Captive Black Mamba (Dendroaspis Polylepis) Bite Leading to Respiratory Failure.

BACKGROUND: Of the 8000-10,000 snake envenomations evaluated in U.S. emergency departments (ED) annually, approximately 1% are due to non-native snakes. We describe a 26-year-old man who was bitten by his captive black mamba (Dendroaspis polylepis) as he was packing it up for transport to another snake collector. CASE REPORT: The patient presented to the ED 1 h after being bitten on the forearm, complaining of left arm pain, oral paresthesias, and dyspnea. His vital signs: heart rate 96 beats/min, blood pressure 167/101 mm Hg, temperature 36.7°C (97.9°F), respiratory rate 20 breaths/min, and room air oxygen saturation 100%. Two mildly tender puncture wounds without swelling or ecchymosis were found on the posterior aspect of the forearm. Over the ensuing 30 min his dyspnea worsened, and he developed objective weakness. He was intubated and placed on mechanical ventilation. He was treated with atropine 2 mg for bronchorrhea. Five vials of South African Vaccine Producers (Johannesburg, South Africa) polyvalent antivenom were administered 2.5 h post-bite and the patient was admitted to the intensive care unit. He was extubated 18 h post-envenomation and discharged the following day. He has remained asymptomatic since leaving the hospital. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: The primary manifestations of D. polylepis envenomings are neurological. Initial signs may include paresthesias, dysarthria, dysphagia, and ptosis. Progressive descending paralysis leading to respiratory failure develops within 60 min. Muscarinic features are frequently observed. Cardiotoxicity and hematologic laboratory abnormalities may be present. Although pain is common, significant local tissue injury does not occur. In addition to supportive care, several non-native antivenoms are indicated for D. polylepis envenomations. Black mamba envenomings differ from the native snakebites with which U.S. physicians are familiar. Rapid, progressive neurological toxicity and muscarinic features are most common. Treatment consists of supportive care and appropriate antivenom administration.

Ammonium metavanadate (NH4VO3): a highly efficient and eco-friendly catalyst for one-pot synthesis of pyridines and 1,4-dihydropyridines.

In this study, we reported the ammonium metavanadate (NH4VO3) as an efficient, cost-effective, and mild catalyst for the synthesis of substituted pyridines via a one-pot pseudo four-component reaction. Furthermore, we investigated Hantzsch 1,4-dihydropyridines (1,4-DHPs) synthesis and oxidation of 1,4-DHPs to their corresponding pyridines. The present approach offers a rapid methodology for accessing various pyridines with broad functional group tolerance and good yields using NH4VO3 catalyst as a green catalyst.

Synthesis and evaluation of composite TiO2@ZnO quantum dots on hybrid nanostructure perovskite solar cell.

This research is an interdisciplinary study aimed at helping the environment and producing clean energy. Therefore, one of the goals of this research towards the field of nanotechnology is the application of nanotechnology in the preparation of solar cells and the provision of optimal and efficient cells. Perovskite solar cells are of particular importance because of the high efficiencies that they have achieved in recent years. The use of quantum dots has also played an important role in the efficiency of these cells and their efficiency. The TiO2@ZnO nanocomposite was selected and synthesized for this study. The application of this nanocomposite with different ratios of TiO2 and ZnO quantum dots was investigated and their efficiency was determined. Although the efficiency of the fabricated cell was reported to be about 5% in a solar cell made of TiO2@ZnO composite, the efficiency can be increased by optimizing conditions such as the optimal location for these cells or by compositing with other materials.

Mediatory role of the dopaminergic system through D1 receptor on glycine-induced hypophagia in neonatal broiler-type chickens.

The present study aimed to examine the mediatory role of the dopaminergic system in the food intake induced by intracerebroventricular (ICV) injection of glycine in neonatal 3-h feed-deprived (FD3) meat-type chickens. In the first and second experiments, birds were ICV injected using low and high doses of glycine (50, 100 and 200 nmol) and strychnine (50, 100 and 200 nmol), respectively. In experiments 3-9, the behaviorally subeffective doses of dopamine (10 nmol), 6-OHDA (2.5 nmol), SCH 23,390 (D1 antagonist; 5 nmol), AMI-193 (D2 antagonist; 5 nmol), NGB2904 (D3 antagonist; 6.4 nmol) and L-741,742 (D4 antagonist; 6 nmol) were, respectively, co-administrated with glycine (200 nmol) in FD3 5-day-old chicks to investigate possible interplay of dopamine receptors in glycine-induced feeding behavior. Then, cumulative food intake based on body weight percentage (%BW) was determined at 30, 60 and 120 min after the injection. According to the results, dopamine significantly boosted the hypophagia induced by glycine at all-time intervals (p ≤ 0.001). These results combined with the previous findings suggest an interplay between dopamine and glycine in chicken's brain in which D1 receptor-mediated food intake induced by glycine.

Fabrication of Fe3O4@PVA-Cu Nanocomposite and Its Application for Facile and Selective Oxidation of Alcohols.

Fe3O4@PVA-Cu nanocomposite was introduced as an affordable catalyst for selective oxidation of alcohols into various aldehydes and ketones. The synthesized nanocomposite was characterized by applying essential analyses. The peaks that are appeared in FT-IR spectroscopy confirmed the production of the Fe3O4@PVA-Cu nanocomposite. In addition, EDX analysis proved the presence of oxygen, carbon, iron, and copper elements in the catalyst. Further, TGA analysis showed high thermal stability of the nanocomposite. VSM technique was applied to examine the magnetic property of the nanocomposite. The results demonstrated a high magnetic property in the catalyst, which enables easy separation of it from the reaction solution. TEM and SEM imaging showed the nanoscale size of the particles (~20 nm) in the catalyst. Additionally, XRD data was compatible with that of Fe3O4 nanoparticles. The application of the nanocomposite has been studied in the selective oxidation of alcohols in the presence of acetonitrile as solvent, and hydrogen peroxide as a supplementary oxidizing agent. This technique is remarkably facile and inexpensive. Further, the products showed high yields. In addition, the calculated TON and TOF values indicated the phenomenal efficiency of the nanocomposite in preparation of targeted products.

Cellulose-Supported Sulfonated Magnetic Nanoparticles: Utilized for One-pot Synthesis of α-Iminonitrile Derivatives.

ntroduction: An instrumental strategy for α-iminonitrile derivatives preparation by Fe3O4@cellulose-OSO3H (MCSA) as an eco-friendly nanocatalyst and oxidative agent in aerobic condition, is presented. MATERIALS AND METHODS: Through this method, a one-pot three-component condensation reaction of various aldehydes, primary amines and trimethylsilylcyanide (TMSCN) were applied to synthesize the desired products. It was performed in absolute ethanol and under a mild condition by using the presented nanocatalyst. High reaction yields were obtained through using the presented magnetic agent, as well. Moreover, the threecomponent reactions were executed using accessible and economical precursors. The convenient separation and recyclability of the used nanocatalyst were also precisely investigated. RESULTS AND DISCUSSION: In this research, we identified novel α-iminonitrile derivatives using 1H NMR, 13C NMR, CHN, and FT-IR analyses, as well. In order to determine the well-known derivatives, we used FT-IR method as well as comparing their melting points with those of reported. CONCLUSION: In summary, an extremely efficient method was used for the environmentally-friendly synthesis of α-iminonitrile derivatives that are important bioactive substances. The catalytic oxidative coupling reaction afforded the products via a one-pot three-component condensation reaction of various aldehydes, primary amines and TMSCN with great reaction yields, in ethanol under mild conditions.

Synergistic catalytic effect between ultrasound waves and pyrimidine-2,4-diamine-functionalized magnetic nanoparticles: Applied for synthesis of 1,4-dihydropyridine pharmaceutical derivatives.

A convenient strategy for synthesis of the various derivatives of 1,4-dihydropyridine (1,4-DHP), as one of the most important pharmaceutical compounds, is presented in this study. For this purpose, firstly, magnetic iron oxide nanoparticles (Fe3O4 NPs) were fabricated and suitably coated by silica network (SiO2) and trimethoxy vinylsilane (TMVS). Then, their surfaces were well functionalized with pyrimidine-2,4-diamine (PDA) as the main active sites for catalyzing the synthesis reactions. In this regard, the performance of three different methods including reflux, microwave (MW) and ultrasound wave (USW) irradiations have been comparatively monitored via studying various analyses on the fabricated nanocatalyst (Fe3O4/SiO2-PDA). Concisely, high efficiency of the USW irradiation (in an ultrasound cleaning bath with a frequency of 50 kHz and power of 250 W/L) has been well proven through the investigation of the main factors such as excellent surface-functionalization, core/shell structure conservation, particle uniformity, close size distribution of the particles, and great inhibition of the particle aggregation. Then, the effectiveness of the USW irradiation as a promising co-catalyst agent has been clearly demonstrated in the 1,4-DHP synthesis reactions. It has been concluded that the USW could provide more appropriate conditions for activation of the catalytic sites of Fe3O4/SiO2-PDA NPs. However, high reaction yields (89%) have been obtained in the short reaction times (10 min) due to the substantial synergistic effect between the presented nanocatalyst and USW.

Facile Peptide Bond Formation: Effective Interplay between Isothiazolone Rings and Silanol Groups at Silver/Iron Oxide Nanocomposite Surfaces.

Proportional to considerable progress in protein-drug conjugations, attention to the efficient peptide coupling reagents is being increased. Hence, in this study, a versatile heterogeneous nanoscale reagent is presented for chemical, biological, and medical purposes. A combination of silver and silica-coated iron oxide nanoparticles (Ag/Fe3O4) has been well functionalized with isothiazolone rings via a silver-modified Heck mechanism. An appropriate condition is provided for peptide bond formation through the surface interplay between silanol groups and the loaded isothiazolone rings. A logical mechanism including a series of successive covalent bonds onto the surface of Ag/Fe3O4 nanocomposites is suggested for this catalyzed peptide bond formation. Accurate comparisons have been made to obtain the optimum value of the nanocatalyst and suitable conditions. As an additional application, the biological activity of the desired product has also been investigated through antibacterial assay tests. The results showed that our desired product could also be used as an effective heterogeneous nanoscale antibacterial agent for different purposes. In this regard, all of the essential structural and practical analyses have been carried out and precisely interpreted.

Design and preparation of Fe3O4@PVA polymeric magnetic nanocomposite film and surface coating by sulfonic acid via in situ methods and evaluation of its catalytic performance in the synthesis of dihydropyrimidines.

For the first time, the design and preparation of magnetic polyvinyl alcohol (Fe3O4@PVA) nanocomposite film as a novel nanocatalyst was accomplished by in situ precipitation method. To enhance the catalysis activity, the surface modification of this nanocomposite was carried out by sulfonic acid. After the synthesis of this nanocomposite film, Fourier-transform infrared (FT-IR) spectroscopy, energy-dispersive X-ray (EDX) analysis, field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) images, X-ray diffraction (XRD) pattern, N2 adsorption-desorption by Brunauer-Emmett-Teller (BET), thermogravimetric analysis (TGA) and vibrating sample magnetometer (VSM) were utilized to confirm the structure of the nanocomposite. The catalytic activity of Fe3O4@PVA was investigated by the synthesis of dihydropyrimidine derivatives from an aldehyde, ß-ketoester and urea or thiourea. This heterogeneous nanocatalyst can be easily separated by an external magnet and reused for several times without any significant loss of activity. Simple work-up, mild reaction conditions and easily recoverable catalyst are the advantageous of this nanocomposite film.

Cellulose matrix embedded copper decorated magnetic bionanocomposite as a green catalyst in the synthesis of dihydropyridines and polyhydroquinolines.

A new biopolymer-based magnetic nanocomposite was prepared and characterized by Fourier transform infrared (FT-IR) spectroscopy, energy-dispersive X-ray (EDX) analysis, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images, inductively-coupled plasma atomic emission spectroscopy (ICP-AES) analysis, thermogravimetric/differential thermal (TG/DT) analysis and atomic force microscopy (AFM) image analysis. Then, it was applied as an efficient heterogeneous catalyst in two important three- and four-component one-pot organic condensation reactions for the synthesis of Hantzsch 1,4-dihydropyridine and polyhydroquinoline derivatives in high yields under solvent-free condition at room temperature. The first design and development of a low-leaching bionanostructure, easy separation and reusability of the nanocatalyst, simple work-up procedure, mild, green and environmentally friendly conditions are some important features and advantages of the present work.

Green in water sonochemical synthesis of tetrazolopyrimidine derivatives by a novel core-shell magnetic nanostructure catalyst.

A green approach for the one-pot four-component sonochemical synthesis of 5-methyl-7-aryl-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylic esters from the reaction of 2-cyano-guanidine, sodium azide, various aromatic aldehydes and methyl or ethyl acetoacetate in the presence of a catalytic amount of Fe2O3@SiO2-(CH2)3NHC(O)(CH2)2PPh2 as a new hybrid organic-inorganic core-shell nanomagnetic catalyst is described. This is the first design, preparation, characterization and application of the present nanomaterial and also the first ultrasound irradiated synthesis of the biologically and pharmaceutically important heterocyclic compounds in water as a green solvent. This novel sonocatalysis/nanocatalysis protocol offers several advantages such as high yields, short reaction times, environmentally-friendly reaction media, easily isolation of the products, simple preparation, full characterization and recoverability of the nanocatalyst by an external magnet and reusing several times without significant loss of activity.