Dense NiCo2 O4 Nanoneedles Grown on Carbon Foam Showing Excellent Electrochemical and Microwave Absorption Properties.

Electromagnetic pollution could harm sensitive electronic equipment due to the rising use of electronic devices and communication infrastructure. The supercapacitor's electrochemical performance should be enhanced, and electromagnetic damage should be prevented. This study proposes NiCo2 O4 /CF composites for supercapacitors and microwave absorption. They are made by combining hydrothermal and annealing processes. Dense NiCo2 O4 nanoneedles were uniformly grown on the outer layer of carbon foam (CF) as a growth skeleton, preventing the agglomeration of NiCo2 O4 . The composite had a specific capacitance of 537.5 F/g at 1 A/g. When the current density was set to 1 A/g, the supercapacitor that used NiCo2 O4 /CF as the cathode had a specific capacitance of 70.7 F/g, and when the current density was increased to 10 A/g, the original specific capacitance of 87.2 % could still be maintained after 5000 charge-discharge cycles. At a power density of 3695.5 W/kg, an energy density of 22.1 Wh/kg could be maintained. Furthermore, we performed a microwave absorption test and determined its reflection loss curve for various sample thicknesses. Recombination enhanced the composite material's microwave absorption capability by greatly reducing the dielectric loss and the magnetic loss.

Study of antidiabetic activity of two novel Schiff base derived dibromo and dichloro substituted compounds in streptozotocin-nicotinamide-induced diabetic rats: pilot study

Abstract Schiff bases are aldehyde-or ketone-like chemical compounds in which an imine or azomethine group replaces the carbonyl group. Such compounds show various beneficial biological activities, such as anti-inflammation and antioxidants. The present study addresses comprehensiveevaluation of antidiabetic effect of two novel dibromides and dichlorides substituted Schiff bases substituted Schiff bases (2,2'-[1,2-cyclohexanediylbis (nitriloethylidyne)]bis[4-chlorophenol] (CNCP) and 2, 2'-[1,2-cyclohexanediylbis(nitriloethylidyne)]bis[4-bromophenol] (CNBP) with two different doses, high (LD) and low (LD) in streptozotocin and nicotinamide induced diabetic rats. The rats were separated into normal, untreated, treated and reference groups. Except for the normal group, diabetes traits were induced in the rest animals. Insulin level was measured, and the effect of the compounds on biochemical parameters of liver function and lipid profile were evaluated. High glucose and decreased insulin level are observed in the groups. The histological evaluation confirms that the hepatic architecture in the treated animals with a low dose of CNCP is quite similar to that of the normal hepatic structure and characterized by normal central vein, hepatocytes without any fatty alterations and mild red blood cell infiltration. CNCP (LD) and CNBP (HD) are more successful in enhancing cell survival in the diabetic rat's liver and can be responsible for causing much healthier structure and notable morphology improvement.

One-Step Solvothermal Synthesis of Raspberry-like NiCo-MOF for High-Performance Flexible Supercapacitors for a Wide Operation Temperature Range.

As a novel electrode material for energy storage, metal-organic frameworks (MOFs) emerge with plenty of merits and certain drawbacks in the field of supercapacitors. Nevertheless, most MOFs synthesized for the moment are faced with dimension/distribution issues and dissatisfactory electrical conductivity. Hence, in this paper, NiCo-MOF was successfully fabricated by applying a one-step solvothermal method, from which NiCo-MOF-3 presents an optimal electrochemical performance compared to other NiCo-MOFs and Ni/Co-MOF. Owing to its unique three-dimensional spherical raspberry structure, NiCo-MOF-3 demonstrates an available internal resistance and electron transfer resistance to ameliorate electrical energy storage, exhibiting an excellent mass specific capacitance of 639.8 F/g at 1 A/g. Then, a flexible quasi-solid-state asymmetric supercapacitor was assembled with NiCo-MOF-3 as the positive electrode. The introduction of K3[Fe(CN)6] and glycerin in the gel electrolyte facilitates the maximum energy density of 66.3 Wh/kg of the device, with a corresponding power density reaching its maximum of 12,047 W/kg. The device's apparent energy density, excellent flexibility, and temperature resistance reveal that our method to prepare supercapacitor electrode material possesses more advantages than those in the former literature.

Nucleic acid-based electrochemical biosensors for rapid clinical diagnosis: advances, challenges, and opportunities.

Clinical diagnostic tests should be quick, reliable, simple to perform, and affordable for diagnosis and treatment of diseases. In this regard, owing to their novel properties, biosensors have attracted the attention of scientists as well as end-users. They are efficient, stable, and relatively cheap. Biosensors have broad applications in medical diagnosis, including point-of-care (POC) monitoring, forensics, and biomedical research. The electrochemical nucleic acid (NA) biosensor, the latest invention in this field, combines the sensitivity of electroanalytical methods with the inherent bioselectivity of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). The NA biosensor exploits the affinity of single-stranded DNA/RNA for its complementary strand and is used to detect complementary sequences of NA based on hybridization. After the NA component in the sensor detects the analyte, a catalytic reaction or binding event that generates an electrical signal in the transducer ensues. Since 2000, much progress has been made in this field, but there are still numerous challenges. This critical review describes the advances, challenges, and prospects of NA-based electrochemical biosensors for clinical diagnosis. It includes the basic principles, classification, sensing enhancement strategies, and applications of biosensors as well as their advantages, limitations, and future prospects, and thus it should be useful to academics as well as industry in the improvement and application of EC NA biosensors.

A Green Alternative for Aryl Iodide Preparation from Aromatic Amines.

BACKGROUND: In continuation of our previous work and the applications of saccharin, we encouraged to investigate the one-pot synthesis of the aryl iodides by the diazotization of the arene diazonium saccharin salts. OBJECTIVE: Arene diazonium salts play an important role in organic synthesis as intermediate and a wide variety of aromatic compounds have been prepared using them. A serious drawback of arene diazonium salts is their instability in a dry state; therefore, they must be stored and handled carefully to avoid spontaneous explosion and other hazard events. METHODS: The arene diazonium saccharin salts were prepared as active intermediates in situ through the reaction of various aryl amines with tert-butyl nitrite (TBN) in the presence of saccharin (Sac-H). Then, in situ obtained intermediates were used into the diazotization step without separation and purification in the current protocol. RESULTS: A variety of aryl iodides were synthesized at a greener and low-cost method in the presence of TBN, Sac-H, glacial acetic acid, and TEAI. CONCLUSION: In summary, a telescopic reaction is developed for the synthesis of aryl iodides. The current methodology is safe, cost-effective, broad substrate scope, and metal-free. All used reagents are commercially available and inert to moisture and air. Also, the saccharine and tetraethylammonium cation could be partially recovered from the reaction residue, which reduces waste generation, energy consumption, raw material, and waste disposal costs.

Arene diazonium saccharin intermediates: a greener and cost-effective alternative method for the preparation of aryl iodide.

In the current protocol, the arene diazonium saccharin derivatives were initially produced from various substituted aromatic amines; subsequently, these intermediates were treated with a greener organic iodide for the preparation of the aryl iodide. We tried to choose low-cost, commercially available, biodegradable, recoverable, ecofriendly, and safe reagents and solvents. The arene diazonium saccharin intermediates could be stored in the liquid phase into a refrigerator for a long time with no significant loss activity. The outstanding merits of the current protocol (a) included the partial recovering of saccharin and tetraethylammonium salt, (b) reduce the use of solvents and the reaction steps due to eliminating separation and purification of intermediates, (c) good yield of the sterically hindered substrates, and (d) avoid the generation of heavy metal or corrosive waste.

New protocols for the synthesis of 5-amino-7-(4-phenyl)-4,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylate esters using an efficient additive.

This work introduces a new additive named 4,4'-trimethylenedipiperidine for the practical and ecofriendly preparation of ethyl 5-amino-7-(4-phenyl)-4,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylate derivatives. This chemical is commercially available and easy to handle. It also possesses a low melting point and a broad liquid range temperature, high thermal stability, and good solubility in water. Based on green chemistry principles, the reaction was performed in a) a mixture of green solvents i.e. water and ethanol (1:1 v/v) at reflux temperature, and b) the additive was liquefied at 65 °C and the reaction was conducted in the liquid state of the additive. High yields of the desired triazolo-pyrimidines were obtained under both aforementioned conditions. Our results demonstrated that this additive, containing 2 Lewis base sites and able to act as an acceptor-donor hydrogen bonding group, is a novel and efficient alternative to piperidine, owing to its unique properties such as its reduced toxicity, nonflammable nature, nonvolatile state, broad liquid range temperature, high thermal stability, and ability to be safely handled. Furthermore, this additive could be completely recovered and exhibited high recyclability without any change in its chemical structure and no significant reduction in its activity. The current methodology has several advantages: (a) it avoids the use of hazardous materials, as well as toxic, volatile, and flammable solvents, (b) it does not entail tedious processes, harsh conditions, and the multistep preparation of catalysts, (c) it uses a metal-free and noncorrosive catalyst, and (d) reduces the generation of hazardous waste and simple work-up processes. The most important result of this study is that 4,4'-trimethylenedipiperidine can be a promising alternative for toxic, volatile, and flammable base reagents in organic synthesis owing to its unique properties.

Advancements in electrochemical DNA sensor for detection of human papilloma virus - A review.

Human papillomavirus (HPV) is one of the most common sexually transmitted disease, transmitted through intimate skin contact or mucosal membrane. The HPV virus consists of a double-stranded circular DNA and the role of HPV virus in cervical cancer has been studied extensively. Thus it is critical to develop rapid identification method for early detection of the virus. A portable biosensing device could give rapid and reliable results for the identification and quantitative determination of the virus. The fabrication of electrochemical biosensors is one of the current techniques utilized to achieve this aim. In such electrochemical biosensors, a single-strand DNA is immobilized onto an electrically conducting surface and the changes in electrical parameters due to the hybridization on the electrode surface are measured. This review covers the recent developments in electrochemical DNA biosensors for the detection of HPV virus. Due to the several advantages of electrochemical DNA biosensors, their applications have witnessed an increased interest and research focus nowadays.

Can We Optimize Arc Discharge and Laser Ablation for Well-Controlled Carbon Nanotube Synthesis?

Although many methods have been documented for carbon nanotube (CNT) synthesis, still, we notice many arguments, criticisms, and appeals for its optimization and process control. Industrial grade CNT production is urgent such that invention of novel methods and engineering principles for large-scale synthesis are needed. Here, we comprehensively review arc discharge (AD) and laser ablation (LA) methods with highlighted features for CNT production. We also display the growth mechanisms of CNT with reasonable grassroots knowledge to make the synthesis more efficient. We postulate the latest developments in engineering carbon feedstock, catalysts, and temperature cum other minor reaction parameters to optimize the CNT yield with desired diameter and chirality. The rate limiting steps of AD and LA are highlighted because of their direct role in tuning the growth process. Future roadmap towards the exploration of CNT synthesis methods is also outlined.