RESUMEN
We studied lithium azide (LiN(3)) by x-ray diffraction and Raman spectroscopy at hydrostatic compression up to pressures above 60 GPa at room temperature. The results of x-ray diffraction analyses reveal the stability of the ambient-pressure C 2/m crystal structure up to the highest pressure. The pressure dependence of librational modes provides evidence for an order-disorder transition at low pressures (below 3 GPa), similar to the transition observed previously at low temperatures. The observed structure stability indicates that this transition is not associated with structural changes. The phase stability of LiN(3) is in contrast to that of sodium azide (which is isostructural at ambient pressure), for which a set of phase transitions has been reported at pressures below 50 GPa.
RESUMEN
Two structural transitions in covalent aluminum hydride AlH3 were characterized at high pressure. A metallic phase stable above 100 GPa is found to have a remarkably simple cubic structure with shortest first-neighbor H-H distances ever measured except in H2 molecule. Although the high-pressure phase is predicted to be superconductive, this was not observed experimentally down to 4 K over the pressure range 120-164 GPa. The results indicate that the superconducting behavior may be more complex than anticipated.
RESUMEN
The metallization of hydrogen directly would require pressure in excess of 400 gigapascals (GPa), out of the reach of present experimental techniques. The dense group IVa hydrides attract considerable attention because hydrogen in these compounds is chemically precompressed and a metallic state is expected to be achievable at experimentally accessible pressures. We report the transformation of insulating molecular silane to a metal at 50 GPa, becoming superconducting at a transition temperature of Tc = 17 kelvin at 96 and 120 GPa. The metallic phase has a hexagonal close-packed structure with a high density of atomic hydrogen, creating a three-dimensional conducting network. These experimental findings support the idea of modeling metallic hydrogen with hydrogen-rich alloy.
RESUMEN
The high-pressure behavior of nitrogen in NaN(3) was studied to 160 GPa at 120-3300 K using Raman spectroscopy, electrical conductivity, laser heating, and shear deformation methods. Nitrogen in sodium azide is in a molecularlike form; azide ions N(3-) are straight chains of three atoms linked with covalent bonds and weakly interact with each other. By application of high pressures we strongly increased interaction between ions. We found that at pressures above 19 GPa a new phase appeared, indicating a strong coupling between the azide ions. Another transformation occurs at about 50 GPa, accompanied by the appearance of new Raman peaks and a darkening of the sample. With increasing pressure, the sample becomes completely opaque above 120 GPa, and the azide molecular vibron disappears, evidencing completion of the transformation to a nonmolecular nitrogen state with amorphouslike structure which crystallizes after laser heating up to 3300 K. Laser heating and the application of shear stress accelerates the transformation and causes the transformations to occur at lower pressures. These changes can be interpreted in terms of a transformation of the azide ions to larger nitrogen clusters and then polymeric nitrogen net. The polymeric forms can be preserved on decompression in the diamond anvil cell but transform back to the starting azide and other new phases under ambient conditions.
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The transformation of molecular nitrogen to a single-bonded atomic nitrogen is of significant interest from a fundamental stand point and because it is the most energetic non-nuclear material predicted. We performed an x-ray diffraction of nitrogen at pressures up to 170 GPa. At 60 GPa, we found a transition from the rhombohedral (R3c) epsilon-N(2) phase to the zeta-N(2) phase, which we identified as orthorhombic with space group P222(1) and with four molecules per unit cell. This transition is accompanied by increasing intramolecular and decreasing intermolecular distances. The major transformation of this diatomic phase into the single-bonded (polymeric) phase, recently determined to have the cubic gauche structure (cg-N), proceeds as a first-order transition with a volume change of 22%.
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OBJECTIVE: To analyze the data on patients operated on for pulmonary tuberculosis (TB) with (Group I) or without (Group II) a correct TB diagnosis and preoperative anti-TB treatment. METHODS: Between 1980 and 1997, 144 resections for TB (Groups I+II) were performed. The 80 patients in Group I underwent therapeutic resections: 32 cases involved recurrent cavities or tuberculomas, three involved post-TB bronchiectasis, 13 involved progression of cavities or tuberculomas, and 32 involved persistent tuberculomas after 6 months of anti-TB therapy. The 64 patients in Group II were operated on for a suspicion of malignancy in 49 cases, for cavitary lesions with haemophthysis in six cases, for multiple lesions in seven cases, and for recurrent hydrothorax in two cases. RESULTS: Groups I and II included 0 and five pneumonectomies, 32 and 29 lobectomies, 48 and 20 wedge resections, 0 and nine videothoracoscopic biopsies, and 0 and one hilar lymphadenectomy, respectively. In Groups I and II, the mean duration of postoperative hospitalization was 13.2 and 10.4 days, and the frequency of postoperative pneumothorax was 11.25 and 4.6%, respectively. The incidence of bronchopleural fistula was 1.25 and 0%, the mortality was 0 and 3.1%, and the morbidity was 53.7 and 35.9% in Groups I and II, respectively. Two patients with active disease died in Group II. Pathology demonstrated that the frequency of acid-fast bacilli in Groups I and II was 40 and 25%, respectively. CONCLUSIONS: Patients without a correct preoperative TB diagnosis underwent more extensive parenchyma resection. Postoperative complications increased when acid-fast bacilli were present. The lack of preoperative anti-TB treatment did not involve a higher risk of minor complications, but death occurred only in this group.
Asunto(s)
Antibióticos Antituberculosos/administración & dosificación , Neumonectomía , Tuberculosis Pulmonar/cirugía , Adulto , Anciano , Antibióticos Antituberculosos/efectos adversos , Biopsia , Terapia Combinada , Femenino , Estudios de Seguimiento , Humanos , Pulmón/patología , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/tratamiento farmacológico , Complicaciones Posoperatorias/mortalidad , Complicaciones Posoperatorias/patología , Complicaciones Posoperatorias/cirugía , Premedicación , Recurrencia , Reoperación , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia , Cirugía Torácica Asistida por Video , Tuberculosis Pulmonar/tratamiento farmacológico , Tuberculosis Pulmonar/mortalidad , Tuberculosis Pulmonar/patologíaRESUMEN
This article demonstrates the usefulness of ultrasound (US)-guided core needle biopsy in the diagnosis of thoracic lesions. Between January 1997 and June 2000, 45 US-guided core needle biopsies were performed in the department of radiology. This method was chosen in every case when the lesion abutted the chest wall. Conventional histologic examinations supplemented by immunohistochemical methods were performed. The location and size of the mass, the number of samplings, the needle size, the histologic results, and any complications were recorded. Twenty-two lesions reached the anterior, six reached the lateral, and 14 reached the posterior chest wall. Biopsies were performed on three masses from the supraclavicular region. The mean diameter was 4.5 cm and the number of passes was 1.8; 18-G, 16-G, and 14-G needles were used in 41, two, and two cases, respectively. In 43 of the 45 cases (95.68%), an exact histologic diagnosis could be provided. In two cases, only necrotic tissue was seen in the biopsy sample. No major complications occurred. Minor complications, including pain and collaptiform weakness, were documented in four patients. Ultrasound-guided core needle biopsy of thoracic lesions is a safe, quick, and accurate method. For diagnosing thoracic lesions, a single sample with an 18-G biopsy needle is sufficient to achieve a final diagnosis when using appropriate histologic methods.
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AIM: To report our VATS procedure and results in the treatment of PTX. METHODS: Between 1992-1995, 156 patients with primary PTX were admitted and drained. On the basis of permanent air leak, lung reexpansion and type of PTX, 78 patients were operated on by VATS with early indications. In first episode PTX cases we performed "emergency VATS" in haemopneumothorax and "early or late acute VATS" between 8-48 hours after acute drainage in the others. In recurrent cases "late acute VATS" was done in 24 hours after acute drainage with permanent air leak. We performed "under water-test". In 57 Vanderschueren stage II-III-IV cases the lung disorders and the place of air leakage were resected. In 21 Vanderschueren stage I cases "blind apical resection" was performed. We carried out pleural abrasion, and two pleural drains were inserted. RESULTS: In every "blind resection" case the pathology revealed lung disorders: cystic deformation, fibrosis or inflammation. We had no operative deaths. In 1 case because of intercostal artery bleeding, thoracotomy had to be performed. We had 1 recurrent PTX. There was no late complications. CONCLUSION: The early indications reduced the hospitalization. The "blind apical resections" remove abnormal lung tissue, diagnose the underlying lung disease and the metal staples can cause adhesion reaction in the apex region.
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Neumotórax/cirugía , Cirugía Torácica Asistida por Video , Enfermedad Aguda , Adolescente , Adulto , Anciano , Drenaje , Urgencias Médicas , Femenino , Hemoneumotórax/etiología , Hemoneumotórax/cirugía , Humanos , Enfermedades Pulmonares/complicaciones , Masculino , Persona de Mediana Edad , Neumotórax/etiología , Fibrosis Pulmonar/complicaciones , Factores de TiempoRESUMEN
Authors report a case of a left side subclavian steal syndrome, caused by occlusion of the subclavian artery, combined with a high grade stenosis of the innominate artery. The rare combination of arteriosclerotic lesions of the supraaortic arteries have been treated by an aorto-bisubclavian bypass procedure performed from a median sternotomy. This is the first publication of this method in the Hungarian surgical literature.
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Arteriopatías Oclusivas/cirugía , Tronco Braquiocefálico/cirugía , Síndrome del Robo de la Subclavia/cirugía , Angiografía , Aorta Torácica/diagnóstico por imagen , Aorta Torácica/cirugía , Arteriopatías Oclusivas/diagnóstico por imagen , Arteriosclerosis/complicaciones , Arteriosclerosis/cirugía , Tronco Braquiocefálico/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Esternón/cirugía , Arteria Subclavia/diagnóstico por imagen , Arteria Subclavia/cirugía , Síndrome del Robo de la Subclavia/diagnóstico por imagenRESUMEN
Authors analyse the cases of lung metastasectomy collected during fourteen years in eleven thoracic surgical departments in Hungary. 668 operations were carried out on 620 patients. The primary tumor originated mainly from kidney, testis and colo-rectum. Most of the interventions were performed through median sternotomy. The tumors were removed by tissue sparing lung resections (wedge resection). The prognosis depends basically on tumor free interval, however the number and the size of the metastases and the histology of the primary tumor have also impact on it. When lung lesions appear in a cancer patient, thoracic surgeon should be consulted to consider operability. In certain cases metastasectomies can result in longer survival and better quality of life.
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Neoplasias Pulmonares/secundario , Metástasis de la Neoplasia , Neoplasias Colorrectales/patología , Femenino , Humanos , Neoplasias Renales/patología , Neoplasias Pulmonares/cirugía , Masculino , Neumonectomía/métodos , Neoplasias Testiculares/patologíaRESUMEN
Bronchoplastic procedures involving the main carina are declared as central bronchoplasties. A nation-wide collection of these interventions performed between 1980 and 1993 is analysed. The study is on a total of 154 operations, that were 16 bifurcation resections and 14 stem bronchus resections without parenchyma sacrifice, 61 sleeve or wedge pneumonectomies and 63 tracheal sleeve or wedge right upper lobectomies or carina-plasties. Surgery alone-without multimodality therapy-was the choice of treatment almost exclusively. About 90% of these interventions were performed for highly malignant, histologically peripheral-type, but centrally located bronchial cancers. The hospital mortality and morbidity were found up to 30% (an average of appr. 17%), depending on surgical subsets. Cause of death were surgical at 11% (leakage, anastomotic dehiscence and bleeding) and non surgical at 5.8% respectively. Complications at another 9% were related to surgery. Data of survival suggest, that nodal state is the strongest predictor, but the unfavourable N2 group comprises longer survivors as well. Certain part of this kind of interventions is to be chosen without alternatives (isolated tracheobronchial resections without parenchyma-resection, extended pneumonectomies) while extended lobectomies are alternatives of the extended pneumonectomies in strict conditions. A central bronchoplastic procedure is justified only with hope of complete resection for its high complication rate.
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Neoplasias de los Bronquios/cirugía , Neoplasias Pulmonares/cirugía , Anastomosis Quirúrgica , Humanos , Hungría , Neumonectomía , Estudios Retrospectivos , Tasa de Supervivencia , Cirugía Torácica/normas , Resultado del TratamientoRESUMEN
The success of surgery performed for pulmonary carcinoma is based on the selection of the patients for operation. Cytological or histological verification of the tumour prior to surgery is important as concerns the choice of the type of surgery and the complex antitumour therapy. It is currently considered that patients with tumours in stages I, II and IIIa are suitable for surgery. Operations are also performed in cases involving solitary cerebral metastases, and centrally-lying tumours which reach the bifurcation carina or the lower portion of the trachea (T4) are similar rarely resectable. The basic operation for pulmonary carcinoma is lobectomy. In selected cases of squamous cell carcinomas in stage T1N0, atypical wedge resection too may be considered. Extended surgery is also performed, depending on the size of the tumour. For all types of tumours, it is essential to take a sample from the lymph nodes for accurate staging. Prospective randomized clinical trials on 288 patients undergoing resection for pulmonary cancer revealed that extended medistinal lymphadenectomy improved the 5-year survival rate in cases of adenocarcinomas and squamous cell carcinoma, involving lymph node metastases. Intraoperative cytological examinations or frozen sections are extremely important as concerns the indication of extended mediastinal lymphadenectomy and adjuvant antitumour treatment.
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Neoplasias Pulmonares/cirugía , Ensayos Clínicos como Asunto , Humanos , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/patología , Escisión del Ganglio Linfático , Metástasis Linfática , Estadificación de Neoplasias , Selección de Paciente , Neumonectomía/métodos , Pronóstico , Tasa de SupervivenciaRESUMEN
Pressure and volume flow measurements were performed on a simple model of the tracheobronchial tree using a catheter-jet-ventilation apparatus. This type of respiration is particularly favourable in tracheo-bronchial surgery, i.e. resections and anastomosing, due to the experience of model as well as animal experiments. Under consideration of the particularities of catheter-jet-ventilation, this type of respiration provides excellent conditions for the surgeon. This is valid for the overview of the site of operation and possible manipulation within this region. This method of respiration is suggested as a reliable tool in the hands of less skilled anaesthetists, too, for its easy handling.
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Ventilación con Chorro de Alta Frecuencia/instrumentación , Modelos Biológicos , Anastomosis Quirúrgica , Animales , Bronquios/cirugía , Perros , Mediciones del Volumen Pulmonar , Presión , Tráquea/cirugíaRESUMEN
Serum lysosomal cysteine proteinases cathepsin B, H, L and metalloproteinase (MMP7-ase) activities of 14 patients suffering from gastrointestinal and bronchial carcinomas were investigated. The serum cathepsin B and H activities were significantly diminished in the carcinoma group as compared to the controls, while the activity of cathepsin L and of MMP7-ase was normal.
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Catepsinas/sangre , Cisteína Endopeptidasas , Endopeptidasas , Neoplasias Gastrointestinales/enzimología , Neoplasias Pulmonares/enzimología , Metaloendopeptidasas/sangre , Catepsina B/sangre , Catepsina H , Catepsina L , Neoplasias Gastrointestinales/sangre , Humanos , Neoplasias Pulmonares/sangre , Lisosomas/enzimología , Valores de ReferenciaAsunto(s)
Neoplasias de la Tráquea/cirugía , Neoplasias Esofágicas/patología , Neoplasias Esofágicas/cirugía , Humanos , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/cirugía , Métodos , Radiografía , Neoplasias de la Tiroides/patología , Neoplasias de la Tiroides/cirugía , Tráquea/cirugía , Neoplasias de la Tráquea/diagnóstico por imagen , Neoplasias de la Tráquea/secundarioRESUMEN
Reinforced Gore-Tex prostheses were implanted into the trachea, above the bifurcation, in 11 dogs. The first 3 animals died within a few days, due to an inappropriate surgical technique. The remaining animals were subjected to an adequate surgical procedure and all survived for a period of at least several months, except one which died of an esophago-tracheal fistula after 6 weeks. Ingrowth of respiratory epithelium into the prostheses was observed 5 to 7 weeks postoperatively.
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Bioprótesis , Tráquea/cirugía , Animales , Perros , Politetrafluoroetileno , Complicaciones Posoperatorias , Reoperación , Tráquea/ultraestructuraRESUMEN
In open chest anaesthetized dogs the haemodynamic effects of solutions of equal hyperosmolarity (viz. NaHCO3 8%, NaCl k.6%, and glucose 34.3%, solutions) given into the bronchial artery were studied. Administration of any of these solutions directly into the bronchial artery resulted in increased cardiac output, stroke volume, bronchial blood flow, and bronchial fraction of the cardiac output, and decreased heart rate and bronchial as well as pulmonary vascular resistances. When given into the pulmonary circulation, the same solutions evoked similar reactions of smaller magnitude. To exclude the effect of major surgical trauma and the open-chest condition, another experimental model closer to the physiological situation was also developed. In this preparation NaHCO3 failed to produce the above haemodynamic response even when given into the bronchial artery. After a one-hour bleeding period resulting in a drop of arterial blood pressure to 40 mmHg, while using the same preparation, the administration f NaHCO3 solution into the bronchial artery caused a significant rise in blood pressure in both the systemic and pulmonary arteries. In these experiments a correlation was found between arterial oxygen tension and the extent of change in blood pressure. The exact mechanism of action of the observed haemodynamic changes is still not clear. However, it is likely that receptors localized in the area of the bronchial circulation and sensitive to hypoxia might have played a role in the development of the haemodynamic effects described.
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Bicarbonatos/farmacología , Arterias Bronquiales , Hemodinámica/efectos de los fármacos , Circulación Pulmonar/efectos de los fármacos , Animales , Bicarbonatos/administración & dosificación , Presión Sanguínea/efectos de los fármacos , Perros , Femenino , Solución Hipertónica de Glucosa , Soluciones Hipertónicas , Cinética , Masculino , Solución Salina Hipertónica , Bicarbonato de SodioRESUMEN
Experimental results suggested that in normovolaemia 0.5% of the total pulmonary circulation flows through the bronchial arteries. In haemorrhagic shock bronchial flow dropped to 0.04% of the total pulmonary circulation and ceased completely below 40 mmHg. The authors claim that a hypoperfusion of both circulatory systems (pulmonary and bronchial) is an important pathogenetic factor in the first step of the development of the shock lung. A two-hour abolishment of the nutritive circulation of the lung caused already hypotension, hypoxaemia and metabolic acidosis. Tissue hypoxia was confirmed by the rise in the enzymatic activity of the lung tissue. An abolishment of bronchial circulation in the described manner was enough to induce the development of the shock lung, as confirmed by the visible changes (changed colour, greater weight, development of congestive atelectasis and oedema) of the lung and by the haemodynamic and respiratory changes. Here too the increase in pulmonary vascular resistance is attributed an important role due perhaps in the beginning to an enhancement of the sympathetic tone and later to hypoxia and metabolic acidosis. If the effect of haemorrhage alone is compared to the effect of simultaneous haemorrhage and elimination of the bronchial artery, it appears that the functional lesion of the lung becomes considerably more pronounced with the abolishment of the nutritive circulation. Severe hypoxia and metabolic acidosis cause an extreme rise of the pulmonary vascular resistance. The severity of metabolic acidosis, the degree to which pulmonary vascular resistance has increased and its duration seem decisive from the aspect of both the development and outcome of the shock lung.
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Bronquios/irrigación sanguínea , Circulación Pulmonar , Síndrome de Dificultad Respiratoria/fisiopatología , Animales , Presión Sanguínea , Perros , Femenino , Rendimiento Pulmonar , Masculino , Arteria Pulmonar/fisiología , Flujo Sanguíneo Regional , Síndrome de Dificultad Respiratoria/complicaciones , Síndrome de Dificultad Respiratoria/enzimología , Choque Hemorrágico/complicaciones , Choque Hemorrágico/fisiopatología , Resistencia VascularRESUMEN
An experimental model was worked out for the isolated study of the vasculal system of the bronchial artery. The model allowed to study 1) the role of bronchiar circulation in the pathomechanism of the shock lung; 2) the effect of charges in fusion of the isolated circulation of the microstructure of the lungs; 3) the effect of changes in pH, CO2 level and O2 tension on the greater and lesser circulation, on ventilation, CO2 loss, and O2 uptake were studied.