Filtration Time Research Articles

Norepinephrine as an Enhancer Promoting Corneal Penetration of Riboflavin for Transepithelial Corneal Crosslinking.

Previously, we found norepinephrine (NE) could affect the corneal epithelial integrity, herein we investigated the feasibility and safety of NE serving as a chemical enhancer to promote corneal penetration of riboflavin during transepithelial corneal crosslinking (CXL). The dosage of NE that could promote riboflavin diffusion through the healthy epithelial barrier without inducing epithelial damage in C57BL/6 mice was determined. The safety of NE treatment was confirmed by morphological and histological examinations of the whole cornea. The efficacy of NE in promoting riboflavin penetration was verified by slit lamp and scanning electron microscope (SEM), and corneal biomechanical measurement after CXL. To better fit the clinical scenario, increased NE dosage and shortened riboflavin infiltration time were further evaluated. The lowest dosage of NE (1 mg/mL) that facilitated transepithelial riboflavin permeation was 2 µL. No visible corneal structure alteration was observed after NE treatment. SEM indicated dissociation of intercellular junctions among corneal epithelial cells. Homogenous distribution of riboflavin throughout corneal stroma was observed. NE-treated corneas reached comparable biomechanical properties after CXL, including stress-relaxation curve and elastic modulus, with corneas treated with the commercially available transepithelial drug Peschke TE. To better fit the clinical scenario, increasing NE up to 5.5 µL helped riboflavin infiltrate the corneal stroma within 30 minutes. After CXL with 9 mW/cm2 ultraviolet-A (UVA) for 2.5 minutes, the cornea showed significantly enhanced corneal biomechanical properties with undisturbed corneal endothelium. NE serves as an effective enhancer in increasing riboflavin diffusion with limited impairment on corneal epithelium and has great potential for clinical application. NE serves as an effective enhancer for riboflavin penetration and clinical transepithelial CXL.

Revisiting of a Three-Parameter One-Dimensional Vertical Infiltration Equation

In the present study, the three-parameter one-dimensional vertical infiltration equation recently proposed by Poulovassilis and Argyrokastritis is examined. The equation includes the saturated hydraulic conductivity (Ks), soil sorptivity (S), and an additional parameter c; it is valid for all infiltration times. The c parameter is a fitting parameter that depends on the type of porous medium. The equation is characterized by the incorporation of the exact contribution of the pressure head gradient to flow during the vertical infiltration process. The application of the equation in eight porous media showed that it approaches to the known two-parameter Green–Ampt infiltration equation for parameter c = 0.300, while it approaches to the two-parameter infiltration equation of Talsma–Parlange for c = 0.750, which are the two extreme limits of the cumulative infiltration of soils. The c parameter value of 0.500 can be representative of the infiltration behavior of many soils for non-ponded conditions, and consequently, the equation can be converted into a two-parameter one. The determination of Ks, S, and c using one-dimensional vertical infiltration data from eight soils was also investigated with the help of the Excel Solver application. The results showed that when all three parameters are considered as adjustment parameters, accurate predictions of S and Ks are not achieved, while if the parameter c is fixed at 0.500, the prediction of S and Ks is very satisfactory. Specifically, in the first case, the maximum relative error values were 33.29% and 39.53% for S and Ks, respectively, while for the second case, the corresponding values were 13.25% and 17.42%.

Gentle milk fat separation using silicon carbide ceramic membranes

Due to their high hydrophilicity, ceramic silicon carbide (SiC) membranes are suitable for fat separation from raw milk, as alternative to centrifugation. The filtration performance during separation of fat globules (MFGs) from raw milk showed 95% fat separation at 15 °C, 93% at 25 °C, 88% at 35 °C and 91% at 50 °C, while permeating skimmed milk with a fat concentration ranging from 0.11 ± 0.03 to 0.34 ± 0.23% (w/w). The filtration time ranged from 12 to 106 min, respectively for 50 and 15 °C. Fouling of the membranes was investigated using scanning electron microscopy and elemental composition by energy dispersive X-ray. The SiC membranes showed a defect-free morphology, excellent water permeability and no irreversible fouling after the filtration process. Separation at 50 °C showed a higher distribution of larger MFGs in the permeate due to increased flexibility of the MFGs. Industrial relevanceMicrofiltration has previously been proposed to be a gentler separation method compared to traditional centrifugation. In this study, for the first time was demonstrated that highly hydrophilic ceramic silicon carbide (SiC) membranes are an efficient process for separation of fat from raw milk. The effect of filtration temperature on filtration performance and properties of the resulting streams provided new insights for industrial application of this process.

Analysis of risk factors for advanced age in patients with frozen shoulder.

To explore the risk factors of elderly patients with frozen shoulder. 262 cases of scapulohumeral periarthritis treated in our hospital from January 2020 to December 2020 were analyzed retrospectively. According to the age of patients, patients younger than 60years old were divided into middle-aged group (101 cases), patients between 60 and 75years old were divided into old-aged group (91 cases), and patients ≥ 75years old were divided into old-aged group (70 cases). The general demographic data and clinical data of the three groups were compared. Visual analogue scale (VAS) was used to evaluate the degree of pain. Finally, the dependent variable is set as whether the onset age of scapulohumeral periarthritis patients is advanced. Univariate and multivariate Logistic regression was used to analyze the risk factors of frozen shoulder patients at an advanced age. There were no significant differences in general demographic data, fixed position, hypertension history, smoking history, drinking history, supraspinatus muscular atrophy and physical exercise among the three groups (all P > 0.05). The course of disease, diabetes, surgical treatment, pain degree, operation time, cholecystitis, coronary heart disease, pain degree three months after operation and cervical spondylosis in the elderly group were all higher than those in the middle-aged group and the elderly group, and the differences were statistically significant (all P < 0.05). The course of scapulohumeral periarthritis, the degree of pain and the degree of pain 3months after operation in the elderly group were higher than those in the middle-aged group, with significant differences (all P < 0.05). Univariate Logistic regression analysis showed that the risk factors of scapulohumeral periarthritis in the elderly included diabetes mellitus (OR = 3.067, 95% CI 1.881-4.587, P < 0.001), operative treatment (OR = 3.076, 95% CI 1.365-6.765, P = 0.006), VAS score (OR = 2.267, 95% CI 1.117-3.887, P = 0.013), operation time (OR = 1.537, 95% CI 1.305-2.579, P < 0.001), cholecystitis (OR = 2.143, 95% CI 1.019-4.876, P = 0.023), coronary heart disease(OR = 3.128, 95% CI 1.428-7.019, P = 0.005), VAS at 3months after operation (OR = 1.537, 95% CI 0.786-2.635, P = 0.002), and cervical spondylosis(OR = 1.162, 95% CI 1.029-1.321, P = 0.012). Multivariate logistic regression analysis showed that the risk factors for the onset of the disease at advanced age included fatty infiltration (OR = 4.021, 95% CI 2.981-9.682, P < 0.001), surgical treatment (OR = 4.109, 95% CI 1.419-7.832, P = 0.008), VAS score (OR = 3.081, 95% CI 1.042-7.931, P = 0.046) and operation time (OR = 1.537, 95% CI 1.305-2.579, P < 0.001). Risk factors of frozen shoulder at advanced age include fat infiltration, surgical treatment, VAS score and surgical time. In clinical practice, we should refer to the above indicators to help patients with early medical intervention and prevent their onset.

Impact of Transient Infiltration on the Ultimate Bearing Capacity of Obliquely and Eccentrically Loaded Strip Footings on Partially Saturated Soils

Soils above the groundwater table and near the ground surface are often partially saturated, and the changes in the degree of saturation and matric suction caused by infiltration may have substantial effects on the stability of geotechnical systems. This work evaluates the significant effect of transient flow on the ultimate bearing capacity of strip footings founded on unsaturated soils under the simultaneous actions of vertical and horizontal loads and moment using the lower-bound theorems of the finite-element limit analysis and the incorporation of second-order cone programming. The unified effective stress theory is incorporated into the soil yield function to model the partially saturated state, and the closed-form solution for one-dimensional transient flow is adopted so as to evaluate the tempo-spatial variations of suction stress. For both sand and clay underlying soils, it is found that the increase of infiltration time leads to a notable decrease of the size of the normalized failure envelopes for either obliquely or eccentrically loaded shallow foundations. The impact of transient flow on the ultimate bearing capacity of surface footings is also observed to be greater for clay soils as compared with sand deposits due to the significant contribution of higher induced suction stress.

Single-stage chromatographic clarification of Chinese Hamster Ovary cell harvest reduces cost of protein production.

A single-stage clarification was developed using a single-use chromatographic clarification device (CCD) to recover a recombinant protein from Chinese Hamster Ovary (CHO) harvest cell culture fluid (HCCF). Clarification of a CHO HCCF is a complex and costly process, involving multiple stages of centrifugation and/or depth filtration to remove cells and debris and to reduce process-related impurities such as host cell protein (HCP), nucleic acids, and lipids. When using depth filtration, the filter train consists of multiple filters of varying ratios, layers, pore sizes, and adsorptive properties. The depth filters, in combination with a 0.2-micron membrane filter, clarify the HCCF based on size-exclusion, adsorptive, and charge-based mechanisms, and provide robust bioburden control. Each stage of the clarification process requires time, labor, and utilities, with product loss at each step. Here, use of the 3M™ Harvest RC Chromatographic Clarifier, a single-stage CCD, is identified as an alternative strategy to a three-stage filtration train. The CCD results in less overall filter area, less volume for flushing, and higher yield. Using bioprocess cost modeling, the single-stage clarification process was compared to a three-stage filtration process. By compressing the CHO HCCF clarification to a single chromatographic stage, the overall cost of the clarification process was reduced by 17%-30%, depending on bioreactor scale. The main drivers for the cost reduction were reduced total filtration area, labor, time, and utilities. The benefits of the single-stage harvest process extended throughout the downstream process, resulting in a 25% relative increase in cumulative yield with comparable impurity clearance.

Exact solution to non-linear filtration in heterogeneous porous media

Many technological processes of chemical and environmental engineering are associated with the filtration of fine particles in porous media, specifically in heterogeneous reservoirs. A one-dimensional model of deep bed filtration of suspensions and colloids in a heterogeneous porous medium is derived. The model includes the mass balance equation with variable porosity for the concentrations of suspended and retained particles and the deposit growth equation with the non-linear filtration function depending on the retained concentration and on the spatial coordinate. Using the method of characteristics, a formula for the curvilinear concentration front is obtained. The problem is reduced to one nonlinear equation in partial derivatives of the first order. An exact solution is obtained for the hyperbolic heterogeneity, and a Riemann invariant providing a relation between the solutions on the characteristics, is found. The properties of the solutions are studied. The cases of infinite and finite filtration time are considered.

Optimization of environmental DNA analysis using pumped deep-sea water for the monitoring of fish biodiversity

Deep-sea ecosystems present difficulties in surveying and continuous monitoring of the biodiversity of deep-sea ecosystems because of the logistical constraints, high cost, and limited opportunities for sampling. Environmental DNA (eDNA) metabarcoding analysis provides a useful method for estimating the biodiversity in aquatic ecosystems but has rarely been applied to the study of deep-sea fish communities. In this study, we utilized pumped deep-sea water for the continuous monitoring of deep-sea fish communities by eDNA metabarcoding. In order to develop an optimum method for continuous monitoring of deep-sea fish biodiversity by eDNA metabarcoding, we determined the appropriate amount of pumped deep-sea water to be filtered and the practical number of filtered sample replicates required for biodiversity monitoring of deep-sea fish communities. Pumped deep-sea water samples were filtered in various volumes (5–53 L) at two sites (Akazawa: pumping depth 800 m, and Yaizu: pumping depth 400 m, Shizuoka, Japan) of deep-sea water pumping facilities. Based on the result of evaluations of filtration time, efficiency of PCR amplification, and number of detected fish reads, the filtration of 20 L of pumped deep-sea water from Akazawa and filtration of 10 L from Yaizu were demonstrated to be suitable filtration volumes for the present study. Fish biodiversity obtained by the eDNA metabarcoding analyses showed a clear difference between the Akazawa and Yaizu samples. We also evaluated the effect of the number of filter replicates on the species richness detected by eDNA metabarcoding from the pumped deep-sea water. At both sites, more than 10 sample replicates were required for the detection of commonly occurring fish species. Our optimized method using pumped deep-sea water and eDNA metabarcoding can be applied to eDNA-based continuous biodiversity monitoring of deep-sea fish to better understand the effects of climate change on deep-sea ecosystems.

Enhancing sludge dewatering efficiency through bioleaching facilitated by increasing reactive oxygen species

Bioleaching facilitated by iron-oxidizing bacteria is regarded as a promising sludge dewatering method due to excellent dewaterability and low cost. However, a two-days bioleaching time for sludge conditioning decreased its daily treatment capacity. In fact, Fe2+ easily reacts with O2 to produce reactive oxygen species (ROS) with high oxidizing activity. Can bioleaching performed in Fe2+-rich system generate ROS to decompose sludge extracellular polymeric substances (EPS)? Here both contribution of ROS produced in bioleaching to improve sludge dewaterability and the increase of ROS content to shorten sludge bioleaching treatment time were investigated. The introduction of H2O2 in sludge bioleaching treatment (BS+H2O2) to increase ROS could simultaneously improve sludge dewaterability and decrease bioleaching time. Specific resistance to filtration (SRF) and capillary suction time (CST) reduction ratios (90.3% and 80.9%) in BS+H2O2 process were much higher than those in other processes after only 30 min reaction. Mechanisms of improving sludge dewaterability in BS+H2O2 mainly included ROS oxidation and Fe3+ flocculation by analysis of the contribution factors. These findings not only provide an effectively method to promote sludge dewatering efficiency of bioleaching, but also give new sights into the design of cost-efficient processes for improving the sludge dewatering.

Technological properties and composition of volatile compounds in winter wheat malts grown with addition of seed meals into soil

Wheat malts are necessary to produce wheat beers. In this study, wheat was grown with addition of seed meals into the soil, to determine whether such agricultural practice could improve the quality of the grain and, therefore, improve the quality of wheat malt produced from these grains. It was determined, that malt produced from the grains of the winter wheat cultivated with the use of seed meals is characterised with improved technological properties, such as saccharification time, filtration time and extract content and some of the seed meals had a positive impact on the content of various volatile compounds present in the produced malts.

Establishment of a projection-pursuit-regression-based prediction model for the filtration performance of a micro-pressure filtration and cleaning tank for micro-irrigation

Filtration is a key process of a micro-irrigation system. To achieve water conservation, improve the energy efficiency, and meet the low-carbon environmental requirements, this study investigates a new type of pre-pump filtration measure—the micro-pressure filtration and cleaning tank, and the sediment removal (SR), mass of intercepted sediment (Ma), and filtration time (t) are used as evaluation indicators. A uniform orthogonal test was designed to evaluate the influences of the initial sediment concentration, flow rate, and filter area. We carried out simulations using the projection pursuit regression (PPR) method based on physical measurement data, and then NSGA-II (fast elitist non-dominated sorting genetic algorithm) algorithm was used to find the optimal parameter values. The results showed that the order of the factors influencing the SR and Ma of the micro-pressure filtration and cleaning tank was the filter area > initial sediment concentration > flow rate. The order of the factors influencing the filtration time was flow rate > initial sediment concentration > filter area. A PPR prediction model was built based on the filter area, initial sediment concentration, flow rate, and assessment indicators, and the optimal operating conditions were determined (initial sediment concentration: 0.36 kg/m3, flow rate: 7 m3/h, and filter area: 2000 cm2). The research results demonstrated the filtration performance of the micro-pressure filtration and cleaning tank and provide a theoretical basis for the popularization and application of such tanks as well as a reference for sustainable new irrigation technologies.

Modulating the Morphological Features of Hydrothermally Derived Nickel Cobaltite for Supercapacitor Application: Role of Precursor Anions.

Morphologically engineered porous electrodes show great promise in energy applications as they exhibit improved electrochemical activity owing to increased electrical conductivity, increased surface area, and a shorter path length for ion transport. Herein, the role of precursors (chlorides, acetates and nitrates) on the crystallinity and textural features of Nickel Cobaltite, obtained by the controlled precipitation through hydrothermal synthesis, is studied. The synthesis yielded urchin like structures with morphological variations in substructures based on the precursor anion types. The surface area values obtained for nickel cobaltite derived from the chloride (NCO-C), nitrate (NCO-N), and acetate precursors (NCO-A) were 30,110 and 115 m2 g-1 , confirming the influence of anions on the textural features. The time dependant electrolyte (2 M KOH) infiltration behaviour on the electrode surfaces based on contact angle measurements is invoked to correlate its morphological and textural attributes with the electrolyte transport kinetics. The electrochemical performances were derived from cyclic voltammetry, galvanostatic charge discharge analysis and impedance measurements. The electrolyte infiltration studies established a dependence on the precursor anion. NCO-A facilitated faster electrolyte infiltration time of 7800 ms compared to 16200 ms and 54,000 ms for NCO-N and NCO-C electrodes, respectively. Furthermore, NCO-A exhibited a greater specific capacitance of 802 F g-1 than NCO-N (500 F g-1 ) and NCO-C (342 F g-1 ). The morphology modulation coupled with optimal porosity led to conducive pathways for reversible electrolyte infiltration resulting in increased capacitive contribution in NCO-A. The study revealed that the size of intercalating anions exercised a significant impact on the morphological and electrochemical features, signifying the importance of synthetic approaches in determining the functional properties of electrode materials.

STUDY OF THE POTENTIAL OF CALCIUM HYDROXIDE SYNTHESIZED FROM PERIWINKLE SHELL AS A pH ENHANCER IN WATER BASED DRILLING MUD

Reservoirs that contain acidic gases can lead to the corrosion of the drilling string and casing which could result in incessant down time and also increase the cost of drilling operation. This research work aimed at investigating the potential of using locally sourced materials such as Periwinkle Shell Ash (PSA) that can serve as substitutes to imported chemicals used in the industry, to help raise the mud pH to the API standard (9.5-12.5) whilst reducing the cost of drilling operation. Calcium hydroxide (Ca (OH2)) was extracted from Periwinkle Shell using two different process routes (via the calcination of the PSA and without it). Characterization tools were used to assess the functional groups present and the elemental composition of the periwinkle shell. Various laboratory equipment was used to observe the impact the additives would have on the mud properties (pH, mud weight, filtration characteristics and rheological properties) of the new drilling fluid. Results showed that as the mass of the synthesized Ca (OH2) from the calcined PSA, the uncalcined PSA and the commercial Ca (OH2) was increased, the pH of the mud samples was observed to have increased the pH of the base mud by 20.9%, 15.1% and 10%. Therefore, this research showed that the extracted Ca (OH2) acted primarily as a pH enhancer. However, the addition of Ca (OH2) from all sources exhibited poor filtration characteristics as there was high filtrate loss as the filtration time and the additive concentration increased which could affect the formulation and the performance of the drilling mud.

Flushing or mixing? Stable water isotopes reveal differences in arctic forest and peatland soil water seasonality

AbstractUnderstanding the relative importance of different water sources that replenish soil water storage is necessary to assess the vulnerability of sub‐arctic areas to changes in climate and altered rain and snow conditions, reflected in the timing and magnitude of water infiltration. We examine spatiotemporal variability and seasonal origin of soil water at the soil‐vegetation interface in Pallas catchment, located in northern Finland. The field study was conducted from May 2019 to June 2020 over two snowmelt seasons and one summer growing season. We sampled soil cores up to a 1‐m depth and stem water of dominant tree species at four sites located in forests and forested peatlands for stable water isotopes. Seasonal rainfall variation and late snowmelt events were well identifiable in the well‐drained soils of forested areas, while this input signal is heavily attenuated in wetter, forested peatland areas. Spatiotemporal variability of soil water in two forest sites was similar, whereas soil water storage in peatland sites was controlled by the extent of hydrologic connectivity to the adjoining water pools. A mixture of both summer and winter precipitation was present in peatlands during the entire study period, while forest mineral soils showed an ephemeral response to water input and got nearly fully flushed twice during the hydrological year. Meltwater signal in forest soils was dominant after snowmelt and in early spring but became displaced by isotopically enriched rainfall during the summer. Seasonal evolution of soil water pools was not reflected in tree stem dynamics but offset between soil and stem water isotopic signals was less pronounced in forested peatlands. This field data set uncovered seasonal changes of soil water isotopic signal at high depth‐resolution, quantifying the importance of snowmelt water in replenishing and sustaining soil water storage in sub‐arctic conditions.

Single Vs Multichannel Silica-Pectin Ultrafiltration Membranes for Treatment of Natural Peat Water

A comparative study was undertaken to investigate the potential of silica-pectin ultrafiltration membrane on varied operation pressure (0.1-0.3 MPa). Cross-flow ultrafiltration works were explored with tubular alumina substrates in single and multichannel configuration. The silica-pectin sol was prepared from TEOS as silica precursor by sol-gel method, afterward pectin was templated into the silica sol to induce carbon on it. Thereafter, both of single and multichannel alumina substrates was coated by the silica-pectin sol via inner coating technique. The study exhibited better performance of multichannel silica-pectin ultrafiltration membrane (with 4 bores) compared to the single channel membrane in terms of the permeate quality of UV254 rejection, as well as the permeate flux. The UV254 rejection of multichannel silica-pectin ultrafiltration membranes conducted over 84% in compliance with highest permeate fluxes of 234.3 L.m-2.h-1.bar-1 at high operation pressure (TMP 0.3 MPa). The multichannel ultrafiltration membrane permeate flux in this work is slightly high 60-75% over single channel. Hence, both single and multichannel silica-pectin membranes exhibited steady neutralized permeate fluxes under TMP 0.3 MPa conditions for natural 100% peat water concentration, which indicates that fouling is not occurred during filtration time up to 60 min. Therefore, multichannel silica-pectin ultrafiltration membrane in this work is success to treatment of natural peat water, that the natural organic matter removal was found to be fit for uses as clean water sources.

Variasi Sinar Ultraviolet terhadap Fluks untuk Pengolahan Air Gambut Sistem Membran Ultrafiltrasi

Abstract-Peat water treatment still has many obstacles, one of the alternatives that can be used to overcome this obstacle is membrane technology and UV light variais. This study aims to determine the effect of UV rays on the flux and content of BOD, TSS, pH, Turbidity, Color and E.Coli Bacteria. This study used a combined method, namely ultraviolet (UV) light poses using a UV Water Sterilizer, the filtration process using the KUF-3 ultrafiltration membrane and the phytoremediation method with kiambang plants. The results of this study showed the highest removal rate of BOD in the filtration process with UV 6 watts at 90 minutes of filtration time with an efficiency of 94.71%. The color removal rate in the filtration process with UV is 6 watts at 90 minutes of filtration time with an efficiency of 70.92%. Turbidity removal rate in the filtration process with UV 6 watts at 90 minutes filtration time with an efficiency of 99.97%%. The TSS removal rate in the filtration process with UV is 6 watts at 90 minutes of filtration time with an efficiency of 47.77%. The pH removal rate in the filtration process with UV is 6 watts at 90 minutes of filtration time with an efficiency of 24.79%. The elimination rate of E.coli bacteria in the filtration process with UV is 6 watts at 90 minutes of filtration time with 100% efficiency

A Measurement Method for the Pore Structure of Coal Slime Filter Cake

The accurate determination of the coal slime filter cake pore structure has always been a problem in the field of solid–liquid separation. An innovative measurement method for the pore structure of filter cake after filtration dehydration of coal slime water, including the preparation of coal slime filter cake, the solidification of the filter cake, and the preparation and measurement of test filter cake, was established in this paper. Epoxy resin and curing agent can ensure the strength of the filter cake, and red colorant can realize the accurate separation of coal particles and pores. The most suitable perfusate consists of epoxy resin, red colorant, and curing reagent, and the optimal ratio is 12:3:5. The application of the method to the study of the effect of filtration time on the coal slime filter cake pores shows that the modified method is effective. At the initial stage of filtration, intergranular pores formed by coarse particles are the main pores. With increasing filtration time, the macropores formed by the coarse particles are mainly filled with fine particles, and the pore size of the filter cake rapidly decreases. These measuring results and rules are accurate. This method can be conveniently used to study the microstructure of filter cake, pore channel regulation, filtration dehydration mechanisms, etc.

Soil water balance and wettability methods in soil treated with biochar and/or compost

The impacts of biochar application in combination with compost on soil hydrological conditions such as infiltration, water-storage capacity, and methods of soil wettability, are not well understood. The aim of this study was to fill this knowledge gap and propose the best composition proportion of compost and/or biochar to improve sand soil water balance. For this purpose, we examined three different mixtures of sand and compost and six different mixtures of sand, compost, and biochar with respect to their wettability and water infiltration using tree methods, (I) Water Droplet Penetration Time Test (WDPT test), (II) Wilhelmy Plate Method (WPM) and (III) Capillary Rise Method (CRM) applied at different soil water potential (pF) levels. The different mixtures were characterized by texture, bulk density, field capacity, and soil water holding capacity through measurement of the water content of soil columns. Increasing biochar plus compost or compost alone had contributed to increasing the soil water holding capacity and water available content. The best composition with the highest water storage capacity, plant-available water, and wettability was: 0.6% of biochar, 5.4% soil organic matter (SOM), and 93.99% of sand. According to the WDPT test, the increased content of biochar contributed to improving the soil wettability, this test was preferred since 1) WDPT appeared to allow the best estimates of wetting behavior of the different mixtures, 2) the column samples were the least disturbed, and 3) the test was particularly feasible at different water content levels. However, WDPT was strongly dependent on the conductor of the experiment and the accurate measurement of short infiltration times (0s - 2s) proved challenging. The WDPT results indicate that biochar might enhance the infiltration capacity under natural conditions and the combined results indicate that biochar-compost-applications are not expected to cause ecologically critical hydrophobicity or a critical lowering of the sandy soil infiltration capacity.Graphical abstract

Novel PLCL nanofibrous/keratin hydrogel bilayer wound dressing for skin wound repair

In this study, a novel poly(L-lactate-caprolactone) copolymer (PLCL) nanofibrous/keratin hydrogel bilayer wound dressing loaded with fibroblast growth factor (FGF-2) was prepared by the low-pressure filtration-assisted method. The ability of the keratin hydrogel in the bilayer dressing to mimic the dermis and that of the nanofibrous PLCL to mimic the epidermis were discussed. Keratin hydrogel exhibited good porosity and maximum water absorption of 874.09%. Compared with that of the dressing prepared by the coating method, the interface of the bilayer dressing manufactured by the low-pressure filtration-assisted method (filtration time: 20 min) was tightly bonded, and its bilayer dressing interface could not be easily peeled off. The elastic modulus of hydrogel was about 44 kPa, which was similar to the elastic modulus of the dermis (2–80 kPa). Additionally, PLCL nanofibers had certain toughness and flexibility suitable for simulating the epidermal structures. In vitro studies showed that the bilayer dressing was biocompatible and biodegradable. In vivo studies indicated that PLCL/keratin-FGF-2 bilayer dressing could promote re-epithelialization, collagen deposition, skin appendages (hair follicles) regeneration, microangiogenesis construction, and adipose-derived stem cells (ADSCs) recruitment. The introduction of FGF-2 resulted in a better repair effect. The bilayer dressing also solved the problems of poor interface adhesion of hydrogel/electrospinning nanofibers. This paper also explored the preliminary role and mechanism of bilayer dressing in promoting skin healing, showing that its potential applications as a biomedical wound dressing in the field of skin tissue engineering.

Composite bioceramic scaffolds with controllable photothermal performance fabricated by digital light processing and vacuum infiltration

Photothermal scaffolds can help clear bone tumor cells after resection. In this work, hydroxyapatite-akermanite-Fe3O4 (HA-AK-FE) bioceramic scaffolds were fabricated by infiltrating digital light processing (DLP)-printed HA-AK scaffolds in nano-Fe3O4 solution. The prepared HA-AK-FE samples exhibited excellent and controllable photothermal performance under the irradiation of 808 nm near-infrared light. By controlling nano-Fe3O4 concentration, irradiation power and infiltration time, temperature of HA-AK-FE samples could be regulated in a wide range from room temperature to 150 °C within 15 s. Photothermal temperature remained stable after 4 times repeated irradiations. In SBF solution and under subcutaneous tissue, the heating rate and photothermal temperature decreased obviously compared with in air, but they could still meet the needs of killing tumors (41–48 °C). The Fe release concentration of wafers after immersing in SBF for 1 day was 0.037 mg/L and non-venomous. These results confirm the feasibility and controllability of fabricating photothermal scaffolds by coating nano-Fe3O4 with vacuum infiltration, and the prepared HA-AK-FE scaffolds are hopeful to be used in photothermal therapy of bone tumors.