Irreversible Structural Changes Research Articles

Chemical response of thioaldehydes to compression between magnesium oxide surfaces: A first-principles molecular dynamics study

First-principles molecular dynamics (FPMD) simulations are used to investigate the chemical response of thioaldehyde (MeCHS) to compression between (001) surfaces of magnesium oxide (MgO), with the external load reaching values as high as 20 GPa. The results demonstrate that the application of a load transforms the MeCHS molecules into oligomers through the formation of CS, SS, and CC bonds between MeCHS monomers and through proton transfer. The application of a load facilitates the reactions by decreasing the distance between the reacting molecules. The oligomers bonded to the MgO surface through the formation of CO and SO bonds, involving an oxygen atom in the surface. Proton transfer between the oligomers and the surface was also observed. No reactions were observed to take place between the oligomers and the magnesium atoms. The formation of bonds with the oxygen atoms in the surface led to an increase in the MgO distances within the surfaces, and thus a large disruption of the surface structure. The changes in structure were found to be reversible until 18 GPa, suggesting that the MeCHS oligomers may be effective at inhibiting wear by preventing direct surface-surface contacts without introducing new sources of irreversible changes in the surface structure for a certain range of loads (until 18 GPa). As a whole, the study describes in detail the chemical behavior of MeCHS in response to compression between MgO surfaces. This information could be applied to other molecules containing sulfinyl chemical groups and other metal oxides surfaces.

Structural Changes in Adsorbed Cytochrome c upon Applied Potential Characterized by Neutron Reflectometry.

The structural behavior of an electron-transfer protein, cytochrome c, at the 316L stainless steel electrode/aqueous interface was investigated over a range of applied potentials using neutron reflectometry supported by solution depletion isotherms, X-ray reflectometry, and quartz crystal microbalance measurements. A custom-made electrochemical cell allowed in situ observation of the adsorbed protein across a range of applied potentials; models fitted to the NR data showed a compact inner protein layer at the metal/electrolyte interface and a further thicker but highly diffuse layer that could be removed by rinsing. The overall amount adsorbed was found to be strongly dependent on the applied potential and buffer pH. Subtle but significant changes in the structure of the adsorbed protein layer were seen as the potential was swept between ±0.40 V, reflecting changing attractive/repulsive interactions between the protein's charged side groups and the surface. At greater applied potentials, irreversible changes in the stainless steel film structure were also observed and attributed to deuterium absorption into the metal.

Treatment options for the symptomatic post-meniscectomy knee.

To provide a current review on the evidence for management of the symptomatic meniscus-deficient knee. A literature review was performed detailing the natural history and origin of symptoms in a meniscus-deficient knee, in addition to strategies for non-surgical management, meniscus scaffolds, meniscus allograft transplantation (MAT), isolated cartilage repair, unloading osteotomies, meniscus prosthesis, and joint replacements which were revealed as treatment possibilities. Meniscus deficiency was recognized to lead to an early onset knee osteoarthritis (OA). A subset of patients develop post-meniscectomy syndrome: dull and nagging pain after a short pain-free interval subsequently to meniscectomy, which can be accompanied by transient effusions. Evidence for non-surgical management of post-meniscectomy knee pain is lacking. Two available meniscus scaffolds, indicated for symptomatic segmental meniscus deficiency, show pain relief at mid-term follow-up, and effect on joint preservation is unclear. MAT represents a durable solution for sub/total meniscus deficiency (80% survival at 10years), but it is still considered a temporary solution for post-meniscectomy pain. MAT may also reduce the progression of OA. Isolated cartilage repair without a meniscus reconstruction is commonly performed, but better results were reported with preserved or reconstructed menisci. Osteotomies are used in the combination of misaligned knee and meniscus reconstruction or as pain solution for irreversible unilateral knee structural changes following a meniscectomy. Polycarbonate-urethane medial meniscus prosthesis is currently undergoing clinical trial. Joint replacements should be limited to later stages of post-meniscectomy OA. Post-meniscectomy pain syndrome and post-meniscectomy knee OA are common findings after meniscus resection. Short-term pain relief is provided by non-surgical management, mid-term pain relief by meniscus scaffolds, and long-term relief by MAT, though each has differing indications. In later stages, osteotomies and joint replacements are indicated. IV.

Melt viscosity of nanocrystalline alloys in the model of free volume

In this paper we investigated the viscosity and density of melts Fe73.5Cu1M3Si13,5B9 where M = Nb, Mo, V, Cr. It is shown that the lowest viscosity and activation energy of viscous flow has a melt with Nb, whose atomic radius is the largest. It is shown that the free volume of the melt is higher during cooling compared to heating, and it indicates irreversible structural changes in the melt. The critical temperature Tk = 1770 K is found, above which the activation energy of the viscous flow changes.

HIFU tissue lesion quantification by optical coherence tomography

Heating of tissue by high-intensity focused ultrasound (HIFU) can result in sufficient temperature elevation to cause irreversible changes in the tissue structure. The contiguous volume occupied by these changes, a lesion, and the extent of the tissue changes may be quantified histologically or estimated through techniques such as ultrasonic elastography. We have shown that changes in tissue optical scattering could be used as a proxy to improve sensing and imaging of HIFU lesion formation as an alternative to thermometry. Optical coherence tomography (OCT) is a light-based method appropriate for optically accessible tissues, which we have used to quantify lesion volume, shape, and quality based upon the irreversible changes in optical scattering that occurs with protein denaturation. We have adapted OCT to take into account changes in optical polarization of the tissue, providing sensitivity to changes in the collagen orientation of skin with heating. This technique has potential in detecting antecedents of skin burn during HIFU exposures, thereby increasing safety and reducing treatment times.

The Personalized Approach to the Chronic Central Serous Chorioretinopathy Treatment Based on the Navigated Micropulse Laser Technology

The Purpose— to develop the technology and to evaluate the clinical results of personalized laser treatment of patients with chronic central serous chorioretinopathy (CSC) in a micropulse mode with individual selection of energy parameters on the navigation system Navilas 577s.Patients and Methods. 19 patients (22 eyes) with CSC after micropulse laser treatment were analyzed. The initial best corrected visual acuity (BCVA) was 0.4 to 1.0. According to OCT, the height of the detachment of the neurosensory retina varied from 83 to 259 microns. Retinal sensitivity of the central zone was from 20.2 to 29.7 dB. Before laser treatment were individually selected the optimal energy parameters for each patient. The treatment was performed on a Navilas 577s laser system. The follow-up were 1 and 3 months.Results. 1 month after treatment the positive dynamics of functional and anatomical results in all patients was observed. Mean BCVA increased in the group to 0.81 ± 0.04. The central retinal sensitivity raised on average in the group up to 25.7 ± 0.6 dB. After 3 months, mean BCVA was 0.96 ± 0.02. Mean central retinal sensitivity increased to 26.4 ± 0.57 dB. The study revealed a high correlation between visual acuity and the central retinal thickness (0.72) and medium correlation between foveal retinal sensitivity and central retinal thickness in fovea (0.60), respectively. The correlation among visual acuity, retinal sensitivity and the symptom’s duration of the disease is negative medium (-0.63) and significant (-0.72), respectively.Conclusions. The developed personalized technology of laser treatment of chronic central serous chorioretinopathy with a micropulse mode with an individual selection of energy parameters on the Navilas 577s navigation system showed high clinical efficiency and safety. It has been established that in the course of the longstanding duration of the disease irreversible changes in the chorioretinal complex structure occured, thinning of the foveal photoreceptors layer leading to a decrease in the central retinal sensitivity and visual acuity, which substantiate the necessity for early and maximally functional-saving treatment.

Time course analyses of structural changes in the infrapatellar fat pad and synovial membrane during inflammation-induced persistent pain development in rat knee joint

BackgroundOsteoarthritis (OA) is a common joint disease in aging societies, which is accompanied by chronic inflammation and degeneration of the joint structure. Inflammation of the infrapatellar fat pad (IFP) and synovial membrane (IFP surface) plays essential roles in persistent pain development in patients with OA. To identify the point during the inflammatory process critical for persistent pain development, we performed a time course histological analysis in a rat arthritis model.MethodsWistar rats received single intra-articular injection of monoiodoacetic acid (MIA, 0.2 or 1.0 mg/30 μL) in the right knees or phosphate-buffered saline (PBS, 30 μL) as a control in the left knees. Pain avoidance behaviors (weight-bearing asymmetry and tactile hypersensitivity of the plantar surface of the hind paw) were evaluated on days 0, 1, 3, 5, 7, and 14 after injection. Histological assessments of the knee joint were performed on days 0, 1, 3, 5, and 7 after MIA injection.ResultsWeight-bearing asymmetry was observed along with the onset of acute inflammation in both the low- (0.2 mg) and high-dose (1.0 mg) groups. In the low-dose group, weight-bearing asymmetry was completely reversed on day 10, indicating that joint pain seemed to alleviate between days 7 and 10. In contrast, we observed persistent joint pain after day 10 in the high-dose group. Histological assessments of the high-dose group indicated that the initial sign of inflammatory responses was observed in the perivascular region inside the IFP. Inflammatory cell infiltration from the perivascular region to the parenchymal region of the IFP was observed on day 3 and reached the IFP surface (synovial membrane) on day 7. Extensive fibrosis throughout the IFP was observed between days 5 and 7 after MIA injection.ConclusionOur data indicated that acute joint pain occurs along with the onset of acute inflammatory process. Irreversible structural changes in the IFP, such as extensive fibrosis, are observed prior to persistent pain development. Thus, we consider that this process may play important roles in persistent pain development.

Physicochemical characterization of carbamylated human serum albumin: an in vitro study.

Carbamylation is an ubiquitous process in which cyanate (OCN−) reacts with the N-terminal amino or ε-amino moiety and generates α-carbamyl amino acids and ε-carbamyl-lysine (homocitrulline). The process leads to irreversible changes in protein charge, structure and function. In this study, we have investigated the effect of carbamyl (generated from potassium cyanate) on human serum albumin (HSA) structure and function. The carbamylated-HSA (c-HSA) showed various modifications when examined by UV, fluorescence, FT-IR and far-UV CD spectroscopies. c-HSA exhibited hypochromicity, loss in α-helical content, changes in the amide I and amide II band, etc. Native-PAGE showed increase in the mobility of c-HSA compared to native-HSA. Aggregate(s) formation in c-HSA was detected by thioflavin T dye. The biochemical investigations carried out on c-HSA suggested increase in carbonyl content and decreased binding of TNBS (trinitrobenzenesulphonic acid) and Sakaguchi reagent. The attachment of the carbamyl moiety to HSA was confirmed from MALDI-TOF results. The functional defects in c-HSA were confirmed from the low binding of bilirubin. Taken together, carbamylation of albumin caused changes in the structural and functional properties of HSA. To the best of our knowledge, this is the first report on detailed biophysical characterization of carbamylated-HSA.

Взаимосвязи между неоднородностью распределения механических свойств углей на микро- и наноуровнях и их способностью к внезапным выбросам и разрушению

The outbursts of coal and gas is one of the main coal mining hazards, therefore, for the coal mining industry, studying of mechanisms and predisposing factors for these events is of the utmost importance. It is demonstrated here that the micro/nano scale structure of coal samples is one of predisposing factors for the coal propensity to outburst. The same is related to the coal propensity to crushing and formation of fine powder (dust). The results of micro/nanoindentation experimental studies of heterogeneity of spatial distribution brittleness and mechanical properties of coals at micro/nano scales are presented for samples taken from both hazardous (outburstprone) and non-hazardous strata (packs) of the same coal seam. The experiments were performed on both ‘as received’ coal samples and ones after sorption treatment by dimethylformamide. The latter treatment allowed to partially discharge the internal stresses that exist in the coal samples. The mapping the indentation results enabled us to reveal the actual heterogeneity of distribution of mechanical properties at nanoscale. It has been confirmed that hardness of coals at microand nanoscale is not an informative parameter for characterization of their propensity to destruction. It was established that higher heterogeneity of stiffness could be a reason to formation of multiple cracks at coals after microhardness tests. The part of energy spent for the irreversible changes in the material structure within the total work of indentation is the parameter indicating clearly the propensity of coal samples to crushing and formation of fine powder (dust). Coal samples from the non-hazardous packs have a low ratio of inclusions prone to irreversible changes of the structure and those prone to keeping their structural integrity, while the ratio is about a unity for samples from the hazardous packs. Thus, there is a natural distinction of the mechanical properties between two coal samples having similar origin and rank but different in their proneness to instantaneous outbursts.

COPDGene® 2019: Redefining the Diagnosis of Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD) remains a major cause of morbidity and mortality. Present-day diagnostic criteria are largely based solely on spirometric criteria. Accumulating evidence has identified a substantial number of individuals without spirometric evidence of COPD who suffer from respiratory symptoms and/or increased morbidity and mortality. There is a clear need for an expanded definition of COPD that is linked to physiologic, structural (computed tomography [CT]) and clinical evidence of disease. Using data from the COPD Genetic Epidemiology study (COPDGene®), we hypothesized that an integrated approach that includes environmental exposure, clinical symptoms, chest CT imaging and spirometry better defines disease and captures the likelihood of progression of respiratory obstruction and mortality. Four key disease characteristics - environmental exposure (cigarette smoking), clinical symptoms (dyspnea and/or chronic bronchitis), chest CT imaging abnormalities (emphysema, gas trapping and/or airway wall thickening), and abnormal spirometry - were evaluated in a group of 8784 current and former smokers who were participants in COPDGene® Phase 1. Using these 4 disease characteristics, 8 categories of participants were identified and evaluated for odds of spirometric disease progression (FEV1 > 350 ml loss over 5 years), and the hazard ratio for all-cause mortality was examined. Using smokers without symptoms, CT imaging abnormalities or airflow obstruction as the reference population, individuals were classified as Possible COPD, Probable COPD and Definite COPD. Current Global initiative for obstructive Lung Disease (GOLD) criteria would diagnose 4062 (46%) of the 8784 study participants with COPD. The proposed COPDGene® 2019 diagnostic criteria would add an additional 3144 participants. Under the new criteria, 82% of the 8784 study participants would be diagnosed with Possible, Probable or Definite COPD. These COPD groups showed increased risk of disease progression and mortality. Mortality increased in patients as the number of their COPD characteristics increased, with a maximum hazard ratio for all cause-mortality of 5.18 (95% confidence interval [CI]: 4.15-6.48) in those with all 4 disease characteristics. A substantial portion of smokers with respiratory symptoms and imaging abnormalities do not manifest spirometric obstruction as defined by population normals. These individuals are at significant risk of death and spirometric disease progression. We propose to redefine the diagnosis of COPD through an integrated approach using environmental exposure, clinical symptoms, CT imaging and spirometric criteria. These expanded criteria offer the potential to stimulate both current and future interventions that could slow or halt disease progression in patients before disability or irreversible lung structural changes develop.

Altered fine motor control and manual dexterity in people with cocaine dependence: An observational study.

Cocaine consumption may result in irreversible structural changes in the brain. The long-term effects of cocaine are related to a wide range of deteriorated cognitive functions. This study aimed to examine the fine motor control and hand-function in cocaine users compared to healthy controls. An observational study was conducted. Sociodemographic variables, substance consumption, the Purdue Pegboard and the Jebsen-Taylor Hand-function Test were evaluated bilaterally in 35 participants who were cocaine users and in 35 healthy participants. Differences between sides (dominant and non-dominant hands) and groups were analysed with analysis of variance (ANOVA). The ANOVA revealed significant differences between groups (P<0.001) and between sides (dominant and non-dominant hands) (P=0.005) for the one-hand pin placement subtest of the Purdue Pegboard Test. Also, ANOVA tests showed significant differences between sides, but not groups, for the simulated feeding (P<0.001) and stacking checkers (P<0.001) Jebsen-Taylor subtests. Cocaine user participants exhibited significantly lower scores in bilateral pin placement andrequired more time for the Jebsen-Taylor subtests compared to healthy participants. Cocaine user participants display deficits of fine motor control and some aspects of manual dexterity when compared to healthy controls. These findings show the convenience of incorporating functional rehabilitation by occupational therapists as a key component within the treatment of cocaine users. This study therefore opens a new field of practice for occupational therapy based on the assessment and treatment of motor deficits in the hand and the upper limb of people who consume cocaine.

Determination of internal residual strain induced by cryogenic thermal cycling in partially-crystalized Fe-based metallic glasses

The intrinsic heterogeneities of the metallic glasses can be activated through cryogenic thermal cycling, making irreversible structural changes after the treatment and inducing rejuvenation to the materials. Although the energy rise after cryogenic thermal cycling can be easily determined from calorimetry, the energy change made by the heterogeneities is unknown because of the difficulty in witnessing these heterogeneities. In this paper, we investigated the changes of a typical heterogeneity: the Fe3Si crystallite, embedded in two partially-crystallized Fe-based metallic glasses, and subsequently deduced its influence on the neighbouring glassy matrix. It was found that even in the initial, partially-crystallized alloys, the Fe3Si nanocrystals were under residual expansion. Furthermore, both expansion and contraction can be detected after cryogenic thermal cycling depending on the applied number of cycles. The maximum residual volumetric strain preserved after CTC is in the order of 0.1%. Moreover, the stored energy of both crystals and glasses are calculated and the total energy rise is determined at the order of 5–50 mJ/g. The study of partially-crystallized alloys not only provides a useful model of heterogeneous materials but also reflects the structural change of the glassy phases, making this method attractive in understanding the effects of thermo-mechanical processing on heterogeneities.

Graphite electrode-assisted electroless deposition of palladium in the absence and presence of poly(3,4-ethylenedioxythiophene) coatings

Electroless deposition of Pd in the absence of solute reducing species is studied on pre-reduced non-coated and poly(3,4-ethylenedioxythiophene)(PEDOT)-coated graphite electrodes. PEDOT coatings doped with either dodecyl sulfate (SDS) or polysterene sulfonate (PSS) ions are used in the studies. Electrochemical reductive pre-treatment occurs at negative enough potential to initiate hydrogen reduction at the modified electrodes. Large amounts of deposited Pd significantly exceeding the quantity that is expected to be reduced at the expense of PEDOT re-oxidation alone are found to deposit irrespective of the polymer coating’s thickness. Pd particles are observed to deposit also at bare pre-reduced graphite electrode. It is suggested that molecular hydrogen entrapped during the reductive treatment plays the role of additional reductant for the electroless Pd deposition. SEM, UV–vis and Raman investigations are used to study possible structural changes of PEDOT provoked by the strong reductive treatment. The data give evidence for irreversible structural change in the PEDOT/SDS case resulting in a dense morphology that inhibits ionic transport and supports Pd electroless deposition.

Changes in vibrational properties of compression wood in conifer due to hygrothermal treatment and their relationship with hygrothermal recovery strain

To clarify the mechanism of irreversible dimensional changes due to the hygrothermal treatment of green wood, i.e., the hygrothermal recovery (HTR), the changes in vibrational properties of compression wood and normal wood were measured after hygrothermal treatment at 60 °C, 80 °C, and 100 °C. In addition, the relationship between those changes and HTR strains were discussed. The hygrothermal treatment induced an increase in mechanical loss tangent (tanδ) and decrease in specific dynamic Young’s modulus (E′/ρ). It seems that the changes in vibrational properties due to hygrothermal treatment had a time–temperature dependency: Higher temperatures and longer treatment durations induce larger increases in tanδ and larger decreases in E′/ρ. In contrast to the quenching effect, tanδ and E′/ρ did not recover to their original state even after 60 days of conditioning in water at 20 °C. For compression wood with a large microfibril angle (MFA), there was a clear relationship between the changes in vibrational properties and HTR strains. The tanδ increased and E′/ρ decreased with hygrothermal treatment, corresponding to dimensional changes in the L-direction. This suggests that structural changes in wood components are responsible for HTR. The most likely mechanism for HTR is that the hygrothermal treatment softens the lignin to release locked-in growth stress. Subsequently, irreversible structural changes in lignin induce both the changes in vibrational properties and HTR. For normal wood, because of the small MFA, the structural changes in lignin in the L-direction are possibly restricted by crystalline cellulose. As a result, the relationship between the changes in vibrational properties and HTR is uncertain.

Pathogenesis and diagnostic evaluation of Fuchs' endothelial corneal dystrophy

Following new treatment options for Fuchs' endothelial corneal dystrophy, our understanding of optical and structural changes in the patient's cornea is also starting to improve. To provide an update on clinical evaluation of Fuchs' dystrophy. Standardized approaches to evaluate patients with Fuchs dystrophy in routine practice and research are discussed, accounting for the progressive and partially irreversible structural changes in all corneal layers. Early structural changes in the cornea can be detected before clinical edema becomes visible on slit-lamp exam. Optical limitations resulting from these structural changes can be quantified not only with high-contrast acuity but also with glare or contrast sensitivity tests. Characteristic vision-related limitations of patients with Fuchs dystrophy can, e.g., be assessed with V-FUCHS, a Fuchs dystrophy-specific "Visual Function and Corneal Health Status" instrument for patient-reported outcomes. Clinical grading of Fuchs dystrophy in an edematous and a non-edematous stage is outdated. Better therapy options and our improved understanding of progressive changes in the entire cornea require a standardized assessment of optical and structural changes and patient-reported limitations.

Valuable polar moieties on cereal-derived biochars

The application of biochar (BC) in various fields of engineering, agriculture and environmental protection demands the task-specific adjustment of the surface characteristics of the carbon material. Polar moieties are those elements which distinguish BC from regular carbon black. The knowledge of polar moieties on the surface of the BC is crucial for its application for polar pollutants removal and resistance of nutrients. In this paper several techniques were applied for the verification of polar moieties of crop-derived biochars (both straw and grain) by several techniques (SBET, FTIR, SEM, EDS, pHPZC, elemental analysis). The characterization was also made for washed BCs. It was found that this carbon material is rich in polar moieties, mostly hydroxyl groups and oxides, the latter being washed away together with salts. The high oxygen content decreased after washing (>15%). The values of pHZPC do not differ between the tested BCs, were in the range of 2.2 to 2.0, and were not changed after the washing of BCs. Thanks to the SBET isotherm analysis, irreversible changes in the material structure by water adsorption were proven. The oxygen content in the surface of BCs can be changed after a very brief time of exposition to natural water or soil with no change in the surface charge. Still, the biochar derived from cereals is a useful material for application in environmental protection purposes.

Relationship Between Chordin Like-1 Protein Level and Patients with Pulmonary Arterial Hypertension Disease

Pulmonary arterial hypertension (PAH) is a serene executioner, which can incite irreversible changes in pneumonic vascular structure and point of confinement, developing pulmonary vascular resistance (PVR), right ventricular disappointment, and death. Background and Objective: This study was done at the Cardiac Centre of Al-Sader Medical City Hospital in Al-Najaf Al-Ashraf province for the period from December 2016 to May 2017 to investigate the level of biomarker of Chordinlike-1for patients with pulmonary arterial hypertension as predictive indicators of the disease for detection, diagnosis and early treatment of patients. Materials and Methods: The study was applied on 88 people aged 30-69 years; 67 patients group with pulmonary arterial hypertension (PAH) and 21 healthy group. The group of patients was divided into subgroups based on gender, age, body mass index (BMI), waist circumference, smokers and non-smokers,type of primary and secondary arterial hypertension, types of secondary arterial hypertension, and disease grade. The healthy group was divided according to gender and age. Results The study emerged a significant decrease (p less than 0.05) in the level of Chordin like-1 in the group of pulmonary arterial hypertension patients compared to the healthy group, the female group compared to the males, the age group at the age of 30 to 69, Secondary compared with a primary and the disease grade group was found that sever lower than moderate and mild.While the level of Chordin like-1 in the healthy group divided by gender and age have no significant differences.The study produced that in comparing secondary PAH types, there was a significant decrease (p less than 0.05) in the level of Chordin like-1 for both COPD and Left Heart Disease systolic dysfunction or diastolic dysfunction (LHD sys or dia) compared with Valvular, Congenital, and Pulmonary embolism. While there was no significant difference in the level of Chordin like-1between Valvular, congenital and pulmonary embolism. The study revealed no significant difference in the level of Chordin like-1 for the patients group of pulmonary arterial hypertension divided according to BMI group (normal weight, overweight, obese weight), waist circumference group (70-80 cm, 81-90 cm, 91-100 cm, 101-110 cm, 111-120 cm) and the group of smokers compared to non-smokers. conclusion: The biomarker Chordin like-1consider cautioning sign as a prognostic marker for determination PAH patients.

Surface Modification of Wool Fabric with POSS® Nanomaterial

Wool fabrics, without any surface treatment, can undergo undesirable and irreversible structural changes of wool fiber during washing under heat and mechanical agitation, leading to high shrinkage of wool garments. The traditional method based on polyamide resin can prevent felting and/or shrinkage of wool textiles, but adversely affect the surface hydrophobicity. In the present study, a treatment solution was developed based on TriSilanolIsooctyl POSS® and 3- mercaptopropyl trimethoxysilane, which created wool surface with increased hydrophobicity and highly resistant to shrinkage or felting, as measured after 3×5A wash cycles (equivalent to 24 domestic washes). After the treatment, the wool fabric appeared to be superhydrophobic with a water contact angle of above 150°, compared to the untreated fabric. The treatment has marginal effect on mechanical performance as observed in tensile properties. Scanning electron microscopic images revealed a coating of POSS® on the wool surface. The dyeing of untreated and treated fabrics appeared to be uniform to the naked eye, though spectrophotometric analysis indicated a difference in the extent of dyeing performance. This research showed that POSS®-based treatment is a potentially effective approach for developing shrink-resistant wool textiles with enhanced surface hydrophobicity, in contrast to traditional chlorine/polyamide resin treatment.

Influence of Zr dopant on microstructural and electrochemical properties of LiCoO2 thin film cathodes by RF sputtering

LiCoO2 thin film cathodes have been well established in Li-ion rechargeable batteries, however, its useful capacity hardly exceeds 50% of the theoretical value. Irreversible structural changes will occur upon exchange of Li ions i.e. >0.5 per unit formula limit, during intercalation/deintercalation reactions. Reportedly, lattice doping phenomenon has noticed an improvement in cyclability of LiCoO2. In this work, the influence of Zr doping on microstructural and electrochemical properties of RF magnetron sputtered LiCoO2 thin film cathodes have been presented. A series of LiZrxCo1−xO2 thin films have been deposited on Au/Ti/SiO2/Si (100) substrates using a Zr–LiCoO2 mosaic target. All the films were deposited at optimized processing conditions. XRD and Raman spectroscopy measurements confirmed the hexagonal layered structure with R3¯m symmetry for Zr doped LiCoO2 film cathodes. The AFM reveals the estimated average grain size is around 50 nm. The cyclic voltammetry studies for these cathodes exhibit narrow potential peak separation of 24 mV and resulting highest diffusion coefficient (D¯Li) of about 1.8 × 10−11 cm2 s−1, respectively. These films exhibited a highest initial discharge capacity of 64.4 μA h cm−2 μm−1 with a capacity retention of 98.5% even after 25 cycles. In non-aqueous region, the cell exhibited an initial discharge capacity of about 65 μA h cm−2 μm−1 with good cycling stability even after 80 cycles, and is observed to be the more promising cathode candidate than the pristine LiCoO2 films.

Electrochemical potassium/lithium-ion intercalation into TiSe2: Kinetics and mechanism

As one promising candidate for next-generation energy storage systems, K-ion batteries (KIBs) attract increasing research attention due to the element abundance, low cost, and competent energy density as compared to Li-ion batteries. However, developing practical electrode materials in particular cathodes for KIBs is still in its infancy, and the related reaction mechanisms of the electrode materials are far from completely understood. In this work, TiSe2 was, for the first time, investigated as an intercalated-type electrode for potassium storage due to its large interlayer space. The potassiation/depotassiation reaction mechanism was unraveled based on the analysis of in-situ X-ray diffraction (XRD), ex-situ X-ray photoelectron spectroscopy (XPS), and ex-situ transmission electron microscope (TEM) results. Meanwhile, the lithium storage behaviour and the relevant lithiation/delithiation reaction mechanism were also studied in detail. The results reveal that K+ show lower diffusion coefficient and hence more sluggish intercalation reaction kinetics as compared with Li+. In addition, the intercalation reaction of K+ would cause irreversible structure changes, while the intercalation reaction is fully reversible for Li+ counterpart.