste bricks (PWBs) were produced through different proportioning (PW: FS) of 20%, 30%, and 40% of the dry mass of FS. The PWBs produced were tested for durability and compressive and tensile strengths and compared to fired clay bricks to evaluate their load-bearing capacity under compression and tension. Furthermore, scanning electron microscopy (SEM) tests were employed to analyze the morphological structure of the bricks. The test results revealed that the PWBs recorded an appreciable strength of 1.5-2 times that of fired clay bricks, and lower water absorption whilst retaining their ultimate strengths after complete immersion in water and acidic concentrations. The morphology of PWB possessed greater intercluster bonds on the surface compared to clay bricks. The findings demonstrate a reasonable methodological approach toward the production of masonry bricks using a mixture of PET waste and spent foundry sands.

A New Species-Specific Typing Method for Salivarius Group Streptococci Based on the Dephospho-Coenzyme A Kinase (coaE) Gene Sequencing.

Viridans streptococci are a group of α-hemolytic streptococcal species. They are mainly commensals, most abundant in the mouth supporting oral health. But they also include important human pathogens such as Streptococcus pneumoniae. Identification and molecular typing of viridans group streptococci are challenging, especially for members of the salivarius group. In this study, we developed a single-locus molecular typing method that is able to differentiate among the highly phylogenetically related members of the salivarius group (S. salivarius, S. vestibularis and S. thermophilus) and might support differentiation in other groups as well. This typing approach is based on the amplification and sequence analysis of the housekeeping gene dephospho-coenzyme A kinase (coaE), a gene with unrecognized taxonomic potential to date. Here, we analysed coaE gene sequences of 154 publicly available genomes and of 30 salivarius group isolates of our own collection that together belong to 20 different gram-positive bacterial (sub) species. Our results revealed that the coaE phylogeny distinguished between streptococcal and non-streptococcal genomes and that coaE gene sequences were species-specific. In contrast to MALDI-TOF MS performance, the coaE typing was able to precisely identify the phylogenetically very closely related members of the salivarius group.

Pavement Quality Index Rating Strategy Using Fracture Energy Analysis for Implementing Smart Road Infrastructure.

Developing a responsive pavement-management infrastructure system is of paramount importance, accentuated by the quest for sustainability through adoption of the Road Traffic Management System. Technological advances have been witnessed in developed countries concerning the development of smart, sustainable transportation infrastructure. However, the same cannot be said of developing countries. In this study, the development of a pavement management system at network level was examined to contribute towards a framework for evaluating a Pavement Quality Index and service life capacity. Environmental surface response models in the form of temperature and moisture variations within the pavement were applied, using sensor devices connected to a data cloud system to carry out mathematical analysis using a distinctive mesh analysis deformation model. The results indicated variation in the Resilient Modulus of the pavement, with increasing moisture content. Increase in moisture propagation increased saturation of the unbound granular base which reduced the elastic modulus of the sub-base and base layer and reduced the strength of the pavement, resulting in bottom-up cracks and cracking failure. The horizontal deformation reduced, indicating that the material was experiencing work hardening and further stress would not result in significant damage. Increasing temperature gradient resulted in reduced stiffness of the asphalt layer. In tropical regions, this can result in rutting failure which, over time, results in top-down cracks and potholes, coupled with increasing moisture content.

Polymeric Dopant-Free Hole Transporting Materials for Perovskite Solar Cells: Structures and Concepts towards Better Performances.

Perovskite solar cells are a hot topic of photovoltaic research, reaching, in few years, an impressive efficiency (25.5%), but their long-term stability still needs to be addressed for industrial production. One of the most sizeable reasons for instability is the doping of the Hole Transporting Material (HTM), being the salt commonly employed as a vector bringing moisture in contact with perovskite film and destroying it. With this respect, the research focused on new and stable "dopant-free" HTMs, which are inherently conductive, being able to effectively work without any addition of dopants. Notwithstanding, they show impressive efficiency and stability results. The dopant-free polymers, often made of alternated donor and acceptor cores, have properties, namely the filming ability, the molecular weight tunability, the stacking and packing peculiarities, and high hole mobility in absence of any dopant, that make them very attractive and a real innovation in the field. In this review, we tried our best to collect all the dopant-free polymeric HTMs known so far in the perovskite solar cells field, providing a brief historical introduction, followed by the classification and analysis of the polymeric structures, based on their building blocks, trying to find structure-activity relationships whenever possible. The research is still increasing and a very simple polymer (PFDT-2F-COOH) approaches PCE = 22% while some more complex ones overcome 22%, up to 22.41% (PPY2).