Investigating the Role of Amino Acids in Short Peptides for Hydroxyapatite Binding and Osteogenic Differentiation of Mesenchymal Stem Cells to Aid Bone Regeneration.

Bone defects show a slow rate of osteoconduction and imperfect reconstruction, and the current treatment strategies to treat bone defects suffer from limitations like immunogenicity, lack of cell adhesion, and the absence of osteogenic activity. In this context, bioactive supramolecular peptides and peptide gels offer unique opportunities to develop biomaterials that can play a dominant role in the biomineralization of bone tissues and promote bone formation. In this article, we have demonstrated the potential of six tetrapeptides for specific binding to hydroxyapatite (HAp), a major inorganic component of the bone, and their effect on the growth and osteogenic differentiation of mesenchymal stem cells (MSCs). We adopted a simplistic approach of rationally designing amphiphilic peptides by incorporating amino acids, Ser, pSer, Pro, Hyp, Asp, and Glu, which are present in either collagenous or noncollagenous proteins and render properties like antioxidant, calcification, and mineralization. A total of six tetrapeptides, Trp-Trp-His-Ser (WWHS), Trp-Trp-His-pSer (WWHJ), Trp-Trp-His-Pro (WWHP), Trp-Trp-His-Hyp (WWHO), Trp-Trp-His-Asp (WWHD), and Trp-Trp-His-Glu (WWHE), were synthesized. Four peptides were found to self-assemble into nanofibrillar gels resembling the extracellular matrix (ECM), and the remaining two peptides (WWHJ, WWHP) self-assembled into nanorods. The peptides showed excellent cell adhesion, encapsulation, proliferation, and migration and induced the differentiation of mesenchymal stem cells (MSCs), as evident from the enhanced mineralization, resulting from the upregulation of osteogenic markers, RUNX 2, COL I, OPN, and OCN, alkaline phosphatase (ALP) production, and calcium deposition. The peptides also induced the downregulation of inflammatory markers, TNF-α and iNOS, and the upregulation of the anti-inflammatory marker, IL-10, resulting in M2 macrophage polarization. RANKL and TRAP genes were downregulated in a coculture system of MC3T3-E1 and RAW 264.7 cells, implying that peptides promote osteogenesis and inhibit osteoclastogenesis. The peptide-based biomaterials developed in this work can enhance bone regeneration capacity and show strong potential as scaffolds for bone tissue engineering.

Automated nonlinear registration of coronary PET to CT angiography using pseudo-CT generated from PET with generative adversarial networks.

BACKGROUND: Coronary 18F-sodium-fluoride (18F-NaF) positron emission tomography (PET) showed promise in imaging coronary artery disease activity. Currently image processing remains subjective due to the need for manual registration of PET and computed tomography (CT) angiography data. We aimed to develop a novel fully automated method to register coronary 18F-NaF PET to CT angiography using pseudo-CT generated by generative adversarial networks (GAN). METHODS: A total of 169 patients, 139 in the training and 30 in the testing sets were considered for generation of pseudo-CT from non-attenuation corrected (NAC) PET using GAN. Non-rigid registration was used to register pseudo-CT to CT angiography and the resulting transformation was used to align PET with CT angiography. We compared translations, maximal standard uptake value (SUVmax) and target to background ratio (TBRmax) at the location of plaques, obtained after observer and automated alignment. RESULTS: Automatic end-to-end registration was performed for 30 patients with 88 coronary vessels and took 27.5 seconds per patient. Difference in displacement motion vectors between GAN-based and observer-based registration in the x-, y-, and z-directions was 0.8 ± 3.0, 0.7 ± 3.0, and 1.7 ± 3.9 mm, respectively. TBRmax had a coefficient of repeatability (CR) of 0.31, mean bias of 0.03 and narrow limits of agreement (LOA) (95% LOA: - 0.29 to 0.33). SUVmax had CR of 0.26, mean bias of 0 and narrow LOA (95% LOA: - 0.26 to 0.26). CONCLUSION: Pseudo-CT generated by GAN are perfectly registered to PET can be used to facilitate quick and fully automated registration of PET and CT angiography.

Opportunistic optimization of inhaler technique in hospitalized adults with asthma: a two-phase educational study.

OBJECTIVE: To investigate effectiveness of two different educational methods to improve inhaler techniques in patients with prior diagnosis of asthma, hospitalized with a non-asthma-related diagnosis. METHODS: We undertook a real-world, opportunistic quality-improvement project. Inhaler technique in hospitalized patients with prior diagnosis of asthma was assessed in two cohorts over two 12-week cycles using a standardized device-specific proforma of seven-step inhaler technique, classed: "good" if 6/7 steps achieved; "fair" if 5/7 compliant; "poor" for others. Baseline data was collected in both cycles. Cycle one involved face-to-face education by a healthcare professional; cycle two involved additional use of an electronic device to show device-specific videos (asthma.org.uk). In both cycles, patients were reassessed within two days for improvements and the two methods compared for effectiveness. RESULTS: During cycle one 32/40 patients were reassessed within 48 h; eight lost to follow-up. During cycle two 38/40 patients were reassessed within 48 h; two lost to follow-up During cycle one, two and 12 had good/fair baseline technique respectively, and 26 poor. Most commonly missed steps were no expiry check/not rinsing mouth after steroid use. On reassessment 17% patients improved from poor to fair/good. During cycle two, initial technique assessment identified: 23 poor; 12 fair; five good. Post-videos, 35% of patients improved from poor to fair/good. Proportion of patients improving from poor to fair, or poor/fair to good increased in cycle two vs one (52.5% vs 33%). CONCLUSION: Visual instruction is associated with improved technique compared to verbal feedback. This is a user-friendly and cost-effective approach to patient education.

Assessment of the Capability to Accurately Capture the Vertical Relationship by the Various Bite Registration Materials.

Background: This research study aimed to evaluate and compare the capability of four various bite registration materials to reproduce precise interocclusal relationships in the vertical dimension. Materials and Methods: Ideal maxillary and mandibular casts were mounted on the semi-adjustable articulator in maximum intercuspation after mock tooth preparation on 46, 47, and 48. Models were scanned by the Medit T500 Dental Lab Scanner, and initial reading was noted at the predetermined points. Ten interocclusal bite registrations were made using four materials (CADbite, Jet Bite, Ramitec, and Aluwax). The mandibular model was demounted and again remounted using the interocclusal records, and the final reading was noted after scanning. Results: Ramitec showed superior results when compared to polyvinyl bite registration material and Aluwax, but the differences between Ramitec, CADbite, and Jet Bite were nonsignificant. Conclusions: Although all four materials are suitable for clinical use, elastomeric materials showed superior results. In that, polyether was found to be the best.

Prosthodontic Rehabilitation With Kennedy's Class I and Class II Using an Extended Precision Attachment: A Report of Two Cases.

Satisfactory restorations can be difficult in partially edentulous patients, especially those with unilateral or bilateral posterior ocular defects. With traditional and modern treatment options, recovery can be successful. Partial dentures with attachments are such a treatment. An implant-supported prosthesis is another option for therapy in these circumstances. Precision extracoronary attachments are the preferred treatment option when implant treatment does not give good results. This research offers two examples of partial cast prosthetic rehabilitation for distal extension utilizing precise attachments.

Biogas production potential of aquatic weeds as the next-generation feedstock for bioenergy production: a review.

Aquatic weeds have exceptionally high reproduction rates, are rich in cellulose and hemicellulose, and contain a negligible amount of lignin, making them an ideal crop for the next generation of biofuels. Previously reported studies proposed that water hyacinth, water lettuce, common duckweeds, and water spinach can be managed or utilized using different advanced techniques; from them, anaerobic digestion is one of the feasible and cost-effective techniques to manage these biowastes. The present study was carried out to investigate the potential of utilizing four common aquatic weed species (water hyacinth, water lettuce, common duckweeds, and water spinach) as substrates for anaerobic digestion in order to produce biogas for use in biofuels. The high reproduction rates and high cellulose and hemicellulose content, coupled with low lignin content, of these aquatic weeds make them ideal candidates for this purpose. The study evaluated the feasibility of using anaerobic digestion as a management technique for these aquatic weeds, which are often considered invasive and difficult to control. The results from various studies indicate that these aquatic weeds are productive feedstock options for anaerobic digestion, yielding a high biogas output. Among the aquatic weeds studied, water hyacinth, water lettuce, and common duckweeds exhibit higher methane production compared to water spinach. The study provides an overview of the characteristics and management strategies of these aquatic weeds in relation to biogas production, with possible future developments in the field.