Plants possess remarkable developmental plasticity and regenerative ability to reshape themselves in response to external stimulations. After localised injuries, they can initiate cellular ...reprogramming at the wound sites to repair or regrow structures that could substitute the functionality of the damaged or lost parts. This way of regeneration in plants is called plant in situ tissue regeneration. Upon wounding like excision, incision or girdling, the original tissue patterns are completely or partially destroyed, the remanent tissues could perceive the wounding signals and thereby initiate cell de-differentiation, trans-differentiation or re-differentiation to reconstruct the lost or damaged tissues. In this review, we summarize the regenerative dynamics and regulatory mechanisms during the major in situ tissue regeneration processes in plants, including secondary vascular tissue (SVT) regeneration after girdling, apex regeneration after excision and tissue reunion after incision. In addition, we compare the features of SVT regeneration, the most relevant system for forestry, with other plant in situ tissue regeneration systems. We further discuss the unsolved issues and the potential applications of plant in situ regeneration for forestry research, aiming to provide new insights for the study of woody plant development.
Skeletal muscles normally have a remarkable ability to repair themselves; however, large muscle injuries and several myopathies diminish this ability leading to permanent loss of function. No ...clinical therapy yet exists that reliably restores muscle integrity and function following severe injury. Consequently, numerous tissue engineering techniques, both acellular and with cells, are being investigated to enhance muscle regeneration. Biomaterials are an essential part of these techniques as they can present physical and biochemical signals that augment the repair process. Successful tissue engineering strategies require regenerative biomaterials that either actively promote endogenous muscle repair or create an environment supportive of regeneration. This review will discuss several acellular biomaterial strategies for skeletal muscle regeneration with a focus on those under investigation in vivo. This includes materials that release bioactive molecules, biomimetic materials and immunomodulatory materials.
Currently, the potential of biomethane derived from biogas is substantial, positioning it to fulfill a considerable share of the United Kingdom’s total energy needs. The primary challenge associated ...with raw biogas lies in purifying it to produce biomethane, a process that necessitates the removal of carbon dioxide and hydrogen sulfide. Among the various methods, adsorption of activated carbon (AC) stands out as a particularly effective and cost-efficient approach for converting biogas into biomethane, provided that the regeneration of AC proves economically viable. In this research, a segment of activated carbon was utilized to assess the adsorption properties when exposed to a gas mixture of CO
2
, H
2
S, and N
2
within a regenerative activated carbon setup. This investigation encompassed the analysis of adsorption and desorption behaviors, process capacities, and the impact of regeneration. To enhance the adsorption of CO
2
, electro-conductive polymers (ECPs) were incorporated into the AC samples, leading to an extension in breakthrough time. Subsequent to adsorption, the electric potential swing desorption (EPSD) was employed for
in situ
regeneration of activated carbon samples, involving potentials of up to 30 V. The findings exhibited that the newly introduced EPSD technique considerably diminished desorption durations for both H
2
S and CO
2
. Moreover, it successfully rejuvenated the accessible adsorption sites, resulting in reduced desorption times compared to the initial breakthrough time during adsorption. Consequently, the EPSD system proves to be a promising candidate for
in situ
regeneration of activated carbon to eliminate CO
2
and H
2
S from biogas. Notably, this approach offers inherent advantages over conventional methods including thermal swing adsorption (TSA) and pressure swing adsorption (PSA) in terms of regeneration. The demonstrated method underscores the potential for more efficient and economically viable cycles of adsorption and desorption, thereby enhancing the overall biogas-to-biomethane conversion process to achieve SDGs 7 and 13 for clean and green energy applications.
Air gasification of waste polyethylene (PE) was conducted using active carbon as a tar removal agent in a new type of three-stage gasifier. The main focus was on the in-situ regeneration of active ...carbon, which was conducted simply with air treatment, which was mainly performed with variations of treatment time and air flow rate. In the experiments, active carbon was found to be very effective in hydrogen production and tar removal. The maximum hydrogen content of the producer gas obtained with active carbon was approximately 27 vol%, while the producer gas was free of tar. Active carbon, treated with air for 10 min, while stopping feeding, had a surface area of 937 m2/g (83% recovery rate). A 4 h of gasification performed with a dolomite guard bed and a mesh type distributor produced a gas having H2 and heavier tar than toluene contents of 28 and 0 vol%, respectively. The regeneration study suggested that a severe coke formation could be diminished, when methods such as frequent air regeneration with short treatment time, the use of other regeneration agents, such as CO2 or H2O and/or the selection of a proper distributor would be applied.
•A three-stage gasification of PE with active carbon was successfully conducted.•In-situ regeneration of active carbon was performed at different conditions.•Surface area of active carbon regenerated after 1 h was a similar to the original.•A 4 h gasification produced a gas having only toluene as a tar component.•Various in-situ regeneration methods for active carbon were suggested.
Bone regeneration heavily relies on bone marrow mesenchymal stem cells (BMSCs). However, recruiting endogenous BMSCs for in situ bone regeneration remains challenging. In this study, we developed a ...novel BMSC-aptamer (BMSC-apt) functionalized hydrogel (BMSC-aptgel) and evaluated its functions in recruiting BMSCs and promoting bone regeneration. The functional hydrogels were synthesized between maleimide-terminated 4-arm polyethylene glycols (PEG) and thiol-flanked PEG crosslinker, allowing rapid in situ gel formation. The aldehyde group-modified BMSC-apt was covalently bonded to a thiol-flanked PEG crosslinker to produce high-density aptamer coverage on the hydrogel surface. In vitro and in vivo studies demonstrated that the BMSC-aptgel significantly increased BMSC recruitment, migration, osteogenic differentiation, and biocompatibility. In vivo fluorescence tomography imaging demonstrated that functionalized hydrogels effectively recruited DiR-labeled BMSCs at the fracture site. Consequently, a mouse femur fracture model significantly enhanced new bone formation and mineralization. The aggregated BMSCs stimulated bone regeneration by balancing osteogenic and osteoclastic activities and reduced the local inflammatory response via paracrine effects. This study's findings suggest that the BMSC-aptgel can be a promising and effective strategy for promoting in situ bone regeneration.
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•BMSC-specific aptamer was incorporated into in situ rapidly formed hydrogels.•BMSC-aptgel efficiently recruited BMSCs and retained activities in vitro and in vivo.•BMSC-aptgel accelerated bone healing by regulating osteogenesis and inflammation.
Triclosan (TCS) has been regarded as an emerging contaminant in aquatic systems, making its efficient removal of great significance. In this study, NPVMo@iPAF-1, with a specific surface area of 665 m
...2
/g, was prepared by incorporating (NH
4
)
5
H
6
PV
8
Mo
4
O
40
into porous aromatic frameworks (PAF). The maximum adsorption capacity of TCS on NPVMo@iPAF-1 reached 917.1 mg/g, as calculated from the Langmuir model. Fixed-bed columns packed with NPVMo@iPAF-1 were employed for TCS removal; the experiment data strongly correlated with the Thomas and Yoon-Nelson models under different operational conditions. Pore preservation, electrostatic effects, and the synergistic effect of π-π interactions contributed to the effective adsorption of TCS onto NPVMo@iPAF-1. The NPVMo@iPAF-1 fixed-bed column could be effectively regenerated through in-situ ozonation for more than 10 regeneration cycles. NPVMo@iPAF-1 turned out to be a promising adsorbent for removing TCS not only from pure water but also from reclaimed water and surface water samples.
Graphical abstract
Produk biogas memiliki spesifikasi yang masih perlu ditingkatkan (mengandung metana, CH4 50-70%, dan karbon dioksida, CO2 30 – 49%), agar dapat bersaing dengan gas alam, yaitu lebih dari 98% metana. ...Metode pemurnian melalui adsorpsi CO2 paling banyak diterapkan, karena tidak memerlukan biaya tinggi, jika dibandingkan teknologi pemisahan konvensional lain. Tetapi, media adsorben karbon aktif akan mengalami kejenuhan dalam waktu tertentu. Salah satu metode yang dapat digunakan untuk meregenerasi karbon aktif yang jenuh oleh CO2 yaitu dengan peningkatan temperatur melalui metoda termal. Pada penelitian ini dilakukan regenerasi in-situ dengan peningkatan temperatur karbon aktif di dalam kolom adsorpsi-desorpsi, dengan alat dapat mengakomodasi tiga pola operasi, yaitu adsorpsi, regenerasi/desorpsi, dan pengosongan gas. Alat terdiri atas kolom yang dilengkapi perpipaaan, blower pendorong udara, heater dan thermostat untuk pemanas dan pengatur temperatur udara. Hasil uji alat menunjukkan bahwa durasi proses adsorpsi hingga mencapai kejenuhan adalah 30 menit pada siklus pertama dan 40 menit pada siklus kedua. Selanjutnya, durasi proses desorpsi dari siklus pertama hingga ketiga menunjukkan peningkatan linier, dipengaruhi oleh temperatur udara pemanas, dengan penurunan konsentrasi Ca(OH)2 hingga masih menunjukkan tren peningkatan. Setelah dilakukan tiga siklus proses adsorspi-desorpsi didapatkan bahwa performa dari karbon aktif masih belum mengalami penurunan kapasitas.
siklus proses adsorspi-desorpsi didapatkan bahwa performa dari karbon aktif masih belum mengalami penurunan kapasitas.
Kata kunci: adsorpsi, desorpsi, karbon aktif, karbon dioksida, regenerasi in-situ, temperatur
ABSTRACT
Biogas have certain specifications that need to be improved (contain methane, CH4, 50-70%, and carbon dioxide, CO2, 30-49%), in order to compete with natural gas ( >98% methane). The adsorption of CO2 is the most widely applied to purify biogas since it considered as low cost, in terms of energy supply and raw materials. However, activated carbon adsorbent will be saturated and must be regenerated. One of the methods that can be used to regenerate CO2-saturated activated carbon is using thermal method. In this research, the in-situ regeneration was carried out by increasing temperature of the activated carbon in adsorption-desorption column, which accommodate three operating patterns, namely adsorption, regeneration/desorption, and gas discharge. The tool consists of columns, piping, blower, heater and thermostat for air heating and controlling temperature. The result showed that the saturation time was 30 minutes and 40 minutes, respectively in 1st and 2nd cycle. The duration of the desorption from the 1st to 3rd cycle showed a linear trend, influenced by heating air temperature. And the reduction in Ca(OH)2 concentration still showed increasing trend after three adsorption-desorption cycles carried out, so the performance or adsorption capacity of activated carbon had not yet been decreased.
Three‐dimensional bioprinting, as a novel technique of fabricating engineered tissues, is positively correlated with the ultimate goal of regenerative medicine, which is the restoration, ...reconstruction, and repair of lost and/or damaged tissue function. The progressive trend of this technology resulted in developing the portable hand‐held bioprinters, which could be used quite easily by surgeons and physicians. With the advent of portable hand‐held bioprinters, the obstacles and challenges of utilizing statistical bioprinters could be resolved. This review attempts to discuss the advantages and challenges of portable hand‐held bioprinters via in situ tissue regeneration. All the tissues that have been investigated by this approach were reviewed, including skin, cartilage, bone, dental, and skeletal muscle regeneration, while the tissues that could be regenerated via this approach are targeted in the authors' perspective. The design and applications of hand‐held bioprinters were discussed widely, and the marketed printers were introduced. It has been prospected that these facilities could ameliorate translating the regenerative medicine science from the bench to the bedside actively.
In this paper, the electrochemical ion exchange technology was adopted, and the self-made swirl bed electrochemical ion exchange device was taken as the research object. The results presented that ...the device had the best water treatment effect with 1:0 of the split ratio and the smaller effluent flow. When the electrochemical device was filled with the mixed ion exchange resin after in-situ regeneration, after 5 h of operation, the hardness removal rates of cathode and anode were 6.25 and 22.5%, respectively. Backwash experiment revealed the treatment effect of power backwash was better than that of large flow backwash.
Developing electrocatalytic reactions with high‐efficiency can make important contributions to carbon neutrality. However, poor long‐term stability of catalysts is a bottleneck for its practical ...application. Herein, an “in situ periodic regeneration of catalyst (PR‐C)” strategy is proposed to give long‐term high efficiency of CO2 electroreduction to generate C2+ products over Cu catalyst by applying a positive potential pulse for a short time periodically in the halide‐containing electrolyte. The high Faradaic efficiency (81.2 %) and current density (22.6 mA cm−2) could be maintained completely at least 36 h, while the activity and selectivity decreased continuously without using the PR‐C method. Control experiments and operando characterization demonstrated that the surface structure and oxidation state of Cu could be recovered periodically by the PR‐C method, which was beneficial for CO2 activation and C−C coupling.
An “in situ periodic regeneration of catalyst (PR‐C)” strategy is proposed to maintain the high efficiency of CO2 electroreduction towards C2+ products over a copper catalyst. A positive potential pulse is applied periodically for a short time in the halide‐containing electrolyte. As a result the surface structure and oxidation state of the Cu could be recovered periodically by the PR‐C method.
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