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Bio-nanomaterials are gaining increasing attention due to their renewable and eco-friendly characteristics. Among these, nanocrystalline cellulose (NCC) stands out as one of the most advanced materials for applications in food, healthcare, composite production, and beyond. In this study, NCC was successfully extracted from cotton-based textile waste using a combination of chemical and mechanical methods. The cellulose fibers were first hydrolyzed using a dilute HCl solution, neutralized, and then dried, resulting in microcrystalline cellulose (MCC) with diameters ranging from 7 to 15 µm and lengths up to 300 µm (as observed via optical microscopy and scanning electron microscopy, SEM). To achieve nanoscale dimensions, NaOH/urea solution with mechanical treatment was applied, resulting in the successful extraction of NCC in the supernatant, particularly under room-temperature conditions. Dynamic light scattering (DLS) analysis confirmed the presence of nanostructures (average sizes ranging from 120 nm to 750 nm), and atomic force microscopy (AFM) analysis verified the nanoscale range (diameters between 2 and 4 nm and lengths from 200 nm to 1 µm). Fourier transform infrared (FTIR) spectroscopy revealed the conversion of cellulose I to cellulose II, confirming the successful transformation into NCC. For the first time, NCC was obtained from undyed cotton textile wastes using NaOH/urea treatment after HCl hydrolysis, eliminating the need for pre-treatment and intermediate steps. [ABSTRACT FROM AUTHOR]

Purpose: Zygomatic implants are considered one of the last options for the rehabilitation of severe maxillary atrophy when standard implants cannot be placed. They offer several advantages but can also present complications. This study aimed to investigate the long-term clinical and radiographic outcomes of zygomatic implant placement. Materials and methods: A retrospective chart review was conducted, and the inclusion criteria consisted of patients previously treated with zygomatic implants who had Class V or VI maxillary bone atrophy according to Cawood and Howell, and with a minimum follow-up period of 2 years after prosthetic loading. Outcome measures included implant and prosthesis survival rate, biological and biomechanical complications, and Lund-Mackay staging score before and after implant placement. Results: The study included 78 patients who received a total of 274 zygomatic implants. The mean follow-up period was 90.4 ± 26.0 months. Seventeen implant failures occurred, resulting in a survival rate of 93.8%, with a statistically significant negative correlation with smoking habits (P = 0.049), anchorage to the two zygomatic bone cortices (bicorticality) (P < 0.001) and soft tissue complications (P < 0.001). The prosthetic success rate was 92.3%. A statistically significant increase in maxillary sinus radiopacity was recorded when comparing the situation before and after surgery (P < 0.001), and the intrasinus pathway had a statistically significant influence on that increase (P = 0.003). Conclusions: Zygomatic implants utilised for rehabilitating patients with severe maxillary atrophy have shown favourable outcomes. Nonetheless, owing to potential complications, strict case selection is necessary, combined with regular recall visits and proper oral hygiene maintenance. Furthermore, this type of surgery necessitates specialised training and expertise on the part of the practitioner. [ABSTRACT FROM AUTHOR]

Bimaxillary orthognathic surgery is widely used for the correction of dentoskeletal deformities. Surgery sequencing (maxilla or mandible first) remains debated, and guidelines and consensus are lacking. This scoping review summarizes the state of the art and compares the advantages and disadvantages of both approaches. The review was conducted following PRISMA-ScR guidelines. Three electronic databases (PubMed, Scopus, Web of Science) were searched using the PICO protocol and key words in orthognathic surgical sequencing. Four reviewers screened the records independently, and disagreement was resolved by consensus. A total of 23 records met the inclusion criteria. The advantages and disadvantages of the two approaches were compared and assessed for accuracy of reporting. Within the limitations of the present study, available evidence for the intrinsic advantages and the accuracy of the mandible-first sequence supports the choice of this approach in most cases. Nevertheless, each clinical case needs to be evaluated individually, as no dogmatic recommendations can be given for sequencing in bimaxillary orthognathic surgery. [ABSTRACT FROM AUTHOR]

The understanding of the behavior of arsenic in highly doped near surface silicon layers is of crucial importance for the formation of N-type ultrashallow junctions in current and future very large scale integrated technology. This is of particular relevance when studying recently developed implantation and annealing methods. Past theoretical as well as experimental investigations have suggested that the increase in As concentration, and therefore the reciprocal proximity of several As atoms, leads to a drastic increase in electrically inactive defects giving only marginal reduction in sheet resistance. Monoclinic SiAs aggregates as well as various arsenic-vacancy clusters contribute to the deactivation of arsenic. This study aims to correlate between the results of electrical activation measurements and x-ray absorption fine structure measurements. Samples were doped with a nominal fluence of 1×1015–3×1015 atoms/cm2, implanted at 2 keV, and annealed by rapid thermal treatments, laser submelt treatments, and a combination of both. Hall effect and sheet resistance measurements have been performed to obtain the density of charge carriers. Secondary ion mass spectrometry has been employed to measure the depth profile and the total retained fluences. The percentage of substitutional arsenic has been obtained by least-squares fits of the measured x-ray absorption spectra with simulated spectra of relaxed structures of the defects obtained by density functional theory. A good agreement with the Hall effect measured electrically active dose fraction has been obtained and a quantification of the population of the different defects involved has been attempted. [ABSTRACT FROM AUTHOR]

We found that As and B diffusion in 90 nm thick Si on SiO2, silicon on insulator, samples is reduced, by ∼20%, with respect to that of bulk Si for thermal processing in a lamp-based system. In contrast, when annealing is performed in a hot-wall furnace system and sample heating is determined by conduction diffusion length in Si–SiO2–Si samples is very similar to that occurring in bulk-Si reference samples. We demonstrate that diffusion in Si–SiO2–Si multilayer structures is primarily determined by an increased sample reflectivity, generated by the presence of the buried Si/SiO2 interface that reduces the amount of heat absorbed by the sample, rather than by the enhanced recombination of point defects at this interface. The latter phenomenon is not ruled out but plays a less relevant role in determining the measured reduction of diffusion. [ABSTRACT FROM AUTHOR]