Good Regeneration Research Articles

Zn-MOF-5-Modified biochar derived from KMnO4-activated waste corncob for enhanced adsorption of gaseous ammonia

Ammonia (NH3) is an odor gas pollutant which has serious harm to the environment and human health. The development of advanced adsorbents to remove NH3 is of great significance. Herein, a new adsorbent for NH3 adsorption with high efficiency was prepared by in-situ growth of Zn-MOF-5 on the KMnO4-activated waste corncob-derived porous biochar (KCB). The optimized M0.6K0.1CB-400 sample was obtained by optimizing the mass ratio of KMnO4 to corncob at 0.1, activation temperature at 400 °C, and the dosage ratio of Zn-MOF-5 to porous biochar at 0.6. The M0.6K0.1CB-400 demonstrated an excellent NH3 adsorption capacity of 6.88 mmol/g at 298.15 K and 1 bar, exhibiting a fast adsorption kinetics with 94 % of the equilibrium adsorption capacity reached in just 10 min. The M0.6K0.1CB-400 composite demonstrated good regeneration functionality by maintaining a NH3 removal capacity of 3.44 mmol/g after 6 regeneration cycles. Based on the thermodynamic and kinetic analyses, along with characterization of the chemical composition and physical structure of the NH3-adsorbed samples, the adsorption process of MKCB on NH3 was proven to involve a combination of physical and chemical adsorption. This study introduces a novel method for synthesizing MOF-modified biochar as a highly efficient NH3 adsorbent, offering new insights into the underlying mechanisms of gas purification.

Effect of bovine hydroxyapatite composite with secretome under normoxia and hypoxia conditions on inflammatory parameters in massive bone defect of rabbit radius bone.

Hydroxyapatite as a scaffold is capable of producing good bone regeneration formation. Incorporating secretome into scaffolds optimizes the bone healing process. The increase in proinflammatory, anti-inflammatory, and growth factors is one of the key factors in bone healing. In this study, we measured the levels of IL-6, IL-10, and FGF-2 to determine the effectiveness of bovine hydroxyapatite with secretome from normoxia and hypoxia on bone healing. This animal study employed a pure experimental research design, utilizing a post-test-only control group design. Bone marrow mesenchymal stem cells from rabbit thigh bones were used to derive secretomes under hypoxic and normoxic conditions. Bovine bone-derived hydroxyapatite (BHA) was treated with secretomes under both conditions. Rabbits' radius bones were implanted with BHA alone, BHA with normoxic secretome, and BHA with hypoxic secretome, then observed for 30 and 60 days. Levels of IL-6, IL-10, and FGF-2 were examined on days 30 and 60. On the 30th day, there was a significant increase in the levels of FGF-2, IL-6, and IL-10, with a dominance of strongly positive levels in BHA alone. However, on the 60th day, the levels of FGF-2, IL-6, and IL-10 started to decrease in all groups, with a dominance of moderately positive levels. Statistical tests showed significant results in all groups on days 30 and 60 (p < .05). Among the three groups, the best levels of growth factors and pro-inflammatory factors, and the lowest levels of anti-inflammatory factors were found in the BHA alone group on evaluation day 30.

Adsorption of titanium-aluminum layered hydroxides for removal of fluorine at low concentrations in water

Layered double hydroxides have good application prospects in the fields of water treatment and defluoridation. In this study, Ti-Al layered hydroxides (Ti-Al LDHs) were synthesized by the co-precipitation method at a Ti/Al molar ratio of 2/8 and a medium solution pH of 6.0. The SEM, XRD, and BET results showed that the Ti-Al LDHs showed a uniform stacking of lamellar structure and existed mainly in dispersed amorphous form, with a wide pore size and a larger specific surface area (108.34 m2/g). The results of adsorption experiments showed that the highest capacity could reach 116.2 mg/g, and the adsorption adsorption of Ti-Al LDHs on fluoride was more in line with the proposed second-order model, and the adsorption isotherm was more in line with the Langmuir model.In addition, Ti-Al LDHs can be applied in a wide pH range (4−10), have strong resistance to anionic competition, and have good regeneration performance after five adsorption-desorption cycles where the adsorption capacity is still equivalent to 73 % of the initial capacity. From the FTIR and XPS results, the adsorption process was mainly attributed to ion exchange, electrostatic attraction and surface complexation. Therefore, Ti-Al LDHs is a layered hydroxide fluoride removal adsorbent with good application prospects.

Auxiliary Partial Orthotopic Liver Transplantation Is a Safe and Effective Option for Yellow Phosphorus Toxin-induced Acute Liver Failure.

Ingestion of yellow phosphorus-containing rodenticides (YPR) or firecrackers is an important cause of acute liver failure (ALF) in young adults and children, particularly in South and South-East Asia and South America. Emergency liver transplantation is indicated in cases refractory to intensive supportive therapy, including low-volume plasma exchange. There are no published reports on the feasibility of auxiliary partial orthotopic liver transplantation (APOLT) for YPR-induced ALF. Clinical details of patients undergoing APOLT for YPR-induced ALF in 1 unit are reported. Details of postoperative follow-up, native remnant regeneration, and immunosuppression withdrawal are also reported. Between January 2021 and December 2023, 3 patients (4 y, 1.5 y, and 26 y) underwent emergency living donor liver transplantation for YPR-induced ALF. All patients were refractory to supportive therapies, including therapeutic plasma exchange, and demonstrated progression of liver injury in the form of severe encephalopathy needing intubation, ventilation, and organ support. APOLT was considered because of their young age and minimal intraoperative inotropic requirement. All explants showed confluent parenchymal necrosis with microvesicular and macrovesicular steatosis. Patients were initially maintained on standard immunosuppression. Good remnant regeneration was noted on follow-up imaging in all cases, enabling gradual withdrawal of immunosuppression. Currently, 1 child has been off immunosuppression for 15 mo and 2 others are on reduced doses of immunosuppression. All patients demonstrated good liver function. APOLT procedure can be an appropriate transplant option in YPR-related ALF for children and young adults without severe hemodynamic instability.

Competitive Adsorption of Moisture and SO2 for Carbon Dioxide Capture by Zeolites FAU 13X and LTA 5A

Zeolites exhibit significant potential as porous materials for selective carbon dioxide (CO2) capture, leveraging their distinctive adsorption properties. However, the presence of moisture (H2O) and sulfur dioxide (SO2) in flue gas streams can significantly affect the efficiency of CO2 capture. This study investigates the CO2 adsorption characteristics of zeolites FAU 5A and LTA 13X, revealing the competitive adsorption mechanism between H2O(g), SO2, and CO2. The zeolites exhibit CO2 adsorption capacities of 93.19 mg/g and 95.80 mg/g for 5A and 13X, respectively, and demonstrate good regeneration potential. Metal cations correlated positively with CO2 adsorption. H2O(g), SO2, and CO2 exhibit a competitive adsorption relationship, with H2O(g) having the highest adsorption capacity, followed by SO2 and CO2. Additionally, the synergistic effect of SO2 and H2O(g) on CO2 adsorption is elucidated. These findings provide valuable insights into the competitive adsorption behavior of moisture and SO2 for CO2 capture using zeolites LTA 5A and FAU 13X, contributing to the development of more efficient CO2 capture processes and the design of tailored adsorbents for industrial applications.

Preparation and Selective Adsorption Performance of the Carboxymethyl Salix psammophila Wood Powder-Imprinted Membrane for Tetracycline.

Carboxymethyl Salix psammophila wood powder-imprinted membranes (CMSM-MIPs) were prepared by using wet spinning technology and molecular-imprinting technology for the selective removal of tetracycline from wastewater. Scanning electron microscopy, X-ray diffraction, thermogravimetry, and X-ray photoelectron spectroscopy characterizations demonstrate that CMSM-MIPs retain the membranous structure of Carboxymethyl Salix psammophila wood powder membranes, successfully encapsulate thin layers of imprinted polymers on the membrane surface, and exhibit excellent thermal stability. The adsorption results showed that CMSM-MIPs had the highest selective adsorption capacity for tetracycline, which was 253.8 mg/g. In addition, the adsorption capacities for oxytetracycline and chlortetracycline were 208.8 and 188 mg/g, respectively. It can be observed that CMSM-MIPs not only exhibit a high adsorption capacity for tetracycline but also demonstrate good adsorption capacities for oxytetracycline and chlortetracycline. The experimental results showed that CMSM-MIPs were best fitted with pseudo-second-order kinetics and most consistent with Freundlich fitting. The regeneration experiment showed that CMSM-MIPs still had good regeneration performance after 5 regeneration cycles. In conclusion, the CMSM-MIPs can not only have the natural adsorption performance of Salix psammophila wood powder but also give it higher selectivity through molecular imprinting, so as to achieve efficient removal of target organic pollutants in water.

Superparamagnetic hydrophilic molecularly imprinted nanoparticles for an efficient and selective removal of tetracycline from water

In this work, a novel superparamagnetic hydrophilic molecularly imprinted nanomaterial for the removal of tetracycline (TC) was synthesized utilizing magnetite (Fe3O4) as the magnetic core, TC as the template molecule, 3-aminopropyltriethoxysilane (APTES) as the functional monomer, and tetraethoxysilane (TEOS) as the cross-linker. Initially, Fe3O4 magnetic nanoparticles (MNP) coated with SiO2 (MNP@SiO2) were synthesized, followed by TC molecular imprinting on the nanoparticles. Initially, Fe3O4 MNP coated with SiO2 (MNP@SiO2) were synthesized, followed by TC molecular imprinting on the nanoparticles. The synthesis method for MNP@SiO2 was optimized, and DLS analysis of 10 replicates showed a nanoparticle size of 70.1 ± 5.8 nm, indicating high method reproducibility. The MNP@SiO2, as well as the imprinted (MNP@SiO2-MIP) and non-imprinted (MNP@SiO2–NIP) nanomaterials, were characterized by FTIR, TEM, VSM, XRD, DLS, Z potential, and BET analysis. The saturation magnetization (Ms) values were 43 emu/g for MNP@SiO2 and 32 emu/g for both MNP@SiO2-MIP and MNP@SiO2–NIP, confirming suitability for magnetic separation using external magnets. Batch binding experiments conducted in water and methanol assessed adsorption isotherms and binding kinetics, with data fitting the Langmuir isotherm model better than the Freundlich model. The developed MIP exhibited significant selectivity against other molecules with similar functional groups and size. In water, the adsorption capacity of the MNP@SiO2-MIP was 23 mg/g, with an imprinting factor of 2.2. Furthermore, the MIP demonstrated good regeneration performance. The material was tested on TC-spiked tap water samples, achieving 80.1 % TC removal with high reproducibility (3.2 %, n = 3). Combining hydrophilic superparamagnetic nanoparticles with molecular imprinting enhances their potential applications in environmental remediation, antibiotic purification, and drug delivery.

Effective elimination of Hg(II) from water bodies with acid-modified magnetic biomass spent coffee grounds: conditional optimization and application.

To maximize the efficiency of biomass waste utilization and waste management, a novel acid-modified magnetic biomass spent coffee grounds (NiFe2O4/SCG) was obtained by pyrolysis at 473K and co-precipitation methods and employed to eliminate bivalent mercury (Hg(II)) in water bodies. The prepared NiFe2O4/SCG adsorbent exhibits remarkable magnetism with a strength of 45.78emu/g and can easily be separated from water via a magnetic force. The adsorption of Hg(II) over the NiFe2O4/SCG has an optimal conditions of pH = 8, T = 39 ℃, and dosage of 0.055 g/L, and the maximal adsorption capacity for Hg(II) is 167.44 mg/g via Response Surface Methodology optimization. The removal of Hg(II) over NiFe2O4/SCG primarily involves ion exchange, electrostatic attraction, and chelation; conforms to the pseudo-second-order kinetic and Langmuir models; and is an endothermic reaction. Additionally, the magnetic biomass NiFe2O4/SCG has good regeneration capability and stability. The application research reveal that inorganic salt ions, nitrogen fertilizer urea, humus, and other contaminants in different actual water bodies (river water, lake water, and the effluent of sewage treatment plant) have little effect on the adsorption of Hg(II) over the NiFe2O4/SCG. The prepared adsorbent NiFe2O4/SCG has practical application value for removing Hg(II) from water bodies.

Photosealed Neurorrhaphy Using Autologous Tissue.

Photochemical sealing of a nerve wrap over the repair site isolates and optimizes the regenerating nerve microenvironment. To facilitate clinical adoption of the technology, we investigated photosealed autologous tissue in a rodent sciatic nerve transection and repair model. Rats underwent transection of the sciatic nerve with repair performed in three groups: standard microsurgical neurorrhaphy (SN) and photochemical sealing with a crosslinked human amnion (xHAM) or autologous vein. Functional recovery was assessed at four-week intervals using footprint analysis. Gastrocnemius muscle mass preservation, histology, and nerve histomorphometry were evaluated at 120 days. Nerves treated with a PTB-sealed autologous vein improved functional recovery at 120 days although the comparison between groups was not significantly different (SN: -58.4 +/- 10.9; XHAM: -57.9 +/- 8.7; Vein: -52.4 +/- 17.1). Good muscle mass preservation was observed in all groups, with no statistical differences between groups (SN: 69 +/- 7%; XHAM: 70 +/- 7%; Vein: 70 +/- 7%). Histomorphometry showed good axonal regeneration in all repair techniques. These results demonstrate that peripheral nerve repair using photosealed autologous veins produced regeneration at least equivalent to current gold-standard microsurgery. The use of autologous veins removes costs and foreign body concerns and would be readily available during surgery. This study illustrates a new repair method that could restore normal endoneurial homeostasis with minimal trauma following severe nerve injury.

Modifications and applications of aerogel prepared with waste palm leaf cellulose in adsorptions for oily contaminations

Abstract Aerogels are essential and effective materials for oily pollution adsorption and recovery. This work described a hydrophobic modified cellulose aerogel using waste palm leaf and its oil adsorption mechanism. By chemical vapor deposition, Methyltrimethoxysilane (MTMS) was employed as a hydrophobic modifier for aerogel of waste palm leaf cellulose at 80 °C for 5 h, and the modified aerogel demonstrated exceptional and stable hydrophobicity with a water contact angle of 132.4° that can still be maintained above 120° after two months of air exposure. After 10 adsorption and extrusion cycles, kerosene adsorption capacity can still reach over 18 times its weight with good regeneration and reuse performance. The kinetic analysis found that the pseudo-second order model was more appropriate for the aerogel’s oil absorption process, including mainly physical adsorption at the beginning and the following chemical adsorption. Owing to its low cost, hydrophobicity, high absorption capacity, and favorable reusability, this aerogel is expected to be used in oils, organic solvent spill cleanup, and oil/water separation fields.

Incorporation of copper ion promoted adsorption of anionic dye (Acid Yellow 36) by acrolein-crosslinked polyethyleneimine/chitosan hydrogel: Adsorption, dynamics, and mechanisms

In this study, a novel adsorbent, A-PEI/CS-Cu2+, was developed by crosslinking polyethyleneimine/chitosan hydrogel with acrolein and loading it with copper ions. The adsorption process of A-PEI/CS-Cu2+ on the anionic dye acid yellow 36 (AY36) was investigated by kinetic, isothermal and thermodynamic modeling. It was noteworthy that A-PEI/CS-Cu2+ exhibited rapid adsorption with a 90 % removal rate achieved within just 5 min, which was much faster than the adsorption rate of A-PEI/CS without load of copper ions and showed its potential for rapid adsorption applications. The maximum adsorption capacity for AY36 could reach up to 3114 mg g−1. In addition, the high concentration of saline wastewater was found to have almost no effect on the adsorption reaction in the salt effect test experiment. In five desorption-regeneration cycle experiments, the sample exhibited good recyclability and regeneration performance. The driving force of the adsorption process mainly originated from the electrostatic interaction, hydrogen bonding, and intermolecular interaction, in which the addition of copper ions led to the enhancement of the electrostatic interaction and chelation between A-PEI/CS-Cu2+ and AY36. Overall, the findings suggest the excellent potential of A-PEI/CS-Cu2+ for rapid and efficient adsorption, as well as its suitability for practical applications in wastewater treatment.

Efficient adsorption of hexavalent chromium in water by torrefaction biochar from lignin-rich kiwifruit branches: The combination of experiment, 2D-COS and DFT calculation

A biochar (KBC) enriched with O functional groups was prepared by torrefaction using lignin-rich kiwifruit branches (KBM) as a raw material, which was characterized, and then KBC was used to adsorb hexavalent chromium (Cr6+) from water. The results showed that KBC contained more functional groups compared to KBM. The maximum adsorption of Cr6+ by KBC could reach 143.64 mg·g−1 and also had better adsorption performance than other adsorbents reported in some other reports. Cr6+ absorption by KBC was mainly a mechanism of electrostatic interaction and adsorption-reduction coupling. FTIR and XPS revealed that -OH, -COOH, CO and CC on KBC participated in Cr6+ adsorption and new groups (C=O) were generated during the process of adsorption, which implied that a redox reaction occurred. 2D-COS and DFT calculations showed that the order of functional groups on KBC interacting with Cr6+ was -OCH3 > -COOH > -OH > phenolic hydroxyl, and the binding tightness of the different functional groups to Cr6+ was -OCH3 (the shortest displacement of both groups after the adsorption) > -COOH > -OH > phenolic hydroxyl. KBC has good regeneration performance, and it is a good adsorbent for Cr6+.

Selective isolation of rubidium with mesoporous silica loaded with ammonium phosphomolybdate via an in-pore crystallization reaction

The scarcity of rubidium (Rb) in ore form makes it a valuable metal, prompting the need to develop reusable adsorbent materials for effective separation of rubidium (Rb+) from salt lake brine, which holds significant importance. Herein, a novel Rb+ selective composite adsorbent was prepared by in-pore crystallization. Macromesoporous silica was prepared using polyoxyethylene (10) octadecyl ether (Brij S10) as a templating agent and the effect of different templating agents on the pore size was investigated. An AMP-SiO2 composite adsorbent for Rb+ was obtained by “growing” ammonium phosphomolybdate on the macro-mesoporous silica by in-pore crystallization reaction. The results indicated that the adsorption of Rb+ by the AMP-SO2 adsorbent adhered to monolayer chemisorption, which was verified by fitting the adsorption data using the pseudo-second-order kinetics and the Langmuir isotherm model, respectively. The loading of AMP was 29.4 %, which increased the adsorption capacity by 115 %. Furthermore, the adsorption rate of Rb+ on AMP-SO2 when interfering ions were present still reached 73.2 % (KCl), 76.4 % (CaCl2), and 86.6 % (MgCl2). Density functional theory simulation indicated that AMP-SiO2 exhibited a higher adsorption energy for Rb+ (−9.79 eV) than K+, Li+, Ca2+, and Mg2+. The Rb 3d and Mo 3d X-ray photoelectron spectra of AMP-SiO2 before and after adsorption of Rb+, indicated that the ion-exchange process between rubidium and lattice cations is the controlling mechanism. In addition, AMP-SiO2 also showed good regeneration performance and maintained a high adsorption rate after five adsorption-resolution experiments. In summary, the AMP-SiO2 composite adsorbent can effectively expose adsorption sites and improve mass transfer efficiency, and has significant potential for future application in rubidium separation and extraction.

Ammonia gas adsorption study using copper impregnated on mesoporous activated carbon from seaweed waste for indoor air purification

Ammonia (NH3), as a toxic gas, has negative impacts on human health even at low concentration, especially in narrowed spaces. In this study, activated carbon was synthesized from seaweed waste and copper was loaded on its surface (Cu/AC filter) to prepare a cost-effective NH3 adsorbent. Pyrolysis (carbonization) temperature can significantly affect the texture properties of activated carbon, and the best activated carbon sample with BET of 1114 m2/g was obtained through pyrolysis at 500 °C followed by KOH-activation at 750 °C. Different from other lignocellulosic biomass-based activated carbons (mainly microporous structure), the prepared algae-based activated carbons mainly have a mesoporous structure (pore size: 7.0–9.0 nm). Copper-impregnation significantly changed the surface chemistry of activated carbon, thereby greatly increasing the NH3 adsorption capacity (max: 128.6 mg/g). The adsorption performance was primarily determined by chemical adsorption (caused by copper impregnation and related inherent functional groups, including O–H, C–H, O–Si–O and SiO–H), followed by physical adsorption (caused by BET). Isotherm studies indicated that NH3 adsorption on Cu/AC filter followed the Langmuir model, whereas the adsorption kinetics followed the pseudo-second-order model. Furthermore, the adsorption mechanism was controlled by intraparticle diffusion model with initial adsorption behavior. This can be attributed to the mesoporous structures of activated carbon, consequently dramatically improving the diffusion efficiency. In addition, the Cu/AC filter showed good regeneration performance, as it can still remain above 90 % after 5 cycles. Finally, this study demonstrated that the seaweed waste is a good precursor for activation carbon and has great potential as excellent NH3 adsorbent for indoor air purification.

Fe doping enhanced Cr(VI) adsorption efficiency of cerium-based adsorbents: Adsorption behaviors and inner removal mechanisms

Cerium-based adsorbents possessed unique advantages of valence variability and abundant oxygen vacancies in hexavalent chromium (Cr(VI)) adsorption, but high cost and unstable properties restricted their application in Cr(VI) contained wastewater treatment. Herein, a series of bimetallic adsorbents with different cerium/iron ratios (CeFe@C) were prepared by adding inexpensive Fe into Ce-based adsorbents (Ce@C), and the effect of Fe doping on adsorption properties of Ce@C for Cr(VI) was investigated thoroughly. Compared with pristine Ce@C, CeFe@C exhibited excellent removal performance for Cr(VI), and the improved maximum adsorption capacity reached 75.11 mg/g at 25℃. Benefiting from Fe doping, CeFe@C had good regeneration property, with only 25 % decrease after five adsorption–desorption cycles. Contents of trivalent cerium (Ce(III)) and oxygen vacancies (Ov) in bimetallic adsorbents were positively correlated with divalent iron (Fe(II)) doping, indicating that the formation of Ce(III) and surface defects on Ce@C could be effectively regulated by Fe doping. Density functional theory (DFT) calculation results further proved that the doped Fe enhanced the electron transfer effectively and lowered the energy barriers of Cr(VI) adsorption onto Ce@C surface, strengthening the reduction and complexation to Cr(VI). This study provides new insights for improving the Cr(VI) removal performance by modified Ce-based adsorbents, and further promotes the utilization potentiality of low-cost and low-toxicity Ce-based adsorbents in Cr(VI)-containing wastewater treatment.

Highly Efficient and Selective Hydrogenation of Biomass-Derived Furfural Using Interface-Active Rice Husk-Based Porous Carbon-Supported NiCu Alloy Catalysts.

A series of bimetallic NixCuy catalysts with different metal molar ratios, supported on nitric acid modified rice husk-based porous carbon (RHPC), were prepared using a simple impregnation method for the liquid-phase hydrogenation of furfural (FFA) to tetrahydrofurfuryl alcohol (THFA). The Ni2Cu1/RHPC catalyst, with an average metal particle size of 9.3 nm, exhibits excellent catalytic performance for the selective hydrogenation of FFA to THFA. The 100% conversion of FFA and the 99% selectivity to THFA were obtained under mild reaction conditions (50 °C, 1 MPa, 1 h), using water as a green reaction solvent. The synergistic effect of NiCu alloy ensures the high catalytic activity. The acid sites and oxygen-containing functional groups on the surface of the modified RHPC can enhance the selectivity of THFA. The Ni2Cu1/RHPC catalyst offers good cyclability and regenerability. The current work proposes a simple method for preparing an NiCu bimetallic catalyst. The catalyst exhibits excellent performance in the catalytic hydrogenation of furfural to tetrahydrofurfuryl alcohol, which broadens the application of non-noble metal bimetallic nanocatalysts in the catalytic hydrogenation of furfural.

Synthesis of titanium silicalite-1 supported zinc catalysts for efficient and clean epoxidation of 1-hexene and methyl oleate

To improve the catalytic epoxidation activity of conventional TS-1 zeolite under acid-free conditions, a series of TS-1-supported zinc (xZn/TS-1) catalysts were prepared and evaluated in the epoxidation of 1-hexene and methyl oleate (MO) with H2O2 oxidant. The microstructure of xZn/TS-1 was investigated using various characterization techniques, and the results showed that the introduction of Zn species was not only well dispersed on the surface of TS-1 but also did not disrupt the crystal structure of TS-1 and tetrahedral framework titanium. Furthermore, the Ti-O-Zn structure can be formed between Zn and Ti species through O-atomic coordination, which improves the vulnerability of the Ti-O bond to attack the H2O2 molecule, and ultimately facilitates the epoxidation reaction between 1-hexene and MO. In addition, the 2% Zn/TS-1 catalysts showed optimal conversions of 45.7 % and 75.41 % for 1-hexene and MO, respectively, and exhibited good catalytic stability and regeneration during the epoxidation process.

Cartilage regeneration and long term survival in medial OA knee patients treated with HTO and OATS

BackgroundOsteoarthritis (OA) of the knee, in most instances primarily, affects medial compartment of knee. Combining Osteochondral Autologous Transfer System (OATS) with Medial Open-Wedge High Tibial Osteotomy (MOWHTO) may represent an integrated approach to sustaining long-term knee functionality in OA patients. Materials and methodsFrom 2009 to 2016, combined OATS and MOWHTO was performed in 66 knees of 63 patients with medial compartment knee OA. Cartilage regeneration was assessed by 2nd look arthroscopy and Knee function was assessed by knee society scoring (KSS) pre-operatively and post-operatively. The survival rate of MOWHTO plus OATS was assessed. Failure is characterized by the need to convert into total knee replacement. ResultsThe KSS knee score (from 48.3 to 90.4) and function score (from 42.6 to 88.7) showed a statistically significant improvement (p-value of <0.0001) at a mean follow-up period of 9.49 years. Second look arthroscopy done at the time of implant removal showed 100 % cartilage regeneration with even hyaline cartilage regeneration in 49 out of 57 knees assessed and partial regeneration in 8 knees. The Kaplan Meier survivorship analysis was 96.7 % at the mean 9.49 years after surgery. Only 2 patients needed TKA conversion in follow-up. ConclusionCombining OATs and valgus MOWHTO provides good option to successfully manage patients of OA and varus malalignment. This resulted in significant improvement in knee function, lowering pain intensity, good cartilage regeneration, and a high survivorship rate for 10 years postoperatively.

Ionic liquid-containing polymer including membrane for the removal of cobalt: Synthesis, adsorption, transport, and modeling studies

This work describes synthesis of polymer inclusion membranes (PIMs), which is prepared by using varying ratios of polyvinylidene fluoride co-hexafluorophosphate (PVDF-HFP) as the base polymer and trioctyldodecylphosphonium bis(2,4,4-trimethylpentyl)phosphinate) (P88812BTMPP) as extractant carrier, and its utilization for the Co(II) sorption and transport. PIM with 40 wt% ionic liquid content showed a high sorption efficiency (>95 %) for 100 mg/L Co(II) feed with 0 and 5 mol/L HCl. Likewise, the transport experiment was achieved with Co(II) in 5 mol/L HCl as feed solution and 2 mol/L H2SO4, which exhibited excellent performance with a recovery factor of more than 85 %. The effect of various parameters on the efficiency of Co(II) sorption and transport was examined systematically. The kinetic and thermodynamic studies revealed that Co(II) sorption onto PIM was chemisorption in nature. Interestingly, the adsorption mechanism of Co(II) was found to be dependent upon the HCl concentration, resulting in two different mode of sorption mechanisms. Moreover, Co(II) desorption (>95 %) was achieved effectively, using 2 mol/L H2SO4. The recycling experiments suggested that PIM could be reused effectively without significant performance loss after six consecutive sorption-stripping cycles. Therefore, the reported PIM holds a good potential as a sorbent of critical metals, such as cobalt, due to its cost-effectiveness, excellent performance in batch-sorption and continuous transport processes, as well as good regeneration properties. To the best of our knowledge, this is the first report on Co(II) transport, employing a membrane transport system with a novel phosphonium-based ionic liquid.

Ridge Preservation Combined With Open Barrier Membrane Technique in Case of Postextractive Oroantral Communication: A Case Series Retrospective Study.

After dental extraction, a physiological phenomenon of reabsorption of the dentoalveolar process is triggered, especially if periradicular lesions are present, which can sometimes be associated with oroantral communication in the upper posterior maxilla. To investigate a minimally invasive approach, 19 patients undergoing tooth extraction in the posterosuperior maxilla were recruited. All cases presented an oroantral communication with a diameter of 2-5 mm after tooth extraction and the alveolar process and, in some cases, with a partial defect of 1 or more bony walls. In these cases, a single surgical procedure was used to preserve the alveolar ridge using an open barrier technique with an exposed dense polytetrafluoroethylene membrane. The bottom of the extraction socket was filled with a collagen fleece. The residual bone process was reconstructed using a biomaterial based on carbonate-apatite derived from porcine cancellous bone. After 6 months, all patients were recalled and subjected to radiographic control associated with an implant-prosthetic rehabilitation plan. Data relating to the sinus health status and the average height and thickness of the regenerated bone were collected. Radiographic evaluation verified the integrity of the maxillary sinus floor with new bone formation, detecting a vertical bone dimension between 3.1 mm and 7.4 mm (average 5.13 ± 1.15 mm) and a horizontal thickness between 4.2 mm and 9.6 mm (average 6.86 ± 1.55 mm). The goal of this study was to highlight the advantage of managing an oroantral communication and, simultaneously, obtain the preservation and regeneration of the alveolar bone crest. The open barrier technique appears to be effective for the minimally invasive management of oroantral communication up to 5 mm in diameter in postextraction sites, with a good regeneration of hard and soft tissue.