Weak-field coherent control of photodissociation in polyatomic molecules.

A coherent control scheme is suggested to modify the output of photodissociation in a polyatomic system. The performance of the scheme is illustrated by applying it to the ultrafast photodissociation of CH3I in the A-band. The control scheme uses a pump laser weak field that combines two pulses of a few femtoseconds delayed in time. By varying the time delay between the pulses, the shape of the laser field spectral profile is modulated, which causes a change in the initial relative populations excited by the pump laser to the different electronic states involved in the photodissociation. Such a change in the relative populations produces different photodissociation outputs, which is the basis of the control achieved. The degree of control obtained over different photodissociation observables, like the branching ratio between the two dissociation channels of CH3I yielding I(2P3/2) and I*(2P1/2) and the fragment angular distributions associated with each channel, is investigated. These magnitudes are found to oscillate strongly with the time delay, with the branching ratio changing by factors between two and three. Substantial variations of the angular distributions also indicate that the scheme provides a high degree of control. Experimental application of the scheme to general polyatomic photodissociation processes should be straightforward.

[Gastrointestinal bleeding caused by small bowel leiomyosarcoma]. / Hemorragia digestiva por leiomiosarcoma de intestino delgado.

The small bowel leiomyosarcoma is a infrequent tumour in the clinical practice. We report the case of a 50 year old male admitted to the hospital on two occasions for gastrointestinal bleeding. On the second occasion a push enteroscopy located in jejunum a tumour. The pathologic diagnosis was a low grade jejunal leiomyosarcoma. The patient required a surgical intervention with resection of the affected portion of the jejunum.

[Evaluation and improvement in the information of the patients who carry out a digestive endoscopy]. / Evaluación y mejora en la información de los pacientes que se realizan una endoscopia.

INTRODUCTION: The information is an important part of the attendance process though in occasions it can be inadequate or deficient. AIM: We detect an opportunity of improvement in the inadequate information of the patients who carry out an endoscopia. The aim is to evaluate and to improve the quality of the information. METHOD: We realize the first evaluation with 100 patients proceeding from consultations, detecting ignorance of the technology. Actions of improvement are applied, for 4 months, to realize the second evaluation, with the same number of patients and to evaluate improvement with regard to the situation of item. RESULTS: A deficit of information has been detected in the moment to indicate the endoscopia (little information contributed by the doctor prescriptor and in an important number of cases informed assent was not contributed) and after realizing the test, not contributing recommendations. We prioritize our action to this level with measures of improvement and after a new evaluation, a significant improvement decides in these situations. CONCLUSIONS: The studies of qualit level allow us to detect deficit situations and to improve situations in the services of health.

[Multiple angiodysplasia of the small intestine. A diagnostic and therapeutic challenge]. / Angiodisplasia múltiple de intestino delgado. Un reto diagnóstico y terapéutico.

Small bowel bleeding is infrequent and presents a challenge to the clinician. Approximately 30-40% of gastrointestinal bleeding localized in the small bowel is due to angiodysplasia, a vascular malformation. We present the case of a patient with multiple angiodysplasia of the small bowel who required push enteroscopy and capsule endoscopy to establish the diagnosis. Treatment with subcutaneous octreotide was successful. In conclusion, in doubtful cases or in patients with persistent hemorrhage, capsule endoscopy can improve the diagnostic yield of enteroscopy in bleeding gastrointestinal vascular lesions such as angiodysplasia. Endoscopic treatment (laser coagulation) and drug therapy (somatostatin or analogs) are valid alternatives in inoperable or non-resectable cases.

[Amebic colitis in an immunocompetent host]. / Colitis amebiana en pacientes inmunocompetente.

Amebic colitis is a low prevalence illness in developed countries. Its diagnosis is infrequent and is usually made in certain groups of risk. Images studies are not useful in differential diagnosis with other illnesses as Inflammatory Bowel Disease (IBS). Next clinical note shows the problems in the diagnosis of amebic colitis in an immunocompetent host without risk factors.