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Using a 1:1 cocrystal of (E)-N-(3,4-difluorophenyl)-1-(pyridin-4-yl)methanimine with acetic acid, C12H8F2N2·C2H4O2, we investigate the influence of F atoms introduced to the aromatic ring on promoting π-π interactions. The cocrystal crystallizes in the triclinic space group P1. Through crystallographic analysis and computational studies, we reveal the molecular arrangement within this cocrystal, demonstrating the presence of hydrogen bonding between the acetic acid molecule and the pyridyl group, along with π-π interactions between the aromatic rings. Our findings highlight the importance of F atoms in promoting π-π interactions without necessitating full halogenation of the aromatic ring.
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cis-2-tert-Butyl-5-(tert-butylsulfonyl)-1,3-dioxane (cis-1) exhibits a high degree of eclipsing in the H-C5-S-C segment in the solid state, the origin of which remains unexplained. The eclipsed conformation that corresponds to an energetic minimum in the solid state practically corresponds to a rotational transition state in solution, which allows an approach to understand transitions states. The difference in the enthalpy of sublimation ΔsubH between cis-1 and the more stable trans-1 is 8.40 kcal mol-1, lets to consider that the intermolecular interactions in the crystalline structure must be responsible for the conformational effect observed in the solid state. The study of the experimental electron density of cis-1 in solid state allowed to establish that CHâ¯OîS intermolecular interaction is the main contribution to the observed eclipsing. The charge density analysis was also performed using the quantum theory of atoms in molecules to evaluate the nature and relevance of the intermolecular interactions in the crystal structure.
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Giardia duodenalis, is a binuclear and microaerophilic protozoan that causes giardiasis. Up to date, several molecular approaches have been taken to understand the molecular mechanisms of diverse cellular processes in this parasitic protozoan. However, the role of many genes involved in these processes needs further analysis. The CRISPR interference (CRISPRi) system has been widely used, as a constitutive expression system for gene silencing purposes in several parasites, including Giardia. The aim of this work was to implement a tunable t-CRISPRi system in Giardia to silence abundant, moderately and low expressed genes, by constructing an optimized and inducible plasmid for the expression of both gRNA and dCas9. A doxycycline inducible pRan promoter was used to express dCas9 and each gRNA, consistently dCas9 expression and nuclear localization were confirmed by Western-blot and immunofluorescence in transfected trophozoites. The transcriptional repression was performed on α-tubulin (high expression), giardipain-1 (moderate expression) and Sir2 and Sir4 (low expression) genes. The α-tubulin gene knock-down caused by dCas9 doxycycline-induction was confirmed by a decrease in its protein expression which was of 50% and 60% at 24 and 48 h, respectively. This induced morphological alterations in flagella. The giardipain-1 knock down, showed a decrease in protein expression of 40 and 50% at 12 and 24 h, respectively, without affecting trophozoites viability, consistent with this a zymogram analysis on giardipain-1 knock down revealed a decrease in giardipain-1 protease activity. When repressing sirtuins expression, a total repression was obtained but trophozoites viability was compromised. This approach provides a molecular tool for a tailored repression to produce specific gene knockdowns.
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Giardia lamblia , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Doxiciclina , Giardia lamblia/genética , Giardia lamblia/metabolismo , Plasmídeos , RNA Guia de Cinetoplastídeos/metabolismo , Tubulina (Proteína)RESUMO
Irradiation of dichloroethane solutions of different bile acids with diacetoxy(iodobenzene) and iodine followed by treatment of the resulting raw mixture with MCPBA led to the 41-50% yields of the corresponding dehomologated alcohols in an uncomplicated one-pot protocol that can be completed in less than one day of work.
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Álcoois/síntese química , Ácidos e Sais Biliares/química , Álcoois/química , Iodo/química , Iodobenzenos/química , Estrutura MolecularRESUMO
INTRODUCTION: Distal Intestinal Obstruction Syndrome is a rare complication in patients with cystic fibrosis, which characterized by the accumulation of viscid fecal material, combined with sticky mucous secretions located in the distal ileum adhere to the intestinal wall, causing complete bowel obstruction. PRESENTATION OF CASE: We report a case of a 45 years old patient with cystic fibrosis, who presented bowel obstruction secondary to accumulation of fecal material, combined with mucous secretions, in the mid-jejunum. A diagnostic laparoscopy was performed where a dilated jejunum was encountered with impaction of fecal content. Surgery was converted to open surgery, where a longitudinal enterotomy of 5 cm after the transition zone was created, evacuating manually the fecal material with mucous secretion. The patient evolved favorably, without complications. DISCUSSION: We present a case of a patient with cystic fibrosis presenting with bowel obstruction due to a proximal intestinal obstruction syndrome, which can be diagnosed with the DIOS definition, with the only distinction of a more proximal location in the gastrointestinal tract, such as the stomach, the duodenum, or the jejunum. CONCLUSION: It is important for the clinician to know the existence of this syndrome at its different locations in the small bowel to treat accordingly.
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Molecular recognition of saccharides is a growing field, which has many implications in cancer therapy, drug discovery, and cellular communication among others. The participation of CH/π interactions in this event is well known. Nevertheless, the intrinsic role of CH/π for modulating chemical reactions is still far from being applicable. In this experimental and computational work we have evaluated the participation of CH/π interactions in the aminolysis reaction of acetyl galactoside promoted with different 6-substituted 2(1H)-pyridones. Two features have been incorporated to the promoter molecular structure, on one end the promoting pyridone group and on the other end the recognition moiety, joined together by an alkyne spacer. The small increment in the observed pseudo-first-order rate constant values (kobs) was related to the stability of the transition state provided by noncovalent interactions, including CH/π interactions. A longer alkyne spacer was necessary to improve the molecular recognition of the galactoside substrate. The trend of the calculated activation energy values (ΔERTS) was in good accordance with the experimental rate constant values.
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Galactosídeos/química , Teoria Quântica , Aminas/química , Configuração de Carboidratos , Ligação de Hidrogênio , Modelos MolecularesRESUMO
BACKGROUND: Pancreatic macrocystic serous cystadenoma is an uncommon benign lesion that can be misdiagnosed as a mucinous cystic neoplasm which, in turn, harbors malignant potential. We present the case of a patient with a pancreatic macrocystic serous cystadenoma and review current diagnostic modalities. CLINICAL CASE: We present the case of a 28-year-old otherwise-healthy female who was incidentally found to have a pancreatic cyst. Computed tomography (CT) and endoscopic ultrasound (EUS) revealed a 3.0 cm lobulated and septated lesion in the head of the pancreas. Fine-needle aspiration (FNA) of the cyst revealed mucoid contents and a carcinoembryonic antigen (CEA) level of 0.69 ng/mL. The presumptive diagnosis of a mucinous cystic neoplasm was made and the lesion was resected by enucleation. Surgical pathology reported a 1.60 cm dominant cystic lesion lined with cuboidal epithelium and multiple adjacent microscopic satellite cysts, consistent with the macrocystic variant of the serous cystadenoma. CONCLUSIONS: Pancreatic macrocystic serous cystadenoma is uncommon and can be misdiagnosed as a mucinous cystic neoplas. In order to make an accurate diagnosis and to select appropriate treatment, surgeons must be familiar with the current diagnostic modalities.
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Cistadenoma Mucinoso/diagnóstico , Cistadenoma Seroso/diagnóstico , Neoplasias Pancreáticas/diagnóstico , Adulto , Diagnóstico Diferencial , Feminino , HumanosRESUMO
Se hace un estudio retrospectivo de 9 casos con dolor por cáncer avanzado en la cabeza y cuello, atendidos por el grupo de la Clínica del Dolor del Instituto Nacional de Oncología y Radiobiología, entre 1988 y 1991. A estos pacientes se les implantó un catéter con reservorio en el espacio epidural, al nivel del sistema nervioso central, para la aplicación de solución morfñinica. Se encontró un alivio total del dolor en 7 enfermos (77,8 por ciento ) y 2 sólo presentaron dolor ligero perfectamente controlable. Las complicaciones más frecuentes fueron fiebre (3 casos) y toma del sensorio (2 casos). No se reportaron sepsis. Se señala la importancia de una correcta preparación del paciente y un seguimiento estricto del mismo, en lo cual desempeña un papel muy importante la labor del personal de Enfermería oncológica
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Humanos , Analgesia Epidural/enfermagem , Neoplasias de Cabeça e Pescoço/terapia , Morfina , Cuidados Pós-Operatórios , Cuidados Pré-OperatóriosRESUMO
Se expone una sistemática de estudio y tratamiento aplicada en el Instituto Nacional de Oncología y Radiobilogía para los tumores no seminomatosos del testículo, que comprende todo lo necesario para su estadiamiento desde el punto de vista diagnóstico que incluye el uso de los marcadores tumores como método bilógico auxiliar de valor pronóstico, así como el tratamiento multidisciplinario que comprende el uso de la cirugía, las radiaciones ionizantes y la quimioterapia con drogas de primera línea como el cis-platino. Se muestran los resultados obtenidos en los 11 primeros pacientes. Se propone como línea a seguir por la institución