Residual N2 Research Articles

Surgical Resection for Residual N 2 Disease After Induction Chemotherapy

Induction therapy is a common treatment modality for patients with stage IIIA non-small cell lung cancer (NSCLC). Although mediastinal nodal downstaging after induction therapy is generally considered a favorable prognostic feature, the benefit of resection in the presence of residual N2 disease is controversial. In this study we analyzed our experience with resection after induction chemotherapy in patients with residual N2 disease to more precisely define the role of surgical resection in this group of patients. In this retrospective analysis, we reviewed the records of 78 patients with N2 disease who received induction therapy with preoperative intent between 1990 and 2003. All patients had potentially resectable disease. Survival analysis was performed using the Kaplan-Meier method. A Cox proportional hazards regression model was used to evaluate multiple prognostic factors. There were 78 patients (39 men) with a median age of 64 years. Sixty had nonsquamous histology. Resection was performed in 52 patients (47 R0). Hospital mortality was 1.9%. A complete pathologic response occurred in 2 of 52 (3.8%) patients and 19 of 52 (36%) patients had no residual N2 disease. Overall 5-year survival for resected patients was 23%. Overall 5-year survival was 30% for N0-N1 patients and 19% for those with residual N2 disease. Multivariable analysis identified clinical response to therapy (p = 0.0007) and histology (p = 0.01), but not residual N2 disease (p = 0.65), as important prognostic variables. Surgical resection may be a viable option for patients with residual N2 disease after induction chemotherapy, provided an R0 resection can be performed.

Structural characterization and mechanical properties of Ti?Zr?N coatings, deposited by vacuum arc

TiN/ZrN multilayers and (Ti–Zr)N films were obtained by a vacuum-arc deposition method, using Ti and Zr plasma flows in residual N2 atmosphere, combined with ion bombardment of samples surface. The TiN/ZrN multilayered films consisted of TiN and ZrN layers with cubic structure and (1 1 1)-preferred orientation. It was shown that, for multicomponent Ti–Zr–N coatings, solid solutions were formed. The dominant preferred orientation of (Ti,Zr)N coatings was (1 1 1) and the residual stresses were in the range of −6 to −4 GPa, depending on the bias voltage applied to the substrate. The nanohardness of TiN/ZrN multilayers increased to 29 GPa and Young's modulus decrease to 291 GPa with decreasing Λ, as compared with monolithic ZrN films (25 and 349 GPa, respectively). For (Ti,Zr)N coatings, nanohardness values were ranging from 35 to 40 GPa.

Crop rotation and soil N amendment effects on maize production in eastern Canada

Relying less on fertilizer N and more on crop residual and biological N2 fixation by legume crops has been suggested as an effective way to meet the challenge of maximizing economic return while minimizing environmental pollution. A field study was conducted on a Brandon loam soil (Orthic Humic Gleysol) to determine the effects of crop rotation and N amendments on grain yield, crop growth, N uptake and use efficiency (NUE) of maize ( Zea mays L.) and fertilizer replacement values of legume. The rotations included maize in annual rotation with soybean [Glycine max (L.) Merrill], alfalfa ( Medicago sativa L.) or continuous maize. The soil N amendments included no amendment, NH4NO3 at 100 kg N ha-1, stockpiled or rotted dairy manure at 50 Mg ha-1 (wet weight). Averaged across 4 yr, increases in maize grain yield, total plant N uptake, and NUE ranged from 13 to 35% in the maize-soybean and maize-alfalfa rotations compared to continuous maize monoculture. During the study, total dry matter production was 15 to 35% higher and crop growth rate was 13 to 23% higher for maize following alfalfa than for continuous maize monoculture. The effect of legumes on the subsequent growth of maize (i.e., total dry matter production a n d crop growth rate) was most apparent during the grain filling period. Total maize dry matter production was similar up to silking stage for all three rotation systems; however, the difference in total dry matter between maize monoculture and maize in rotation with legume continued to increase after this stage so that the greatest differences were observed at physiological maturity. Grain yield was 19% higher in the 100 kg N ha-1 treatment and 23% higher in the repeated manure amendment than in the unfertilized treatment. Fertilizer N replacement values were on average, 68 kg ha-1 for soybean and 133 kg ha-1 for alfalfa. Our results indicate that maize in annual rotation with legume crops could increase the maize yields by as much as 20% and reduce the amount of chemical fertilizer N by as much as 180 kg N ha-1. The effect of legume preceding crop on maize dry matter production and N uptake is expressed mostly in the later stages of crop growth in this mid- to short-growing- season region. Key words: Rotation, Zea mays, dry matter accumulation, crop growth rate, manure, nitrogen use efficiency

The impact of residual multi-level N2 disease after induction therapy for non-small cell lung cancer

Background: The presence of residual N2 disease following induction therapy for locally advanced non-small cell lung cancer (NSCLC) has been proposed as a contraindication to surgery. However, single level N2 metastases found in the operative specimens of patients with clinical N0 NSCLC who did not receive induction therapy is associated with prolonged survival. In order to investigate whether residual single level N2 disease following induction therapy was similarly associated with prolonged survival, we conducted a retrospective review of patients with stages IIIa and IIIb NSCLC who had undergone induction therapy followed by surgery. Methods: A retrospective review was performed of the hospital records of patients with stages IIIa and IIIb NSCLC who had undergone induction therapy consisting of chemotherapy and/or radiotherapy followed by tumor resection and mediastinal lymph node dissection at 11 Japanese national referral hospitals. Survival was analyzed by the Kaplan–Meier method and prognostic factors were determined by the log-rank and Cox regression methods. Results: One hundred thirty-one patients underwent induction therapy of NSCLC stages IIIa (n=95) and IIIb (n=36) followed by complete tumor resection during a 12-year interval. Clinical N2 disease was present in 114 (87%) patients and N3 disease in 17 (13%) patients. Median follow up was 48 months. Eighteen patients had residual single level N2 disease and 25 patients had multiple residual N2 level metastases. The 5-year survival was 54% for patients with pathologic single level N2 disease and 11% for patients with multiple N2 level disease ( P<0.01). In a multivariate analysis, only the pathologic N status significantly influenced survival. Conclusion: Patents who have multiple levels of N2 disease have a much worse prognosis than patients who have single level of N2.

Highly accurate gas chromatographic analysis of reference gases for use in vehicle emission measurements

A highly accurate gas chromatographic analytical method has been developed for the determination of the composition of gas mixtures. It was tested using a reference gas as an example consisting of 3.5% of CO, 14% of CO2, 0.2% of propane and residual N2 intended for the use in vehicle emission measurements. The method is based on comparison measurements with samples of a calibration gas, whose composition is iteratively adapted to that of the sample investigated using a gravimetric gas mixing method. For the gas chromatographic measurement, a molecular sieve column and a polymer column are used in parallel and in isothermal operation. All gas components can be determined by a single gas chromatographic measurement, and the relative uncertainty of measurement achievable is ?0.4%.

Subsurface Energy Storage and Transport for Solar-Powered Geysers on Triton

The location of active geyser-like eruptions and related features close to the current subsolar latitude on Triton suggests a solar energy source for these phenomena. Solidstate greenhouse calculations have shown that sunlight can generate substantially elevated subsurface temperatures. A variety of models for the storage of solar energy in a sub-greenhouse layer and for the supply of gas and energy to a geyser are examined. "Leaky greenhouse" models with only vertical gas transport are inconsistent with the observed upper limit on geyser radius of approximately 1.5 kilometers. However, lateral transport of energy by gas flow in a porous N(2) layer with a block size on the order of a meter can supply the required amount of gas to a source region approximately 1 kilometer in radius. The decline of gas output to steady state may occur over a period comparable with the inferred active geyser lifetime of five Earth years. The required subsurface permeability may be maintained by thermal fracturing of the residual N2 polar cap. A lower limit on geyser source radius of approximately 50 to 100 meters predicted by a theory of negatively buoyant jets is not readily attained.

Effect of body posture on gas distribution in the lungs.

Postural changes of functional residual capacity (FRC) and pulmonary N2 clearance efficiency were studied in six male subjects placed supine on a tilting table, in head-up, horizontal and head-down positions. FRC varied linearly with the angle of tilt. The lung clearance index (LCI) increased significantly in the supine and head-down positions, compared to the head-up positions, which indicates less uniform gas distribution in the former postures. This was confirmed by analysis of semilogarithmic graphs of N2 washout. Inhalation of epinephrine did not affect the postural changes of FRC and LCI, but caused a small increase of LCI irrespective of posture. The increased uneven distribution in head-down and supine positions is probably a consequence of the lung volume decrease in these postures, and may be explained by mechanical factors such as surface tension, which tend to close lung units when the lungs are deflated. Bronchomotor tone has no appreciable influence on these postural changes in normal subjects. Submitted on July 13, 1961