Reaction Technique Research Articles

Designing Tb3+‐Sensitized Silica‐Nanoparticles‐Aided Eu3+‐Doped Sr2SiO4 Phosphors with Enhanced Luminescence for Anti‐Counterfeiting Applications

Silica‐nanoparticles‐assisted Eu3+‐doped Sr2SiO4 and Tb3+‐ and Eu3+‐co‐doped Sr2SiO4 phosphors, as potential phosphors for anti‐counterfeiting application are synthesized via a solid‐state reaction technique. The crystal structure, photoluminescence, and decay times are investigated. The characteristic emission of Eu3+‐doped Sr2SiO4 phosphors exhibits two major peaks at 617 and 595 nm under an excitation wavelength of 394 nm, which corresponds to 5D0 → 7F2 and 5D0 → 7F1 electron transitions of Eu3+ ions. Upon co‐doping with Tb3+, the red emission intensities of the Eu3+‐doped Sr2SiO4 phosphors are enhanced by 1.78‐fold times through an energy‐transfer process. The optimized Tb3+‐ and Eu3+‐co‐doped Sr2SiO4 phosphors show a decay time of 0.49 ns and an energy‐transfer efficiency of 73%. The calculated International Commission on Illumination value (x, y) and color purity are (0.63, 0.37) and 94%, respectively. Subsequently, a luminescent ink is formulated using the optimized phosphor and tested for efficiency on currency notes. Additionally, a flexible film is fabricated, and its luminescence properties are studied. The formulated ink can serve as security ink in the anti‐counterfeiting application.

Enhanced low‐field energy storage performance in Nd3+‐doped (Bi0.40K0.2Na0.2Sr0.2)TiO3 high‐entropy ceramics

AbstractThe burgeoning requirement for compact electronic devices has intensified research into lead‐free dielectric ceramics that offer superior recoverable energy storage density and efficiency at low electric fields. In this study, we report the synthesis of Nd3+‐doped (Bi0.4K0.2Na0.2Sr0.2)TiO3 perovskite ceramics via the solid‐state reaction technique. The synthesized ceramics adopted a tetragonal crystal structure. As the concentration of Nd3+ ions increased, both the maximum dielectric constant (εm) and its corresponding temperature (Tm) decrease. The incorporation of Nd3+ ions perturbed the long‐range ferroelectric order, leading to diminished maximum polarization (Pm) and remanent polarization (Pr). The ceramics achieved optimal properties with 12 mol% Nd3+ doping, showcasing a significant recoverable energy storage density of 1.50 J/cm3 at a low electric field of 140 kV/cm, along with an exceptional storage efficiency of 94.6%. This research not only highlights a promising candidate for dielectric materials in low electric field applications but also introduces an innovative approach to enhance energy storage performance.

Accelerating the discovery of high‐entropy hexaborides by data‐driven prediction: From equimolar to non‐equimolar

AbstractEstimating the synthesizability is the prerequisite to discovering novel high‐entropy ceramics with exotic properties. Herein, combined with the high‐throughput experiments and machine learning (ML) methods, the synthesizability of high‐entropy hexaborides (HEB6) is investigated. To construct the database, 100 equimolar quinary HEB6 samples synthesized using a self‐developed high‐throughput solid‐state reaction technique and 20 potential synthesizability descriptors calculated from fundamental parameters of constituent precursors are simultaneously collected. By employing the ML and the genetic algorithms, an optimal model consisting of five synthesizability descriptors (, , , , and ) is determined for predicting the synthesizability of equimolar HEB6 with a high validation accuracy (93.0%), and 7 005 new equimolar quinary HEB6 are then proposed. Moreover, the applicability of our established model on non‐equimolar HEB6 is explored by the prediction of 30 synthesizability diagrams of non‐equimolar quinary HEB6. A high accuracy of 90.9% is further validated by the synthesis experiments of 11 non‐equimolar HEB6 candidates. Our work establishes an effective ML model for assessing the synthesizability of both equimolar and non‐equimolar HEB6 and paves a promising way to accelerate the discovery of new synthetic accessible high‐entropy ceramics.

A Photoelectrochemical Sensor for the Sensitive Detection of Cysteine Based on Cadmium Sulfide/Tungsten Disulfide Nanocomposites.

In this work, a CdS-nanoparticle-decorated WS2 nanosheet heterojunction was successfully prepared and first used to modify ITO electrodes for the construction of a novel photoelectrochemical sensor (CdS/WS2/ITO). The thin-film electrode was fabricated by combining electrophoretic deposition with successive ion layer adsorption and reaction techniques. The results indicated that the synthesized heterojunction nanomaterials displayed excellent photoelectrochemical performance which was much better than that of pristine CdS nanoparticles and 2D WS2 nanosheets. Owing to the formation of the surface heterojunction and the effective interfacial electric field, the enhanced separation of photogenerated electron-hole pairs led to a remarkable improvement in the photoelectrochemical activity of CdS/WS2/ITO. This heterojunction architecture can protect CdS against photocorrosion, resulting in a stable photocurrent. Based on the specific recognition between cysteine and CdS/WS2/ITO, through the specificity of Cd-S bonds, a visible-light-driven photoelectrochemical sensor was fabricated for cysteine detection. The novel photoelectrochemical biosensor exhibited outstanding analytical capabilities in detecting cysteine, with an extremely low detection limit of 5.29 nM and excellent selectivity. Hence, CdS-WS2 heterostructure nanocomposites are promising candidates as novel advanced photosensitive materials in the field of photoelectrochemical biosensing.

Green Emission of Erbium Doped SYW Phosphors for Optical Thermometry And Solid‐State Lighting

AbstractA series of Er3+ ions doped Sr9Y2W4O24 (SYW) phosphors have been synthesised using solid‐state reaction technique. For optical thermometry and solid state lighting applications, the crystal structure, morphological, and luminescence features of the SYW : Er3+ phosphors were explored. X‐ray diffraction (XRD) reveal that synthesized phosphors having single phase with a tetragonal crystal structure and I41/a space group. Scanning electron microscopy (SEM) was used to examine the morphological behaviour and presence of composition elements. The optical bandgap of the phosphor was evaluated using UV‐Vis diffuse reflection spectra (DRS). The photoluminescence (PL) emission spectra were captured under 380 nm excitation, and the peak with the maximum intensity was identified at 563 nm ascribed to transition 4S3/2→4I15/2, that emits green color in visible region. The temperature dependent PL (TD‐PL) spectra show that SYW phosphor is substantially more thermally stable, having thermal activation energy of about 0.247 eV. Additionally, the fluorescence intensity ratio (FIR) was used to study the optical sensing characteristics of the thermal quenching transitions (2H11/2, 4S3/2) with maximum relative sensitivity (SR) and an absolute sensitivity (SA) being 1.33 % K−1and 0.307 % K−1, respectively. All of the aforementioned findings demonstrate that SYW : Er3+ ions doped phosphors have potential for optical thermometry and other photonic devices.

Enhanced CO2 gas sensing at room temperature using Ag-plated Na-doped CuO thin films synthesized by successive ionic layer adsorption and reaction technique

In this study, we synthesized undoped, Zn-doped, and Na-doped CuO films using the Successive Ionic Layer Adsorption and Reaction (SILAR) method to enhance CO2 gas sensing capabilities. The characterization of the films revealed a monoclinic tenorite phase structure across all samples. The crystallite size was observed to decrease from 83.5 nm in pure CuO to 73.15 nm and 63.08 nm in Zn-doped and Na-doped CuO films, respectively. Notably, Na-doped CuO films exhibited a reduced band gap, increased specific surface area, enhanced surface roughness, and improved electrical conductivity compared to their counterparts. The gas sensing performance was assessed based on sensitivity, selectivity, recovery and response times, and the limit of detection for CO2. The Na-doped CuO films demonstrated superior sensitivity, with sensor responses at 3.3 %, 4.86 %, and 12.8 % for undoped, Zn-doped, and Na-doped films, respectively, at a CO2 flow rate of 100 SCCM. Further modification of the Na-doped CuO films with Ag plasmonics markedly increased the sensor response to 914.8 % under the same conditions at a standard room temperature of 30 °C. Additional evaluations of selectivity, consistency, repeatability, and both quantification and detection limits underscored the enhanced performance of the modified Na-doped CuO films, indicating their potential for efficient CO2 gas detection applications.

Insight into the gas pollutants emission of rural solid waste during the gasification-combustion process: Influencing factors and mechanisms

With the rapid development of rural areas, effective disposal of rural solid waste (RSW) has emerged as a critical concern. In this study, the gasification-combustion technology concerning air-staged technology was employed in the treatment of RSW and its main components (rubber, PVC, and food waste(FW)). This study focused on analyzing the emission patterns and total amounts of NOx, SO2, and HCl. For RSW, the gasification-combustion experiment effectively reduced NOx and SO2 emissions compared to the combustion experiment. The amount and patterns of gaseous pollutant emissions were significantly impacted by changes in gasification temperature, combustion temperature, and proportion of air (PA). Besides, due to the interplay of RSW's constituents, the change in gasification temperature and PA resulted in different emission patterns for FW and RSW. Under the combined action of constituents, the trend of RSW SO2 emission amount was distinct from its S sources due to the potential sulfation impact. The RSW's HCl emissions were found to be minimally affected by changes in temperature, PA, and reaction technique. This research manages the miniaturized centralized incinerator disposal of RSW and helps the control of gas pollutants emission.

Precisely Manipulating the Self‐Reduction of Manganese in MgGa2O4 through Lithium Incorporation for Optical Thermometry and Anti‐Counterfeiting

AbstractManganese (Mn) doped MgGa2O4 (MGO) phosphors are prepared by a solid‐state reaction technique in air. Upon UV light excitation, the featured green and red emissions of Mn2+ and Mn4+, respectively, are detected in the Mn‐doped MGO phosphors, indicating the incomplete self‐reduction behavior of Mn in the MGO host lattices. To clarify the incomplete self‐reduction behavior, theoretical calculations based on density functional theory and bond energy theory are performed. Moreover, the self‐reduction behavior of Mn can be manipulated by the incorporation of Li+, leading to the precise regulation of the Mn2+ and Mn4+ contents in the MGO host lattices. Based on the ionic radii, the inhibited self‐reduction mechanism is triggered by Li+ occupying the tetrahedral Mg2+ site, leading to the reduced occupancy of tetrahedral Mg2+ sites by Mn ions, and forcing Mn to take up the octahedral Ga3+ sites. Furthermore, the afterglow properties of phosphors with wide and continuous multiple traps are studied in detail. Finally, based on unique luminescence properties of the phosphors, their potential application in ratiometric optical thermometer and optical anti‐counterfeiting is also systematically exploited.

Nanostructured CuO Thin-Film-Based Conductometric Sensors for Real-Time Tracking of Sweat Loss.

Enhanced sweat sensors lead to real-time, sustained, noninvasive tracking of sweat loss, ensure insight into individual health conditions at the molecular level, and have obtained prominent interest for their hopeful implementations in customized health tracking. Metal-oxide-based nanostructured electrochemical amperometric sensing materials are the best selection for continuous sweat monitoring devices owing to their high stability, high-sensing capacity, cost-effectiveness, miniaturization, and wide applicability. In this research, CuO thin films have been fabricated by successive ionic layer adsorption and reaction technique (SILAR) with and without the addition of Lawsonia inermis L. (Henna, (LiL)) leaf extract (C10H6O3, 2-hydroxy-1,4-naphthoquinone) with a high-sensitive and rapid response for sweat solution. Despite the pristine film being responsive to the 65.50 mM sweat solution (S = 2.66), the response characteristic improves to 3.95 for the 1.0% LiL-implemented CuO film. Unmodified, 1.0% LiL and 3.0% LiL-substituted thin-film materials assure considerable linearity with linear regression ranges, R2, of 0.989, 0.997, and 0.998, respectively. It is noteworthy here that this research aims to determine an enhanced system that could potentially be implemented in real-life sweat-tracking administrations. Real-time sweat loss tracking capabilities of CuO samples was found to be promising. Derived from these outcomes, we concluded that the fabricated nanostructured CuO-based sensing system is a useful application for the continuous observation of sweat loss as a biological argument and compatibility with other microelectronic technologies.

Diacylated anthocyanins from purple sweet potato (Ipomoeabatatas L.) attenuate hyperglycemia and hyperuricemia in mice induced by a high-fructose/high-fat diet.

Studies have shown that targeting xanthine oxidase (XO) can be a feasible treatment for fructose-induced hyperuricemia and hyperglycemia. This study aimed to evaluate the dual regulatory effects and molecular mechanisms of diacylated anthocyanins from purple sweet potato (diacylated AF-PSPs) on hyperglycemia and hyperuricemia induced by a high-fructose/high-fat diet. The body weight, organ index, serum biochemical indexes, and liver antioxidant indexes of mice were measured, and the kidneys were observed in pathological sections. The relative expression levels of messenger RNAs (mRNAs) of fructose metabolism pathway enzymes in kidney were detected by fluorescent real-time quantitative polymerase chain (qPCR) reaction technique, and the expression of renal transporter protein and inflammatory factor pathway protein was determined by immunohistochemistry (IHC) technique. Results showed that diacylated AF-PSPs alleviated hyperuricemia in mice, and that this effect might be related to the regulation of liver XO activity, lipid accumulation, and relevant renal transporters. Diacylated AF-PSPs reduced body weight and relieved lipid metabolism disorder, liver lipid accumulation, and liver oxidative stress, thereby enhancing insulin utilization and sensitivity, lowering blood sugar, and reducing hyperglycemia in mice. Also, diacylated AF-PSPs restored mRNA levels related to renal fructose metabolism, and reduced kidney injury and inflammation. This study provided experimental evidence for the mechanisms of dual regulation of blood glucose and uric acid (UA) by diacylated AF-PSPs and their utilization as functional foods in the management of metabolic syndrome.

Suppressed Self‐Reduction of Manganese in Mg2SnO4 via Li+ Incorporation with Polychromatic Luminescence for Versatile Applications

AbstractHerein, the self‐reduction behavior of manganese (Mn) in Mg2SnO4 (MSO) host lattices prepared by using the solid‐state reaction technique in air atmosphere is reported. Excited by 282 nm, only the emission of Mn2+ is seen, and the observed results are confirmed by theoretical calculation based on the density functional theory. Noteworthy, with the codoping of Li+, the self‐reduction process of Mn is suppressed, leading to the coexistence of Mn2+ and Mn4+ in MSO host lattices along with the multicolor emissions. For the suppressed self‐reduction behavior, possible hypotheses are proposed to elucidate the corresponding mechanisms. Furthermore, benefiting from the different thermal quenching behaviors of Mn2+ and Mn4+, ratiometric optical thermometers with high sensitivity of 6.59% K−1 are designed. Moreover, the prepared phosphors possess a good green afterglow phenomenon, in which their trap depth are 0.71 and 0.91 eV. In addition, via using the designed phosphors, applications in anti‐counterfeiting, fingerprint identification, and optical information storage are also realized.

A novel activation technique for integrated cross section measurements using accelerator mass spectrometry

41Ca (t1/2 = 9.94 × 104 yrs) is an important stellar radionuclide and its production in the Early Solar System from various irradiation scenarios can help determine the viability of models of early stellar processes. A novel reaction technique has been under development and recently tested at the Nuclear Science Laboratory at the University of Notre Dame. This technique utilizes an “in-cathode” reaction method, where natural CaF2 material is packed into an ion source sample holder (cathode) and then irradiated and subsequently measured using Accelerator Mass Spectrometry (AMS) without the need for chemical processing afterward. The setup for the irradiation was performed using a 3He beam to measure the reaction natCa(3He,x)41Ca. Initial AMS results suggest additional complexity due to ion source sputtering rates and geometry, which will need to be explored further.

Involvement of Caspase-3 Pathway in Anti-cancer Properties of Genistein in AGS Gastric Cancer Cell Line is Still Enigmatic

Background: Genistein is an isoflavone that has been reported to have various anti-cancer properties. Objectives: This study aimed to reveal whether or not the anti-cancer properties of genistein in AGS gastric cancer cell line were mediated through caspase-3 enzyme. Methods: AGS gastric cancer cells were treated with different concentrations of genistein for 12, 24, and 48 hours and, then, the viability of the cells and IC50 were determined. To determine the effect of genistein on AGS cell migration potency, the wound healing assay was performed. The genistein-induced apoptosis in AGS gastric cells was evaluated by flow cytometry. Caspase-3 gene (CASP3) expression level and its enzyme activity level were determined by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and colorimetric techniques, respectively. Results: The IC50 value was calculated as 70 µM concentration for 24 hours of incubation with genistein. Genistein significantly reduced AGS cell migration compared to the untreated control cells (P<0.001). Genistein increased the early and late apoptosis of the cells (P<0.001) and upregulated the caspase-3 gene expression (P<0.001), but did not significantly enhance the caspase-3 enzyme activity in treated cells. Conclusion: Genistein exhibited anti-cancer effects on AGS cells to some extent by reducing cellular migration, increasing apoptosis, and upregulating CASP3 gene expression; however, it did not alter the caspse-3 activity. Therefore, it was recommended that more studies should be carried out to delineate the role of caspase-3 in health benefits attributed to the genistein.

Spectral-domain optical coherence tomography assessment of retinal and choroidal changes in patients with coronavirus disease 2019: a case-control study

ObjectivesThis study aimed to evaluate the retinal and choroidal changes in the macular region of patients with Coronavirus Disease 2019 (COVID-19) using structural spectral-domain optical coherence tomography (SD-OCT) analysis.MethodsThis cross-sectional observational case-control study included patients recovered from COVID-19. The COVID-19 in all participants was confirmed using the reverse transcription-polymerase chain reaction (RT-PCR) technique. The participants had mild to moderate degree of disease without a history of hospitalization, steroid usage, or blood saturation below 92%. Macular SD-OCT was performed at least two weeks and up to one month after recovery from systemic COVID-19. Quantitative and qualitative changes detected by macular SD-OCT imaging were evaluated in COVID-19 recovered patients and compared with the results of age-matched normal controls.ResultsParticipants in this study included 30 cases (60 eyes) and 60 healthy controls (120 eyes). In total, 17 (28.3%) eyes in patient group showed at least one abnormal finding indicated by macular SD-OCT imaging included hyperreflective lesions in different retinal layers. In addition, dilated choroidal vessels and retinal pigment epitheliopathy were evident in 41 (68.3.6%) and 4 (6.6%) eyes in patient group, respectively, and their OCT findings resembled those with pachychoroid spectrum. No statistically significant differences were observed in retinal layers or retinal volume between the two groups. The mean ± SD subfoveal choroidal thickness (SFCT) was determined at 380.3 ± 12.40 μm, which was significantly thicker than that in control group (310.7 ± 57.5 μm) (P < 0.001).ConclusionRegarding retinal thickness, no significant change was observed in different retina layers of patients with COVID-19; however, there were striking qualitative changes, such as hyperreflective lesions in different retinal layers. The evaluation of choroidal structure and thickness demonstrated remarkable abnormal pachyvessels and significant thickening of the SFCT but the clinical significance of these findings is unknown.

The structural, morphological, optical and gas-sensing properties of Mn3O4 thin films grown by successive ionic layer adsorption and reaction technique

The structural, morphological, optical and gas-sensing properties of Mn3O4 thin films grown by successive ionic layer adsorption and reaction technique

Integrated carbon capture and utilization based on bifunctional ionic liquids to save energy and emissions

The combination of CO2 capture and conversion (CCU) to produce value-added chemicals is proposed as strategy to mitigate environmental impacts and resolve the cost for CO2 conditioning, transport and storage. Although there are several CCU pathways in the literature, there are not large-scale designs of CCU processes based on ionic liquids (ILs). This work attempts to take advantage of the reported bifunctionality of ILs, as CO2 chemical absorbents and CO2 conversion catalysts, for designing new valuable CCU systems using well-stated absorption and reaction techniques. Separated and integrated CCU processes for propylene carbonate production based on trihexyl(tetradecyl)phosphonium 2-cyanopyrrolide ([P66614][CNPyr]) were successfully modelled utilizing the COSMO-based/Aspen methodology. The performance of both CCU approaches was evaluated attending to energy consumption, utility costs and net CO2 emissions. A novel integrated CCU process achieved promising energy (10.1 MW) and net CO2 emissions (0.23 kg-eq. CO2/kg CO2 absorbed) results, demonstrating not only that dual-functional ILs can be suitable materials for CCU but also the successful integration of IL-based carbon capture and utilization with enhanced process performance.

Evaluation of the sensitivity and specificity of three diagnostic tests for Coxiella burnetii infection in cattle and buffaloes in Punjab (India) using Bayesian latent class analysis.

Q Fever is a zoonotic disease of significant animal and public health concern, caused by Coxiella burnetii (C. burnetii), an obligate intracellular bacterium. This study was done to evaluate the diagnostic sensitivity (DSe) and diagnostic specificity (DSp) of three diagnostic methods to diagnose C. burnetii infection in cattle and buffaloes in Punjab, India: an indirect ELISA method applied in serum samples and a trans-Polymerase Chain Reaction (trans-PCR) technique applied in milk samples and genital swabs, using a Bayesian latent class analysis. Conditional independence was assumed between the tests, given (i) the different biological principle of ELISA and trans-PCR and (ii) the fact that the trans-PCR was performed on different tissues. The ELISA method in the serum samples showed the highest DSe of 0.97 (95% Probability Intervals (PIs): 0.93; 0.99) compared to the trans-PCR method applied in milk samples 0.76 (0.63; 0.87) and genital swabs 0.73 (0.58; 0.85). The DSps of all tests were high, with trans-PCR in genital swabs recording the highest DSp of 0.99 (0.98; 1), while the DSp of trans-PCR in milk samples and ELISA in serum samples were 0.97 (0.95; 0.99) and 0.95 (0.93; 0.97) respectively. The study results show that none of the applied tests are perfect, therefore, a testing regimen based on the diagnostic characteristic of the tests may be considered for diagnosis of C. burnetii.

Development of a new highly sensitive and selective spectrophotometric method for the determination of cobalt at nanotrace levels in various complex matrices using N,N’-bis(salicylidene)-ethylenediamine

A new spectrophotometric reagent, N,N'-bis(salicylidene)-ethylenediamine (Salen), has been synthesized and characterized through novel reaction techniques. A very simple, ultrasensitive, and nonextractive spectrophotometric method has been developed for the determination of the picotrace amount of cobalt (II) using Salen. Salen undergoes a reaction in a slightly acidic solution (0.001-0.003 M H2S04) with cobalt in 20% ethanol to give a light orange chelate, which has an absorption maximum at 459 nm. The reaction is instantaneous, and the absorbance remains stable for over 24 hours. The average molar absorption co-efficient and Sandell’s sensitivity were found to be 6.04×105 L/mol.cm and 5.0 ng/cm2 of Co, respectively. Linear calibration graphs were obtained for 0.001-40 mg/Lof Co with a detection limit of 0.1 µg/L and RSD of 0-2 %. The stoichiometric composition of the chelate is 1:1 (Co:Salen). A large excess of over 60 cations, anions and some common complexing agents such as chloride, azide, tartrate, EDTA, SCN- etc. do not interfere in the determination. The developed method was successfully used in the determination of cobalt in several Certified Reference Materials (Alloys, steel, bovine liver, human hair, drinking water, sewage sludge, soil, and sediments) as well as in some environmental waters (Potable and polluted), biological fluids (Human blood, urine, and milk), soil samples, food samples (Vegetables, rice, and wheat) and pharmaceutical samples and solutions containing both cobalt (II) and cobalt (III) as well as complex synthetic mixtures. The results of the proposed method for assessing biological, soil, food and vegetable samples were comparable with ICP-OES and AAS were found to be in excellent agreement. The method has high precision and accuracy (s = ±0.01 for 0.5 mg/L).

Development of core-shell nanomaterials for energy storage devices using chemical solution method

Professor Tomoya Ohno and Associate Professor Shigeto Hirai, Kitami Institute of Technology, Kitami, Japan, are collaborating on research on the composition and coating of catalysts used in rechargeable metal-air batteries. Ohno specialises in surface coatings and powder technology and Hirai is an expert in electro- and solid-state chemistry and so these combined specialisms lend themselves well to the work. The researchers are developing long-life, high-performance bi-functional catalyst particles that can be mounted on rechargeable metal-air batteries, and are also proposing positive particles coated with a solid electrolyte for use in all-solid state lithium-ion batteries. Due to the high density associated with the design of the metal-air battery, it has the potential to store a lot more energy than conventional batteries. This means that metal-air batteries could prove transformative for industry, with the potential to be used in electric cars, national grid energy storage and other devices that require regular charging. However, the technology of the metal-air battery is still in progress and key concerns are the reliability of the cathode as well as the harsh effects of charging at high cathodic potentials. Ohno and Hirai are working to overcome these challenges by using chemical reaction and powder engineering techniques to add thin films of protective materials for the potential catalysts that could help stabilise the cathode. So far, the researchers have found that the protective layer on the bi-functional catalyst particles that were mounted on the metal-air secondary battery significantly improved the stability. They also found that the effect varies depending on the structure of the coating layer.

A Taxonomic Study comparing the two types of Medicinal Leeches available in Iraq

Medical leeches are ectoparasites invertebrates which are widely used in medical and surgical treatments because it was found since the ancient time that many diseases can be cured by medicinal leeches, then it was discovered that leech saliva contains anti-inflammatory, analgesic, antibacterial, anticoagulant, and even anticancer enzymes, also they found that medicinal leeches have a great role in treating diabetic ulcers. Tow samples of leeches were collected from two regions in Iraq from September to the end of December 2020. These samples were examined a live by dissecting microscope and then they were examined after fixing them in formaldehyde 5%. The samples of leeches that were used to analyze their genetic DNA were fixed and preserved in absolute ethanol. The classification process was done through a molecular diagnosis of samples of medical leeches by using polymerase chain reaction PCR and technique tracking nitrogenous bases in the nucleic acid chain, and the molecular diagnosis depending on Cytochrome oxidase subunit 1 (CO1), and then the result of PCR of medical leech samples was sent with the primers of the resulting bands and the gene sequences were read depending on the Genetic Analyser Device 3130 supplied by Japanese Hitachi company. Then the gene sequences were matched with gene sequences documented in the National Center Biotechnology Information NCBI. The results were analyzed depending on the BLAST program through which two types of medical leeches were detected Hirudo medicinalis and Hirudo verbena.