Systemic Absorption Research Articles

Maximizing thermal management of photovoltaic-thermal systems with proper configuration of porous fins and phase change materials

Effective thermal management is crucial to enhance the performance and longevity of photovoltaic-thermal (PVT) systems. Phase change materials (PCMs) offer a promising solution for absorbing excess heat from PV modules; however, their poor thermal conductivity limits their effectiveness. This work explores the incorporation of porous fins within PCMs to improve heat absorption and thermal regulation in PVT systems. A detailed mathematical model is developed to analyze the effects of varying fin porosity (0.85 to 0.95), fin thickness (7 to 21 mm), fin height (7 to 21 mm), and fin inclination (-15° to 30°) on PCM melting and PVT cooling performance. Results show that optimally configured porous fins significantly enhance PCM melting rates and heat extraction from PV cells. Incorporating optimal fins reduces peak PV temperatures by up to 5°C compared to PCM alone at irradiation rate of 1000 W/m2. Meanwhile, reducing the fin thickness from 21 to 7 mm accelerates the overall PCM melting rate by 14%. The cooling performance also shows a nonlinear increase with fin tilt angle, with maximum enhancement occurring at 15° downward tilt for the studied configuration. The optimized fin-enhanced PVT design achieves 3.1% higher electrical efficiency and 15% increase in thermal efficiency compared to conventional PCM-PVT systems without fins. Findings provide design guidance to harness porous fins for maximized PCM-based cooling of PVT systems.

A multi-bionic design strategy for modular energy absorption system based on interlocking suture integrated with Bouligand-like arranged perforations

Thin-walled tubes are widely used in the field of cushioning energy absorption as an ideal structural unit. However, the performance of the thin-walled tube system is greatly limited by the presence of redundant connection structures. To address these issues, a multi-bionic design strategy for high-performance modular system was developed in this work, which innovatively combines the robust joint structure of the interlocking suture with the efficient deformation mode of the Bouligand structures. In the design process, the suture-inspired system was studied separately, and its mechanical behaviors were investigated by FEM simulations and experiments. The results showed that the modular system has good structural scalability and tunable deformation mode, and can be adjusted on demand to accommodate different loads and geometric features. Furthermore, in order to reduce the weight and improve the deformation degree of the system, an optimization strategy inspired by the efficient deformation mode of the Bouligand structure was proposed by perforating a sequence of helix-arranged guide holes in the sidewalls of the tubes. The results showed that the double-helix perforated system can reduce the weight by 10% while increasing the specific energy absorption by 58% compared with the unperforated system. In addition, the specific energy absorption and energy absorption efficiency of the system are as high as 48.25 J/g and 56.17%, which is comparable to traditional honeycomb sandwich panels while retaining structural stability and adjustable performance. Therefore, this multi-bionic strategy can integrate the advantages of various natural structures and provide new insights for the design of high-performance protective systems.

Rifaximin and alternative agents in the management of irritable bowel syndrome: A comprehensive review.

Rifaximin, a broad-spectrum antibiotic, boasts a unique chemical composition and pharmacokinetic profile, rendering it highly effective in treating irritable bowel syndrome (IBS). Its minimal systemic absorption confines its impact to the gastrointestinal (GI) tract, where it yields significant therapeutic benefits. This review examines rifaximin's physico-chemical attributes and its role in managing IBS symptoms. Its molecular structure facilitates intestinal lumen retention postoral administration, minimizing systemic exposure and adverse effects. This targeted action is crucial in addressing the gut microbiota's role in IBS pathophysiology. By modifying microbial populations and their metabolite production, rifaximin mitigates symptoms like bloating, irregular bowel habits, and abdominal pain associated with IBS. It achieves this by reducing pathogenic bacteria and altering bacterial metabolism, enhancing mucosal and immune function. Clinical trials affirm rifaximin's superiority over placebo and conventional therapies in alleviating overall IBS symptoms and addressing small intestine bacterial overgrowth (SIBO). Despite its promising efficacy and sustained symptom relief, further research is essential to optimize long-term effectiveness and dosing regimens. Rifaximin stands as a vital treatment option for IBS due to its distinctive properties and clinical utility; yet, ongoing investigation is imperative for maximizing its therapeutic benefits.

An Insight into the Mechanism, Safety and Efficacy for Photoprotection and Dermatological Conditions of Polypodium leucotomos Extract

Abstract: Numerous photoprotective techniques have been employed to successfully shield against the harmful effects of ultraviolet radiation. Current photoprotective techniques have limitations due to the amount of topical application, insufficient physical protection, and adverse responses to topical agents. A newer option that offers a promising defense against solar radiation is systemic agents, the well-researched Polypodium leucotomos is significant in this category, and several studies have found to be effective ―oral sunscreenǁ. Polypodium leucotomos (PL) extract has gained significant attention as a potential therapeutic agent in the field of dermatology, particularly in the photoprotection and management of various dermatological conditions. This abstract provides a comprehensive overview of the mechanism, safety, and efficacy of Polypodium leucotomos extract in relation to photoprotection and dermatological conditions. Our primary aim is to review Polypodium leucotomos' photoprotective results from studies that are currently available, and our secondary goal is to describe Polypodium leucotomos' applications in different dermatological conditions. Articles discussing Polypodium leucotomos uses in photoprotection and dermatologic conditions are searched and downloaded from publicly available databases such as PubMed, JSTOR, PLOS, Science Direct, DOAJ, Google Scholar, and Web of Science and evaluate the outcomes of the Polypodium leucotomos effect. Firstly, we delve into the mechanisms underlying the photoprotective properties of PL extract. Extensive research has demonstrated that PL extract exerts its protective effects through multiple pathways, including antioxidant activity, DNA repair stimulation, immunomodulation, and inhibition of inflammatory mediators. These mechanisms collectively contribute to the prevention of photodamage, such as sunburn, DNA damage, and photoaging. Furthermore, we explore the safety profile of PL extract, emphasizing its remarkable tolerability and minimal adverse effects reported in clinical studies. The absence of systemic absorption and its compatibility with other treatments make PL extract a promising option for long-term use in photoprotection and dermatological care. A promising alternative to traditional photoprotection may be Polypodium leucotomos. Additional thorough clinical trials are necessary to ascertain its role and effectiveness more accurately. The efficacy of PL extract in managing various dermatological conditions is also discussed. Multiple studies have demonstrated its beneficial effects in conditions such as vitiligo, melasma, psoriasis, and atopic dermatitis. The anti-inflammatory and immunomodulatory properties of PL extract have shown promise in reducing disease severity, improving skin symptoms, and enhancing the quality of life for patients. Additionally, the abstract highlights the potential future directions and areas of research for PL extract. Investigating its combination therapy with other photoprotective agents, exploring optimal dosage regimens, and further elucidating the molecular mechanisms are areas that warrant attention. In conclusion, this abstract provides an insightful overview of the mechanisms, safety, and efficacy of PL extract in photoprotection and dermatological conditions. The remarkable properties of PL extract, combined with its favorable safety profile, position it as a promising therapeutic intervention in dermatology. Further research and clinical trials are needed to fully exploit its potential and establish its place in the management of various skin conditions.

The homeostasis of ions and reactive oxygen species in root and shoot play crucial roles in the tolerance of alfalfa to salt alkali stress

High pH saline-alkali stress, mainly NaHCO3, limited the development of animal husbandry in Songnen Plain. Ion imbalance and reactive oxygen species (ROS) metabolism disorder caused by saline-alkali stress inhibited plant growth. In this study, we compared the differences in ion absorption, transport and ROS metabolism between saline-tolerant alfalfa (ZD) and saline-sensitive alfalfa (ZM) under NaHCO3 stress using physiology and transcripomics techniques. WGCNA analysis identified key genes associated with NaHCO3 stress-induced changes. NaHCO3 stress inhibited the absorption of K+ and Mg2+, but activated Ca2+ signal. Furthermore, ZD maintained higher K+, Mg2+ and Ca2+ contents and the K+/Na+ ratio than ZM, this is mainly related to the higher expression of proteins or channel-encoding genes involved in ion absorption and transport in ZD. Antioxidant enzyme systems can be activated in response to NaHCO3 stress. Peroxidase (EC 1.11.1.6), catalase (EC 1.11.1.7) and glutathione transferase (EC 2.5.1.18) activities were higher in ZD than ZM, and most genes encoding the relevant enzymes also demonstrated a stronger up-regulation trend in ZD. Although NaHCO3 stress inhibited Trx-Prx pathway, ZD related enzymes and their genes were also inhibited less than ZM. WGCNA results identified many genes involved in ion absorption, transport and antioxidant systems that play an important role in NaHCO3 stress adaptation. Collectively, ZD has the stronger ion homeostasis regulation and ROS scavenging ability, so it's more resistant to NaHCO3. The results provide theoretical guidance for further understanding of the molecular mechanism of NaHCO3 resistance and provide potential genes for research to improve saline-alkali tolerance in alfalfa.

Sustained co-release of ciprofloxacin and dexamethasone in rabbit maxillary sinus using polyvinyl alcohol-based hydrogel microparticle

Topical delivery to paranasal sinuses through sustained-release stents is one of the new horizons in treating chronic rhinosinusitis (CRS). This study aims to introduce and evaluate sustained co-release of encapsulated ciprofloxacin (CIP) and dexamethasone (DEX) in polyvinyl alcohol-based carriers within the maxillary sinus of rabbit animals. DEX and CIP were loaded in a tyramine-substituted polyvinyl alcohol microparticle (PVATyr MP). The mechanical stability, degradability, and sustained-release patterns of both drugs as well as cellular cytocompatibility were assessed in vitro. The PVATyr MPs were then injected into the maxillary sinus of rabbits and they were monitored weekly for 21 days. Nasal endoscopy, MRI imaging, and tissue microscopy were used to follow the changes and compared them with the control condition. Also, the concentrations of drugs were evaluated in the maxillary sinus and blood samples over the study period. Produced PVA-based MPs possessed a relatively narrow particle size distribution (CV 7.7%) with proper physical stability until 30 days of incubation. The uniform-sized PVATyr MPs and their surrounding hydrogel showed sustained-release profiles for DEX and CIP for up to 32 days in vitro. The injected drugs-loaded hydrogel showed complete clearance from the maxillary sinus of rabbits within 28 days. The concentrations of DEX and CIP in mucosal remained within the therapeutic window when measured on days 7, 14, and 21, which were well above the plasma concentrations without any pathological changes in endoscopy, MRI imaging, and histological examinations. DEX/CIP loaded PVATyr MPs provided an effective, controlled, and safe sustained-drug delivery in both in vitro and in vivo analyses at therapeutic concentrations with minimal systemic absorption, suggesting a promising treatment approach for CRS.Graphical

Enhancement of CO2 removal from flue gas in an oscillatory baffled column using potassium carbonate solution

One of the efficient methods for reducing CO2 emissions from flue gas streams in oil refineries and power plants is the CO2absorption process using alkali solution. Potassium carbonate (K2CO3) solution, as CO2 absorbent, was used in the present study due to its high CO2 absorption capacity. However, K2CO3 has a drawback which is represented by its slow reaction with CO2. To overcome this issue, an oscillatory baffled column (OBC) was utilized as a contactor to maintain a high degree of mixing in the CO2 absorption system and thereby increasing the reaction rate between K2CO3 and CO2 as well as enhancing the mass transfer rate. In this study the effect of different operation conditions of the process namely; inlet flue gas flow rate (15 % (v/v) CO2 balanced with N2) and oscillation conditions on CO2 absorption in a semi-batch OBC were investigated. The experiments were performed with range of modified Reynolds Number of Oscillation (Reo′ = 0⎼1450) and aeration rates (0⎼1 vvm) using K2CO3 (100 g/L, 0.72 M)0.1.8–3.5-fold of enhancement of CO2 absorption rates was achieved by using OBC with respect to that obtained by baffled column (BC) (only baffles without oscillation) and plane bubble column (PBC) (without baffles and oscillation), respectively.The use of K₂CO₃ as a solvent in an oscillating reactor (OBR) to remove CO₂ represents a new method due to the high reactivity of K₂CO₃ with CO₂, forming stable bicarbonate and carbonate compounds. OBR's enhanced mixing capabilities improve mass transfer rates and reaction efficiency, allowing for more effective CO2 capture compared to conventional reactors. This combination leverages the strengths of both the chemical reactivity of K₂CO₃ and the mechanical benefits of OBR, potentially leading to more efficient and scalable CO2 removal processes.

Construction of Chiral-Magnetic-Dielectric Trinity Structures with Different Magnetic Systems for Efficient Low-Frequency Microwave Absorption.

The fabrication of carbon nanocoil (CNC)-based chiral-dielectric-magnetic trinity composites holds great significance in low-frequency microwave absorption fields. However, it is not clear that how the different magnetic systems affect the magnetic and frequency responses of the composites. Herein, four types of magnetic metals, FeCo, CoNi, FeNi, and FeCoNi, are selected to be combined with the chiral templates respectively, resulting in four types of chiral-dielectric-magnetic composites with similar morphology. The CNC templates endow all the composites with excellent dielectric loss. Further permeability analysis and the micro-magnetic simulation confirm that the frequency response region can be well adjusted by changing the magnetic systems with specific magnetic resonance modes and magnetic domain motion. Due to the synergistic effect between magnetism, chirality, and dielectricity, the FeNi-based composites exhibit the best low-frequency microwave absorption performance. The minimum RL of -60.7 dB is achieved at 6.7 GHz with an ultra-low filling ratio of 10%, and the EAB value in low-frequency region is extended to 3.7 GHz. This study provides further guidelines for the design of the chiral-dielectric-magnetic trinity composites in low-frequency microwave absorption.

A Hybrid Perovskite-Based Electromagnetic Wave Absorber with Enhanced Conduction Loss and Interfacial Polarization through Carbon Sphere Embedding.

Electronic equipment brings great convenience to daily life but also causes a lot of electromagnetic radiation pollution. Therefore, there is an urgent demand for electromagnetic wave-absorbing materials with a low thickness, wide bandwidth, and strong absorption. This work obtained a high-performance electromagnetic wave absorption system by adding conductive carbon spheres (CSs) to the CH3NH3PbI3 (MAPbI3) absorber. In this system, MAPbI3, with strong dipole and relaxation polarization, acts dominant to the wave absorber. The carbon spheres provide a free electron transport channel between MAPbI3 lattices and constructs interfacial polarization loss in MAPbI3/CS. By regulating the content of CSs, we speculate that this increased effective absorption bandwidth and reflection loss intensity are attributed to the conductive channel of the carbon sphere and the interfacial polarization. As a result, when the mass ratio of the carbon sphere is 7.7%, the reflection loss intensity of MAPbI3/CS reaches -54 dB at 12 GHz, the corresponding effective absorption bandwidth is 4 GHz (10.24-14.24 GHz), and the absorber thickness is 2.96 mm. This work proves that enhancing conduction loss and interfacial polarization loss is an effective strategy for regulating the properties of dielectric loss-type absorbing materials. It also indicates that organic-inorganic hybrid perovskites have great potential in the field of electromagnetic wave absorption.

Energy absorption structure with negative stepped plateau force characteristics under quasi-static loads

The force-displacement curve is the key to determine the energy absorption performance. Customizing the force-displacement curve enables the design of more advanced and efficient energy absorption systems. In this paper, we introduce a negative stepped plateau force structure (NSPFS) design by combining crooked plate units with curved and straight combined cross-section (CSCC) units. First, the NSPFS is fabricated by using additive manufacturing technology, and a compression experiment is conducted to validate the design methodology. Then, a finite element model is developed and compared with the experimental results to verify its effectiveness. The peak force (PF) and mean crushing force (MCF) of the crooked plate unit are primarily controlled by wall thickness t1 and initial angle θ1. When θ1 = 1.146° and t1 = 1.0 mm of crooked plate unit, the lowest point of the plateau phase decreases by 84 % compared to the PF, and the ratio of PF to MCF is 4.9. When the PF of the crooked plate unit is greater than the PF of the CSCC unit, the structure has the characteristics of negative stepped plateau force. More phase plateau forces can be obtained when multiple NSPFS are compressed in series. When multiple NSPFS units are compressed in parallel, multi-phase continuous negative stepped plateau force can be achieved. Therefore, NSPFS allows for the customization of complex force-displacement curves through series and parallel design.

Heavy Metals and Cosmetics Industry: A Review Article

Trace amounts of heavy metals are present during cosmetic products manufacturing. (1) Therefore, they should be kept to a minimum acceptable level as stated by the FDA and pharmacopeias. (2) It is so far known that human external contact with these substances rarely result in a significant systemic exposure. However, many research studies showed that frequent local exposure to cosmetic products containing heavy metals may pose a risk of heavy metal contamination. (1,2) Heavy metals such as mercury (Hg) are added to skin-whitening products, causing acute or chronic damage to human skin cells. (1) Moreover, contamination of hair dyes and deodorants with Aluminum (Al) and Lead (Pb) threaten consumers' health dangerously for carcinogenic effects. Other possible side effects included microcytic anemia and osteomalacia. (3) Additionally, it was found that Al provokes further side effects on human mental health as dialysis dementia and it has also been associated with the neurodegenerative disease, Alzheimer's disease (AD) in adults. (4) Furthermore, Pb is a core component of many lipsticks, which reflects a high systemic absorption due to wrong consumers' habits. Frequent use of lipsticks containing Pb specially by children and adolescents has been significantly linked to neurodevelopmental disorders such as autism and attention-deficit-hyperactivity-disorder (ADHD) symptoms in children. (5) Therefore, strict regulations should be set for cosmetics manufacturing and quality control measurements should be assigned for pre- and post-marketed cosmetic products.

Modeling of an advanced renewable energy system coupled with hydrogen production and liquefaction for sustainable communities

The primary objective of this study is to develop a sustainable and efficient renewable energy-based multigeneration system that is specifically designed to meet diverse energy demands, such as heat, cooling, electricity and hydrogen. The system comprises several subsystems: a digester for biomass processing, a solar energy collection system, a thermal energy storage system, a multistage Brayton cycle, a steam Rankine cycle with reheat, a double-effect absorption system, a sonic hydrogen production unit, and a multistage hydrogen liquefaction system. The methodology involves conducting energy and exergy analyses, economic evaluation, and environmental impact assessment to determine the system's performance and viability. The energy efficiency results show that the Brayton cycle, steam Rankine cycle and liquefaction system have efficiencies of 30.92 %, 30.18 %, and 64.53 %, respectively. The exergy efficiencies for these subsystems are 50.10 %, 67.21 %, and 11.29 %, respectively. The double-effect absorption system exhibits energetic and exergetic coefficients of performance of 1.68 and 0.64, respectively. The overall energy and exergy efficiencies of the system are 36.41 % and 55.74 %, respectively. The economic analysis indicates a significant revenue potential, with the project reaching its break-even point in 2031 and achieving a net present value of $6.60 million. The results of an environmental impact assessment study highlight a reduction in CO2 emissions compared to conventional systems, emphasizing the system's contribution to sustainable energy solutions.

Effect of operating variables on isopropanol absorbed by triethylene glycol solution and discussions on the mass transfer coefficient predicted by artificial neural network

The mass transfer performance of isopropanol (IPA) absorption by triethylene glycol (TEG) aqueous solution in a spray-bed absorber was investigated, and the mass transfer coefficients predicted by an artificial neural network (ANN) and response surface methodology were compared in this study. The operating variables affecting the mass transfer performance of a spray-bed absorber include the gas and TEG fluxes, concentration of IPA, concentration of TEG aqueous solution, and operating temperature. The experimental results demonstrated that the mass transfer coefficient of a spray-bed absorber increased with increases in gas and liquid fluxes and decreased with increases in concentration of IPA. The Back-Propagation algorithm in the ANN model was selected to predict the mass transfer coefficients of the spray–bed absorption system. Hidden layers with 2, 4 and 6 neurons respectively were set to analyze the effect of the number of neurons on the target value, and then different transfer functions were used to compare the accuracy in predicting mass transfer coefficient. Finally, the influences of the number of hidden layers and different learning rules on the prediction of mass transfer coefficients were examined. The simulated results showed that the average error of the ANN using the TanhAxon transfer function, the Conjugate Gradient learning rule, two hidden layers, and 6 neurons in each hidden layer was within 1%. The results not only verified the successful establishment of the experimental device but also proved the accurate prediction of mass transfer coefficients by the ANN model.

Molecular docking analysis of Salvia sclarea flower extracts evaluated for protein target affinity based on different extraction methods

AbstractThis study evaluates the antioxidant activity and total phenolic, flavonoid, flavonol, and tannin contents of extracts obtained from the flower parts of Salvia sclarea using different extraction methods, such as maceration and rotavapor (RE). The results indicate that the maceration method yields extracts with higher antioxidant activity compared to the rotavapor method (DPPH IC50: 260.70 ± 65.41 mg/mL vs. 345.48 ± 27.91 mg/mL). Additionally, the maceration method produces higher values in terms of total phenolic (26.4 ± 7.78 mg GAE/g extract), flavonoid (10.44 ± 0.21 mg QE/g extract), flavonol (9.20 ± 0.84 mg QE/g extract), and tannin contents (8.36 ± 0.39 mg GAE/g extract), whereas the RE method shows lower values (phenolics: 19.8 ± 3.31 mg GAE/g extract, flavonoids: 10.35 ± 0.35 mg QE/g extract, flavanol's: 5.45 ± 0.01 mg QE/g extract, and tannins: 7.72 ± 0.10 mg GAE/g extract). The gas chromatography–mass spectrometry (GC–MS) analysis of the extracts identified various bioactive compounds. Molecular docking studies revealed that Terpinen‐4‐ol obtained through maceration exhibits a strong binding affinity to a specific protein target, indicating potential biological activity. The predicted pharmacokinetic (ADME (absorption, distribution, metabolism, and excretion)) parameters for Terpinen‐4‐ol suggest favorable absorption and central nervous system (CNS) penetration, while Squalene obtained through maceration shows different pharmacokinetic properties. S. sclarea highlights significant antioxidant potential and provides insight into the bioactive compounds obtained through different extraction methods. To further investigate the potential biological interactions arising from these differences, molecular docking studies were conducted.

Analysis of a nonlinear dynamic absorption system

Analysis of a nonlinear dynamic absorption system

Isotopic abundance of carbon in the DLA towards QSO B1331+170

ABSTRACT Chemical evolution models predict a gradual build-up of 13C in the Universe, based on empirical nuclear reaction rates and assumptions on the properties of stellar populations. However, old metal-poor stars within the Galaxy contain more 13C than is predicted, suggesting that further refinements to the models are necessary. Gas at high-redshift provides important supplementary information at metallicities $-2\lesssim \left[{\rm Fe/H}\right]\lesssim -1$, for which there are only a few measurements in the Galaxy. We obtained new, high-quality, VLT/ESPRESSO observations of the QSO B1331$+$170 and used them to measure 12C/13C in the damped Lyman-$\alpha$ system (DLA) at $z_{\rm abs}=1.776$, with $\left[{\rm Fe/H}\right]$ = −1.27. ai-vpfit, an artificial intelligence tool based on genetic algorithms and guided by a spectroscopic information criterion, was used to explore different possible kinematic structures of the carbon gas. Three hundred independent ai-vpfit models of the absorption system were produced using pre-set 12C/13C values, ranging from 4 to 500. Our results show that ${\rm ^{12}C / ^{13}C}=28.5^{+51.5}_{-10.4}$, suggesting a possibility of 13C production at low metallicity.

Kinetics of fluoride after brushing with the no-rinse method

BackgroundFluoride plays a vital role in preventing dental caries, with its addition to oral care products significantly promoting oral hygiene. A no-rinse brushing method aims to increase fluoride retention in the oral cavity, as rinsing with water decreases fluoride levels in saliva, which could affect remineralization. While the no-rinse brushing method holds promise for improving fluoride retention in the oral cavity, critical inquiries persist regarding its safety. This study investigated the kinetics of oral fluoride and potential risks to fully assess its effectiveness and implications for oral health.MethodsTen healthy adults participated in a crossover study comparing the no-rinse with the rinse method. All subjects followed American Dental Association (ADA) brushing guidelines. Levels of fluoride in saliva (supernatant and sediment) and urine were measured over time, and plasma fluoride was measured one hour after brushing. Pharmacokinetic parameters were also calculated from the data.ResultsParticipants using the no-rinse method had higher fluoride levels in supernatant immediately and up to 30 min post-brushing compared to the rinse method. Fluoride levels in sediment were higher only immediately after brushing. The total fluoride concentration in saliva remained elevated for up to 5 min with the no-rinse method. Systemic fluoride absorption showed no significant difference between the two methods based on blood and urine analysis.ConclusionThis research indicates that the no-rinse method can enhance fluoride retention in the oral cavity for up to 30 min after a single brushing. In addition, our findings suggest that this method does not significantly influence systemic fluoride levels or toxicity.RegistryThai Clinical Trials Registry, TCTR (http://thaiclinicaltrials.org). Clinical trial registration number: TCTR20231104001 (4/11/2023).

The Role of Pulmonary Drug Delivery in Modern Therapeutics: An Overview.

The pulmonary drug delivery system is a promising and evolving technology in which the prescribed medicine is breathed through the lungs, and subsequently, it enters the circulation via the alveolar epithelium. This category of pulmonary drug delivery system is an appealing and non-invasive administration method. Pulmonary drug delivery is most commonly utilized to treat airway problems by providing locally active medicines directly to their site of action. The dose required to have a pharmacological effect is reduced when medicines are delivered directly to their site of action. In addition to locally acting medications, the pulmonary route can be utilized to deliver compounds with systemic effects, such as in the case of insulin inhalation therapy for systemic absorption. Particle size, bioavailability, device compatibility, and other aspects must be addressed, including the formulation of drugs into an acceptable dosage for inhalation with sufficient stability. This formulation must also be used in conjunction with a suitable inhaler device that produces an aerosol with a particle or droplet size that assures deposition in the required targeted area of the pulmonary system. Recent advancements in pulmonary drug delivery include the development of targeted nanoparticles and inhalable biologics, which enhance drug absorption and efficacy while minimizing systemic side effects. Future directions focus on personalized medicine approaches and advanced inhalation technologies, although limitations such as variable patient adherence and the need for precise dosing continue to pose challenges.

Predicting Human Subcutaneous Bioavailability of Therapeutic Monoclonal Antibodies from Systemic Clearance and Volume of Distribution.

Subcutaneous delivery of monoclonal antibody therapeutics is often preferred to intravenous delivery due to better patient compliance and overall lower cost to the healthcare system. However, the systemic absorption of biologics dosed subcutaneously is often incomplete. The aim of this work was to describe a human bioavailability prediction method for monoclonal antibodies delivered subcutaneously that utilizes intravenous pharmacokinetic parameters as input. A two-compartment pharmacokinetic model featuring a parallel-competitive absorption pathway and a presystemic metabolism pathway was employed. A training data set comprised 19 monoclonal antibodies (geometric mean bioavailability of 68%), with previously reported human pharmacokinetic parameters, while a validation set included data compiled from 5 commercial drug products (geometric mean bioavailability of 69%). A single fitted absorption rate constant, paired with compound-specific estimates of presystemic metabolism rate proportional to compound-specific systemic clearance parameters, resulted in calculations of human subcutaneous bioavailability closely mimicking clinical data in the training data set with a root-mean-square error of 5.5%. Application of the same approach to the validation data set resulted in predictions characterized by 12.6% root-mean-square error. Factors that may have impacted the prediction accuracy include a limited number of validation data set compounds and an uncertainty in the absorption rate, which were subsequently discussed. The predictive method described herein provides an initial estimate of the subcutaneous bioavailability based exclusively on pharmacokinetic parameters available from intravenous dosing.

Parametric Based Techno‐Economic Evaluation for a Solar Thermal‐PV Integrated Multi‐Commodity Storage Facility

ABSTRACTPostharvest losses and spoilage of agricultural products are a major problem for tropical countries, and it is even more challenging for countries encountering fluctuating power shortages, such as Pakistan. Therefore, this study focused on the energy and economic analysis of cold storage to store three products (potatoes, pomegranates, and potatoes) according to the season and storage span throughout the year. The cooling load of the cold store was supported by a LiBr‐H2O vapor absorption and vapor compression refrigeration system to maintain the desired temperature for each product during cold storage. A solar thermal PV system is installed to operate cold storage refrigeration systems. Cold storage performance was analyzed by developing thermal models of integrated systems using the ambient conditions of Lahore, Pakistan. A parametric study was also conducted to analyze the impact of various working parameters on integrated system performance, and it was found that the maximum peak cooling load of 91 kW inside cold storage is attributed to pomegranates owing to high ambient conditions during its loading month. The product loading rate significantly affects the cooling load of cold storage and varies directly with it, as observed for an increase in the product loading rate from 0 to 50 000 kg/day cooling load also increases from 34 to 87 kW. To meet the thermal demand of the generator of the vapor absorption system, parabolic troughs were installed to operate cold storage, and it was found that a minimum of four PTC were needed to support the peak cooling load at the maximum product loading rate and minimum DNI value. To meet the electrical demand of cold storage electrical equipment and the compressor of the vapor compression system, solar photovoltaic panels were installed, and it was found that a minimum of 618 panels was required at a minimum tilted radiation value. To validate the viability of proposed design system economic analysis was also conducted which revealed a payback period of 12 years for Kinnow and potatoes and 16 years for pomegranates.