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Biomedical subjects

T Tritschler

Publications and source records attributed to T Tritschler.

11 recordsLinked to original sources
PubMed2005

Variation of the carrier-envelope phase of few-cycle laser pulses owing to the Gouy phase: a solid-state-based measurement.

The carrier-envelope phase of a laser pulse has recently become an important quantity in extreme nonlinear optics. Because of the topological Gouy phase, it changes while the pulse propagates through the focus of a lens. This variation is measured by a simple solid-state-based approach. The experimental results are analyzed by comparison with simple analytical model calculations.

Journal Article↗
PubMed2004

Light-induced gaps in semiconductor band-to-band transitions.

We observe a triplet around the third harmonic of the semiconductor band gap when exciting 50-100 nm thin GaAs films with 5 fs pulses at 3 x 10(12) W/cm(2). The comparison with solutions of the semiconductor Bloch equations allows us to interpret the observed peak structure as being due to a two-band Mollow triplet. This triplet in the optical spectrum is a result of light-induced gaps in the band structure, which arise from coherent band mixing. The theory is formulated for full tight-binding bands and uses no rotating-wave approximation.

Journal Article↗
PubMed2003

Evidence for third-harmonic generation in disguise of second-harmonic generation in extreme nonlinear optics.

In contrast with traditional nonlinear optics, a peak at the spectral position of the second harmonic of a laser can also be generated in an inversion-symmetric medium in the regime of extreme nonlinear optics. We describe the underlying mechanism of such third-harmonic generation in disguise of second-harmonic generation and compare theory with the optical as well as the radio-frequency spectra measured in recent experiments on thin ZnO films. The peak at twice the carrier-envelope offset frequency in the radio-frequency spectra is shown to be an unambiguous signature of such a process.

Journal Article↗
PubMed2002

Role of the carrier-envelope offset phase of few-cycle pulses in nonperturbative resonant nonlinear optics.

We study the influence of the carrier-envelope offset phase of few-cycle pulses on nonperturbative resonant extreme nonlinear optics in a semiconductor. If the Rabi frequency becomes comparable to the light frequency, the different Rabi sidebands interfere around twice the laser center frequency, giving rise to a signal which strongly depends on the carrier-envelope offset phase. This signature should be measurable in GaAs samples.

Journal Article↗
PubMed2001

Signatures of carrier-wave Rabi flopping in GaAs.

For excitation of the model semiconductor GaAs with optical pulses which are both extremely short ( 5 fs) and extremely intense ( approximately 10(12) W cm(-2)), we can meet the condition that the Rabi frequency becomes comparable to the band gap frequency-a highly unusual and previously inaccessible situation. Specifically, in this regime, we observe carrier-wave Rabi flopping, a novel effect of nonlinear optics which has been predicted theoretically and which is related to the failure of the area theorem.

Journal Article↗
PubMed2001

[How much strength is needed for fitness?].

In order to tolerate the exertion in fitness exercise in the long term a sufficiently strong trunk musculature should be aimed at. In order to stabilize and balance the trunk and the pelvis there should be an optimal interaction of the muscles of the abdomen, the lateral trunk, the back and the flexors and extensors of the hip. If that balance is disrupted, muscular imbalance and a weakening or shortening of the muscles involved can occur. That imbalance leads to inadequate and excessive strain of the functional system of spine and pelvis. The functional anatomy of the trunk is described with clinical references in order to elucidate this context. A program of strength and stretching exercises for the trunk is presented suited to the needs of those practicing fitness exercise.

Exercise Therapy↗
PubMed2001

[Physiotherapy for the recreational athlete].

Physiotherapy plays a significant role in the treatment of sport injuries and can be especially adapted for this purpose. The physiotherapist has two tasks: 1. As a therapist treating a well defined pathologic entity or functional deficit. 2. Instructing the patient in further self-treatment and appropriate measures, behavioral changes and preventive approaches. The therapeutic emphasis is presented in seven interdependent groups: pain/swelling, flexibility, strength, coordination, endurance, psychological measures, preventive measures. The aim of treatment is to resume training activities. For each group there is a description of clinical symptoms, diagnosis according to functional tests and recommended treatment measures. The therapy group(s) and their priorities should be listed when making an individual therapeutic decision.

Accident Prevention↗
PubMed1999

[Manual therapy in lumbo-vertebral syndromes].

Based upon the shortly presented survey among the members of the Swiss Medical Association for Manual Medicine, the low back pain problems are approached by the means of manual therapy on average 805 times per year and physician. On average each case with low back pain is treated 1,4 times by a general practitioner with experience in manual medicine while specialists who are dealing with more complex cases on average 4 to 5 times. The functional disorders of the lumbar spine treated by manual therapy are superior to the physiotherapy approach or in comparison with a "placebo group" (information by general practitioner about low back pain and application of medication). An appropriate indication for manual therapy is relevant to avoid or reduce the possible risk of the treatment procedure. The physician who performs the manual therapy has to know the limits of the method. Also the knowledge of contraindications for manual therapy will reduce the incidence of possible complication. However based upon the survey among the swiss association the side effects and complications due to manual therapy of the lumbal spine are extremely seldom.

Humans↗
PubMed1997

[Stretching].

Static stretching exercises have become very popular over the past fifteen years both in professional and amateur sports. In the fields of physical therapy and in manual therapy, in particular, static stretching has become part of a standard and successful treatment modality. Together with an appropriate strengthening program, static stretching techniques have become the therapy of choice for treatment of muscle imbalances associated with functional disturbances of the musculoskeletal system. Specific muscle length testing procedures have been developed to determine muscle shortening in clinical practice. In this article, the fundamental principles of the different types of muscle stretching techniques are described, including the dynamic stretching and static stretching techniques. The exercises are organized along the concepts of passive static or neuromuscular stretching principles. The pertaining neurophysiologic fundamentals are discussed, as are the benefits of the individual methods of a functional exercise program. Examples are provided for the most important muscle groups.

Exercise↗
PubMed1997

[General muscle rehabilitation practice].

This article presents a five-step approach to the rehabilitation of sports injuries. (1) pain management; (2) specific exercise instruction for treatment of localized functional disturbances/motion restrictions; (3) training therapy to increase localized and general physical performance; (4) patient education and instruction of an individualized home/gym program and for precautions and injury prevention; and (5) enhancement of psychological performance. Described are the negative sequelae of a sports-related injury or immobilization after surgery on joints, bones and circulatory system, with particular emphasis of the effects on the involved musculature. The negative impact of an injury on generalized physical performance is presented (deconditioning syndrome). The course of rehabilitation requires a specific functional diagnosis, so as to implement an individualized treatment plan. Regular and objective follow-up/monitoring is suggested within the context of projected goals. The specific steps are described. Pain and discomfort can impede the restoration process and must be addressed effectively. Even though many questions remain to be answered in the field of muscular rehabilitation, the present day knowledge coupled with successful empirical interventions allow the introduction of effective and efficient rehabilitation concepts.

Athletic Injuries↗