Development of BAR-peptide nanoparticles and electrospun fibers for the prevention and treatment of oral biofilms.

Background: Periodontal diseases are globally prevalent inflammatory disorders that affect ~47% of U.S adults. Porphyromonas gingivalis (Pg) has been identified as a “keystone” pathogen that disrupts host-microbe homeostasis and contributes to the initiation and progression of periodontitis. Pg associates with oral streptococci in supragingival plaque and this interaction represents a potential target for therapeutic intervention. Previously our group developed a peptide (designated BAR), that potently inhibits Pg/Streptococcus gordonii (Sg) adherence in vitro and Pg virulence in a murine model of periodontitis. While efficacious, BAR (SspB Adherence Region) provided transient inhibition and required higher concentrations of BAR to disrupt established biofilms. Hypothesis and Aims: To address these challenges, we hypothesized that BAR-surface modified and BAR-encapsulated poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) may more potently inhibit and disrupt biofilms in vitro and in vivo, relative to free BAR. In addition, a new rapid-release platform, composed of polymeric electrospun fibers (EFs) that encapsulate BAR peptide, was developed. Given this, our objectives were to evaluate BAR-surface modified NPs in a murine model of periodontitis; to fabricate and assess the ability of BAR-encapsulated NPs to inhibit and disrupt in vitro oral biofilm formation, and to evaluate a new dosage form, electrospun fibers, to inhibit andformation, and to evaluate a new dosage form, electrospun fibers, to inhibit and disrupt in vitro oral biofilm formation. In addition, the safety of all platforms was determined via viability, apoptosis, adenosine triphosphate (ATP), lactate dehydrogenase (LDH) and oxidative DNA assays using telomerase immortalized gingival keratinocytes (TIGKs). Methods: BAR-encapsulated and BAR-surface modified PLGA NPs were synthesized using adapted double- and single-emulsion techniques, respectively. Electrospun fibers were formed using a uniaxial approach, with different hydrophobic polymers (PLGA, polycaprolactone, poly(L-lactic acid)); each blended with different polyethylene oxide ratios (PEO: 0, 10, 20, or 40% w/w) to achieve maximal release of BAR. Both BAR-encapsulated NPs and EFs were assessed for inhibition of two-species biofilm formation and for disruption of pre-existing biofilms, against an equimolar free BAR concentration. In vivo efficacy of BAR-surface modified NPs was assessed using a murine model of periodontitis by measuring alveolar bone resorption and gingival IL-17 expression as outcomes of Pg-induced inflammation. Results: BAR-encapsulated NPs and EFs inhibited biofilm formation (IC50s = 0.7 and 1.3 μM, respectively) in a dose-dependent manner, relative to free BAR (IC50 = 1.3 µM). In addition, BAR-encapsulated NPs and EFs efficiently disrupted established dual-species biofilms (IC50s = 1.3 and 2 μM, respectively). Treatment of Pg/Sg infected mice with BAR-surface modified NPs reduced alveolar bone loss and IL-17 expression almost to the levels of sham-infected mice and to a greater extent than treatment with an equimolar amount of free BAR. The in vitro cytotoxicity studies, which utilized the maximum concentration of BAR-encapsulated NPs, BAR-surface modified NPs, BAR EFs, and free BAR (1.3 and 3.4 μM) demonstrated \u3e 90% viability for all samples and showed no significant lysis or apoptosis relative to untreated cells. In addition, all tested formulations exhibited a lack of hemolytic activity. Conclusion: These data suggested that BAR NPs and EFs provide novel and potent platforms to inhibit and disrupt dual-species biofilms. All formulations exhibited minimal cellular toxicity or hemolytic activity, highlighting the potential of NPs and EFs as a biocompatible platform for translatable oral biofilm applications

Low Salinity Flooding in a Selected Carbonate Reservoir: Experimental Approach

Low-salinity water flooding LoSalTM has been used to improve oil recovery for many decades. Historically, the mechanisms behind this improvement in oil recovery were attributed to the pressure maintenance and displacement of oil by injected water, i.e. physical mechanism. Recently, evidence from laboratory and field tests indicated that water flooding also involves chemical processes and that modifying of the injection brine salinity and its ionic composition can significantly impact the oil recovery. Several theories regarding the mechanism of LoSalTM flooding have been discussed in the literature. These include interfacial tension reduction, wettability alteration (cation exchange), change in pH (increase), emulsion formation, and clay migration. It is clear from the literature that there is no agreement among the researchers regarding the mechanism of LoSalTM flooding and although limited work has been done on carbonates, some studies have concluded that LoSal™ have no effect on oil recovery. This work presents the results of core flooding tests with sea water, and two of Abu Dhabi oil field injection waters UER (197,584 ppm) and SIM (224,987 ppm) to evaluate the effects of brine salinity and ionic composition on the possible interactions of limestone rock/brine/ and oil, and to identify the recovery mechanism. The original injection waters were diluted to salinities of 5000 and 1000 ppm and the optimum salinity system was modified by varying the sulfate and calcium ion concentrations. Wettability alteration is determined by contact angle measurements. Interfacial tensions measurements of the studied systems were also performed in an attempt to evaluate the flow mechanism with LowsalTM flooding. The experimental results revealed that a significant improvement in the oil recovery can be achieved through alteration of the injection water salinity. Reducing the salinity of UER water from 197,362 ppm to 5000 ppm resulted in an improvement of oil recovery from 63% to 84.5% of OOIP, respectively. Therefore, the salinity of 5000 ppm UER was considered as the optimum salinity to evaluate the effect of sulfate and calcium ion concentrations. Results also indicated that sulfate concentration has a significant effect on the process and increasing the sulfate concentration beyond the optimum concentration (47 ppm) resulted in a negative effect. Contact angle measurements indicated that lowering the solution salinity could shift the wettability of the system toward intermediate wettability levels and that the UER water exhibits higher shift toward intermediate wettability compared to other waters. Results also indicated that there is no clear correlation between the improvements in oil recovery and interfacial tension and the pH of the studied systems

3D Printing of Continuous Wire Polymer Composite for Mechanical and Thermal Applications

Recently, continuous fiber reinforcement has been combined with 3D printing techniques such as fused filament fabrication to create stronger and stiffer printed composite components. The continuous nature of the reinforcing material can improve both mechanical and thermal properties of the polymeric material significantly. However, several parameters can affect the printed composite properties such as filler volume fraction, type of polymer matrix and filler treatment. The work presented in this study addresses the effect of reinforcing polymers with continuous metal wire on the composites properties and the potential applications for these composites. In the first part of this study we presented a novel 3D printing technique in which metal wires were combined with polymer matrixes in order to improve both mechanical and thermal properties of the printed components. In the second part, we investigated the tensile and bending properties of the continuous wire polymer composites which was superior compared to the base polymer. In addition, we studied the effect of introducing continuous wires to the polymer matrix on the effective thermal conductivity which was found to increase significantly. In addition, we investigated the use of the fabricated composites as a novel fabrication technique for low-temperature heating elements and explored this technology for de-icing and anti-icing applications

Simulation algorithms for inductive effects

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Includes bibliographical references (p. 105-110).by Yehia Mahmoud Massoud.Ph.D

An Integrated Framework for Delivering Healthcare Services through Information Technology

Egyptian integrated healthcare services delivery is undergoing a transformative shift driven by the rapid advancements in information technology . This paper presents an integrated framework designed to leverage IT solutions for the efficient delivery of healthcare services for patients. The proposed framework encompasses various components, including electronic health records , telemedicine, and interoperability standards.The integration of electronic health records serves as the foundation for seamless information exchange among healthcare providers, ensuring a comprehensive and up-to-date view of patient health. Telemedicine, a key aspect of the framework, facilitates remote consultations, enabling healthcare professionals to extend their reach and provide timely interventions. Additionally, the framework incorporates advanced data analytics techniques to derive meaningful insights from the vast amount of healthcare data generated

Will Direct Oral Anticoagulants Have a Chance in Prosthetic Valves?

Although there are abundant data highlighting the safety and efficacy of direct oral anticoagulants, to date, recent guidelines have limited their use to stroke prevention in patients with non-valvular AF, as well as in the prevention and treatment of venous thromboembolism and pulmonary embolism. Encouraging data about the off-label use of direct oral anticoagulants have been shown in several other indications, such as intracardiac thrombi, left ventricular thrombi and left atrial appendage, but a large sector of patients are still not addressed, such as valvular and prosthetic patients

Selective allocation of patients with vaginal apical prolapse to either mesh augmented open abdominal repair or vaginal sacrospinous colpopexy improve functional and anatomical outcomes

Background: To evaluate the functional and anatomical outcomes after allocation of patients with apical vaginal prolapse to either mesh augmented abdominal repair or vaginal sacrospinous-colpopexy based on proposed selection criteria.Methods: A non-randomized trial was conducted at Ain-Shams university maternity hospital on patients with apical vaginal prolapse stage ≥2 based on pelvic organ prolapse quantification system. Certain criteria were proposed for patient selection to either mesh augmented abdominal repair or vaginal sacrospinous-colpopexy. Seventy-eight patients were assigned for sacrospinous-colpopexy and 47-patients for abdominal repair. Primary outcomes were the functional outcome using urogenital distress inventory questionnaire and patient global impression of improvement (PGI-I). Both were measured at 1-year’s follow-up. Secondary outcomes involved the anatomical success (defined as no apical prolapse ≥POP-Q stage 2), perioperative data and long-term complications.Results: There was improvement in all UDI domains for sacrospinous-colpopexy and abdominal repair groups with genital prolapse domain of median (interquartile range) 0 (0-10), 0 (0-0) respectively. Eighty-nine percent of abdominal repair group and 85% of sacrospinous-colpopexy group reported scale of 1 or 2 on PGI-I scale at 1-year follow-up. PGI-I score and improvements in UDI domains were maintained till 5-year follow-up. The anatomic success rate at 1-year follow-up was 97.9% in abdominal repair group and 78.2% in the sacrospinous-colpopexy group. No long-term mesh complications were detected in mesh augmented abdominal repair over the whole follow-up periods.Conclusion: The resulting meritorious functional and anatomical outcomes favor adoption of our proposed selection criteria in the initiation of guidelines and recommendations for managing vaginal apical prolapse

Medial sural artery perforator flap in reconstruction of soft tissue defect in upper and lower extremities: a clinical study

Background: The quality of soft tissue reconstruction in upper and lower extremities caused by trauma, infection, burns, and tumor resection affects the patient function and esthetic outcome. Many flaps have been described in the literature to reconstruct such defects. Medial sural artery perforator flap is one of the options for reconstruction of upper and lower extremities. Patients and methods: Starting from July 2019 through August 2020, 20 pedicled and free MSAP flaps were used for reconstruction of upper and lower limbs soft tissue defects. Results: total flap loss occurred in two cases, partial flap loss occurred in two cases and the flap was abandoned in two cases. Otherwise, all flaps survived well. Conclusion: MSAP flap is an excellent option in the reconstruction of soft tissue defects in upper and lower extremities

Veri

SPHINCS+ is a stateless hash-based digital signature scheme and an alternate candidate in round 3 of the NIST Post- Quantum Cryptography standardization competition. Although not considered as a finalist because of its performance, SPHINCS+ may be considered for standardization by NIST after another round of evaluations. In this paper, we propose a Verfi able Obtained Random Subsets (v-ORS) generation mechanism which with one extra hash computation binds the message with the signing FORS instance (the underlying few-time signature algorithm). This enables SPHINCS+ to off er more security against generic attacks because the proposed modi cation restricts the ORS generation to use a hash key from the utilized signing FORS instance. Consequently, such a modi cation enables the exploration of di erent parameter sets for FORS to achieve better performance at the same security level. For instance, when using v-ORS, one parameter set for SPHINCS+-256s provides 82.9% reduction in the computation cost of FORS which leads to around 27% reduction in the number of hash calls of the signing procedure. Given that NIST has identfi ed the performance of SPHINCS+ as its main drawback, these results are a step forward in the path to standardization