Three-dimensional manipulation with scanning near-field optical nanotweezers.

Recent advances in nanotechnologies have prompted the need for tools to accurately and non-invasively manipulate individual nano-objects. Among the possible strategies, optical forces have been predicted to provide researchers with nano-optical tweezers capable of trapping a specimen and moving it in three dimensions. In practice, however, the combination of weak optical forces and photothermal issues has thus far prevented their experimental realization. Here, we demonstrate the first three-dimensional optical manipulation of single 50 nm dielectric objects with near-field nanotweezers. The nano-optical trap is built by engineering a bowtie plasmonic aperture at the extremity of a tapered metal-coated optical fibre. Both the trapping operation and monitoring are performed through the optical fibre, making these nanotweezers totally autonomous and free of bulky optical elements. The achieved trapping performances allow for the trapped specimen to be moved over tens of micrometres over a period of several minutes with very low in-trap intensities. This non-invasive approach is foreseen to open new horizons in nanosciences by offering an unprecedented level of control of nanosized objects, including heat-sensitive biospecimens.

Waste gas exposure to sevoflurane and nitrous oxide during anaesthesia using the oesophageal-tracheal Combitube small adult.

Exposure to sevoflurane (SEV) and nitrous oxide during ventilation using a Combitube (37Fr) small adult (SA) was compared with waste gas exposure using conventional endotracheal tubes. Trace concentrations of SEV and nitrous oxide were assessed using a direct reading spectrometer during 40 gynaecological laparoscopic procedures under general anaesthesia. Measurements were made at the patients' mouth and in the anaesthetists' breathing zone. Mean (SD) concentrations of SEV and nitrous oxide measured at the patients' mouth were comparable in the Combitube SA (SEV 0.6 (0.2) p.p.m.; nitrous oxide 9.7 (8.5) p.p.m.) and endotracheal tube group (SEV 1.2 (0.8) p.p.m.; nitrous oxide 17.2 (10.6) p.p.m.). These values caused comparable contamination of the anaesthetists' breathing zone (SEV 0.6 (0.2) p.p.m. and nitrous oxide 4.3 (3.7) p.p.m. for the Combitube SA group, compared with SEV 0.5 (0.2) p.p.m. and nitrous oxide 4.1 (1.8) p.p.m. for the endotracheal tube group). We conclude that the use of the Combitube SA during positive pressure ventilation is not necessarily associated with increased waste gas exposure, especially when air conditioning and scavenging devices are available.

Effects of temperature on partial thromboplastin time in heparinized plasma in vitro.

BACKGROUND AND OBJECTIVE: Perioperative hypothermia has been found to impair the coagulation cascade and to increase blood loss and transfusion requirements. The effect of concomitant in vitro heparinization on coagulation during hypo- and hyperthermic conditions has not been well defined. METHODS: In the present study, activated partial thromboplastin time was examined in vitro at 33 degrees C, 35 degrees C, 37 degrees C, 39 degrees C and 41 degrees C in normal human plasma in response to unfractionated heparin. RESULTS: Hypothermia

Endogenous heparin-like substances significantly impair coagulation in patients undergoing orthotopic liver transplantation.

UNLABELLED: Orthotopic liver transplantation (OLT) is associated with severe bleeding, especially after reperfusion of the grafted liver. Heparin released from the liver graft contributes to postreperfusion coagulopathy. Although patients with liver cirrhosis have increased levels of endogenous heparinoids, the role of these substances during liver transplantation is unclear. Therefore, we performed native and heparinase-modified thrombelastography (TEG) in 72 patients undergoing OLT. TEG was performed at skin incision, 10 min before and 10 min after clamping of the vena cava, 10 min before and 10 min after graft perfusion, and at the end of surgery. Heparinase-modified TEG compared with native TEG demonstrated heparin activity. In contrast to other investigations, we found significant heparin effects before reperfusion, although patients received no exogenous heparin. These heparin effects were greater in patients with cirrhosis compared with patients with cancer as the underlying disease leading to OLT. Administration of coagulation factors is the usual treatment of coagulopathies during OLT. The comparison of native versus heparinase-modified TEG can distinguish between heparin activity or coagulation factor deficiency as a cause of bleeding complications and provides a rational approach to the treatment of bleeding during OLT. IMPLICATIONS: Impaired coagulation function, contributed to by heparin or heparin-like substances, is frequently observed after reperfusion of a transplanted liver. This study demonstrates that a heparinase-modified thrombelastography can identify significant heparin effects in the absence of exogenous heparin administration in patients undergoing liver transplantation.

[Endobronchial metastases in extrapulmonary malignant tumors]. / Endobronhijalne metastaze vanplucnih malignih tumora.

Endobronchial metastases of extrapulmonary malignant tumors are very rare and they appear in 1-2% of all the pulmonary metastases cases. By their endoscopic presentation, they are similar to primary bronchogenic carcinoma. Eleven patients with endobronchial metastases were presented, 8 male and 3 female. The average age was 58.27 years (from 37 to 72 years). Primary renal carcinoma existed in 2 patients. The one was operated 5 years before the metastases appeared in bronchus, and the metastases in bronchial wall contributed to the discovery of primary tumor in the other patient. Endobronchial metastases appeared in 3 patients, 2 years after the surgery of malignant colonic or rectal tumor, and in fourth patient it appeared 5 years after the surgery. One female patient sustained mastectomy and the radiation therapy was performed 11 years before the bronchial metastases occurred and the other female patient had the disease revealed a year ago and the polytherapy was performed. In the female patient with non Hodgkin Lymphoma, the change in bronchus was revealed simultaneously as the primary disease. Endobronchial metastases appeared in 2 patients two years after the surgery of malignant melanoma. The disease diagnosis was set by clinical-radiological examination, by endoscopy and by the comparison of histopathologic finding of primary carcinoma and metastases.

[Personal experience in the treatment of tuberculosis in patients in war areas]. / Nasa iskustva u lecenju tuberkuloze kod obolelih sa ratnih podrucja.

In the four-year period (1991-1995), 96 tuberculosis patients from the war areas of former Yugoslavia were treated in the Clinic for Lung Diseases of Military Medical Academy, that makes 31% of total number of sick and treated for tuberculosis-309 (100%). In group I (patients from war areas) there were 45 cases of cavernous pulmonary tuberculosis (47%), 28 bilateral (29%), 16 pleurisy (16.7%) and 6 cases of extensive pulmonary tuberculosis (5.1%). Among 213 patients (100%) from group II (patients from FR Yugoslavia), 81 patients had cavernous pulmonary tuberculosis (38%), 49 patients had bilateral (23%), 33 patients had pleurisy (15.5%) and 6 patients had extensive pulmonary tuberculosis (2.8%). In group I the diagnosis was bacteriologically and/or histopathologically proved in 94.8% cases: by finding of acid-resistant bacilli in sputum and other biological materials in 69 patients (72%), by positive Löwenstein's cultures in 73 patients (76%) and by histopathological result of tuberculosis inflammation in 34 patients (35.4%). In group II tuberculosis was bacteriologically and/or histopathologically proved in 134 patients (63%) by acid-resistant bacilli in sputum and other biological materials, in 141 patient (66%) by positive Löwenstein's culture and in 71 patient by positive histopathological results. Pulmonary tuberculosis in war areas is characterized by greater frequency of severe clinical forms (cavernous, bilateral and extensive) and by high direct bacillarity.

[Long-term home oxygen therapy]. / Dugotrajna oksigenoterapija u kucnim uslovima.

The analysis of medical reports was done for 30 patients in five years period (1988-1992) who received long-term oxygen therapy in home environment. The average values of respiratory functions were: forced vital capacity-43.3%, forced expired volume in the first second-27,4%; partial oxygen pressure in the arterial blood at rest-51 mmHg (6.8% kPa); partial carbon dioxide pressure in arterial blood at rest-46.2 mmHg (6.43% kPa) and oxygen saturation of hemoglobin-84.6%. After introduction of the constant oxygen therapy with flow of 1 to 2 l/min the values of arterial blood gasses at rest were: PaO2: 74.5 mmHg (9.94 kPa), PaCO2: 44.65 mmHg (6.22 kPa), the average value of SAT 93.4%. The average duration of oxygen therapy was 18 months; 11 patients died, with the average survival time under the oxygen therapy of 12.6 months. As the source of oxygen 18 patients used electric concentrator, and 12 of them the compressed gas in steel bottles.

[Results of combined therapy of small cell bronchogenic carcinoma in a 5-year period (1984-1988)]. / Rezultati kombinovanog lecenja bronhogenog karcinoma malih celija u petogodisnjem periodu (1984-1988).

Within the five-year period (1984-1988) the oat cell bronchogenic carcinoma was diagnosed and treated in 151 patients. Analysed were 74 patients having received complete treatment. Patients with disseminated form received only polychemotherapy in 6 cycles (cyclophosphamide, doxorubicin, vincristine and etoposide) and those with limited disease also received additional, local-regional radiotherapy of 45-50 Gy. In complete respondents preventive brain irradiation was applied. In selected patients with initial forms of the disease surgical resection with additional polychemotherapy were applied. The best survival showed respondents with limited disease and operated patients. Average survival of the whole group was 72 weeks. One year survived 31 out of 74 (41.9%) patients and two years survived 10 out of 74 (13.5%) patients.