48 research outputs found
Lagrangian form of Schr\"odinger equation
Lagrangian formulation of quantum mechanical Schr\"odinger equation is
developed in general and illustrated in the eigenbasis of the Hamiltonian and
in the coordinate representation. The Lagrangian formulation of physically
plausible quantum system results in a well defined second order equation on a
real vector space. The Klein-Gordon equation for a real field is shown to be
the Lagrangian form of the corresponding Schr\"odinger equation.Comment: To appear in Foundation of Physic
Design, Implementation, and Performance of the Astro-H Soft X-Ray Spectrometer Aperture Assembly and Blocking Filters
The calorimeter array of the JAXA Astro-H (renamed Hitomi) soft x-ray spectrometer (SXS) was designed to provide unprecedented spectral resolution of spatially extended cosmic x-ray sources and of all cosmic x-ray sources in the Fe-K band around 6 keV. The properties that made the SXS array a powerful x-ray spectrometer also made it sensitive to photons from the entire electromagnetic band as well as particles. If characterized as a bolometer, it would have had a noise equivalent power of <4 10(exp 18) W/((Hz)(exp 0.5)). Thus, it was imperative to shield the detector from thermal radiation from the instrument and optical and UV photons from the sky. In addition, it was necessary to shield the coldest stages of the instrument from the thermal radiation emanating from the warmer stages. These needs were addressed by a series of five thin-film radiation-blocking filters, anchored to the nested temperature stages, that blocked long-wavelength radiation while minimizing x-ray attenuation. The aperture assembly was a system of barriers, baffles, filter carriers, and filter mounts that supported the filters and inhibited their potential contamination. The three outer filters also had been equipped with thermometers and heaters for decontamination. We present the requirements, design, implementation, and performance of the SXS aperture assembly and blocking filters
Increased blood pressure in adult offspring of families with Balkan Endemic Nephropathy: a prospective study
BACKGROUND: Previous studies have linked smaller kidney dimensions to increased blood pressure. However, patients with Balkan Endemic Nephropathy (BEN), whose kidneys shrink during the course of the disease, do not manifest increased blood pressure. The authors evaluated the relationship between kidney cortex width, kidney length, and blood pressure in the offspring of BEN patients and controls. METHODS: 102 offspring of BEN patients and 99 control offspring of non-BEN hospital patients in the Vratza District, Bulgaria, were enrolled in a prospective study and examined twice (2003/04 and 2004/05). Kidney dimensions were determined using ultrasound, blood pressure was measured, and medical information was collected. The parental disease of BEN was categorized into three groups: mother, father, or both parents. Repeated measurements were analyzed with mixed regression models. RESULTS: In all participants, a decrease in minimal kidney cortex width of 1 mm was related to an increase in systolic blood pressure of 1.4 mm Hg (p = 0.005). There was no association between kidney length and blood pressure. A maternal history of BEN was associated with an increase in systolic blood pressure of 6.7 mm Hg (p = 0.03); paternal BEN, +3.2 mm Hg (p = 0.35); or both parents affected, +9.9 mm Hg (p = 0.002). There was a similar relation of kidney cortex width and parental history of BEN with pulse pressure; however, no association with diastolic blood pressure was found. CONCLUSION: In BEN and control offspring, a smaller kidney cortex width predisposed to higher blood pressure. Unexpectedly, a maternal history of BEN was associated with average increased systolic blood pressure in offspring
Metals and kidney markers in adult offspring of endemic nephropathy patients and controls: a two-year follow-up study
Abstract Background The etiology of Balkan Endemic Nephropathy, (BEN), a tubulointerstitial kidney disease, is unknown. Although this disease is endemic in rural areas of Bosnia, Bulgaria, Croatia, Romania, and Serbia, similar manifestations are reported to occur in other regions, for instance Tunisia and Sri Lanka. A number of explanations have been stated including lignites, aristolochic acid, ochratoxin A, metals, and metalloids. Etiologic claims are often based on one or a few studies without sound scientific evidence. In this systematic study, we tested whether exposures to metals (cadmium and lead) and metalloids (arsenic and selenium) are related to Balkan Endemic Nephropathy. Methods In 2003/04 we recruited 102 adults whose parents had BEN and who resided in one of three communities (Vratza, Bistretz, or Beli Izvor, Bulgaria). A control group comprised of 99 adults having non-BEN hospitalized parents was enrolled in the study during the same time. We conducted face-to-face interviews, ultrasound kidney measurements, and determined kidney function in two consecutive investigations (2003/04 and 2004/05). Metals and metalloids were measured in urine and blood samples. To assess the agreement between these consecutive measurements, we calculated intraclass correlation coefficients. Repeated measurement data were analyzed using mixed models. Results We found that cadmium and arsenic were associated with neither kidney size nor function. Lead had a significant but negligible effect on creatinine clearance. Selenium showed a weak but significant negative association with two of the four kidney parameters, namely creatinine clearance and β2-microglobulin. It was positively related to kidney length. These associations were not restricted to the offspring of BEN patients. Adding credence to these findings are reports showing comparable kidney effects in animals exposed to selenium. Conclusion The findings of this 2-year follow-up study indicate that metals and metalloids do not play a role in the etiology of Balkan Endemic Nephropathy. Against the assumption in the literature, selenium was not protective but a risk factor. Since comparable associations were observed in animals, future studies are needed to explore whether selenium may have adverse renal effects in humans.</p
The Design, Implementation, and Performance of the Astro-H SXS Aperture Assembly and Blocking Filters
The calorimeter array of the JAXA Astro-H (renamed Hitomi) Soft X-ray Spectrometer (SXS) was designed to provide unprecedented spectral resolution of spatially extended cosmic x-ray sources and of all cosmic x-ray sources in the Fe-K band around 6 keV. The properties that make the SXS a powerful x-ray spectrometer also make it sensitive to the entire electromagnetic band. If characterized as a bolometer, it would have a noise equivalent power (NEP) of < 4x10(exp -18) W/(Hz)0.5. Thus it was imperative to shield the detector from thermal radiation from the instrument and optical and UV photons from the sky. Additionally, it was necessary to shield the coldest stages of the instrument from the thermal radiation emanating from the warmer stages. These needs are addressed by a series of five thin-film radiation blocking filters that block long-wavelength radiation while minimizing x-ray attenuation. The SXS aperture assembly is a system of barriers, baffles, filter carriers, and filter mounts that supports the filters and inhibits their potential contamination. The three warmer filters also were equipped with thermometers and heaters for decontamination
