Intravenous Tenecteplase vs Alteplase Before Mechanical Thrombectomy in Patients with Large Vessel Occlusion Stroke. A Systematic Review & Meta-analysis.

BACKGROUND: The use of Alteplase (ALT) bridging to endovascular mechanical thrombectomy (MT) has become the standard approach in treating patients with large vessel stroke (LVO). Tenecteplase (TNK) has emerged as an equivalent fibrinolytic agent in treating ischemic stroke due to its remarkable pharmacological characteristics. This study aims to compare the use of intravenous TNK to ALT bridging to MT in patients with LVO. METHODS: We included observational and randomized controlled trials of patients with LVO who received bridging TNK vs ALT before undergoing MT. Efficacy outcomes included functional independence which is indicated by a modified Rankin Scale [mRS] score of 0-2 at 90 days. Radiological outcomes included the rate of successful recanalization post-MT (Modified Treatment in Cerebral Ischemia [mTICI] score of 2b/3), and the rate of pre-MT recanalization, indicated by an mTICI of 2b/3 at the first angiographic assessment. The all-cause mortality at 90 days (mRS of 6) was considered the primary safety outcome, while the symptomatic intracranial hemorrhage (sICH) rate was reported as an adverse event. RESULTS: We identified 5 comparative observational studies and 1 randomized controlled trial, totaling 4,186 patients with LVO. The crude odds ratio for post-MT recanalization in patients with LVO who received TNK was comparable to those who received ALT (OR = 1.14; 95% CI 0.57-2.27, I² = 54%). The rate of pre-MT recanalization was significantly higher in those given TNK as a bridging therapy to MT compared to those who received ALT (OR = 2.66; 95% CI 1.60-4.41, I² = 0%; P = <0.001). Functional independence at 90 days was not significantly different between patients with stroke who received TNK and those who were given ALT before MT (OR = 1.41; 95% CI 0.84-2.35; I² = 45%). The 90-day mortality was similar between patients with LVO who received TNK and those who were given ALT prior to undergoing MT (OR = 0.74; 95% CI 0.46-1.21; I² = 0%). CONCLUSIONS: Patients with LVO who received TNK as the primary fibrinolytic agent bridging to MT demonstrated higher rates of pre-MT recanalization, similar rates in post-MT recanalization, and equivalent functional independence outcomes at 90 days compared to those who received ALT. The administration of TNK before MT showed comparable results in the 90-day all-cause mortality rate compared to those who received ALT. These results warrant further trials for TNK to be used as a superior fibrinolytic agent to ALT in LVO-MT candidates.

Thermal Sensing of Photo-Activated Dental Resin Composites Using Infrared Thermography.

OBJECTIVE: The goal of this study was to compare the pulp temperature increase during light curing of different composite thicknesses in deep class I cavities using two thermal sensing tools. METHODOLOGY: Round occlusal class I cavities with a remaining dentin thickness (RDT) of 1 mm from the cavity floor were performed on 15 extracted sound molars. Samples were divided into three groups (n = 5). In group A, cavities were restored using the Filtek Z350 XT conventional composite through the incremental filling technique, whereas group B cavities were restored using the Filtek Bulk-Fill flowable composite through the bulk-fill technique. Specimens of the Filtek Bulk-Fill flowable composite using the incremental filling technique were used to restore cavities in group C. An infrared thermal camera (IRT; Flir, Wilsonville, OR, USA) and K-type thermocouple (Perfect Prime TC0520, New York, NY, USA) were used to measure the heat generated during composite photo-polymerization. RESULTS: There were no significant differences within the same group using either the thermocouple or IRT (p > 0.05). One-way ANOVA showed no significant differences between groups A and C (p > 0.05), whereas group B was significantly different from groups A and C with each sensing tool (p < 0.05). CONCLUSION: IRT and thermocouple heat readings were comparable. Based on the current findings, the bulk-fill technique resulted in the lowest heat generation among the groups. Therefore, increasing the light-curing time and the number of composite increments was directly correlated with increases in intra-pulpal temperature.

A Giant Eyelid Molluscum Contagiosum Revealing an HIV Infection: A Case Report and Literature Review.

Molluscum contagiosum (MC) is a common benign cutaneous viral infection. It can affect any part of the skin with a high propensity for facial skin, especially in human immunodeficiency virus (HIV) patients with low CD4 count. We report a case of a 16-year-old female patient who presented with a giant isolated right upper eyelid MC lesion that served as the first clinical indicator of her HIV infection and acquired immunodeficiency syndrome (AIDS). A final diagnosis of MC was made based on the history, clinical findings, and histopathological examination. Moreover, due to its vital location, large size, and atypical presentation, a surgical excision by simple unroofing and curettage was performed under local anesthesia to speed recovery, prevent corneal complications, and reduce transmission. Her follow-up visits showed satisfactory clinical and cosmetic outcomes. Patients presenting with giant atypical eyelid lesions must be thoroughly investigated for immunosuppressive states, especially HIV infection. MC can have atypical presentations in HIV patients. To our knowledge, this is one of a few cases in the literature reporting a giant isolated eyelid MC lesion leading to a diagnosis of HIV infection with AIDS.

A Ganglion Cyst in the Anterior Cruciate Ligament of a 13-Year-Old Boy.

Intra-articular ganglion cysts of the knee are a rare occurrence in pediatric patients, particularly involving the anterior cruciate ligament (ACL). Only a handful of case reports have been documented in the medical literature, highlighting the rarity of this condition. Patients with intra-articular cysts often experience knee discomfort and mechanical symptoms like locking of the knee. We present the case of a 13-year-old boy who had a unilateral intra-articular ganglion cyst of the ACL in his left knee. To diagnose and treat the cyst, we conducted radiographs and MRIs, and arthroscopic drainage was performed, resulting in a successful cyst decompression. Our case report provides an overview of the pathogenesis, diagnostic methods, treatment options, and complications of treatment for intra-articular cysts of the ACL. It highlights the rarity of this condition in pediatric patients and underscores the importance of prompt diagnosis and appropriate management.

Influence of twin-headed gemini micellar system on the study of methionine amino acid with ninhydrin in buffer solution.

The influence of double-headed gemini was examined in the present study by studying the amino acid methionine mixed with ninhydrin in CH3COOH-CH3COONa buffer solvent. The absorbance was monitored at fixed time intervals with UV-vis spectroscopy. An impact typical of surfactants was observed on the ninhydrin-methionine reaction and explained by a pseudo-phase model of micelles. The effect of different temperatures (343 to 363 K) was also determined. Based on data showing the impact of temperature on kψ , several relevant thermodynamic quantities, ΔH #, ΔS #, and E a, were calculated using linear least-squares regression. In addition, the influence of the other reaction ingredients on the reaction, that is, pH and the concentration of ninhydrin and methionine, was studied. The CMC (critical micelle concentration) of pure geminis and the surfactant system with methionine and ninhydrin was evaluated at two temperatures, i.e. at 303 K and 353 K by conductivity measurements. The CMC values of pure gemini surfactants evaluated in the existing case at 303 K are concordant with the results stated before. Moreover, other parameters, including rates and binding constants, were calculated.

Design and Preparation of Biomass-Derived Activated Carbon Loaded TiO2 Photocatalyst for Photocatalytic Degradation of Reactive Red 120 and Ofloxacin.

The design and development of novel photocatalysts for treating toxic substances such as industrial waste, dyes, pesticides, and pharmaceutical wastes remain a challenging task even today. To this end, a biowaste pistachio-shell-derived activated carbon (AC) loaded TiO2 (AC-TiO2) nanocomposite was fabricated and effectively utilized towards the photocatalytic degradation of toxic azo dye Reactive Red 120 (RR 120) and ofloxacin (OFL) under UV-A light. The synthesized materials were characterized for their structural and surface morphology features through various spectroscopic and microscopic techniques, including high-resolution transmission electron microscope (HR-TEM), field emission scanning electron microscope (FE-SEM) along with energy dispersive spectra (EDS), diffuse reflectance spectra (DRS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, photoluminescence spectra (PL) and BET surface area measurements. AC-TiO2 shows enhanced photocatalytic activity compared to bare TiO2 due to the change in the bandgap energy and effective charge separation. The degradation rate of dyes was affected by the bandgap of the semiconductor, which was the result of the deposition weight percentage of AC onto the TiO2. The presence of AC influences the photocatalytic activity of AC-TiO2 composite towards RR 120 and OFL degradation. The presence of heteroatoms-enriched AC enhances the charge mobility and suppresses the electron-hole recombination in AC-TiO2 composite, which enhances the photocatalytic activity of the composite. The hybrid material AC-TiO2 composite displayed a higher photocatalytic activity against Reactive Red 120 and ofloxacin. The stability of the AC-TiO2 was tested against RR 120 dye degradation with multiple runs. GC-MS analyzed the degradation intermediates, and a suitable degradation pathway was also proposed. These results demonstrate that AC-TiO2 composite could be effectively used as an ecofriendly, cost-effective, stable, and highly efficient photocatalyst.

A Lightweight Image Encryption Algorithm Based on Chaotic Map and Random Substitution.

Chaotic-maps-based image encryption methods have been a topic of research interest for a decade. However, most of the proposed methods suffer from slow encryption time or compromise on the security of the encryption to achieve faster encryption. This paper proposes a lightweight, secure, and efficient image encryption algorithm based on logistic map, permutations, and AES S-box. In the proposed algorithm, SHA-2 based on the plaintext image, a pre-shared key, and an initialization vector (IV) are used to generate the initial parameters for the logistic map. The logistic map chaotically generates random numbers, which are then used for the permutations and substitutions. The security, quality, and efficiency of the proposed algorithm are tested and analyzed using a number of metrics, such as correlation coefficient, chi-square, entropy, mean square error, mean absolute error, peak signal-to-noise ratio, maximum deviation, irregular deviation, deviation from uniform histogram, number of pixel change rate, unified average changing intensity, resistance to noise and data loss attacks, homogeneity, contrast, energy, and key space and key sensitivity analysis. Experimental results reveal that the proposed algorithm is up to 15.33× faster compared to other contemporary encryption methods.

Impact of Thymus vulgaris extract on sodium nitrite-induced alteration of renal redox and oxidative stress: Biochemical, molecular, and immunohistochemical study.

Thyme (Thymus vulgaris) is an herbal plant with pleiotropic medicinal properties. In this study, we examined the possible protective effect of an ethanolic extract of thyme leaves against the renal oxidative stress induced by sodium nitrite (NaNO2 ). Male Swiss mice received either saline or thyme extract for 15 days (0.5 g/kg body weight, orally). NaNO2 (60 mg/kg) was injected intraperitoneally at Day 14. The protective group received the thyme extract for 15 days and NaNO2 on Day 14. Blood and kidney samples were taken from all groups to measure serum urea, blood urea nitrogen (BUN), creatinine, serum, tissue antioxidant activity, and the inflammatory cytokines IL-1ß and IL-6. Quantitative real-time PCR (qRT-PCR) was used to examine the expression of kidney injury marker-1 (Kim-1), TNF-α, nuclear factor erythroid-2 related factor 2 (Nrf2), and hemoxygenase-1 (HO-1), all of which are associated with kidney redox and oxidative stress. Pretreatment with thyme extract reduced the effects of NaNO2 on urea, BUN, and creatinine, and reversed its effect on tissue and serum antioxidants. NaNO2 -induced nephritis as demonstrated by the upregulation in mRNA expression of Kim-1 and TNF-α, which was, however, recovered and protected by pretreatment with thyme extract. Expression of Nrf2 and HO-1 was upregulated by treatment with thyme extract and downregulated by NaNO2 intoxication. NaNO2 -induced congestion in glomeruli and dilatation of the renal tubules, conditions that were restored in the group pretreated with thyme extract. NaNO2 upregulated Bax immunoreactivity and caused apoptosis in renal structures. Thus, thyme extract is effective in managing the renal toxicity associated with oxidative stress and renal redox. PRACTICAL APPLICATIONS: The results from this study have shown that use of thyme extract may promote better health due to its high antioxidant activity. For instance, it could be ingested to alleviate the symptoms of renal inflammation and oxidative stress associated with nitrite toxicity. Thyme extract regulated renal redox, oxidative stress, antioxidant levels, and inflammation-associated genes at the molecular, biochemical, and cellular immunohistochemical levels.

Effects of various media on micellization, adsorption and thermodynamic behaviour of imipramine hydrochloride and antimicrobial surfactant mixtures.

The effect of various media (aqueous, NaCl, urea (U) and thiourea (TU)) on the micellization and adsorption activity of varied mixtures of imipramine hydrochloride (IMP) and benzethonium chloride (BZCl) is investigated via tensiometry. In an aqueous medium, the interactions between IMP and BZCl are also evaluated using UV-visible and FTIR spectroscopy. The interaction between components increases with increased mole fraction (α 1) of BZCl in the mixed system (IMP + BZCl). Different parameters, such as micellar and the mixed monolayer component composition, the interaction parameters of the solution and the interface, the activity coefficients of the components in solution and at the interface, and thermodynamic parameters, are computed using different proposed theoretical models (i.e. Clint, Motomura, Rubingh and Rosen). The cmc values obtained for the pure components and mixtures (IMP + BZCl) of all the compositions are found to be less in NaCl than in the aqueous solution while found more in the presence of U or TU. TU is more effective in increasing the cmc of the pure and mixed systems than U. The Gibbs free energy ( Δ G mic ∘ ) values of the studied pure and mixed systems are negative, showing the spontaneous nature of the reaction.

Awareness and attitude about basic life support among medical school students in Jeddah University, 2019: A cross-sectional study.

OBJECTIVES: To measure the level of knowledge and awareness towards basic life support (BLS) among students in preclinical years at Jeddah University (JU), and to determine their willingness to participate in BLS training in the near future. SUBJECTS AND METHODS: A cross-sectional study was conducted among first-, second-, and third-year medical students of JU. A 27-item questionnaire measured the level of awareness and knowledge about BLS, including: 1) basic Information (seven items); 2) rescue reflex (eight items); and 3) CPR technique and process (12 items). Demographic and academic data, experience and exposure to BLS, and attitude regarding BLS (six items) were analysed as factors of adequate knowledge. RESULTS: One hundred and four male students participated and 65 (62.5%) of them were in the second academic year. The correct answers varied from 10.6% to 67.3%, with eight items having <30% correct answers; and seven items showed >50% correct answers. Mean (SD) and median (P75) overall knowledge scores were 37.86 (13.92) and 37.04 (44.44) out of 100, respectively. Twenty-four (23.11%) participants attended a training course in BLS and 13 (12.5%) have ever performed BLS, either voluntarily or not voluntarily, and 18 (17.3%) felt that their current knowledge was sufficient. Knowledge level showed no statistically significant association with any of the investigated factors. CONCLUSION: There is an urgent need to integrate BLS courses to medical students to enrich their knowledge and improve resuscitation skills and ensure implementation of correct resuscitation techniques.

Effect of Isolated Obesity on Left Ventricular Function and Structure: A Single-Center Experience.

Background and objectives Obesity can increase cardiac mass and affect cardiac performance independently from other risk factors. Several studies have identified an association in patients who already have comorbidities, however, few studies focused on obesity as an isolated risk factor. This study aimed to assess the associations between isolated obesity and heart morphological and functional characteristics. Methods This was a cross-sectional study that recruited 114 patients referred for echocardiographic study in King Faisal Cardiac Center. Adult patients who had a body mass index (BMI) above 25 kg/m2 were included, while patients with comorbidities such as hypertension, diabetes mellitus, dyslipidemia, or those who use medications for chronic diseases were excluded from this study. Variables of interest that we collected were age, gender, weight, BMI, and those related to morphological and functional changes in the heart including left ventricular mass index (LVMI), LV end-diastolic volume, and left ventricular ejection fraction (LVEF). Results Most of the study participants (63.8%) were class II or class III obesity and about 80% were males. The mean ± SD of LVEF was 55.7% ± 2.8%, while the mean of the left ventricular mass index was 28.5±5.84. The mean of LV end-diastolic volume index (LVEDVI) was slightly higher among males than females (48.8±11.6 versus 46.4±11.7 ml/m2), however, this difference was not statistically significant (p-value= 0.395). There was no correlation between BMI and LVMI in females (R - 0.226, R2 0.05, P-value 0.37), while the LVMI was found to have a negative correlation between BMI and male gender that was significant (R - 0.292, R2 0.09, P-value 0.0052). It was found that there is no correlation between LVEF and BMI for males and females (male= R 0.093, R2 0.032, P-value 0.093; female= R 0.172, R2 0.029, P-value 0.434). With regards to the LVEDVI, there was a negative correlation between higher BMI and male gender that was significant (male= R - 0.396, R2 0.157, P-value 0.0001) while it was not significant in females (R -0.0298, R2 0.0009, P-value 0.893). Conclusions We have found that cardiac function is not affected by isolated obesity. However, indexed cardiac parameters like LVM and LV end diastolic volume were negatively correlated with higher BMI and positively correlated with relative wall thickness (RWT) only in males. This negative correlation might be one of the triggers to the development of obesity-induced cardiomyopathy.

The prevalence of comorbidities among adult people diagnosed with HIV infection in a tertiary care hospital in western Saudi Arabia.

BACKGROUND: The life expectancy of people living with HIV is markedly increasing with the introduction of effective antiretroviral medications. However, these patients face an increased risk of developing multi-morbidities-especially with advanced age. This study was conducted to assess the prevalence of and risk factors associated with the occurrence of chronic comorbidities among patients diagnosed with HIV infection. METHODS: A retrospective chart review was conducted on the medical records of patients with HIV diagnoses from 2000 to 2018. Data were collected on age, sex, date of diagnosis, associated co-morbidities, antiretroviral medications (ART) and status at time of data collection (alive or deceased). Only adult patients 18 years or above were studied. RESULTS: A total of 130 confirmed HIV cases were included. Patient ages ranged from 23 to 86 years old (mean±SD 50.1±12.6). Almost half of the patients (48.5%) had at least one associated comorbidity. The most common chronic comorbidity was diabetes mellitus (15.4%), followed by dyslipidemia (10.8%), hypertension (10.8%) and lymphoma (10.0%). Comorbidity proportions increased with advanced patient age (p=0.047). Three or more comorbidities were reported in 40.7% of patients aged 60 years old or above. Using logistic regression analysis, only patients aged 50 years old or above were more likely to have at least one comorbidity (OR=7.59, 95%CI=2.25, 25.61). CONCLUSIONS: The burden of chronic comorbidities among people diagnosed with HIV is high, especially among older age individuals, with an increasing number of comorbidities per patient. Proper counseling for HIV patients is highly recommended-not only for prevention of other infectious diseases (e.g., vaccination) but also for lifestyle modification and self-management for those with chronic conditions.

Correction: Deep Neck Space Infections: A Retrospective Study of 183 Cases at a Tertiary Hospital.

[This corrects the article DOI: 10.7759/cureus.6841.].

Deep Neck Space Infections: A Retrospective Study of 183 Cases at a Tertiary Hospital.

Objective Our study was performed to identify the clinical findings, risk factors, and complications of deep neck space infections (DNSI) at our center and compare our experience with the experiences of others. Methods Retrospectively, 183 cases of DNSI met our inclusion criteria from 2000 to 2018 at King Abdulaziz Medical City (KAMC) in Jeddah, Western Region, Saudi Arabia. Results In our study, analysis showed that males are more likely to have DNSI (88.7%). The most common site of infection is the peritonsillar abscess (30.6%). Dental infections were found to be the most common etiological factor for DNSI (42.6%). Streptococcus pyogenes was found to be the most common microorganism (39.3%) followed by Staphylococcus aureus (21.3%). Diabetes and hypertension (45.2% and 23.7%, respectively) are the most commonly associated disorders in patients with DNSI. Extension to another space was the most common complication of DNSI. Conclusion Despite the wide usage of antibiotics, DNSI still occur and are life-threatening conditions that need urgent management to avoid unpleasant complications.

Hierarchical Tubular Architecture Constructed by Vertically Aligned CoS2 -MoS2 Nanosheets for Hydrogen Evolution Electrocatalysis.

Developing efficient electrocatalysts for the hydrogen evolution reaction (HER) is crucial for establishing a sustainable and environmentally friendly energy system, but it is still a challenging issue. Herein, hierarchical tubular-structured CoS2 -MoS2 /C as efficient electrocatalysts are fabricated through a unique metal-organic framework (MOF) mediated self-sacrificial templating. Core-shell structured MoO3 @ZIF-67 nanorods are used both as a precursor and a sacrificial template to form the one-dimensional tubular heterostructure where vertically aligned two-dimensional CoS2 -MoS2 nanosheets are formed on the MOF-derived carbon tube. Trace amounts of noble metals (Pd, Rh, and Ru) are successfully introduced to enhance the electrocatalytic property of the CoS2 -MoS2 /C nanocomposites. The as-synthesized hierarchical tubular heterostructures exhibit excellent HER catalytic performance owing to the merits of the hierarchical hollow architecture with abundantly exposed edges and the uniformly dispersed active sites. Impressively, the optimal Pd-CoS2 -MoS2 /C-600 catalyst delivers a current density of 10 mA cm-2 at a low overpotential of 144 mV and a small Tafel slope of 59.9 mV/dec in 0.5 m H2 SO4 . Overall, this MOF-mediated strategy can be extended to the rational design and synthesis of other hollow heterogeneous catalysts for scalable hydrogen generation.

A Mutation in Cathepsin C Gene Causing Papillon-Lefèvre Syndrome in a Saudi Patient: A Case Report.

Papillon-Lefèvre syndrome (PLS) is a rare genetic disease that causes dermatological and dental symptoms that usually start from early age. Dermatological findings include hyperkeratoderma over the palms and soles that are usually thought of as persistent psoriasis at first. Dental findings include severe caries in the teeth that lead to premature dental loss. We present a case of an otherwise healthy seven-year-old child with classical presentation of PLS with both dermatological and dental findings. He first presented to the dermatology clinic when he was five years old brought by his parents complaining of dry scaly patches on the palm of the hands and soles of the feet. On further history it was found that he is a child of first-degree consanguinity, and he had these patches since he was four months old. On examination, he was found to have an erythematous hyperkeratotic skin plaques and papules with scales over the planter and palmar aspect of both hands with similar lesions observed on both feet, legs, scalp, and ears with nail pitting. The diagnosis of PLS was confirmed by whole-exome sequencing (WES) and the patient was started on acitretin capsules and started to show improvement.

Effects of temperature and polyols on the ciprofloxacin hydrochloride-mediated micellization of sodium dodecyl sulfate.

Herein, a conductivity method was engaged to explore the effects of a fluoroquinolone drug, namely ciprofloxacin hydrochloride (CFH)/CFH + polyols (organic compounds with multiple hydroxyl groups (glucose and fructose)), on the aggregation phenomenon of sodium dodecyl sulfate (SDS) at different temperatures (298.15-318.15 K) while maintaining a gap of 5 K. In this study, the critical micelle concentration (cmc) of the SDS/SDS + CFH mixture in water and polyols media was determined from plots of the specific conductivity versus the concentration of SDS to gain knowledge of the effects of CFH/CFH + polyols on the micelle formation behavior of SDS. The cmc value of the surfactant decreases in the presence of CFH in an aqueous medium; thus, CFH favors the micellization of SDS. The cmc values of SDS and the SDS + CFH mixture were enhanced in polyols media. The cmc values of SDS/SDS + CFH show a U-shaped behavior with temperature. The counterion dissociation (α) of the pure surfactant is higher in the presence of the drug and is further enhanced through an increase in the CFH concentration in water/polyols media. Different thermodynamic parameters, such as the Gibbs free energy of micellization , standard enthalpy , entropy , different transfer energies and enthalpy-entropy compensation parameters of micellization were determined and illustrated in detail to compare these parameters between the pure SDS and SDS + CFH mixture in polyols media. The negative values of for the SDS/SDS + CFH mixture in all cases indicate spontaneous micelle formation. The and values indicate the presence of both hydrophobic and electrostatic interactions amongst the studied components.

Iron phosphide anchored nanoporous carbon as an efficient electrode for supercapacitors and the oxygen reduction reaction.

Inspired by their distinctive properties, transition metal phosphides have gained immense attention as promising electrode materials for energy storage and conversion applications. The introduction of a safe and large-scale method of synthesizing a composite of these materials with carbon is of great significance in the fields of electrochemical and materials sciences. In the current effort, we successfully synthesize an iron phosphide/carbon (FeP/C) with a high specific surface area by the pyrolysis of the gel resulting from the hydrothermal treatment of an iron nitrate-phytic acid mixed solution. In comparison with the blank (P/C), the as-synthesized FeP/C appears to be an efficient electrode material for supercapacitor as well as oxygen reduction reaction (ORR) applications in an alkaline medium in a three-electrode system. In the study of supercapacitors, FeP/C shows areal capacitance of 313 mF cm-2 at 1.2 mA cm-2 while retaining 95% of its initial capacitance value after 10 000 cycles, while in the ORR, the synthesized material exhibits high electrocatalytic activity with an onset potential of ca. 0.86 V vs. RHE through the preferred four-electron pathway and less than 6% H2O2 production calculated in the potential range of 0.0-0.7 V vs. RHE. The stability is found to be better than those of the benchmark Pt/C (20 wt%) catalyst.

Synthesis of Hollow Co-Fe Prussian Blue Analogue Cubes by using Silica Spheres as a Sacrificial Template.

Herein, we report a novel method for the formation of hollow Prussian blue analogue (CoFe-PBA) nanocubes, using spherical silica particles as sacrificial templates. In the first step, silica cores are coated by a CoFe-PBA shell and then removed by etching with hydrofluoric acid (HF). The cubic shape of CoFe-PBA is well-retained even after the removal of the silica cores, resulting in the formation of hollow CoFe-PBA cubes. The specific capacity of the hollow CoFe-PBA nanocubes electrodes is about two times higher than that of solid CoFe-PBA nanocubes as storage materials for sodium ions. Such an improvement in the electrochemical properties can be attributed to their hollow internal nanostructure. The hollow architecture can offer a larger interfacial area between the electrolyte and the electrode, leading to an improvement in the electrochemical activity. This strategy can be applied to develop PBAs with hollow interiors for a wide range of applications.

Thin layer chitosan-coated cellulose filter paper as substrate for immobilization of catalytic cobalt nanoparticles.

A facile approach utilizing synthesis of cobalt nanoparticles in green polymers of chitosan (CS) coating layer on high surface area cellulose microfibers of filter paper (CFP) is described for the catalytic reduction of nitrophenol and an organic dye using NaBH4. Simple steps of CFP coating with 1wt% CS aqueous solution followed by Co2+ ions adsorption from 0.2M CoCl2 aqueous solution were carried out to prepare pre-catalytic strips. The Co2+ loaded pre-catalytic strips of CS-CFP were treated with 0.19M NaBH4 aqueous solution to convert the ions into nanoparticles. Successful Co nanoparticles formation was assessed by various characterization techniques of FESEM, EDX and XRD analyzes. TGA analyses were carried out on CFP, CS-CFP, and Co-CS-CFP for the determination of the amount of Co particles formed on the CS-FP, and to track their thermal properties. Furthermore, we demonstrated that the Co-CS-CFP showed an excellent catalytic activity and reusability in the reduction reactions a nitroaromatic compound of 2,6-dintirophenol (2,6-DNP) and brilliant cresyl blue (BCB) dye by NaBH4. The Co-CS-CFP catalyzed the reduction reactions of 2,6-DNP and BCB by NaBH4 with psuedo-first order rate constants of 0.0451 and 0.1987min-1, respectively.