RESUMEN
The reaction of indigo with two equivalents of the electrophile ethyl bromoacetate with caesium carbonate as a base result in the formation of structurally complex polyheterocyclics, including a fused spiroimidazole and a spiro[1,3]oxazino derivative, together with a biindigoid-type derivative, through a convenient one-pot reaction. Further assessment of the reaction using five equivalents of the electrophile gave rise to other molecules incorporating the 2-(7,13,14-trioxo-6,7,13,14-tetrahydropyrazino[1,2-a:4,3-a']diindol-6-yl) scaffold. The reaction of ethyl bromoacetate with the less reactive indirubin resulted in the synthesis of three derivatives of a new class of polyheterocyclic system via a cascade process, although yields were low. These compounds were derived from the parent indolo[1,2-b]pyrrolo[4,3,2-de]isoquinoline skeleton. Despite the modest yields of the reactions, they represent quick cascade routes to a variety of heterocycles from cheap starting materials, with these structures otherwise being difficult to synthesise in a traditional stepwise manner. These outcomes also contribute significantly to the detailed understanding of the indigo/indirubin cascade reaction pathways initiated by base-catalysed N-alkylation.
RESUMEN
Continuous reaction networks, which do not rely on purification or timely additions of reagents, serve as models for chemical evolution and have been demonstrated for compounds thought to have played important roles for the origins of life such as amino acids, hydroxy acids, and sugars. Step-by-step chemical protocols for ribonucleotide synthesis are known, but demonstrating their synthesis in the context of continuous reaction networks remains a major challenge. Herein, compounds proposed to be important for prebiotic RNA synthesis, including glycolaldehyde, cyanamide, 2-aminooxazole, and 2-aminoimidazole, are generated from a continuous reaction network, starting from an aqueous mixture of NaCl, NH4Cl, phosphate, and HCN as the only carbon source. No well-timed addition of any other reagents is required. The reaction network is driven by a combination of γ radiolysis and dry-down. γ Radiolysis results in a complex mixture of organics, including the glycolaldehyde-derived glyceronitrile and cyanamide. This mixture is then dried down, generating free glycolaldehyde that then reacts with cyanamide/NH3 to furnish a combination of 2-aminooxazole and 2-aminoimidazole. This continuous reaction network models how precursors for generating RNA and other classes of compounds may arise spontaneously from a complex mixture that originates from simple reagents.
Asunto(s)
Evolución Química , Modelos Químicos , ARN/química , ARN/síntesis química , Acetaldehído/análogos & derivados , Acetaldehído/síntesis química , Acetaldehído/química , Cianamida/síntesis química , Cianamida/química , Rayos gamma , Imidazoles/síntesis química , Imidazoles/química , Origen de la Vida , Oxazoles/síntesis química , Oxazoles/química , Fotoquímica , Agua/químicaRESUMEN
Median cleft lip with nasal dermoid is a very rare occurrence. Midline nasal dermoid results from the abnormal fusion of embryological processes. They can present as asymptomatic midline nasal swelling, infection, or meningitis due to intracranial extension. Median cleft lip also results from failure of fusion of embryological processes and can be complete or incomplete or associated with other congenital anomalies or as a part of syndrome. We present a rare combination of both in a 7-month-old female child who was surgically treated.
RESUMEN
Bacillus genera, especially among rhizobacteria, are known for their ability to promote plant growth and their effectiveness in alleviating several stress conditions. This study aimed to utilize indigenous Bacillus cereus PM38 to degrade four organophosphate pesticides (OPs) such as chlorpyrifos (CP), profenofos (PF), monocrotophos (MCP), and dimethoate (DMT) to mitigate the adverse effects of these pesticides on cotton crop growth. Strain PM38 exhibited distinct characteristics that set it apart from other Bacillus species. These include the production of extracellular enzymes, hydrogen cyanide, exopolysaccharides, Indol-3-acetic acid (166.8 µg/mL), siderophores (47.3 µg/mL), 1-aminocyclopropane-1-carboxylate deaminase activity (32.4 µg/mL), and phosphorus solubilization (162.9 µg/mL), all observed at higher concentrations. This strain has also shown tolerance to salinity (1200 mM), drought (20% PEG-6000), and copper and cadmium (1200 mg/L). The amplification of multi-stress-responsive genes, such as acdS, ituC, czcD, nifH, sfp, and pqqE, further confirmed the plant growth regulation and abiotic stress tolerance capability in strain PM38. Following the high-performance liquid chromatography (HPLC) analysis, the results showed striking compatibility with the first kinetic model. Strain PM38 efficiently degraded CP (98.4%), PF (99.7%), MCP (100%), and DMT (95.5%) at a concentration of 300 ppm over 48 h at 35 °C under optimum pH conditions, showing high coefficients of determination (R2) of 0.974, 0.967, 0.992, and 0.972, respectively. The Fourier transform infrared spectroscopy (FTIR) analysis and the presence of opd, mpd, and opdA genes in the strain PM38 further supported the potential to degrade OPs. In addition, inoculating cotton seedlings with PM38 improved root length under stressful conditions. Inoculation of strain PM38 reduces stress by minimizing proline, thiobarbituric acid-reactive compounds, and electrolyte leakage. The strain PM38 has the potential to be a good multi-stress-tolerant option for a biological pest control agent capable of improving global food security and managing contaminated sites.
Asunto(s)
Bacillus cereus , Cloropirifos , Monocrotofos , Cloropirifos/metabolismo , Cloropirifos/toxicidad , Bacillus cereus/metabolismo , Monocrotofos/toxicidad , Dimetoato/toxicidad , Gossypium , Biodegradación Ambiental , Organotiofosfatos , Rizosfera , FosforamidasRESUMEN
Hepatic haemangioma is the most common benign tumour of liver. Most of them remain asymptomatic and are detected incidentally. Tc 99m RBC blood pool imaging is highly specific diagnostic modality of choice for hepatic haemangioma as its hypervascular nature may create equivocal result on CT or MRI. The sensitivity and specificity increases using SPECT especially in lesion less than 2 cm. Therefore all patients suspected of having hepatic haemangioma should undergo Tc 99m blood pool imaging.
Asunto(s)
Eritrocitos/diagnóstico por imagen , Hemangioma/diagnóstico por imagen , Neoplasias Hepáticas/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Tecnecio , Tomografía Computarizada de Emisión de Fotón Único/métodos , Tomografía Computarizada por Rayos XRESUMEN
We herein describe the successful anesthetic management of a patient with stiff person syndrome undergoing right total hip replacement under spinal anesthesia. We also describe the problems associated with general anesthesia. The advantage of using regional anesthesia in these patients is the avoidance of muscle relaxants. The use of general anesthesia carries the risk of hypotonia in stiff person syndrome postoperatively due to enhancement of γ aminobutyric acid (GABA) action on synaptic transmission by drugs that have a γ GABA agonistic action.