RESUMEN
In waste-to-energy plants, the determination of the flue gas flow rate in the post-combustion section is of the utmost importance, e.g., for the verification of the compliance to the minimum residence time requirements (tres>2s) or for the control of flue gas treatment reactant injection, but the harsh conditions (high temperature and content of pollutants) do not allow for a direct measurement. The present work reports an experimental assessment of an indirect approach to estimate the flue gas flow rate in the post-combustion section of a rotary kiln plant with reduced uncertainty. This method consists on the direct measurement of the flow rate at a "colder" section of the plant (the boiler outlet) combined to the simultaneous measurements of flue gas composition measurements upstream and downstream of the boiler. From these measurements it is then possible to determine the mass of false air and to retrieve the actual flue gas flow-rate in the post-combustion chamber. A massive experimental campaign has been conducted at a full-scale medical waste incinerator, in which flue gas flow rate was estimated at different waste loads and ambient conditions. The results show that the percentage of false air can be significant and simply neglecting it can lead to substantial under-performance of the plant. Issues related to the practical implementation of the methods are illustrated in detail and the possibility to extend the methodology towards an online determination of post-combustion flue gas flow rate is discussed.
Asunto(s)
Contaminantes Atmosféricos , Contaminantes Ambientales , Incineración , Contaminantes Atmosféricos/análisis , Calor , FríoRESUMEN
BACKGROUND: Laparoscopic total mesorectal excision for low rectal cancer is not considered a gold standard treatment due to the high conversion rate and the long operation time. METHODS: A retrospective review examined a surgical series of 174 laparoscopic low rectal resections involving total mesorectal excision (1995-2006), with particular reference to technical points as well as surgical and oncologic outcomes. Miles operations and partial mesorectal excisions were excluded. RESULTS: The cancer affected the low rectum in 110 cases and the medium rectum in 64 cases. A total of 68 patients were subjected to neoadjuvant radiochemotherapy. The anastomosis was mechanical for 83.3% of the cases and intersphinteric through the perineum for 16.6% of the cases. Protective ileostomy was performed in 112 cases. The conversion rate was 4.6%. The mesorectum remained intact in 91.6% of the cases and was partially interrupted in 15 of the cases. In no case was it totally discontinued. The postoperative morbidity rate was 16.7%, and the mortality rate was 0.57%. The incidence of anastomotic fistulas was 14.4%. The percentage was higher for males (18.6 vs 8.3%) and correlated with the low distance of the tumor from the anal verge (18.2 vs 7.8%) and the absence of a protection ileostomy (20.9 vs 10.7%). After an average follow-up period of 48.6 months (range, 24-149 months), six patients (3.44%) experienced a pelvic recurrence. The 5-year overall survival rate was 75.4%, and the disease-free survival rate was 61.9%. CONCLUSION: Laparoscopic total mesorectal excision for low rectal cancer is safe and effective, allowing surgical and oncologic outcomes similar to those reported for open surgery.
Asunto(s)
Adenocarcinoma/cirugía , Laparoscopía/métodos , Recurrencia Local de Neoplasia/patología , Neoplasias del Recto/cirugía , Adenocarcinoma/mortalidad , Adenocarcinoma/patología , Adulto , Anciano , Anciano de 80 o más Años , Canal Anal , Anastomosis Quirúrgica/métodos , Estudios de Cohortes , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Mucosa Intestinal/patología , Mucosa Intestinal/cirugía , Estimación de Kaplan-Meier , Laparoscopía/efectos adversos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/cirugía , Estadificación de Neoplasias , Complicaciones Posoperatorias/fisiopatología , Complicaciones Posoperatorias/cirugía , Proctoscopía/métodos , Neoplasias del Recto/mortalidad , Neoplasias del Recto/patología , Estudios Retrospectivos , Medición de Riesgo , Tasa de Supervivencia , Factores de Tiempo , Resultado del TratamientoRESUMEN
Six retro-inverso tri- and tetrapeptide analogues of RGD were prepared and their anti-aggregatory activity was determined by platelet aggregation tests in comparison with the corresponding parent peptides. An efficient method for the introduction of a malonyl-aspartic residue into a peptide chain is described for the first time. A 2-3-fold decrease in potency or total loss of bioactivity was observed with the new peptides; structure-activity relationships are discussed.
Asunto(s)
Oligopéptidos/farmacología , Inhibidores de Agregación Plaquetaria/farmacología , Amidas/química , Humanos , Enlace de Hidrógeno , Estructura Molecular , Oligopéptidos/síntesis química , Oligopéptidos/química , Agregación Plaquetaria/efectos de los fármacos , Inhibidores de Agregación Plaquetaria/síntesis química , Inhibidores de Agregación Plaquetaria/química , Conformación Proteica , Relación Estructura-ActividadRESUMEN
The effects of Gly-His-Lys-Cu and of three synthetic analogues (I, II and III) on wound healing of the guinea-pig dorsal skin, as well as on cultured fibroblasts, were examined. Gly-His-Lys-Cu and peptide I-Cu were tested in vivo. Hydroxyproline, proteins, DNA and semicarbazide-sensitive amine oxidase, with a high affinity for benzylamine, were measured, and the histology of the wounds was observed after staining with hematoxylin/eosin. Another set of wounds was treated in parallel with equivalent amounts of copper acetate. Gly-His-Lys-Cu and the analogues caused a decrease of the activity of semicarbazide-sensitive amine oxidase, with a high affinity for benzylamine, 4-8 days after surgery, followed by an increase on day 11 that was higher than in the control group. No significant difference was found between the two peptides. A slower reorganization of the skin and a delayed activation of fibroblasts are the main effects observed with these peptides-Cu complexes. Preliminary studies on cultured fibroblasts were monitored to see whether these peptides had a direct effect on fibroblasts. The products studied at a concentration of 10(-7) M, decreased cell reproduction and increased collagen expression.
Asunto(s)
Cobre/farmacología , Fibroblastos/efectos de los fármacos , Sustancias de Crecimiento/farmacología , Oligopéptidos/farmacología , Piel/efectos de los fármacos , Cicatrización de Heridas/efectos de los fármacos , Amina Oxidasa (conteniendo Cobre)/metabolismo , Análisis de Varianza , Animales , Carcinógenos/toxicidad , Células Cultivadas , Cobre/administración & dosificación , Cobre/metabolismo , ADN/metabolismo , Fibroblastos/citología , Sustancias de Crecimiento/administración & dosificación , Sustancias de Crecimiento/metabolismo , Cobayas , Hidroxiprolina/metabolismo , Masculino , Oligopéptidos/administración & dosificación , Oligopéptidos/metabolismo , Compuestos Organometálicos/administración & dosificación , Compuestos Organometálicos/farmacología , Proteínas/metabolismo , Piel/citología , Coloración y EtiquetadoRESUMEN
Five hundred and seventy-two US-guided fine-needle biopsies were performed on 561 patients (1.2 puncture/patient); in two cases only minor complications were observed. The patients were 12 to 86 years old--most of them ranging 40 to 75. In 5.42% of cases FNAB proved inadequate; 1.75% of the diagnoses was questionable, 28.89% was negative, and 63.98% positive. A comparison with histology was possible in 218 cases: 2 false positives and 5 false negatives were observed. The low rate of false-positive findings demonstrates US-guided FNAB to have high positive predictive value. The method had 95% sensitivity, 98.4% specificity and 84.3% accuracy. The high reliability of FNAB depends on the possibility of centering the lesion through the direct US visualization of the needle tip. This characteristic, together with the presence of the cytologist, who immediately evaluates the aspirated material, helps reduce the number of unnecessary biopsies and, consequently, complications.
Asunto(s)
Neoplasias Abdominales/patología , Neoplasias Torácicas/patología , Abdomen/diagnóstico por imagen , Abdomen/patología , Neoplasias Abdominales/diagnóstico por imagen , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Biopsia con Aguja/instrumentación , Biopsia con Aguja/métodos , Niño , Reacciones Falso Negativas , Reacciones Falso Positivas , Humanos , Persona de Mediana Edad , Agujas , Sensibilidad y Especificidad , Neoplasias Torácicas/diagnóstico por imagen , Tórax/diagnóstico por imagen , Tórax/patología , UltrasonografíaRESUMEN
The permeation rates through isolated epidermis of a homologous series of glycol, polyglycol, and alkyl esters of nicotinic acid were measured in vitro in a two-compartment diffusion cell assembly, using an isotonic buffered solution as the receiving phase. The esters were applied from aqueous solutions and also as the pure liquids. The results were consistent with those reported by other using compounds of equal or different structures either in vitro or in vivo. The experiments are compared in terms of partition equilibrium between vehicle and tissue and distribution from tissue to the receiving phase. It was demonstrated that the plateau observed in skin permeabilities of the compounds beyond a certain degree of lipophilicity is the result of the effect of water when used as the vehicle in the laboratory models.
Asunto(s)
Ácidos Nicotínicos/farmacocinética , Absorción Cutánea/fisiología , Cromatografía Líquida de Alta Presión , Humanos , Técnicas In Vitro , Matemática , Modelos Biológicos , Miristatos , Permeabilidad , AguaAsunto(s)
Heparina/farmacocinética , Absorción Intestinal , Animales , Inhibidores del Factor Xa , Masculino , RatasRESUMEN
Sixty-one non-traumatic perforations in free peritoneum are reported. The principal aetiology is diverticulitis (35 cases) followed by cancer (22 cases). 18 derivations were carried out, 34 colectomies without anastomosis, 5 ideal colectomies and 4 diverticulectomies. Total mortality was 19.7-14% for diverticulitis, 22.2% for perforations at the cancer site, 50% from diastasic perforations. Stress is laid on the need to treat colic perforation by colectomy without anastomosis, confining derivation openeum. Sixty-one cases.
Asunto(s)
Enfermedades del Colon/cirugía , Perforación Intestinal/cirugía , Enfermedades Peritoneales/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Enfermedades del Colon/etiología , Femenino , Humanos , Perforación Intestinal/etiología , Masculino , Persona de Mediana Edad , Enfermedades Peritoneales/etiologíaRESUMEN
Seven-hundred-two needle aspirates were taken from palpable lymph nodes between january 1982 and june 1987. Cytohistological correlation in about 70% of the preparations showed that the technique is capable of detecting neoplastic cells in 99% of metastases and in 90% of lymphoma cases. Certain technical aspects of smear preparation are pointed out with a view to reducing the percentage of inadequate samples (14% in the present series) and the position of the technique among other diagnostic procedures is discussed, with evaluation of advantages and limitations.
Asunto(s)
Citodiagnóstico , Ganglios Linfáticos/patología , Biopsia con Aguja , Femenino , Enfermedad de Hodgkin/diagnóstico , Enfermedad de Hodgkin/patología , Humanos , Metástasis Linfática/diagnóstico , Metástasis Linfática/patología , Linfoma/diagnóstico , Linfoma/patología , Linfoma no Hodgkin/diagnóstico , Linfoma no Hodgkin/patología , PalpaciónRESUMEN
The authors report two cases of haemoperitoneum due to intra-abdominal rupture of the round ligament in cirrhotic patients with portal hypertension. A review of the literature on the subject reveals the rarity of such observations. The eventuality must be borne in mind, however, in the treatment of the haemorrhagic complications of portal hypertension in view of the associated high mortality. Simple ligature of the bleeding varix is the operation which offers the greatest possibility of survival.
Asunto(s)
Hemoperitoneo/etiología , Ligamentos , Cirrosis Hepática/complicaciones , Várices/complicaciones , Hemoperitoneo/cirugía , Humanos , Cirrosis Hepática Alcohólica/complicaciones , Masculino , Persona de Mediana Edad , Rotura Espontánea , Várices/cirugíaRESUMEN
A number of 3-carbonylacrylic acid derivatives were prepared, with a view to varying systematically the stereoelectronic environment of the conjugated double bond. The rates of reaction with cysteine were measured spectrophotometrically when possible or by stopped flow when very fast. Some of the final reaction products were isolated. Other properties examined were partition substituent constants and antimicrobial activity. On the basis of published data and these studies, the activity appears to be the combined effect of at least two mechanisms, one probably related to the effect of these structures on surface tension, the other to the electrophilic properties of the unsaturated system.
Asunto(s)
Acrilatos/farmacología , Antiinfecciosos/síntesis química , Cisteína/metabolismo , Antibacterianos , Antiinfecciosos/farmacología , Espectroscopía de Resonancia Magnética , Microsporum/efectos de los fármacos , Espectrofotometría , Staphylococcus aureus/efectos de los fármacos , Relación Estructura-ActividadRESUMEN
Eight new aroyl-acrylic esters of polyethylene glycols were prepared using different synthetic ways. They are supposed to possess a higher activity as antimicotic agents for topical use, by favouring skin absorption. Except in few cases, the antimicrobial activity of the oligomeric derivatives resulted generally decreased in vitro, in comparison to simple alkyl esters previously prepared. However, only pharmacological screenings for antimicotic activity in vivo will give a definite response on whether the new derivatives are advantageous for topical use.
Asunto(s)
Acrilatos/síntesis química , Antiinfecciosos/síntesis química , Antifúngicos/síntesis química , Polietilenglicoles/síntesis química , Acrilatos/farmacología , Fenómenos Químicos , Química , Cromatografía en Capa Delgada , Pruebas de Sensibilidad Microbiana , Polietilenglicoles/farmacologíaRESUMEN
The authors report a case of chylothorax due to blunt trauma with fracture of the spine in a man aged 60. After mentioning the possible pathogenesis and clinics of the case shown, the Authors explain the treatment successfully adopted, that is, the ligature of thorax duct at his inlet in the thorax through right thoracotomy on the 5th intercostal space.