73 research outputs found
Ignition of sounding rocket motors with hand-pumped air
Method demonstrates inexpensive, safe, and foolproof concept for solid propellant rocket motors, using simple handpump to deliver air. Flueric ignition was accomplished using system without stored energy and with complete absence of electrical energy and wiring
Liver metastases from colorectal cancer: regional intra-arterial treatment following failure of systemic chemotherapy
This study was designed to determine response rate, survival and toxicity associated with combination chemotherapy delivered intra-arterially to liver in patients with hepatic metastases of colorectal origin refractory to standard systemic treatment. A total of 28 patients who failed prior systemic treatment with fluoropyrimidines received a median of 5 cycles of intra-arterial treatment consisting of 5-fluorouracil 700 mg/m2/d, leucovorin 120 mg/m2/d, and cisplatin 20 mg/m2/d for 5 consecutive days. Cycles were repeated at intervals of 5–6 weeks. A major response was achieved in 48% of patients: complete response in 8% and partial response in 40%. The median duration of response was 11.5 months. Median survival was 12 months at a median follow up of 12 months. On multivariate analysis, the only variables with a significant impact on survival were response to treatment and performance status. Toxicity was moderate: grades III–IV neutropenia occurred in 29% of patients. Most of the patients complained of fatigue lasting for a few days following each cycle. There were no cases of hepatobiliary toxicity. These findings indicate that regional intra-arterial treatment should be considered in selected patients with predominantly liver disease following failure of standard treatment. © 2001 Cancer Research Campaign http://www.bjcancer.co
Prediction of outcome in locally advanced breast cancer by post-chemotherapy nodal status and baseline serum tumour markers
In spite of the apparent improvement in outcome in locally advanced breast cancer, the prognosis remains dismal in many patients. The aim of this study was to define prognostic subgroups within this heterogeneous entity. Between 1990 and 1999, 104 consecutive patients with locally advanced breast cancer were treated by a multimodality programme consisting of 4–6 courses of CAF induction chemotherapy followed by surgery, breast-conserving when feasible. In most cases, chemotherapy was then resumed, up to a total of eight courses, followed by locoregional radiation therapy. Patients with hormone receptor-positive tumours received tamoxifen (20 mg day−1) for 5 years. At a median follow-up of 57 months, the 5-year overall survival for the entire group and the disease-free survival for the 94 operated patients were 65% and 53%, respectively. Univariate analysis identified 10 prognostic factors of overall and disease-free survival, of which four retained significance on multivariate analysis: inflammatory breast cancer (P=0.0000, P=0.0004, respectively), baseline tumour markers (P=0.003 for both), post-chemotherapy number of involved nodes (P=0.003; P=0.017) and extracapsular spread (P=0.052; P=0.014). In conclusion, besides inflammatory features, baseline tumour markers and post-chemotherapy nodal status are strong predictors of outcome in locally advanced breast cancer
Recommended from our members
First Lasing of a High-Gain Harmonic Generation Free-Electron Laser Experiment.
We report on the first lasing of a high-gain harmonic generation (HGHG) free-electron laser (FEL). The experiment was conducted at the Accelerator Test Facility (ATF) at Brookhaven National Laboratory (BNL). This is a BNL experiment in collaboration with the Advanced Photon Source (APS) at Argonne National Laboratory. A preliminary measurement gives a high-gain harmonic generation (HGHG) pulse energy that is 2 x 10{sup 7} times larger than the spontaneous radiation, In a purely self-amplified spontaneous emission (SASE) mode of operation, the signal was measured as 10 times larger than the spontaneous radiation in the same distance ({approximately}2 m) through the same wiggler. This means the HGHG signal is 2 x 10{sup 6} times larger than the SASE signal. To obtain the same saturated output power by the SASE process, the radiator would have to be 3 times longer (6 m)
An international effort towards developing standards for best practices in analysis, interpretation and reporting of clinical genome sequencing results in the CLARITY Challenge
There is tremendous potential for genome sequencing to improve clinical diagnosis and care once it becomes routinely accessible, but this will require formalizing research methods into clinical best practices in the areas of sequence data generation, analysis, interpretation and reporting. The CLARITY Challenge was designed to spur convergence in methods for diagnosing genetic disease starting from clinical case history and genome sequencing data. DNA samples were obtained from three families with heritable genetic disorders and genomic sequence data were donated by sequencing platform vendors. The challenge was to analyze and interpret these data with the goals of identifying disease-causing variants and reporting the findings in a clinically useful format. Participating contestant groups were solicited broadly, and an independent panel of judges evaluated their performance.
RESULTS:
A total of 30 international groups were engaged. The entries reveal a general convergence of practices on most elements of the analysis and interpretation process. However, even given this commonality of approach, only two groups identified the consensus candidate variants in all disease cases, demonstrating a need for consistent fine-tuning of the generally accepted methods. There was greater diversity of the final clinical report content and in the patient consenting process, demonstrating that these areas require additional exploration and standardization.
CONCLUSIONS:
The CLARITY Challenge provides a comprehensive assessment of current practices for using genome sequencing to diagnose and report genetic diseases. There is remarkable convergence in bioinformatic techniques, but medical interpretation and reporting are areas that require further development by many groups
THE B STATE OF THE SODIUM TRIMER: PSEUDOROTATION, ROTATION, AND CORIOLIES INTERRACTION
Author Institution: Department of Physics, The Pensylvania State UniversityDue to a pseudo-Jahn-Teller interaction of a and a state, the lowest potential surface of the B state of allows for an almost free pseudorotational motion of the three Na nuclei. In this talk, a summary of the results from resonant two photon ionization and optical-optical double resonance spectroscopy of the B-X system is given. In the ground state the molecule has a geometry of an obtuse isosceles triangle, while the rotational structure reflects an unusual behavior: vibronic states with no excitation of the pseudoratational motion, i. e. vibronic angular momentum j=0, indicate shallow minima of the potential surface for an acute triangular shape with bond angle and r = 4.02(3) {\AA} bond length. The ``equivalent” equilateral triangle would have r = 3.76(5) {\AA}. States with are pseudorotating with a time constant , are approximated best by an equilateral triangle with r=3.74(5) {\AA} and show a large coriolies splitting of the rotational levels which is described by a term being the rotational constant about the rotational axis of the molecule perpendicular to the plane of the triangle, K the corresponding rotational quantum number and an effective coriolis coupling constant. Moreover, an effective spin-rotation coupling parameter had to be introduced which mainly accounts for the interaction with the nearby state
HIGH RESOLUTION SPECTROSCOPY OF THE B-X SYSTEM
[1] G. Delacretaz, E.R. Grant, R.L. Whetten, L. Woeste, J.W. Zwanziger, Phys.Rev.Lett. 56, 2598 (1986) [2] W.Meyer: Kaiserslautern; private communicationAuthor Institution: Department of Physics, The Pennsylvania State UniversityCw RTPI spectroscopy of has been performed in a supersonic molecular beam. The spectra of several vibraonic bands of the B-X transition were recorded at rotational resolution. As result of previous experiments at vibrational resolution, these bands had been interpreted in terms of the dynamic Jahn-Teller effect [1]. In this picture, the B-state vibronic levels have to be described by half-odd quantum numbers j for the vibronic angular momentum. Our rotationally resolved spectra show distinct differences between the lowest radial vibration in the B-state and all excited vibrational states (v^{\prime}1). This indicates a low localization energy and the excited vibrational states can be approximated by a symmetric rotor with a bond angle of . Depending on the degeneracy of the vibronic state j, different coriolis coupling terms have been taken into account in model calculations in which the ground state was approximated as asymmetric rotor [2]. For a number of rotational lines 00DR spectra were recorded whcih helped to identify the different branches
INTEGER QUANTIZATION OF THE PSEUDOROTATIONAL MOTION IN THE B STATE
[1],[2],[3] see ``Geometrical Phases in Physics'', eds Shapere \& Wilczek, World Scientific, Singapore (1989), p.74, 124, 240. [4] R.Meiswinkel and H.K\""{o}ppel, Chem. Phys. 144, 117 (1990).Author Institution: Department of Physics, The Pennsylvania State UniversityThe early theoretical treatment of the Jahn-Teller effect in symmetric top molecules by Herzberg and Longuet-Higgins [1] revealed the phenomenon that the electronic wave function changes its sign, if the nuclear coordinates traverse a circuit which encloses a point of degeneracy on the potential surface. In molecules this corresponds to a periodic alteration of the triangular geometry in a pseudorotational motion characterized by a vibronic angular momentum j. The sign change in the wave function of molecules is now recognized as a special case of Berry's phase [2]. The B state of the Na trimer represents the first example in which the assignment of half odd vibronic angular momentum quantum numbers j to the vibronic states suggested this phase behavior [3]. Alternatively, the observed vibronic structure could be explained by the interaction of the B-state with a nearby nondegenerate electronic state (pseudo-Jahn-Teller effect) [4]. In this case the pseudorotational motion can be described by integer quantum numbers j. In a laser spectroscopic investigation of the B-X transition, we recorded 12 vibronic bands at rotational resolution. An analysis of the 4 lowest j substates reveals that the rotational structure can only be explained by choosing integer values and 3 leading to a Coriolis splitting of rotational levels only for and 3. By labeling individual rotational levels in the ground state in an optical-optical double resonance scheme, we observed twice as many transitions into as into . In conclusion, we see no indication of a sign change in the wave function and think that the interpretation in terms of the pseudo-Jahn-Teller effect is correct
- …