Detergent Solution Research Articles

Developing Biodegradable Liquid Soap Detergent Solution for Domestic and Industrial Applications

Liquid soap solution is a versatile and widely used personal care product, offers a convenient and hygienic way to maintain cleanliness. This abstract summarizes the key aspects of liquid soap. This is soap in a liquid form. Generally liquid detergent are used with soft water. Where as in case of detergent powder cloths can be washed in hard as well as soft water. Liquid soap for Industrial use as well as house hold use can be manufactured by employing a very simple process. A typical formula for 1 kg of product is given below. This is called 25% liquid soap, since the acid slurry (active matter) used is 25% For lesser Concentration the quantity of acid slurry may be decreased correspondingly. The main aim of this project is to develop the liquid soap solution.

How to isolate channel-forming membrane proteins using the E. coli expression system.

The recombinant expression, isolation and characterization of pore-forming proteins is one of the most commonly used strategies for understanding the permeability properties of the biological membrane into which they are embedded. This protocol describes how to quantify the expression of your protein of interest and use this information to optimize its production using the Escherichia coli strain BL21Gold(de3)ΔABCF. It explains with a step-by-step approach how to separate the bacterial compartments according to their solubility and how to extract your protein of interest in its native conformation using detergent solutions. Finally, it describes how to improve its purity via ion-exchange chromatography and insert the purified porins into outer membrane vesicles, from which they can be copurified. The protocol is simpler and less empirical than those described for most channel-forming membrane proteins and also provides a solid foundation for the isolation of soluble proteins. Several parameters can be optimized on a case-by-case basis: expression time and temperature, concentration of the inducer, nature and concentration of the detergent, incubation time and temperature, pH and ionic strength of the purification buffers. This protocol is effective with prokaryotic channel-forming membrane proteins and can be employed for the production of pore-forming proteins from chloroplasts, mitochondria or eukaryotes in general. With minor optimization, this protocol can be adapted for the isolation of receptors, carrier, pumps or any other membrane-active proteins.

Regional use of extracellular microvesicles of mesenchymal stromal cells in acute necrotizing pancreatitis in an experiment

Background. The significance of the problem of treatment of acute pancreatitis is due to an increase in the incidence with an increase in the number of necrotizing forms, accompanied by a high incidence of severe complications and high mortality.Objective. To identify the impact of regionally used extracellular microvesicles of mesenchymal stromal cells on the endogenous intoxication markers in acute necrotizing pancreatitis in the experiment.Material and methods. Acute pancreatitis was induced by the introduction of a 0.3 ml of 5% solution of non-ionic polyethylene glycol octylphenol ether detergent into the caudal part of the rat pancreas. The study was conducted on 42 adult Wistar rats, which were randomly divided into 4 groups. Group I (n=6) included intact animals, Group II (control group) (n=12) included rats with pancreatitis without treatment, Group III (n=12) consisted of rats with pancreatitis treated with analgesia + infusions of 0.9% sodium chloride solution (saline), Group IV (n=12) included rats with pancreatitis treated with analgesia+ saline infusions + regional application of extracellular microvesicles of mesenchymal stromal cells. Cells were obtained from the bone marrow of healthy animals. Microvesicles were obtained by differential centrifugation under sterile conditions. Microvesicles were administered one day after the pancreatitis induction through the catheter installed into the pathologically altered part of the pancreas. The dose of microvesicles was calculated as equivalent to (derived from) 1 million mesenchymal stromal cells. The hematological parameters, markers of the systemic manifestation of the pathological process (alpha-amylase, aspartate aminotransferase, alanine aminotransferase), the endogenous intoxication markers (lipid peroxidation activity, nitric oxide level), the systemic inflammatory response markers (tumor necrosis factor-alpha, interleukin-6) were studied on the 3rd and 7th day from the start of disease modeling.Results. Regional use of extracellular microvesicles of mesenchymal stromal cells in the treatment of acute experimental necrotizing pancreatitis at an early stage helped to normalize the level of blood platelets, reduce enzymeemia, elements of endogenous intoxication (interleukin-6, tumor necrosis factor-alpha), and the nitric oxide level.Conclusion. The early application of extracellular microvesicles of mesenchymal stromal cells in the treatment of acute necrotizing pancreatitis in an experiment has a positive effect on parameters, which are key links of pathogenesis and leading markers of this disease severity.

Multifunctional Amino‐Boranes Isomer Room‐Temperature Phosphorescent Material: Multi‐Substrate Multicolor Luminescence, Multi‐Level Anti‐Counterfeiting, Light‐Controlled Data Erasing/Writing, Data Logic Operation, and High Anti‐Laundry Detergent Performance

AbstractSignificant advances are made in understanding the structure‐property relationship in room‐temperature phosphorescence (RTP) materials. For example, intramolecular charge transfer (ICT) structural molecules based on electron donors(D) and electron acceptors(A) are an efficient method to achieve RTP. However, the ability to precisely regulate the singlet‐triplet energy gap (ΔEST) through molecular design to control RTP emissions remains constrained. Herein, a group of 4BN‐NP and 5BN‐NP isomers is reported with D and A position isomerization, where 4BN‐NP exhibits a photo‐induced orange afterglow phenomenon in PMMA. Calculations show that the spin‐orbit coupling (SOC) value of 4BN‐NP is greater compared to 5BN‐NP and the intersystem crossing (ISC) channel is more efficient, resulting in a smaller ΔEST value for 4BN‐NP. This indicates that the short ICT channel is more conducive to inducing phosphorescence emission. In addition, compound 4BN‐NP co‐doped with red fluorescent dyes (RhB, Rh6G, and RBNN) in PMMA produces phosphorescence resonance energy transfer (PRET), inducing red afterglow emission. Surprisingly, light‐activated yellow RTP can be obtained by attaching 4BN‐NP with polymethyl methacrylate (PMMA) to nylon filaments, and its phosphorescence intensity does not diminish even when it is immersed in water containing detergent solution, thus expanding the prospects of its application in textile encryption.

Biochemical and immunomodulatory insights of extracellular matrix from decellularized human whole cervix: recellularization and in vivo ECM remodeling interplay

Extracellular matrix (ECM) rich whole organ bio-scaffolds, preserving structural integrity and essential growth factors, has potential towards regeneration and reconstruction. Women with cervical anomalies or trauma can benefit from clinical cervicovaginal repair using constructs rich in site specific ECM. In this study, complete human cervix decellularization was achieved using a modified perfusion-based stir bench top decellularization method. This was followed by physico-chemical processes including perfusion of ionic agents, enzymatic treatment and washing using detergent solutions for a duration of 10–12 d. Histopathological analysis, as well as DNA quantification confirmed the efficacy of the decellularization process. Tissue ultrastructure integrity was preserved and the same was validated via scanning electron microscopy and transmission electron microscopy studies. Biochemical analysis and structural characterizations like Fourier transform infrared, Raman spectroscopy of decellularized tissues demonstrated preservation of important proteins, crucial growth factors, collagen, and glycosaminoglycans. In vitro studies, using THP-1 and human umbilical vein endothelial cell (HUVEC) cells, demonstrated macrophage polarization from M1 to M2 and vascular functional genes enhancement, respectively, when treated with decellularized human cervical matrix (DHCp). Crosslinked DHC scaffolds were recellularized with site specific human cervical epithelial cells and HUVEC, showing non-cytotoxic cell viability and enhanced proliferation. Furthermore, DHC scaffolds showed immunomodulatory effects in vivo on small rodent model via upregulation of M2 macrophage genes as compared to decellularized rat cervix matrix scaffolds (DRC). DHC scaffolds underwent neo-vascularization followed by ECM remodeling with enhanced tissue integration.

Anticorrosion Additive for Aqueous Solutions of Detergents Based on Natural Raw Materials

Anticorrosion Additive for Aqueous Solutions of Detergents Based on Natural Raw Materials

Bi-layered oil encapsulates formed by polydopamine-supported in situ complex coacervation: Investigation of structure formation and sustained release performance

In polydopamine (PDA)-supported in situ complex coacervation, PDA is pre-coated onto emulsion droplets, and further applied as an interlayer to support the interfacial immobilization of coacervates biopolymers. In the current research, the stepwise immobilization of gelatin (GE) and gum Arabic (GA) onto PDA layer is monitored to in-depth investigate the mechanism of PDA layer as coating material and functional substrates. GE and GA were applied as adsorbates, with different forms of PDA (spherical shell, planar solid, and nanoparticles) as substrates. Real-time observations of the binding steps were performed using quartz crystal monitor with dissipation (QCM-D) and isothermal titration calorimetry (ITC). Meanwhile, using PDA-supported coacervates as encapsulating material, sustained release of essential oil volatiles was also evaluated, either dispersed in detergent solution or freeze dried in open air. The anti-oxidation performance was determined by measuring the absorbance of lipid hydroperoxide using UV spectrophotometer. The results revealed that PDA enabled synergistic immobilization of biopolymers through chemical bonding and adhesive force during the processing of in situ complex coacervation, thus enhanced protection of core compounds with two-stage releasing kinetics and prevented hyperoxidation. Also, PDA-based colloids and substrates also exhibit controllable conformation characteristic, provide a promising prospect as versatile intermediate functional biomaterials for encapsulation.

Application of mesenchymal stem cells in severe acute experimental pancreatitis

Background. The significance of the problem of acute pancreatitis is due to an increase in the incidence with an increase in the number of common forms of pancreatic necrosis, accompanied by a high incidence of severe complications.Aim. To determine the effect of regional application of mesenchymal stromal cells on the systemic manifestations of severe acute experimental pancreatitis.Material and methods. This experimental study was carried out on 42 adults Wistar rats. Acute pancreatitis was induced by administering 0.3 ml of 5% solution of non-ionic polyethylene glycol octylphenol ether detergent into the caudal part of the pancreas. The animals were randomly divided into 4 groups: Group I (n=6) consisting of intact animals, Group II (control group) (n=12) of rats with untreated pancreatitis, Group III (n=12) of rats with pancreatitis treated: anesthesia + infusions of 0.9% sodium chloride solution (saline), and Group IV (n=12) of rats with pancreatitis treated: anesthesia + infusions of saline + regional application of mesenchymal stromal cells. Animals were taken out of the experiment by euthanasia on the 3rd and 7th day. The hematological parameters, markers of systemic manifestation of the pathological process (pancreatic amylase, aspartate aminotransferase, alanine aminotransferase, urea, creatinine), markers of endogenous intoxication (lipid peroxidation activity, nitric oxide level), markers of systemic inflammatory response (C-reactive protein, tumour necrosis factor-alpha, interleukin-6) have been evaluated.Results. The application of mesenchymal stromal cells in the early stages of acute pancreatitis made a favourable effect on the platelet count, the level of glycemia, helped to reduce the content of endogenous intoxication elements (malonic dialdehyde, nitric oxide) and of those of the systemic inflammatory response (interleukin-6, tumor necrosis factor-α, C-reactive protein), which are key links in the pathogenesis of severe acute pancreatitis.Conclusion. Comparison of different treatment regimens for acute experimental pancreatitis has shown that the early use of mesenchymal stromal cells has a systemic positive effect and confirms the therapeutic efficacy of the method in the treatment of this disease.

Detection and quantification of etomidate and metomidate in human hairs by ultraperformance liquid chromatography with triple quadrupole mass spectrometry (UPLC-MS/MS).

Intravenous narcotic agents, such as etomidate and metomidate, has been widely spread and abused in the world, including in Korea and China; thus, it is important to establish validated and sensitive analytical method for these compounds. Human hair as a biological sample has various advantages, including a wide detection window of drugs, compared to other typical samples, such as urine and blood in investigation. The purpose of this communication is to develop a reliable and useful method for the simultaneous detection and quantification of etomidate and metomidate in human hair samples by ultraperformance liquid chromatography combined with triple quadrupole mass spectrometry (UPLC-MS/MS), and to apply it for authentic samples in abuse cases. The hair samples were washed with a detergent solution, followed by with water and acetone. After drying, they were cut into approximately 2mm sections and then ground to powder by a low-temperature grinder. The 20mg of hair powder plus internal standard in 1mL of methanol was vortexed and then centrifuged to obtain the supernatant layer, followed by subjecting to analysis. The coefficient of determination (r2) values of the calibration curves of etomidate and metomidate in the hair samples were both more than 0.99 in the range of 1-500ng/mg and 1-500pg/mg, respectively. The limits of detection and lower limits of quantification were 0.5 and 1pg/mg, respectively, for the both target compounds. Other tested validation data were all satisfactory. Etomidate and metomidate could be detected in the all hair samples and cigarette oil, which were seized by the police. The concentrations of etomidate and metomidate obtained from 10 samples from suspects were 5.48-45.7ng/mg and 3.60-377pg/mg, respectively. The concentrations of etomidate and metomidate in the cigarette oil were 95.8μg/mg and 2.8μg/mg, respectively. In this study, a simple and reliable analytical method for etomidate and metomidate in the human hair has been established. To the best of our knowledge, this is the first report to establish a method for the simultaneous detection and quantification of etomidate and metomidate in the human hair, and to apply it to authentic samples seized in authentic cases.

Immediate reuse of patch-clamp pipettes after ultrasonic cleaning

The patch-clamp technique has revolutionized neurophysiology by allowing to study single neuronal excitability, synaptic connectivity, morphology, and the transcriptomic profile. However, the throughput in recordings is limited because of the manual replacement of patch-pipettes after each attempt which are often also unsuccessful. This has been overcome by automated cleaning the tips in detergent solutions, allowing to reuse the pipette for further recordings. Here, we developed a novel method of automated cleaning by sonicating the tips within the bath solution wherein the cells are placed, reducing the risk of contaminating the bath solution or internal solution of the recording pipette by any detergent and avoiding the necessity of a separate chamber for cleaning. We showed that the patch-pipettes can be used consecutively at least ten times and that the cleaning process does not negatively impact neither the brain slices nor other patched neurons. This method, combined with automated patch-clamp, highly improves the throughput for single and especially multiple recordings.

Reversible thermochromic fibers with excellent elasticity and hydrophobicity for wearable temperature sensors.

Color-changing fibers, which can intuitively convey information to the human eye, can be used to facilely add functionality to various types of clothing. However, they are often expensive and complex, and can suffer from low durability. Therefore, in this study, we developed highly elastic and hydrophobic thermochromic fibers as wearable temperature sensors using a simple method that does not require an electric current. A thermochromic pigment was embedded inside and outside hydrophobic silica aerogel particles, following which the thermochromic aerogel was fixed to highly elastic spandex fibers using polydimethylsiloxane as a flexible binder. In particular, multi-strand spandex fibers were used instead of single strands, resulting in the thermochromic aerogels penetrating the inside of the strands upon their expansion by solvent swelling. During drying, the thermochromic aerogel adhered more tightly to the fibers by compressing the strands. The thermochromic fiber was purple at room temperature (25 °C), but exhibited a two-stage color change to blue and then white as the temperature increased to 37 °C. In addition, even after 100 cycles of tension-contraction at 200%, the thermochromic aerogel did not detach and was strongly attached to the fiber. Additionally, it was confirmed that color change due to temperature was stable even after exposure to 1 wt% NaCl (artificial sweat) and 0.1 wt% detergent solutions. The developed thermochromic fiber therefore exhibited excellent elasticity and hydrophobicity, and is expected to be widely utilized as an economical wearable temperature sensor as it does not require electrical devices.

Laundry Waste Filtration Performance at Ultra Low Pressure

Laundry waste pollution can be handled through the development of filtration with the Gravity Driven Membrane (GDM) method which is designed to follow the criteria of the unloading module design, low polarization control, cost-effective, separation process using thrust in the form of a strong pressure difference. This type of research was an experiment. This study aimed to determine the performance of laundry waste filtration at ultra low pressure using clean water permeability and detergent solution as standardization. GDM filtration performance was tested by measuring permeability at a pressure of 1-10 kPa with two repetitions and long-term filtration for 35 days at a pressure of 6 kPa, the sample was replaced every 7 days without membrane washing. The results showed that as the pressure increases and the filtration time increases, the permeability of laundry waste decreases, this phenomenon is caused by compaction and clogging of the membrane pores (fouling). Permeability decreases from 1 kPa to 10 kPa pressure, the same applies to repetition. Long-term filtration permeability decreased significantly from the first day to the eighth day of filtration respectively 707.9 , 151.7, 115.8, 104.4, 97.5, 107.1, 102.1 and 103. 0 L/m2.hour.bar. On the 9th to 35th day the decrease was stable, this was caused by fouling on the membrane which resulted in the membrane becoming more compact and saturated. GDM filtration can take place for 35 days without washing the membrane with a permeability from the first day of 707.9 and the 35th day of 5.5 L/m2.hour.bar. The best performance of this filtration process lasts until the 9th day

Fiber-based hydrophobic and stretchable UV-photochromic textile

Wearable sensors composed of fabric have attracted considerable research interest as they can detect various environmental factors that affect the human body, such as ultraviolet (UV) radiation, temperature, and humidity. Among these sensors, color-conversion sensors are especially valuable as they can provide a visual representation of data without the need for additional electrical devices. For a sensor to be used on the human body, it must maintain its sensing capabilities even when exposed to solutions such as rainwater, sweat, and various cleansing liquids or when subjected to mechanical deformation. Therefore, this study was aimed at fabricating a UV-photochromic fiber that can maintain its color-change reaction to UV light even when exposed to chemical and physical stressors. To this end, UV-photochromic pigment was infused into porous and hydrophobic silica aerogels to create UV-photochromic aerogels, which were then placed between the inner strands of spandex fibers. During the drying process, the UV-photochromic aerogels adhered firmly to the spandex strands and were not separated even when the fibers were stretched and contracted up to 100 times under 200% tensile conditions. The resulting UV-photochromic fibers initially appeared white but transformed to magenta when exposed to UV light. This color change persisted through seven repeated on–off cycles of UV light. Moreover, the hydrophobic nature of the fibers ensured that the color-change reactivity remained stable even under exposure to water, artificial sweat, and detergent solutions. Overall, the proposed UV-photochromic fibers, with enhanced reversibility, stability, and reliability, can promote the commercialization of wearable-based colorimetric sensors.

The mycobacterium lipid transporter MmpL3 is dimeric in detergent solution, SMALPs and reconstituted nanodiscs.

The mycobacterial membrane protein large 3 (MmpL3) transports key precursor lipids to the outer membrane of Mycobacterium species. Multiple structures of MmpL3 from both M. tuberculosis and M. smegmatis in various conformational states indicate that the protein is both structurally and functionally monomeric. However, most other resistance, nodulation and cell division (RND) transporters structurally characterised to date are either dimeric or trimeric. Here we present an in depth biophysical and computational analysis revealing that MmpL3 from M. smegmatis exists as a dimer in a variety of membrane mimetic systems (SMALPs, detergent-based solution and nanodiscs). Sucrose gradient separation of MmpL3 populations from M. smegmatis, reconstituted into nanodiscs, identified monomeric and dimeric populations of the protein using laser induced liquid bead ion desorption (LILBID), a native mass spectrometry technique. Preliminary cryo-EM analysis confirmed that MmpL3 forms physiological dimers. Untargeted lipidomics experiments on membrane protein co-purified lipids revealed PE and PG lipid classes were predominant. Molecular dynamics (MD) simulations, in the presence of physiologically-relevant lipid compositions revealed the likely dimer interface.

Derivation and Characterization of Novel Cytocompatible Decellularized Tissue Scaffold for Myoblast Growth and Differentiation.

The selection of an appropriate scaffold is imperative for the successful development of alternative animal protein in the form of cultured meat or lab-grown meat. Decellularized tissues have been suggested as a potential scaffold for cultured meat production owing to their capacity to support an optimal environment and niche conducive to cell proliferation and growth. This approach facilitates the systematic development of 3D tissues in the laboratory. Decellularized scaffold biomaterials have characteristics of high biocompatibility, biodegradation, and various bioactivities, which could potentially address the limitations associated with synthetic bio-scaffold materials. The present study involved the derivation and characterization of a decellularized scaffold from mushroom tissue following subsequent assessment of the scaffold's capacity to support myogenic differentiation. Mushroom sections were soaked in nuclease and detergent solution for 4 days. Furthermore, decellularization was confirmed by histology and DAPI staining, which showed the removal of cellular components and nuclei. Myoblast cells were seeded onto decellularized tissue, which exhibited excellent cytocompatibility and promoted myogenic growth and differentiation. The study's findings can serve as a foreground for the generation of an edible and natural scaffold for producing a safe and disease-free source of alternative animal protein, potentially reducing the burden on the health sector caused by conventional animal protein production and consumption.

A comparison of maceration methods for the preparation of infant skeletal remains for forensic anthropological analysis

Very little literature currently exists prescribing which maceration method to use when preparing infant human remains, resulting in bone quality that is suitable for forensic anthropological analysis. The aim of the study was to test five maceration methods to determine which is most suitable for infant remains for forensic anthropological analysis. The sample included five neonate pig carcasses (Sus scrofa domesticus), ranging between one to three days old. Five maceration methods were tested on the pig carcasses (one pig per maceration method) to determine their effectiveness. The methods included invertebrate maceration by meal worms, chemical maceration by bleach, chemical maceration by borax solution, enzymatic maceration by laundry detergent and sodium carbonate solution, and chemical maceration by sodium hypochlorite. A scoring method was created to assess the effectiveness of each maceration method. Invertebrate maceration and chemical maceration using bleach were the least successful methods of maceration (total maceration score = 8 respectively). Chemical maceration using borax and chemical maceration using sodium hypochlorite achieved complete maceration of the skeletal remains; however, they both resulted in artifacts that are unsuitable for forensic analysis (total maceration score = 14 respectively). Enzymatic maceration using laundry detergent and sodium carbonate was the most successful method (total maceration score = 17). The detergent technique subsequently successfully macerated all five sets of infant human remains. This study has validated that the enzymatic maceration technique using laundry detergent and sodium carbonate can be used to effectively macerate the remains of infant skeletal remains for forensic anthropological analysis.

Lipidomics Reveals the Effects of Detergents on Skin Surface Lipids in Young Adults

Background: Detergent is a chemical product commonly used in people’s daily life. Contact with detergent solutions can damage the human skin barrier and cause skin diseases. Skin surface lipids (SSLs) play a decisive role in skin barrier function. This study aimed to observe the changes of SSLs in young adults after exposure to detergent solutions to explore the underlying mechanism of skin barrier function damage. Methods: A self-controlled study on youth adults was conducted in Zhengzhou, China, in November 2020. The study lasted for a total of 1 week, and skin barrier function was assessed by trans-epidermal water loss (TEWL) values. The changes of SSLs before and after exposure to the detergent with subjects were measured using ultra-performance liquid chromatography quadrupole time of flight mass spectrometry. Results: The skin barrier function of subjects’ hands was impaired after exposure to detergent (TEWL value increased, p < 0.001). A total of 520 SSLs were detected, divided into 6 main categories. The average relative abundance of these 6 major lipids decreased after exposure. Sphingolipids (mainly ceramides), free fatty acids (mainly long-chain fatty acids), cholesterol lipids, and glycerophospholipids are the most severely damaged lipids. Conclusion: Detergent solutions can damage the skin barrier function and SSLs of young hands; interventions targeting SSLs to eliminate detergent damage to human skin may be of value.

Monitoring of Pest and Natural Enemies Diversity at The Edge and Central of Corn Crops with Pitfall Traps

Efforts to determine the presence and population of pests and natural enemies can be carried out through effective monitoring activities using certain traps. At the beginning of corn growth, plants are still susceptible to plant pests and disease organisms (OPT) on the soil surface. Therefore, pitfall can be used to monitor the insects. Research consisted of two treatments, the location of pitfall traps on the edge and middle of the cornfield. The research area measures 11 x 14 m with 24 pitfalls for each treatment. The pitfall trap was installed using a 220 mL plastic glass buried deep and filled with a detergent solution at a dose of 23 grams in 25 liters of water and left for 24 hours. All insects obtained and identified at the family level and their numbers populations. Data were analyzed using the T-Test. There are seven families whose role as pests are Acrididae, Gryllidae, Carabidae, Agromyzidae, Termitidae, Cicadellidae, and Blattidae. There are four families as natural enemies, namely Libellulidae, Lycosidae, Araneidae, and Formicidae. The percentage of pests and natural enemies on the edge of the field is 33.57% and 66.43%. In addition, the pest percentage in the middle of the cornfield is 28.69%, while natural enemies are 71.31%.

Cryo-EM structures of LHCII in photo-active and photo-protecting states reveal allosteric regulation of light harvesting and excess energy dissipation.

The major light-harvesting complex of photosystem II (LHCII) has a dual regulatory function in a process called non-photochemical quenching to avoid the formation of reactive oxygen. LHCII undergoes reversible conformation transitions to switch between a light-harvesting state for excited-state energy transfer and an energy-quenching state for dissipating excess energy under full sunshine. Here we report cryo-electron microscopy structures of LHCII in membrane nanodiscs, which mimic in vivo LHCII, and in detergent solution at pH 7.8 and 5.4, respectively. We found that, under low pH conditions, the salt bridges at the lumenal side of LHCII are broken, accompanied by the formation of two local α-helices on the lumen side. The formation of α-helices in turn triggers allosterically global protein conformational change, resulting in a smaller crossing angle between transmembrane helices. The fluorescence decay rates corresponding to different conformational states follow the Dexter energy transfer mechanism with a characteristic transition distance of 5.6 Å between Lut1 and Chl612. The experimental observations are consistent with the computed electronic coupling strengths using multistate density function theory.

Assessment of the barrier function of canine skin after repeated decontamination

Working canines often deploy into environments with unknown chemical and biological contaminants. Disaster canines may be deployed for lengthy periods and thus may experience longer periods of environmental exposure with greater possibility for contaminant contact. The skin functions as a protective barrier to prevent potential contaminants and pathogens from entering the system. To mitigate the effects of contaminant exposure to canine and handler, daily decontamination efforts are often required. However, little data exist on the effect of repeated decontamination to the canine skin. The objective of this study was to identify changes to the skin associated with a 14-day serial decontamination program. Labrador retrievers (n = 8) were decontaminated daily using a dish detergent solution (1:8, detergent:water). Skin measurements were collected weekly for pH, trans-epidermal water loss (TEWL), sebum, and moisture. Additionally, visual assessments were recorded for skin health, coat condition, and dander scores (back and body). Statistical tests were conducted with SAS (version 9.4) with measured data analyzed using a PROC GLM two-way ANOVA and visual assessments analyzed using the PROC FREQ Chi-square test. Significance was set at 5% for all tests. Repeated decontamination significantly increased TEWL (P < 0.0001) through day 16 with values returning to baseline by day 49. Sebum was also affected by repeated, daily decontamination efforts (P = 0.0387). However, higher sebum values are seen later in the study, on day 42, and may be associated with recovery. In contrast, moisture content (P = 0.3842) and pH (P = 0.7462) were unaffected by repeated decontamination. Interestingly, dander scores assessed on the back were worsened by repeated decontamination (P = 0.0222), but dander scores assessed across the whole body were unaffected (P = 0.1804). Coat shine and softness were unaffected by decontamination (P = 0.1156 and P = 0.3418, respectively). Overall coat condition remained unchanged as a result of repeated decontamination efforts (P = 0.9466). These data demonstrate negative impacts to the skin barrier associated with daily decontamination, which may increase the risk of inflammation and skin damage (Ananthapadmanabhan et al., 2004; Vidémont et al., 2012). Future work should include investigations into safer methods of decontamination to mitigate these risks.