Semipermeable Film Research Articles

Effect of semi-permeable film stabilisation treatment on dry and wet cyclic corrosion behaviour of Q420qENH weathering steel plates and welded joints in deicing salt media

In this paper, the influence of semi-permeable film stabilisation on the corrosion trend, corrosion type and corrosion mechanism of bridge weathering steel in a deicing salt medium was investigated by dry and wet alternating accelerated corrosion test. The results indicate that the semi-permeable film stabilisation treatment reduces the inflection point of corrosion rate reduction of weathering steel plates and welded specimens in the deicing salt medium, reduces the value of n, which represents the trend of full-scale corrosion, and improves their resistance to full-scale corrosion. After 30 days of corrosion, the peak intensity ratios of Iβ-FeOOH+FeOCl /Iα-FeOOH for untreated plates and welded specimens were 1.092 and 1.132 times higher than that of the semi-permeable film stabilisation treatment specimens, respectively. With a reduction of defects and an increase in densification in the rust layer, and a significant reduction in the concentration of chloride ions at the interface between the rust layer and the substrate. During the whole corrosion process, the self-corrosion potential of the rust layer after the stabilisation treatment of the semi-permeable film was increased by 1.08–1.12 times, the impedance was increased by 1.13–1.32 times, and the electrochemical stability was significantly improved. The semi-permeable film in the pre-corrosion period effectively blocked the penetration of chloride ions, reducing the concentration of corrosion medium in the rust layer, reduced the generation of unstable phases of β-FeOOH and FeOCl. At the same time, the stabiliser treatment improves the Cu, Cr and Ni elements in the rust layer, promoted the formation of the stable phase α-FeOOH in the rust layer and the refinement of the rust grains, thus significantly improving the corrosion resistance of the weathering steel in the deicing salt medium.

Building Semipermeable Films One Monomer at a Time: Structural Advantages via Molecular Layer Deposition vs Interfacial Polymerization.

Molecular layer deposition (MLD) provides the opportunity to perform condensation polymerization one vaporized monomer at a time for the creation of precise, selective nanofilms for desalination membranes. Here, we compare the structure, chemistry, and morphology of two types of commercial interfacial polymerzation (IP) membranes with lab-made MLD films. M-phenylenediamine (MPD) and trimesoyl chloride (TMC) produced a cross-linked, aromatic polyamide often used in reverse osmosis membranes at MLD growth rates of 2.9 Å/cycle at 115 °C. Likewise, piperazine (PIP) and TMC formed polypiperazine amide, a common selective layer in nanofiltration membranes, with MLD growth rates of 1.5 Å/cycle at 115 °C. Ellipsometry and X-ray reflectivity results suggest that the surface of the MLD films is comprised of polymer segments roughly two monomers in length, which are connected at one end to the cross-linked bulk layer. As a result of this structure as well as the triple-functionality of TMC, MPD-TMC had a temperature window of stable growth rate from 115 to 150 °C, which is unlike any non-cross-linked MLD chemistries reported in the literature. Compared to IP films, corresponding MLD films were denser and morphologically conformal, which suggests a reduction in void volumes; this explains the high degree of salt rejection and reduced flux previously observed for exceptionally thin MPD-TMC MLD membranes. Using X-ray photoelectron spectroscopy and infrared spectroscopy, MLD PIP-TMC films evidenced a completely cross-linked internal structure, which lacked amine and carboxyl groups, pointing to a hydrophobic bulk structure, ideal for optimized water flux. Grazing-incidence wide-angle X-ray scattering showed broad features in each polyamide with d-spacings of 5.0 Å in PIP-TMC compared to that of 3.8 Å in MPD-TMC. While MLD and IP films were structurally identical to PIP-TMC, MPD-TMC IP films had a structure that may have been altered by post-treatment compared to MLD films. These results provide foundational insights into the MLD process, structure-performance relationships, and membrane fabrication.

사포그릴레이트 염산염을 함유하는 신규 OROS 정의 제제 설계 및 용출 거동

Sarpogrelate hydrochloride (SGH) is a drug that improves ischemic symptoms such as ulcers, pain, and feeling of cold caused by chronic arterial occlusion, and has a short half-life of 0.6 to 0.8 hours. Also, reference drug (SarpodipilⓇ SR tablet) is affected by drug release depending on pH. To overcome this, the osmotic controlled release oral delivery system (OROS) utilizes push-pull osmotic pump (PPOP) technology that can achieve zero-order drug release over 24 hours by osmotic pressure. OROS tablet is double-layer tablet consisting of a drug layer (L200-PEO) and a push layer (H5,000- PEO). OROS tablet coated with a semi-permeable film has a orifice of a certain size made by a laser drill, so that the drug is released at a constant rate. The dissolution of the OROS tablet was not affected by the amount of sodium chloride in the drug layer and the number of orifice, but was affected by amount of coating, cellulose acetate (CA) : polyethylene glycol 3350 (PEG 3350) ratio and the size of orifice. Accordingly, as the amount of coating increased and PEG 3350 decreased, the dissolution rate decreased. The developed OROS tablet (formulation C), unlike the reference drug, is not affected by pH, showing high similarity factors of 76.0, 86.1, and 91.2 at pH 1.2, pH 4.0, and pH 6.8 when compared to distilled water. In conclusion, we developed OROS tablet containing SGH, showing zero-order release that continuously releases the drug for 24 hours regardless of pH, and confirmed the factors affecting dissolution.

Effect of modified atmosphere packaging on quality of minimally processed fenugreek (Trigonella foenum-graecum L.) microgreens

Fenugreek (Trigonella foenum-graecum L.) microgreens is an underutilized vegetable with limited shelf life having good source of antioxidants, carotenoid as well as vitamins. The study deals with nutritional quality and optimization of a suitable passive modified atmosphere packaging (MAP) for improving the shelf life of fenugreek microgreens in its minimally processed form (MPFM) at 8oC Semipermeable plastic films viz., low density polyethylene, polypropylene, Cryovac PD 961® and stretchable PVC cling film with varying thickness were evaluated as packaging materials to obtain different MAP composition inside MPFM packages. Packaging of MPFM in 40 μm thick polypropylene film resulted in development of in-pack equilibrium MA with 10-14% oxygen and 5-8% carbon dioxide during storage. This in-pack MA maintained ‘fresh-like’ sensory properties, biochemical and nutritional quality in MPFM till 15 days of storage. Significant loss of B vitamins was recorded in all packages during low temperature storage. Packaging in 40 μm thick polypropylene film retained B vitamins significantly better than other semipermeable films. Low temperature storage in modified atmosphere conditions enhanced vitamin E content in MPFM. The outcome of the study will benefit the entrepreneurs and retailers for distant transport and storage of fenugreek microgreens in commercial open chillers maintained in supermarkets in their ready-to-cook form.

A High-Sensitivity Dual-Axis Accelerometer with Two FP Cavities Assembled on Single Optical Fiber.

In this paper, a dual-axis Fabry-Pérot (FP) accelerometer assembled on single optical fiber is proposed. The sensor is equipped with a special beam-splitting prism to split the light into two perpendicular directions (the X- and Y-axes); the prism surface coated with semi-permeable film and the reflective sheet on the corresponding Be-Cu vibration-sensitive spring form two sets of FP cavities of different sizes. When the Be-Cu spring with a proof mass (PM) is subjected to the vibration signal, the cavity length of the corresponding FP cavity is changed and the interference signal returns to the collimator through the original path of the prism. After bandpass filtering and demodulation, the two cavity lengths are obtained, and the acceleration measurement in dual-axis directions is completed. The resonant frequency of the proposed dual-axis fiber optic accelerometer is around 280 Hz. The results of the spectral measurements show 3.93 μm/g (g = 9.8 m/s2: gravity constant) and 4.19 μm/g for the applied acceleration along the X- and Y-axes, respectively, and the cross-axis sensitivity is below 5.1%. Within the angle range of 180°, the maximum error of measured acceleration is less than 3.77%. The proposed fiber optic dual-axis FP accelerometer has high sensitivity and strong immunity to electromagnetic interference. The size of the sensor mainly depends on the size of the prism, which is easy to reduce and mass produce. Moreover, this FP construction method has high flexibility and development potential.

Perfil de compuestos nitrogenados y proliferación bacteriana en carne de conejo almacenada en frio con tres tipos de empaques

Meat is an excellent medium for bacterial growth due to its high water and nutrient content. The nitrogenous compounds (NC) are derived through decarboxylation of amino acids due to microbial enzymes. The objective of this study was to evaluate the concentration of 3 NC and the proliferation of some microorganisms in rabbit meat with three treatments (T) , classified by three types of packaging for 21 days (d) in rabbit meat stored cold. The meat samples were obtained of the Longissimus thoracis et lumborum muscle. Each sample was divided and two groups were formed. The first group was used to measure the physicochemical characteristics of the meat, and the second group was used to quantify NC and bacterial isolation. The pH in the meat decreased from 0 to 21 d in the three T. The brightness (L*) decreased (P<0.05), while the variables a* and b* increased (P<0.05) to 21 d for all groups. Histamine and cadaverine remained low and were similar in the three T (P>0.05). Putrescine (PU) increased (P<0.05) from 7 to 21 d in the Control-Plastic (CP) and Semi-permeable plastic film (SP) groups vs. Vacuum packing (VP). The Enterobacteriaceae remained constant throughout the experimental period in the three T, compared to the aerobic mesophilic, which was higher (P<0.05) until 21 d of the evaluation in CP and SP. The type of packaging and cooling time influenced the concentration of NC. The VP had the lowest level of PU and mesophilic bacteria until 21 d of storage.

Mitigating void growth in out-of-autoclave prepreg processing using a semi-permeable membrane to maintain resin pressure

In this work, we investigate the use of discontinuous resin films in prepregs (semipregs) combined with a semi-permeable (air-permeable, resin-impermeable) release film intended to allow through-thickness air evacuation while simultaneously restricting resin loss. In situ measurements of resin pressure were deployed to test the hypothesis that resin pressure was maintained during prepreg cure when using a semi-permeable release film. Concurrently, visualization of the tool-side surface during cure revealed efficient evacuation of entrapped air. Porosity in laminates formed at high temperatures when using resin-permeable consumables, but did not form when using resin-impermeable (semi-permeable) consumables. To confirm that the observed void growth behavior was due to a loss in resin pressure, experiments were conducted to measure resin pressure during cure with both resin-permeable and resin-impermeable (semi-permeable) consumables. In both cases, resin pressure peaked before decreasing, a finding attributed to resin flowing to fill dry regions in the fabric, present by design. The drop in resin pressure, however, was greater in magnitude and longer in duration when using resin-permeable edge and bag-side surface boundaries, indicating that the observed void growth at elevated temperature was caused by a loss in resin pressure. Use of a semi-permeable membrane was effective in retaining resin content and mitigating such porosity.

The Wound Dressing Influenced Effectiveness of Cryotherapy After Anterior Cruciate Ligament Reconstruction: Case–Control Study Comparing Gauze Versus Film Dressing

PurposeTo compare the clinical effectiveness of cryotherapy after anterior cruciate ligament reconstruction using 2 different wound dressings, conventional postoperative gauze dressings and polyurethane semipermeable transparent film dressings.MethodsIn total, 60 patients who had undergone arthroscopic anterior cruciate ligament reconstruction with an autogenous patellar tendon were assigned to 2 groups. The surgical wound was covered with 5 sheets of gauze with an elastic bandage (control group) in 30 patients and film dressing was used (film group) in the remaining 30 patients. Silicone drainage catheters were inserted at the intercondylar notch, beside the distal outlet of the tibial tunnel for 2 days. After 1 hour of cooling using the device, the knee was chilled with an ice bag every 2 hours until the next morning. The severity of pain was evaluated by the number of times an analgesic, 50 mg of diclofenac sodium suppositories, had to be administered in the 24 hours after surgery. The amount of drainage during the following 2 days, the range of motion at 21 days, the change of hemoglobin concentration at 1 and 7 days, and C-reactive protein (CRP) at 1 and 7 days were examined.ResultsThe number of patients who used an analgesic was 18 in the control group and 7 in the film group (P = .003). The amount of drainage was 165.2 ± 72.9 mL in the control group and 289.7 ± 77.6 mL in the film group (P < .001). The postoperative CRP value was 0.77 ± 0.65 mg/dL at 1 day in the control group and 0.39 ± 0.42 mg/dL in the film group (P = .009). No statistical difference was seen for hemoglobin concentration at 1 or 7 days, CRP at 7 days or range of motion at 21 days.ConclusionsIn this study, we found that film dressing enhanced the effect of cryotherapy with respect to pain control, wound drainage, and inflammation immediately after surgery compared with traditional gauze dressing with elastic wrap.Level of EvidenceIII, case–control study.

Determining the Role of Minerals and Trace Elements in Diabetes and Insulin Resistance

Minerals and trace elements are micronutrients that are required for human health but are only available in trace amounts. Regardless, their organic chemistry roles are well established. Micronutrient deficiencies have been connected to a number of human health issues. This critique focuses on a handful of these mineral and chemical element shortages, as well as their effects on polygenic illness and internal secretion resistance. The degree of trace components varies substantially across entirely different populations depending on the food composition. Trace elements play a major role in many boy processes. Trace elements and minerals are required for a scope of natural synthetic responses, just as working as chemical and protein stabilizers and cofactors. Certain elements control fundamental organic cycles by restricting to the receptor locales of the semipermeable film or changing the state of the receptor to keep specific particles from entering the cell. Micronutrients have a dual role: they keep cell structures stable at ideal levels, however their inadequacy prompts different courses, which can prompt illness. These imperative micronutrients assume a significant part in human wellbeing and have an immediate relationship with Diabetes Mellitus. Here we have reviewed the role of copper [Cu], selenium [Se], and Zinc [Zn].

Molecular layer deposition for the fabrication of desalination membranes with tunable metrics

The recent advancement of semiconductor devices to the near-atomic scale necessitated the development of atomic layer processing methods, including molecular layer deposition (MLD). This gas-phase deposition technique creates semipermeable polymer films with precise control of composition and thickness. Herein, MLD was used to produce thin-film composite reverse osmosis membranes. Aromatic polyamide films as thin as 0.5 nm were applied to NF270 nanofiltration membranes using m-phenylenediamine and trimesoyl chloride. Within two molecular layers, desalination performance was affected. As film thickness increased to 15 nm (48 MLD cycles), performance progressed from nanofiltration to reverse osmosis metrics in terms of salt rejection and water permeance. With film thickness > 5 nm, rejection values exceeded a small sampling of commercial membranes. In all cases, a tradeoff between rejection and permeance was observed. Atomic force microscopy measurements indicate that MLD enhancement led to removal of small-scale roughness features and resulted in a root mean square roughness difference of <0.1 nm from the substrate. These initial MLD studies represent a novel processing approach that offers a potential pathway for the fabrication of membranes with finely tailored properties.

Classification and Production of Polymeric Foams among the Systems for Wound Treatment.

This work represents an overview on types of wounds according to their definition, classification and dressing treatments. Natural and synthetic polymeric wound dressings types have been analyzed, providing a historical overview, from ancient to modern times. Currently, there is a wide choice of materials for the treatment of wounds, such as hydrocolloids, polyurethane and alginate patches, wafers, hydrogels and semi-permeable film dressings. These systems are often loaded with drugs such as antibiotics for the simultaneous delivery of drugs to prevent or cure infections caused by the exposition of blood vessel to open air. Among the presented techniques, a focus on foams has been provided, describing the most diffused branded products and their chemical, physical, biological and mechanical properties. Conventional and high-pressure methods for the production of foams for wound dressing are also analyzed in this work, with a proposed comparison in terms of process steps, efficiency and removal of solvent residue. Case studies, in vivo tests and models have been reported to identify the real applications of the produced foams.

Thermogravimetric Studies of Dehydration of the Cellulose Acetate Layer in UAM-100, UAM-150, and MGA-95 Composite Films

This paper presents an analytical overview of the study of the kinetic and physicochemical characteristics of composite membrane films. UAM-100, UAM-150, and MGA-95 composite films have been studied using thermogravimetry in the temperature range from 30 to 300°C. A kinetic analysis of experimental data by the Freeman–Carroll method is carried out. It was found that hydrated water for all the studied semi-permeable films evaporates in the temperature range from ~95 to ~180°C. Comparison of the ratios of the amount of removed water in the film samples correlates with the geometric parameters of the pores. The values of the activation energy and the pre-exponential factor (E = 26.9 kJ/mol and ln(A ≈ 6.3 (min–1)) in the range 0.2 < α < 0.7 of the degree of dehydration indicate the same regularity in the distribution of water molecules in the polymolecular layer for all composite films. The high dehydration values, e.g., for a sample of a composite semipermeable film MGA-95 at the temperature of the maximum on the thermogravimetry curve (Tmax = 169.6°C) indicate that water molecules form hydrogen bonds both with ionogenic groups of cellulose acetate and with each other.

Care for critically ill patients on the example of patients with severe burns

Background. More than 200,000 patients with burns in Europe and the United States need inpatient treatment every year. In Ukraine, 35,000 people suffer thermal injuries each year. Medical care for burns in Ukraine is provided on 1,060 specialized beds (875 – for adults, 175 – for children). Indications for transporting people to the burn center include burn area &gt;10 % of the body surface in adults; burns of the face, hands, feet, perineum, genitals, large joints; deep burns &gt;3 %; electrical or chemical burns; inhalation burns; circular burns of the extremities or chest; burns in pregnant women, children, the elderly, patients with severe comorbid conditions; burns in combination with polytraumas.&#x0D; Objective. To describe the management of critically ill patients with burns.&#x0D; Materials and methods. Analysis of literature sources on this issue.&#x0D; Results and discussion. Care for patients with burns is divided into general and special. The use of specialized beds “Clinitron” and air-insolating complexes is of paramount importance. Since the heat loss from the burn wound is 580 kcal/h, the temperature in the burn rooms should be maintained at 26-30 °C. Wound surfaces are easily infected with nosocomial microorganisms, so it is necessary to carefully maintain hand hygiene of healthcare workers (HCW). The latter are the cause of the hospital infections in 50-80 % of cases, so when caring for different patients and before the transition from a bacteria-contaminated area of the body to a clean one, the gloves should be changed. All works near the patient must be carried out in the nitrile gloves without powder, as the latter increases the risk of infection and allergies. It is advisable to use high-strength gloves with an elongated cuff. After removing the gloves, hand hygiene must be carried out. To disinfect the hands of HCW in order to prevent the spread of transient microflora, you can use Gorosten (“Yuria-Pharm”) – a solution based on decamethoxine. Gorosten has antibacterial, antifungal, antiviral, anti-inflammatory and desensitizing properties. Hand hygiene should be performed before the contact with the patient, before clean/aseptic procedures, after contact / risk of contact with the patient’s biological fluids, after contact with the patient and his surroundings, after contact with him-/herself and personal protective equipment. In case of big burn area, bandages are changed under general anesthesia, in some cases after a bath with 0.05-0.1 % potassium permanganate solution. Improper care of patients with burns and other patients with severe conditions can cause the following complications: contractures, bedsores, infectious processes in the lungs, injuries and more. For the prevention and treatment of bedsores, it is advisable to use modern dressings: hydrocolloid, semi-permeable film, sponge, and silicone.&#x0D; Conclusions. 1. Indications for the transporting people to the burn center include the area of the burn &gt;10 % of the body surface in adults; burns of the face, hands, feet, perineum, genitals, large joints; deep burns &gt;3 %; electrical or chemical burns; inhalation burns; circular burns of the extremities or chest; burns in pregnant women, children, the elderly, patients with severe comorbid conditions; burns in combination with polytraumas. 2. Wound surfaces are easily infected with nosocomial microorganisms, so it is necessary to carefully maintain hand hygiene of HCW. 3. All works near the patient should be carried out in nitrile gloves without powder. 4. After removing the gloves, hand hygiene should be carried out. 5. Gorosten can be used for disinfection of HCW hands in order to prevent the spread of transient microflora.

Wound Dressings – A Practical Review

There are currently thousands of wound dressing products and materials available on the market. Despite the wide selection, there is no universally superior dressing, which prompts healthcare providers to choose materials that are most suitable to each particular case. This review provides an overview of various types of wound dressings, suggested uses, and recent advancements. Modern dressings have evolved to encompass an expansive array of semipermeable films and foams, hydrofibers, hydrogels, hydrocolloids, and alginates. Recent studies have investigated new technologies such as electrospun biopolymer nanofibers to create sprayable dressings while also exploring new roles for traditional materials such as honey and other non-synthetic derivatives. Wound presentations are diverse and require unique materials to best accommodate their respective healing processes. Future research is aimed at improving versatility and effectiveness of existing wound dressings while also investigating innovative therapeutic approaches to better manage challenging, non-healing wounds.

CFB box wrapping: a new shrink wrapping technology for extension of storage life of colour capsicum (cv. Bachata).

Capsicums lose water very rapidly after harvest and the moisture loss causes severe shriveling making them unmarketable within 2-3days. The moisture loss occurs even under low temperature conditions, though at lesser rates. Bell peppers packed in corrugated fiber board boxes (CFB) tend to lose moisture continuously as these boxes are permeable to both water vapour and respiratory gases even if they are non-ventilated. To reduce the moisture loss and maintain freshness, yellow colour capsicum (cv. Bachata) were packed in CFB boxes and over wrapped with different semi-permeable films using shrink wrapping technology. This box shrink wrapping significantly lowered the weight loss and maintained firmness of capsicum at ambient (25.7-33.2°C and 25-63% RH) and low temperature (8°C ± 0.5 and 80 ± 5% RH) conditions. Yellow colour capsicums packed in this way could be stored for 11days at ambient temperature with a weight loss of < 6% as compared to about 20% weight loss in non-wrapped fruits. The storage life could be extended to 5weeks by storing these shrink wrapped boxes at 8°C without any shriveling and with a weight loss of < 5%. In addition to maintaining high humidity, the lower O2 and higher CO2 levels maintained surrounding the produce in the wrapped boxes helped to avoid shriveling and to retain the quality in terms of surface colour, firmness and other quality traits. The absorption of excessive relative humidity by CFB itself in the over wrapped boxes helped in avoiding condensation of water droplets. This in turn avoided the development of fungal growth and thus the risk of fruit decay.

Overall quality and oxidative damage in packaged freshly shelled walnut kernels during cold storage

In this study, the effect of passive- and active-modified atmosphere packaging (PMA and MAP with 70% N2 and 30% CO2) using semipermeable and barrier films on physicochemical and enzymatic properties and quality of freshly shelled walnut kernels stored at 6 °C for 18 days were investigated. Changes in physicochemical such as free fatty acidity content, peroxide value, colour and enzymatic traits such as polyphenol oxidase, lipoxygenase were tracked in the fresh kernels during cold storage in different packaging systems. The MAP system inhibited polyphenol oxidase activity, delayed browning of tegumented kernels, and helped in maintaining a high total polyphenol content. The PMA system preserved membrane integrity by inhibiting lipoxygenase activity and malondialdehyde accumulation with values of 3.26 ± 0.05 nmol hydroperoxides min−1 g−1 dry weight and 10.90 ± 0.50 nmol g−1 dry weight, respectively after 18 days of cold storage. Moreover, this system inhibited free fatty acid formation and it was characterised by lower peroxide values with 5.17 ± 0.04 mEq O2 kg−1 oil at the end of storage. Principal component analysis provided a global view of the differential qualitative responses of fresh walnut kernels in different packaging systems during cold storage. Our results show that packaging systems could be utilised to extend postharvest shelf life, improve qualitative traits, and inhibit enzyme-mediated browning of fresh kernel walnuts during cold storage.

Just a Flesh Wound? A Detailed Review of Modern Dressings

Dressings are employed across the world as a ubiquitous form of wound treatment in the 21st century. However, the differences between the thousands of wound dressing products currently available on the market can be difficult for clinicians to understand. Common categories of dressings include bioactive, hydrocolloids, hydrogels, alginate-based gels and semi-permeable films among others. However, understanding each dressing’s characteristics is crucial for clinicians to providing the highest standard of care to their patients. This review will highlight the important compositional differences among the most common variants of modern wound dressings and discuss the implications on their clinical applications and antimicrobial properties. As new material is introduced and novel concepts in microbiology are illuminated, more researchers will seek to apply their knowledge to the research and development of modern wound dressings. This review hopes to inspire and guide future studies of wound dressings in an interesting and meaningful direction.

Nanomaterials for Wound Dressings: An Up-to-Date Overview.

As wound healing continues to be a challenge for the medical field, wound management has become an essential factor for healthcare systems. Nanotechnology is a domain that could provide different new approaches concerning regenerative medicine. It is worth mentioning the importance of nanoparticles, which, when embedded in biomaterials, can induce specific properties that make them of interest in applications as materials for wound dressings. In the last years, nano research has taken steps to develop molecular engineering strategies for different self-assembling biocompatible nanoparticles. It is well-known that nanomaterials can improve burn treatment and also the delayed wound healing process. In this review, the first-line of bioactive nanomaterials-based dressing categories frequently applied in clinical practice, including semi-permeable films, semipermeable foam dressings, hydrogel dressings, hydrocolloid dressings, alginate dressings, non-adherent contact layer dressings, and multilayer dressings will be discussed. Additionally, this review will highlight the lack of high-quality evidence and the necessity for future advanced trials because current wound healing therapies generally fail to provide an excellent clinical outcome, either structurally or functionally. The use of nanomaterials in wound management represents a unique tool that can be specifically designed to closely reflect the underlying physiological processes in tissue repair.

A new strategy to efficiently fabricate tungsten carbide coating on tungsten: Two-step interstitial carburization

A tungsten carbide coating on tungsten was fabricated by hot-pressing tungsten with high‑carbon steel. The interstitial carbon atoms in the high‑carbon steel diffused into the tungsten, forming a WC coating. The coating is completely nonporous, and the volume fraction of the carbide phases is close to 100%. By comparing the microstructures of the coatings fabricated by one-step hot-pressing at 1100 °C and 1150 °C, we found that increasing the temperature by 50 °C can markedly increase the growth rate of the coating as desired, but this increase of temperature generates undesired η carbide (Fe6W6C) at the coating/substrate interface. Based on the inference that Fe atoms are diffusible in tungsten but indiffusible in WC at 1150 °C, we proposed a two-step hot-pressing method to fabricate coatings at 1150 °C without introducing η carbide. The sample was first hot-pressed at 1100 °C for 4 h to prepare a pure WC layer and then hot-pressed at 1150 °C for further carburization. The WC layer prepared at 1100 °C was utilized as a semipermeable film to filter out Fe atoms and allow the diffusion of carbon atoms at 1150 °C. The two-step hot-pressing method worked as desired, and the obtained coating exhibits a distinct gradient microstructure with columnar WC grains. Compared to that of the one-step hot-pressing method at 1100 °C, the total carburization time for obtaining a coating with a saturated hardness of 2400 HV is shortened from 8 h to 6 h. Therefore, the two-step interstitial carburization can be used to efficiently fabricate high-quality and high-performance tungsten carbide coatings.

First-Line Interactive Wound Dressing Update: A Comprehensive Review of the Evidence.

Wound management is a significant and growing issue worldwide. Knowledge of dressing products and clinical expertise in dressing selection are two major components in holistic wound management to ensure evidence-based wound care. With expanding global market of dressing products, there is need to update clinician knowledge of dressing properties in wound care. Optimal wound management depends on accurate patient assessment, wound diagnosis, clinicians’ knowledge of the wound healing process and properties of wound dressings. We conducted a comprehensive review of the physical properties of wound dressing products, including the advantages and disadvantages, indications and contraindications and effectiveness of first-line interactive/bioactive dressing groups commonly used in clinical practice. These include semipermeable films, foams, hydroactives, alginates, hydrofibers, hydrocolloids, and hydrogels. In making decisions regarding dressing product selection, clinicians need to ensure a holistic assessment of patient and wound etiology, and understand dressing properties when making clinical decisions using wound management guidelines to ensure optimal patient outcomes. This review has highlighted there is lack of high quality evidence and the need for future well designed trials.