9 research outputs found
Integration of biological control with engineered heterojunction nano-photocatalysts for sustainable and effective management of water hyacinth weed
No full textWater hyacinth (Eichhornia crassipes) is a noxious weed that has gained global attention because of its rapid spread and congested development, causing allergies in navigation, irrigation, and challenges navigation, irrigation, and aquatic life challenges. Different physical, chemical, and biological methods are being used to control water hyacinth. However, cost, duration, toxicity, resurgence, and water pollution remain a bottleneck. Integrated controls are reported to be the most cost-effective choice. The generation of reactive oxygen species (ROS) by chemical herbicides is the primary mechanism of action, which damages cell membranes leading to the inactivation of water hyacinth. The engineered heterojunction photocatalysts efficiently generate ROS under visible light and can be applied as alternatives to herbicides. In addition, these photocatalysts offer the advantage of the simultaneous remediation of wastewater as well. This report examines current research activity in the subject, focusing on the scientific and technological opportunities by visible light photocatalysts (VLP). The preparation of floating photocatalysts via composite granules or porous structures has been highlighted to be utilized to control aquatic weeds. The mechanisms of photocatalytic activity of VLP and inactivation of water hyacinth have been discussed. The integrated photocatalytic and biological controls are proposed for the sustainable and effective management of water hyacinth.</p
A Polyphenol-Based Hydrogel for Enabling Enhanced Metal Ion Sorption, Antimicrobial Activity, and Water Remediation
No full textGolder, Animes Kumar/0000-0001-8144-5316Naturally derived, highly functional, and widely accessible materials represent enabling technologies for sustainable development. However, current bio-derived materials often present a trade-off between sustainability potential and functional performance. Sorbents that can remove potentially toxic elements (PTEs) and inhibit bacterial growth to enable water remediation exemplify this dilemma. Conventional plant-based biopolymer materials are attractive for their low cost and environmental compatibility, but many require additional specialized synthetic components to impart the requisite performance. We now report an approach for preparing majority plant polyphenol hydrogels composed of the widely available tannic acid (TA) at an unprecedented 75% content. A minority seaweed alginate (Alg) matrix is used to bind TA into conveniently handled beads. Convenient application is also demonstrated by conducting all experiments with dried beads rehydrated directly during use. Multifold enhancements in water swelling, sorption of a suite of PTEs, and antimicrobial activity are found with increasing TA content. Moreover, we report a novel additional enhancement of antimicrobial activity based on TA-induced iron incorporation, as characterized by XPS, SEM, TGA, and EDX. Further enhancement of sorption for a PTE in this Alg-TA-Fe matrix is also demonstrated. Our hydrogels can be produced at room temperature in low resource settings and exhibit performance generally superior to other biopolymer sorbents and on par with those combining synthetic functionalities. A qualitative evaluation of our polyphenol hydrogels' sustainability potential is performed based on their novel functionalities, greenhouse gas emissions, environmental compatibility, material abundance, and potential for localized production.A.J. acknowledges support of a Commonwealth Split-site PhD scholarship (INCN-2019-204). K.H.A.L., A.K.G., and L.M.P. thank the U.K. India Education Research Initiative and the Department of Science and Technology, India, for a Research Partnership Grant (DST-UKIERI 2017 18-009). C.M.D. and K.H.A.L. acknowledge the University of Strathclyde for AR's Global Research Scholarship. The authors also thank Drs. J.R. Bame and G.J. Anderson for assistance with ICP-MS at Strathclyde's Pure and Applied Chemistry Mass Spectrometry Facility.University of Strathclyde [INCN-2019-204]; Commonwealth Split-site PhD scholarship; U.K. India Education Research Initiative [DST-UKIERI 2017 18-009]; Department of Science and Technology, India; University of Strathclyd
A polyphenol-based hydrogel for enabling enhanced metal ion sorption, antimicrobial activity, and water remediation
No full textNaturally derived, highly functional, and widely accessible materials represent enabling technologies for sustainable development. However, current bio-derived materials often present a trade-off between sustainability potential and functional performance. Sorbents that can remove potentially toxic elements (PTEs) and inhibit bacterial growth to enable water remediation exemplify this dilemma. Conventional plant-based biopolymer materials are attractive for their low cost and environmental compatibility, but many require additional specialized synthetic components to impart the requisite performance. We now report an approach for preparing majority plant polyphenol hydrogels composed of the widely available tannic acid (TA) at an unprecedented 75% content. A minority seaweed alginate (Alg) matrix is used to bind TA into conveniently handled beads. Convenient application is also demonstrated by conducting all experiments with dried beads rehydrated directly during use. Multifold enhancements in water swelling, sorption of a suite of PTEs, and antimicrobial activity are found with increasing TA content. Moreover, we report a novel additional enhancement of antimicrobial activity based on TA-induced iron incorporation, as characterized by XPS, SEM, TGA, and EDX. Further enhancement of sorption for a PTE in this Alg-TA-Fe matrix is also demonstrated. Our hydrogels can be produced at room temperature in low resource settings and exhibit performance generally superior to other biopolymer sorbents and on par with those combining synthetic functionalities. A qualitative evaluation of our polyphenol hydrogels’ sustainability potential is performed based on their novel functionalities, greenhouse gas emissions, environmental compatibility, material abundance, and potential for localized production
Peptoid self-assembly : from minimal sequences to functional nano-assemblies and biomedical applications
No full textThis chapter provides a tutorial review on peptoid nano-assemblies and their biomedically relevant properties and applications. Peptoids are biomimetic molecules that differ from natural peptides only by a one-atom shift in the attachment position of the functional sidechain along the backbone. This minor change in chemical structure however enables major changes in molecular properties and synthetic protocol that can be very attractive for bioactive supramolecular nanotechnology. In the recent decade, peptoids have gained recognition in self-assembled and functional materials due to the sophistication of nano-assemblies demonstrated, the intrinsic bioactivity of specific sequences discovered, and the importance now placed on bioinspired materials. Indeed, there has been a diversity of inspirations for peptoid supramolecular chemistry, from peptide assembly and block copolymer polymersomes to crystallization and protein folding. Peptoid research is also greatly facilitated by the versatility of peptoid synthesis to enable systematic investigations of sidechain and sequence control for directing assembly of a wide range of nanostructures. These include nanofibers, nanotubes, nanosheets, micellar worms and nested vesicles, and this chapter emphasizes the links between sequence and assembled morphologies. Applications from biosensing to stimuli-responsive drug delivery are reviewed to illustrate the potential of peptoids in tailoring nano-assemblies for bioscience and biomedical applications. While the research from many groups which have been examined, some of our recent results in “minimal” assembling sequences as well as applications towards stem cell culture and antimicrobial lipopeptoids are also highlighted
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Self-assembly of minimal peptoid sequences
No full textPeptoids are biofunctional N-substituted glycine peptidomimics. Their self-assembly is of fundamental interest because they demonstrate alternatives to conventional peptide structures based on backbone chirality and beta-sheet hydrogen bonding. The search for self-assembling, water-soluble "minimal" sequences, be they peptide or peptidomimic, is a further challenge. Such sequences are highly desired for their compatibility with biomacromolecules and convenient synthesis for broader application. We report the self-assembly of a set of trimeric, water-soluble α-peptoids that exhibit a relatively low critical aggregation concentration (CAC ∼0.3 wt %). Cryo-EM and angle-resolved DLS show different sequence-dependent morphologies, namely uniform ca. 6 nm wide nanofibers, sheets, and clusters of globular assemblies. Absorbance and fluorescence spectroscopies indicate unique phenyl environments for π-interactions in the highly ordered nanofibers. Assembly of our peptoids takes place when the sequences are fully ionized, representing a departure from superficially similar amyloid-type hydrogen-bonded peptide nanostructures and expanding the horizons of assembly for sequence-specific bio- and biomimetic macromolecules
Simultaneous ACL Reconstruction and MCL Reconstruction in Patients with High BMI using Modified Lind Technique
No full textIntroduction:
Multiligamentous knee injury (MLKI) is a difficult and devastating injury of the knee defined as tear/disruption (involving grade III) of at least 2 of the 4 major ligaments of the knee. Combined anterior cruciate ligament (ACL) and medial collateral ligament (MCL) injuries are the most common type of MLKI. MCL injuries are concurrent in 20–38% of ACL injuries and are common in sports activities that involve pivoting of the knee joint, forced hyperextension, and rapid deceleration. Many techniques have been described for superficial MCL (sMCL) reconstruction, with single-bundle and double-bundle techniques used for the associated posterior oblique ligament (POL) using both allografts and autografts. Among these, one of the most common techniques with a good outcome (keeping the semitendinosus tibial attachment intact) was described by Lind et al. Our technique for sMCL and POL reconstruction is a modification of the Lind technique. In this technique, the semitendinosus with its intact tibial attachment is rerouted anatomically in the tibial tunnel with an adjustable loop, and on the femoral side, an adjustable loop UltraButton is used with a 2-incision technique. The remaining graft is reattached to the posteromedial tibia as POL using an interference screw
Material and Methods:
We treated patients with chronic ACL injuries combined with grade III valgus laxity. A total of 5 patients met the inclusion criteria of the study, and there were no patients lost to follow-up. The mean age was 26.5 years with a standard deviation of 4.05 years. All surgeries were performed by a single experienced author, Dr RK, at our institution between September 2023 and May 2024. The mean time from injury to surgery was 2.5 months, and the duration of follow-up was 6 months. 3 patients were female and 2 were male patients.
Results:
Out of 5 patients who were treated, 2 were in the age group of 15–20 years and 3 were 20–30 years. 2 were male patients and 3 were females. Road traffic accidents accounted for 66% (3 cases) of the total cases as the most common mechanism of injury followed by sports injuries (34%, 2 cases). All 5 patients operated on with simultaneous ACL and MCL reconstruction (modified Lind technique) had excellent results based on the Lysholm scoring system. Comparative analysis was done between pre-surgery and post-surgery Lysholm scores and we found that there was a statistically significant difference between them with P < 0.001. A significant improvement in the International Knee Documentation Committee subjective score was detected at follow-up.
Conclusion:
In patients with high body mass index >25 kg/m2, chronic ACL-MCL (grade III) injuries, simultaneous ACL-MCL reconstruction with the modified Lind technique improves anterior, valgus, and rotatory stability of the knee and produces a good functional result
Wheel-rail contact models in the presence of switches and crossings
No full textThe development and implementation of wheel-rail contact models in multibody codes are two active research topics, aiming at improving the accuracy of numerical results and computational efficiency of the dynamics analysis. However, the realism of numerical results is challenged when considering switches and crossings (S&C), where the most adverse wheel-rail contact conditions occur. This paper presents a benchmark study where the performance of the multibody codes MUBODyn, VOCO and VI-Rail are assessed using three case scenarios that involve typical contact conditions observed in S&C. A focused description of the relevant methods to determine the wheel-rail contact forces is presented for each software. The three scenarios considered in this work have been designed to represent typical challenging contact conditions observed in S&C, i.e. conformal contact, contact with a sharp edge, and impact loads. The scenarios proposed in this work are fully described, making them easily reproducible. The agreement between results is discussed in the framework of the methods implemented in each code. This work highlights the impact of wheel-rail contact methods on the results as well as on the computational efficiency of the multibody codes.</p
