Strategies for the synthesis of enantiopure compounds focused on organocatalysis

Podeu consultar el llibre complet a: http://hdl.handle.net/2445/32393The preparation of enantiomerically pure compounds (EPC) is a continuous social demand due to the clinical advantages that enantiopure drugs offer over the racemic forms. Here, the best well-established synthetic strategies to access to single-enantiomer compounds are briefly described and compared. In particular, the enantioselective catalysis is introduced paying special attention to the organocatalysis, an emerging and fruitful area in the EPCsynthesis. Of particular interest is the use of small organic molecules as catalysts in cascade reactions. Organocascade reactions involve the formation of several chemical bonds and often generate stereogenic centers with excellent stereoselectivity. Such one-pot reactions avoid time-consuming and costly step-bystep processes and are environmentally friendly as they occur in the absence of metals. Additionally, the chemical waste of the organocatytic cascade reactions is drastically reduced since the intermediates are not isolated and purified

Short-Term Effects of Three Types of Hamstring Stretching on Length, Neurodynamic Response, and Perceived Sense of Effort—A Randomised Cross-Over Trial

Background: Stretching techniques for hamstring muscles have been described both to increase muscle length and to evaluate nerve mechanosensitivity. Aim: We sought to evaluate the short-term effects of three types of hamstring stretching on hamstring length and report the type of response (neural or muscular) produced by ankle dorsiflexion and perceived sense of effort in asymptomatic subjects. Methods: A randomised cross-over clinical trial was conducted. A total of 35 subjects were recruited (15 women, 20 men; mean age 24.60 ± 6.49 years). Straight leg raises (SLR), passive knee extensions (PKE), and maximal hip flexion (MHF) were performed on dominant and non-dominant limbs. In addition, the intensity of the applied force, the type and location of the response to structural differentiation, and the perceived sensation of effort were assessed. Results: All stretching techniques increased hamstring length with no differences between limbs in the time*stretch interaction (p < 0.05). The perceived sensation of effort was similar between all types of stretching except MHF between limbs (p = 0.047). The type of response was mostly musculoskeletal for MHF and the area of more neural response was the posterior knee with SLR stretch. Conclusions: All stretching techniques increased hamstring length. The highest percentage of neural responses was observed in the SLR stretching, which produced a greater increase in overall flexibility

Right Paraduodenal Hernia in an Adult Patient: Diagnostic Approach and Surgical Management

Paraduodenal hernia, a rare congenital anomaly which arises from an error of rotation of the midgut, is the most common type of intraabdominal hernia. There are two variants, right and left paraduodenal hernia, the right being less common. We report the case of a 41-year-old patient with a right paraduodenal hernia with a 6-month history of intermittent episodes of intestinal obstruction. Diagnosis was established by CT scan and upper gastrointestinal series with small bowel follow-through. In a planned laparotomy, herniation of the small bowel loops through the fossa of Waldeyer was found. Division of the lateral right attachments of the colon opened the hernia sac widely, replacing the pre- and postarterial segments of the intestine in the positions they would normally occupy at the end of the first stage of rotation during embryonic development. Six months after the surgery, after an uneventful recovery, the patient remains free of symptoms

Left hepatic lobe herniation through an incisional anterior abdominal wall hernia and right adrenal myelolipoma: a case report and review of the literature

<p>Abstract</p> <p>Introduction</p> <p>Herniation of the liver through an anterior abdominal wall hernia defect is rare. To the best of our knowledge, only three cases have been described in the literature.</p> <p>Case presentation</p> <p>A 70-year-old Mexican woman presented with a one-week history of right upper quadrant abdominal pain, nausea, vomiting, and jaundice to our Department of General Surgery. Her medical history included an open cholecystectomy from 20 years earlier and excessive weight. She presented with jaundice, abdominal distension with a midline surgical scar, right upper quadrant tenderness, and a large midline abdominal wall defect with dullness upon percussion and protrusion of a large, tender, and firm mass. The results of laboratory tests were suggestive of cholestasis. Ultrasound revealed choledocholithiasis. A computed tomography scan showed a protrusion of the left hepatic lobe through the anterior abdominal wall defect and a well-defined, soft tissue density lesion in the right adrenal topography. An endoscopic common bile duct stone extraction was unsuccessful. During surgery, the right adrenal tumor was resected first. The hernia was approached through a median supraumbilical incision; the totality of the left lobe was protruding through the abdominal wall defect, and once the lobe was reduced to its normal position, a common bile duct surgical exploration with multiple stone extraction was performed. Finally, the abdominal wall was reconstructed. Histopathology revealed an adrenal myelolipoma. Six months after the operation, our patient remains in good health.</p> <p>Conclusions</p> <p>The case of liver herniation through an incisional anterior abdominal wall hernia in this report represents, to the best of our knowledge, the fourth such case reported in the literature. The rarity of this medical entity makes it almost impossible to specifically describe predisposing risk factors for liver herniation. Obesity, the right adrenal myelolipoma mass effect, and the previous abdominal surgery are likely to have contributed to incisional hernia formation.</p

Strategies for the synthesis of enantiopure compounds focused on organocatalysis

Podeu consultar el llibre complet a: http://hdl.handle.net/2445/32393The preparation of enantiomerically pure compounds (EPC) is a continuous social demand due to the clinical advantages that enantiopure drugs offer over the racemic forms. Here, the best well-established synthetic strategies to access to single-enantiomer compounds are briefly described and compared. In particular, the enantioselective catalysis is introduced paying special attention to the organocatalysis, an emerging and fruitful area in the EPCsynthesis. Of particular interest is the use of small organic molecules as catalysts in cascade reactions. Organocascade reactions involve the formation of several chemical bonds and often generate stereogenic centers with excellent stereoselectivity. Such one-pot reactions avoid time-consuming and costly step-bystep processes and are environmentally friendly as they occur in the absence of metals. Additionally, the chemical waste of the organocatytic cascade reactions is drastically reduced since the intermediates are not isolated and purified

Zenker's Diverticulum: Diagnostic Approach and Surgical Management

Zenker's diverticulum (ZD), also known as cricopharyngeal, pharyngoesophageal or hypopharyngeal diverticulum, is a rare condition characterized by an acquired outpouching of the mucosal and submucosal layers originating from the pharyngoesophageal junction. This false and pulsion diverticulum occurs dorsally at the pharyngoesophageal wall between the inferior pharyngeal constrictor and the cricopharyngeus muscle. The pathophysiology of ZD involves altered compliance of the cricopharyngeus muscle and raised intrabolus pressure. Decreased compliance of the upper esophageal sphincter and failure to open completely for effective bolus clearance both lead to an increase in the hypopharyngeal pressure gradient. Different open surgical techniques and transoral endoscopic approaches have been described for the management of ZD, although there is no consensus about the best option. We report the case of a 61-year-old patient with a 7-year history of dysphagia and odynophagia for solid food, which after 2 months progressed to dysphagia for liquids and after 4 months to regurgitation 2-6 h after meals. The patient experienced a 12-kg weight loss. Diagnosis was established by esophagogram, which showed a diverticulum through the posterior pharyngeal wall, suggestive of a ZD. Esophagogastroduodenoscopy showed a pouch with erythematous mucosa. Under general anesthesia, diverticulectomy and myotomy were performed. After an uneventful recovery and adequate oral intake, the patient remains free of symptoms at 4 months of follow-up

Los conceptos fundamentales de las matemáticas a través de la experiencia

El tema que nos propusimos investigar en esta red de investigación e innovación docente se encuentra contextualizado en torno a la cuestión de cómo ayudar al alumnado novel o inexperto de los grados de Matemáticas y Física en el estudio y comprensión de los conceptos, metodologías y técnicas de trabajo vinculados a las principales materias de primer curso adscritas al departamento de matemáticas. No cabe duda de que el acceso a estas dos carreras universitarias conlleva en el alumnado un cambio de mentalidad, de forma de trabajar y de razonar, lo que acarrea particularmente una ruptura con su anterior manera de enfrentarse a los problemas y cuestiones matemáticas, tanto de índole teórica como práctica. En algunos casos, este cambio supone una barrera infranqueable e impide al alumnado continuar con su formación académica. En base a esta situación, el trabajo de la red durante este curso ha consistido inicialmente en averiguar cuáles son esas barreras, conceptos y estructuras que, en opinión del alumnado, son especialmente complejas. Una vez identificados los principales problemas, en colaboración estrecha con el alumnado, valoramos su importancia y procedimos a ponderar el grado de dificultad o conflictividad, para los estudiantes, de los conceptos matemáticos involucrados que, a la postre, resultan imprescindibles para su aprendizaje. Así, centrándonos en algunos de estos conceptos clave, una parte importante del trabajo de la red ha consistido en encontrar el lenguaje, el canal y la forma de conseguir que estas nociones lleguen al alumnado de una manera distinta, amena, enérgica y competente. En particular, una de las novedades de este trabajo, en el contexto docente universitario señalado con anterioridad, ha sido el empleo de la herramienta TikTok

Adult intussusception secondary to an ileum hamartoma

Intussusception is a rare condition in the adult population. However, in contrast to its presentation in children, an identifiable etiology is found in the majority of cases. Clinical manifestations of adult intussusception are non-specific and patients may present with acute, intermittent or chronic symptoms, predominantly those of intestinal obstruction. A 27-year-old male patient with recurrent abdominal pain secondary to intussusception is herein reported. The clinical presentation and ultrasonographic findings led to the diagnosis. At laparotomy, an ileal hamartoma was found as the lead point of the intussusception. Surgical management and histopathologic studies are described. A recurrent intestinal obstruction and classic ultrasound findings may lead to the diagnosis of intussusception but surgical exploration remains essential. The principle of resection without reduction is well established

Effects of Diacutaneous Fibrolysis on Passive Neuromuscular Response and Mechanosensitivity in Athletes with Hamstring Shortening: A Randomized Controlled Trial

Introduction. Diacutaneous Fibrolysis is defined as specific instrumental intervention to normalize function in the musculoskeletal system. It is considered a treatment method for the mechanical alterations of the locomotor system, and it is widely used in sports for therapeutic and preventive purposes. Despite the clinical benefits observed in different musculoskeletal conditions, the action mechanism of diacutaneous fibrolysis remains uncertain. There are no studies evaluating the neuromuscular response on the posterior muscular chain of the lower extremity in athletes, where overload, stiffness, and injury incidence are high. Objective. To evaluate the immediate, and 30 min post treatment effects of a single diacutaneous fibrolysis session on passive neuromuscular response and mechanosensitibity on hamstring and gluteus in athletes with shortening. Design. A randomized within participant clinical trial. Methods. Sixty-six athletes with hamstring shortening were included (PKE &lt; 160). The lower limbs were randomized between the experimental limb and control limb, regardless of dominance. A single session of diacutaneous fibrolysis was applied to the posterior gluteus maximus, biceps femoris, and semitendinosus of the experimental lower limb whereas the control limb was not treated. Viscoelastic muscle properties (myotonometry), contractile muscle properties (tensomiography), and mechanosensitivity (algometry) were tested before treatment (T0), after treatment (T1), and 30 min post treatment (T2). Results. Regarding viscoelastic properties, in the intra-group analysis we found statistically significant differences in the experimental limb at T1, decreasing muscle stiffness in gluteus maximus (p &lt; 0.042), in biceps femoris (p &lt; 0.001) and in semitendinosus (p &lt; 0.032). We also observed statistically significant differences in Tone decrease (p &lt; 0.011) and relaxation increase (p &lt; 0.001) in biceps femoris. At T2, the decrease in stiffness in all tested muscles was maintained (p &lt; 0.05). There were statistically significant inter-groups differences in stiffness on gluteus (p &lt; 0.048) and biceps femoris (p &lt; 0.019) and in tone on biceps femoris (p &lt; 0.009) compared to the control limb. For contractile properties, we only found statistically significant differences on maximal radial displacement (Dm) in gluteus, both control and experimental at T2 (p &lt; 0.05) and in biceps femoris control (p &lt; 0.030). No changes were found in the mechanosensitivity. Conclusions. A single session of diacutaneous fibrolysis produces changes in some parameters related to viscoelasticity properties of the biceps femoris and gluteus. There were no changes on contractile properties on semitendinosus. Only small changes on the contractile properties on the gluteus maximus and biceps femoris were found. No effect was found on the mechanosensitivity of the posterior chain muscles in athletes with hamstring shortening