Long-Term Evaluation of Inserted Nanocomposite Hydrogel-Based Phosphorescent Oxygen Biosensors: Evolution of Local Tissue Oxygen Levels and Foreign Body Response.

Phosphorescence-based oxygen-sensing hydrogels are a promising platform technology for an upcoming generation of insertable biosensors that are smaller, softer, and potentially more biocompatible than earlier designs. However, much remains unknown about their long-term performance and biocompatibility in vivo. In this paper, we design and evaluate a range of hydrogel sensors that contain oxygen-sensitive phosphors stabilized by micro- and nanocarrier systems. These devices demonstrated consistently good performance and biocompatibility in young adult rats for over three months. This study thoroughly establishes the biocompatibility and long-term suitability of phosphorescence lifetime sensors in vivo, providing the groundwork for expansion of this platform technology into a family of small, unobtrusive biosensors for a range of clinically relevant metabolites.

Intra-Articular Injectable Biomaterials for Cartilage Repair and Regeneration.

Osteoarthritis is a degenerative joint disease characterized by cartilage deterioration and subsequent inflammatory changes in the underlying bone. Injectable hydrogels have emerged as a promising approach for controlled drug delivery in cartilage therapies. This review focuses on the latest developments in utilizing injectable hydrogels as vehicles for targeted drug delivery to promote cartilage repair and regeneration. The pathogenesis of osteoarthritis is discussed to provide a comprehensive understanding of the disease progression. Subsequently, the various types of injectable hydrogels used for intra-articular delivery are discussed. Specifically, physically and chemically crosslinked injectable hydrogels are critically analyzed, with an emphasis on their fabrication strategies and their capacity to encapsulate and release therapeutic agents in a controlled manner. Furthermore, the potential of incorporating growth factors, anti-inflammatory drugs, and cells within these injectable hydrogels are discussed. Overall, this review offers a comprehensive guide to navigating the landscape of hydrogel-based therapeutics in osteoarthritis.

Techno-economic analysis and optimization of near-zero energy and emission neighborhoods using biomass waste.

The present study aims to simulate and design a near-Zero Energy neighborhood in one of the most significant industrial cities for reducing greenhouse gas emissions. For this building, biomass wastes are used for energy production, and also energy storage is provided using a battery pack system. Additionally, the Fanger model is used to assess the passengers' thermal comfort, and information on hot water usage is given. The transient performance of the aforementioned building is tested for one year using TRNSYS software, which was employed for this simulation. Wind turbines are considered electricity generators for this building, and any extra energy generated is stored in a battery pack for usage when the wind speed is insufficient and electricity is needed. Hot water is created using a biomass waste system and is kept in a hot water tank after being burned using a burner. A humidifier is utilized to ventilate the building, and a heat pump provides both the building's heating and cooling needs. The produced hot water is used to supply the residents' hot water. In addition, The Fanger model is considered and used for the assessment of occupants' thermal comfort. Matlab software is a powerful software used for this task. According to the findings, a wind turbine with a 6 kW generation capacity may supply the building's power needs while also charging the batteries beyond their initial capacity, and the building will have zero energy. Additionally, biomass fuel is used to give the building the required water which should be hot. On average, 200 g of biomass and biofuel are used per hour to maintain this temperature.

An innovative biomass-driven energy systems for green energy and freshwater production with less CO2 emission: Environmental and technical approaches.

Considering the current crisis of fossil energies, the exploitation of renewables and green technologies is necessary and unavoidable. Additionally, the design and development of integrated energy systems with two or more output products and the maximum usage of thermal losses in order to improve efficiency can boost the yield and acceptability of the energy system. In this regard, this paper develops a comprehensive multi-aspect assessment of the operation of a new solar and biomass energies-driven multigeneration system (MGS). The main units installed in MGS are three electric energy generation units based on a gas turbine process, a solid oxide fuel cell unit (SOFCU) and an organic Rankine cycle unit (ORCU), a biomass energy conversion unit to useful thermal energy, a seawater conversion unit into useable freshwater, a unit for converting water and electricity into hydrogen energy and oxygen gas, a unit for converting solar energy into useful thermal energy (based on Fresnel collector), and a cooling load generation unit. The planned MGS has a novel configuration and layout that has not been considered by researchers recently. The current article is based on presenting a multi-aspect evaluation to study thermodynamic-conceptual, environmental and exergoeconomic analyzes. The outcomes indicated that the planned MGS can produce about 6.31 MW of electrical power and 0.49 MW of thermal power. Furthermore, MGS is able to produce various products such as potable water (∼0.977 kg/s), cooling load (∼0.16 MW), hydrogen energy (∼1.578 g/s) and sanitary water (∼0.957 kg/s). The total thermodynamic indexes were calculated as 78.13% and 47.72%, respectively. Also, the total investment and unit exergy costs were 47.16 USD per hour and 11.07 USD per GJ, respectively. Further, the content of CO2 emitted from the desgined system was equal to 10.59 kmol per MWh. A parametric study has been also developed to identify influencing parameters.

NIR Luminescent Oxygen-Sensing Nanoparticles for Continuous Glucose and Lactate Monitoring.

A highly sensitive, biocompatible, and scalable phosphorescent oxygen sensor formulation is designed and evaluated for use in continuous metabolite sensors for biological systems. Ethyl cellulose (EC) and polystyrene (PS) nanoparticles (NPs) stabilized with Pluronic F68 (PF 68), Polydimethylsiloxane-b-polyethyleneglycol methyl ether (PDMS-PEG), sodium dodecylsulfate (SDS), and cetyltimethylammonium bromide (CTAB) were prepared and studied. The resulting NPs with eight different surfactant−polymer matrix combinations were evaluated for physical properties, oxygen sensitivity, effect of changes in dispersion matrix, and cytotoxicity. The EC NPs exhibited a narrower size distribution and 40% higher sensitivity than PS, with Stern−Volmer constants (Ksv) 0.041−0.052 µM−1 for EC, compared to 0.029−0.034 µM−1 for PS. Notably, ethyl cellulose NPs protected with PF68 were selected as the preferred formulation, as they were not cytotoxic towards 3T3 fibroblasts and exhibited a wide phosphorescence lifetime response of >211.1 µs over 258−0 µM and ~100 µs over 2.58−0 µM oxygen, with a limit of detection (LoD) of oxygen in aqueous phase of 0.0016 µM. The EC-PF68 NPs were then efficiently encapsulated in alginate microparticles along with glucose oxidase (GOx) and catalase (CAT) to form phosphorescent nanoparticles-in-microparticle (NIMs) glucose sensing microdomains. The fabricated glucose sensors showed a sensitivity of 0.40 µs dL mg−1 with a dynamic phosphorescence lifetime range of 46.6−197.1 µs over 0−150 mg dL−1 glucose, with a glucose LoD of 18.3 mg dL−1 and maximum distinguishable concentration of 111.1 mg dL−1. Similarly, lactate sensors were prepared with NIMs microdomains containing lactate oxidase (LOx) and found to have a detection range of 0−14 mg dL−1 with LoD of 1.8 mg dL−1 and maximum concentration of 13.7 mg dL−1 with lactate sensitivity of 10.7 µs dL mg−1. Owing to its versatility, the proposed NIMs-based design can be extended to a wide range of metabolites and different oxygen-sensing dyes with different excitation wavelengths based on specific application.

Self-Medication as an Important Risk Factor for Antibiotic Resistance: A Multi-Institutional Survey among Students.

Self-medication is an important issue, especially in developing countries. Self-medication is the concept in which individuals use medicine to ease and manage their minor illnesses. The current survey was designed to conduct interviews at different universities based on the availability of the students from August 2021 to October 2021 in Hazara region of Khyber Pakhtunkhwa (KPK), Pakistan. Overall, 1250 questionnaires were distributed to students from various departments. Students of microbiology (n = 305, 24.4%) and agriculture 236 (n = 18.8%) were the most elevated members in this study, while other participants were from medical lab technology (n = 118, 9.4%), chemistry (n = 103, 8.2%), food science (n = 92, 7.3%), business administration (n = 83, 6.6%), sociology (n = 78, 6.2%), math/physics (n = 6, 14.8%), Pak study (n = 58, 4.6%), English (n = 47, 3.7%), and psychology (n = 19, 1.5%). Students working towards their Bachelor numbered (n = 913, 73.0%), Master (minor) numbered (n = 80, 6.4%), Master (major) numbered (n = 221, 17.6%), and Doctorate numbered (n = 36, 2.8%). The age group of participants was majorly 20-25 years (61.0%), while others belonged to the age groups 25-30 years (20.6%), 30-35 years (9.8%), and 35-40 years (8.4%). The mean and standard deviation of daily practices of self-medication were observed (M = 416.667, SD = 1,026,108.667) and p = 0.002. The mean and standard deviation of daily practices of antibiotic knowledge was (M = 431.5, SD = 1,615,917) and p = 0.002. Antimicrobial agents were leading over others with 631 (50.4%), followed by anti-inflammatory with 331 (26.4%), multivitamins with 142 (11.3%), gynecological purpose with 59 (4.7%), and analgesic with 72 (5.7%), while the lowest frequency rate was observed against herbal remedies with 15 (1.2%). The results of the current study concluded that students practiced self-medication for reasons such as convenience to obtain these medications from cheap sources and to avoid the fee of a physician. They searched for the medicine on social media platforms and purchased it blindly from the pharmacy without any prescription from a physician.

Evaluation of Bi-Lateral Co-Infections and Antibiotic Resistance Rates among COVID-19 Patients.

In addition to the pathogenesis of SARS-CoV-2, bacterial co-infection plays an essential role in the incidence and progression of SARS-CoV-2 infections by increasing the severity of infection, as well as increasing disease symptoms, death rate and antimicrobial resistance (AMR). The current study was conducted in a tertiary-care hospital in Lahore, Pakistan, among hospitalized COVID-19 patients to see the prevalence of bacterial co-infections and the AMR rates among different isolated bacteria. Clinical samples for the laboratory diagnosis were collected from 1165 hospitalized COVID-19 patients, of which 423 were found to be positive for various bacterial infections. Most of the isolated bacteria were Gram-negative rods (n = 366), followed by Gram-positive cocci (n = 57). A significant association (p < 0.05) was noted between the hospitalized COVID-19 patients and bacterial co-infections. Staphylococcus aureus (S. aureus) showed high resistance against tetracycline (61.7%), Streptococcus pyogenes against penicillin (100%), E. coli against Amp-clavulanic acid (88.72%), Klebsiella pneumoniae against ampicillin (100%), and Pseudomonas aeruginosa against ciprofloxacin (75.40%). Acinetobacter baumannii was 100% resistant to the majority of tested antibiotics. The prevalence of methicillin-resistant S. aureus (MRSA) was 14.7%. The topmost symptoms of >50% of COVID-19 patients were fever, fatigue, dyspnea and chest pain with a significant association (p < 0.05) in bacterial co-infected patients. The current study results showed a comparatively high prevalence of AMR, which may become a severe health-related issue in the future. Therefore, strict compliance of antibiotic usage and employment of antibiotic stewardship programs at every public or private institutional level are recommended.

Experimental and Statistical Analysis of Saw Mill Wood Waste Composite Properties for Practical Applications.

The utilization of composite materials is increasing at a growing rate in almost all types of products, due to their strength-to-stiffness ratio. From this perspective, natural waste composites, i.e., wood waste composites, have also been investigated for their effective and sustainable employment. This paper deals with the application of hard and soft wood waste (i.e., acacia and cedar wood) with epoxy resin polymer to develop high strength and thermally stable wood composites. Mechanical (tensile, flexural, impact, and hardness) and thermal properties of samples are studied using Differential Scanning Calorimeter (DSC) and Thermo Gravimetric Analysis (TGA), respectively. The properties are evaluated by varying the type of wood waste and its percentage by weight. Based on the Taguchi Orthogonal Array Mixture Design, eighteen experiments are investigated. Analysis of variance (ANOVA) results show that wood waste type and wood waste content have a significant effect on all mechanical properties. From the TGA analysis, it is predicted that both types of wood waste composites exhibit similar thermal-induced degradation profiles in terms of the initial and final degradation temperatures. From the DSC results, higher glass transition temperature Tg is detected in 10% of the hardwood waste composite, and a reducing tendency of glass transition temperature Tg is observed with exceeding wood waste content. Moreover, hardwood waste at 10% demonstrated improved decomposition temperature Td, due to strong adhesion between waste and matrix.

Investigating Optimal Confinement Behaviour of Low-Strength Concrete through Quantitative and Analytical Approaches.

Reinforced concrete is used worldwide in the construction industry. In past eras, extensive research has been conducted and has clearly shown the performance of stress-strain behaviour and ductility design for high-, standard-, and normal-strength concrete (NSC) in axial compression. Limited research has been conducted on the experimental and analytical investigation of low-strength concrete (LSC) confinement behaviour under axial compression and relative ductility. Meanwhile, analytical equations are not investigated experimentally for the confinement behaviour of LSC by transverse reinforcement. The current study experimentally investigates the concrete confinement behaviour under axial compression and relative ductility of NSC and LSC using volumetric transverse reinforcement (VTR), and comparison with several analytical models such as Mander, Kent, and Park, and Saatcioglu. In this study, a total of 44 reinforced-column specimens at a length of 18 in with a cross-section of 7 in × 7 in were used for uniaxial monotonic loading of NSC and LSC. Three columns of each set were confined with 2 in, 4 in, 6 in, and 8 in c/c lateral ties spacing. The experimental results show that the central concrete stresses are significantly affected by decreasing the spacing between the transverse steel. In the case of the LSC, the core stresses are double the central stress of NSC. However, increasing the VTR, the capacity and the ductility of NSC and LSC increases. Reducing the spacing between the ties from 8 in to 2 in center to center can affect the concrete column's strength by 60% in LSC, but 25% in the NSC. The VTR and the spacing between the ties greatly affected the LSC compared to NSC. It was found that the relative ductility of the confined column samples was almost twice that of the unrestrained column samples. Regarding different models, the Manders model best represents the performance before the ultimate strength, whereas Kent and Park represents post-peak behaviour.

Multi-Response Optimization of Tensile Creep Behavior of PLA 3D Printed Parts Using Categorical Response Surface Methodology.

Three-dimensional printed plastic products developed through fused deposition modeling (FDM) endure long-term loading in most of the applications. The tensile creep behavior of such products is one of the imperative benchmarks to ensure dimensional stability under cyclic and dynamic loads. This research dealt with the optimization of the tensile creep behavior of 3D printed parts produced through fused deposition modeling (FDM) using polylactic acid (PLA) material. The geometry of creep test specimens follows the American Society for Testing and Materials (ASTM D2990) standards. Three-dimensional printing is performed on an open-source MakerBot desktop 3D printer. The Response Surface Methodology (RSM) is employed to predict the creep rate and rupture time by undertaking the layer height, infill percentage, and infill pattern type (linear, hexagonal, and diamond) as input process parameters. A total of 39 experimental runs were planned by means of a categorical central composite design. The analysis of variance (ANOVA) results revealed that the most influencing factors for creep rate were layer height, infill percentage, and infill patterns, whereas, for rupture time, infill pattern was found significant. The optimized levels obtained for both responses for hexagonal pattern were 0.1 mm layer height and 100% infill percentage. Some verification tests were performed to evaluate the effectiveness of the adopted RSM technique. The implemented research is believed to be a comprehensive guide for the additive manufacturing users to determine the optimum process parameters of FDM which influence the product creep rate and rupture time.

Numerical Modeling and Analysis of Ti6Al4V Alloy Chip for Biomedical Applications.

The influence of cutting forces during the machining of titanium alloys has attained prime attention in selecting the optimal cutting conditions to improve the surface integrity of medical implants and biomedical devices. So far, it has not been easy to explain the chip morphology of Ti6Al4V and the thermo-mechanical interactions involved during the cutting process. This paper investigates the chip configuration of the Ti6Al4V alloy under dry milling conditions at a macro and micro scale by employing the Johnson-Cook material damage model. 2D modeling, numerical milling simulations, and post-processing were conducted using the Abaqus/Explicit commercial software. The uncut chip geometry was modeled with variable thicknesses to accomplish the macro to micro-scale cutting by adapting a trochoidal path. Numerical results, predicted for the cutting reaction forces and shearing zone temperatures, were found in close approximation to experimental ones with minor deviations. Further analyses evaluated the influence of cutting speeds and contact friction coefficients over the chip flow stress, equivalent plastic strain, and chip morphology. The methodology developed can be implemented in resolving the industrial problems in the biomedical sector for predicting the chip morphology of the Ti6Al4V alloy, fracture mechanisms of hard-to-cut materials, and the effects of different cutting parameters on workpiece integrity.

Experimental Investigation and Statistical Evaluation of Optimized Cutting Process Parameters and Cutting Conditions to Minimize Cutting Forces and Shape Deviations in Al6026-T9.

Precise, economical and sustainable cutting operations are highly desirable in the advanced manufacturing environment. For this aim, the present study investigated the influence of cutting parameters (i.e., the cutting speed (c), feed rate (f), depth of cut (d) and positive rake angle (p)) and sustainable cutting conditions (dry and minimum quantity lubricant (MQL)) on cutting forces (i.e., feed force (Ff), tangential forces (Ft), radial force (Fr) and resultant cutting forces (Fc) and shape deviations (i.e., circularity and cylindricity) of a 6026-T9 aluminum alloy. The type of lubricant and insert used are virgin olive oil and uncoated tungsten carbide tool. Turning experiments were performed on a TAKISAWA TC-1 CNC lathe machine and cutting forces were measured with the help of a Kistler 9257B dynamometer. Shape deviations were evaluated by means of a Tesa Micro-Hite 3D DCC 474 coordinate measuring machine (CMM). Experimental runs were planned based on Taguchi mixture orthogonal array design L16. Analysis of variance (ANOVA) was performed to study the statistical significance of cutting parameters. Taguchi based signal to noise (S/N) ratios are applied for optimization of single response, while for optimization of multiple responses Taguchi based signal to noise (S/N) ratios coupled with multi-objective optimization on the basis of ratio analysis (MOORA) and criteria importance through inter-criteria correlation (CRITIC) are employed. ANOVA results revealed that feed rate, followed by a depth of cut, are the most influencing and contributing factors for all components of cutting forces (Ff, Ft, Fr, and Fc) and shape deviations (circularity and cylindricity). The optimized cutting parameters obtained for multi responses are c = 600 m/min, f = 0.1 mm/rev, d = 1 mm and p = 25°, while for cutting conditions, MQL is optimal.

Tuberculosis Resistance and Nanoparticles: Combating the Dual Role of Reactive Oxygen Species in Macrophages for Tuberculosis Management.

Increasing drift in antimicrobial therapy failure against Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), and the advent of extended resistant strains strongly demand discovery of mechanisms underlying development of drug resistance. The emergence of resistance against anti-TB drugs has reached an alarming level in various parts of the world, providing an active platform for the design of new targeted drug delivery. Reactive oxygen species (ROS) have an important role in controlling TB pathogenesis. At macrophage activation, ROS that are produced inside macrophages directly kill resident bacteria. These ROS possess a dual character because they can kill macrophages along with the resident bacteria. Targeting these ROS can play a remarkable part in overcoming resistance of conventional drugs. Nanoparticles (NPs) have evolved as a potential drug carrier for targeted delivery and elimination of various resistance mechanisms against antimicrobials. Receptor-mediated targeting of macrophages via different NPs may be a promising strategy for combating drug resistance and enhancing efficacy of old-fashioned antimycobacterial agents.

Innovative Cold Atmospheric Plasma (iCAP) Decreases Mucopurulent Corneal Ulcer Formation and Edema and Reduces Bacterial Load in Pseudomonas Keratitis.

PURPOSE: To evaluate the effect of application of 3% air in helium cold atmospheric plasma jet, using an inexpensive device termed iCAP, in corneal scratch wound closure in vitro and the treatment of Pseudomonas aeruginosa (P. aeruginosa) keratitis in vivo. METHODS: Thermal imaging to measure temperature of surfaces to which iCAP was applied and UV energy density delivered by iCAP were measured. Scratch wounds inflicted on in vitro cultures of a human corneal epithelial cell line were treated with iCAP and wound widths at various times post-application were measured. Rabbit eyes infected with P. aeruginosa were treated with iCAP and slit lamp biomicroscope examination conducted to determine corneal health outcomes 25h post infection. Corneal homogenates were plated on agar and viable bacterial colonies enumerated to determine the effect of iCAP on bacterial load in vivo in P. aeruginosa keratitis. RESULTS: iCAP was shown to operate in the non-thermal regime and also shown to deliver much lower UV energy density than that necessary to cause harmful effects on ocular tissue. iCAP treatment significantly improved the rate of scratch wound gap closure in vitro in a human corneal epithelial cell line compared to controls. In vivo, iCAP treatment of P. aeruginosa keratitis infection in the rabbit eyes (N = 20) significantly reduced the incidence of corneal ulcer (P = 0.003) and corneal edema (P = 0.011) and significantly improved total cornea health (P = 0.034) compared to untreated (N = 10). Finally, in vivo iCAP treatment of P. aeruginosa keratitis infection in the rabbit eyes (N = 19) significantly reduced bacterial loads (P = 0.012) compared to untreated (N = 9). CONCLUSION: Our results strongly suggest that iCAP treatment was effective in improving corneal epithelial defect closure in vitro, reducing ulcer formation and decreasing inflammation in P. aeruginosa infected corneas in vivo and decreasing bacterial loads in P. aeruginosa infected corneas in vivo which led to improved overall cornea health outcomes in vivo. Further studies to investigate iCAP's safety and efficacy against other infectious microbes responsible for causing ulcerative keratitis, with and without co-treatment with antimicrobial therapies are warranted.

Finite Element Analysis of Interfacial Debonding in Copper/Diamond Composites for Thermal Management Applications.

Copper/diamond (Cu/D) composites are famous in thermal management applications for their high thermal conductivity values. They, however, offer some interface related problems like high thermal boundary resistance and excessive debonding. This paper investigates interfacial debonding in Cu/D composites subjected to steady-state and transient thermal cyclic loading. A micro-scale finite element (FE) model was developed from a SEM image of the Cu/20 vol % D composite sample. Several test cases were assumed with respect to the direction of heat flow and the boundary interactions between Cu/uncoated diamonds and Cu/Cr-coated diamonds. It was observed that the debonding behavior varied as a result of the differences in the coefficients of thermal expansions (CTEs) among Cu, diamond, and Cr. Moreover, the separation of interfaces had a direct influence upon the equivalent stress state of the Cu-matrix, since diamond particles only deformed elastically. It was revealed through a fully coupled thermo-mechanical FE analysis that repeated heating and cooling cycles resulted in an extremely high stress state within the Cu-matrix along the diamond interface. Since these stresses lead to interfacial debonding, their computation through numerical means may help in determining the service life of heat sinks for a given application beforehand.

Antibody functionalized graphene biosensor for label-free electrochemical immunosensing of fibrinogen, an indicator of trauma induced coagulopathy.

An antibody, specific to fibrinogen, has been covalently attached to graphene and deposited onto screen printed electrodes using a chitosan hydrogel binder to prepare an inexpensive electrochemical fibrinogen biosensor. Fourier Transform Infrared (FT-IR) spectroscopy has been utilized to confirm the presence of the antibody on the graphene scaffold. Electrochemical Impedance Spectroscopy (EIS) has been utilized to demonstrate that the biosensor responds in a selective manner to fibrinogen in aqueous media even in the presence of plasminogen, a potentially interfering molecule in the coagulopathy cascade. Furthermore, the biosensor was shown to reliably sense fibrinogen in the presence of high background serum albumin levels. Finally, we demonstrated detection of clinically relevant fibrinogen concentrations (938-44,542µg/dL) from human serum and human whole blood samples using this biosensor. This biosensor can potentially be used in a point-of-care device to detect the onset of coagulopathy and monitor response following therapeutic intervention in trauma patients. Thus this biosensor may improve the clinical management of patients with trauma-induced coagulopathy.