67 research outputs found
Effective mass in quantum effects of radiation pressure
We study the quantum effects of radiation pressure in a high-finesse cavity
with a mirror coated on a mechanical resonator. We show that the optomechanical
coupling can be described by an effective susceptibility which takes into
account every acoustic modes of the resonator and their coupling to the light.
At low frequency this effective response is similar to a harmonic response with
an effective mass smaller than the total mass of the mirror. For a plano-convex
resonator the effective mass is related to the light spot size and becomes very
small for small optical waists, thus enhancing the quantum effects of
optomechanical coupling.Comment: 11 pages, 4 figures, RevTe
High-sensitivity optical measurement of mechanical Brownian motion
We describe an experiment in which a laser beam is sent into a high-finesse
optical cavity with a mirror coated on a mechanical resonator. We show that the
reflected light is very sensitive to small mirror displacements. We have
observed the Brownian motion of the resonator with a very high sensitivity.Comment: 4 pages, 4 figures, RevTe
High-sensitivity force measurement using entangled probes
We show the possibility to improve the measurement sensitivity of a weak
force by using two meters in an entangled state. This latter can be achieved by
exploiting radiation pressure effects.Comment: ReVTeX file, 11 pages, 2 eps figure
Efikasi dan Keamanan Dihidroartemisinin-piperakuin (Dhp) pada Penderita Malaria Falsiparum tanpa Komplikasi di Kalimantan dan Sulawesi
Since 2008, Dihydroartemisinin-Piperaquine (DHP) has been used as the first-line drug for treatment of falciparum malaria in Papua, which gradually will also be used in other endemic areas. The objective of the study was to determine the safety and efficacy of DHP. Patients with uncomplicated malaria due to Plasmodium falciparum were enrolled and treated with supervised DHP (arterakin ®, no. batch 010 909) daily dose for three days. Patients were followed for 42 days. Patients during follow up did physical examination and checked for microscopic parasites, measurement of hemoglobin levels (day 0, 14, 28 and 42), making the blood spot PCR (day 0 and day relapse), pregnancy test for women of childbearing age (Day 0 and 28). 119 patients were enrolled in the study. Therapeutic efficacy of DHP by day 42 in ITT and PP population were 98.3% (95% CI: 94.1-99.5%) and 100% (95% CI: 96.9-100%). The means of parasite clearance and fever clearance were 1.0 day and 1.6 days, and clinical symptoms was reduced by over 50% by day-7 follow up. All patients with gametocytes on day 0, generally were cleared on day 28 . There were an increasing number of patients with recovery hemoglobin at day 14, 28 and 42: 61%, 78% and 84%. Adverse events were mild, ie cough (31%) and abdominal pain (10%). Dihydroartemisinin-piperaquine was safe and effective for the treatment of uncomplicated P. falciparum malaria
Hubungan Kepadatan Parasit dengan Manifestasi Klinis pada Malaria Plasmodium Falciparum dan Plasmodium Vivax
Malaria is still a public health problem in Indonesia. The clinical manifestation of malaria is varied, and many factors may influence its clinical manifestation. Despite the species of malaria, density of parasitemia is known related to the severity or Malignancy of malaria. It is worth to analyse the clinical and laboratory data of malaria cases in monitoring dihydroartemisinin-piperaquine (DHP) treatment. The extended analysed was done to assess the relationship between density of parasitemia and clinical manifestations. A subset data of monitoring DHP treatment in subjects with uncomplicated falciparum and vivax malaria in Kalimantan and Sulawesi which were consist of clinical and laboratory day-0 data was used in analysing. Clinical data were recorded through anamnesis and physical examination. Parasite density was counted by health centre microscopist and then cross-checked by certified microscopists of the Natiional Institute of Health Reseach and Development. Haemoglobin level was also measured by health centre analyst using the existing Sahli hemoglobinmeter. For parasite density category, median is used for cut off point. In P.falciparum malaria, the cut off point is 5588/µl and in P.vivax malaria is 3375/µl. The relationship between parasite density and clinical manifestation in falciparum and vivax malaria was determined by bivariate and multivariate analysis with logistic regression using SPSS 17 software. The most of subject with P.falciparum and P.vivax malaria are children (<15 yeras old), male, and non indigenous. From analysis bivariate, variabels that can be analyzed by multivariate in P.falciparum malaria (p<0,25) are children under 15 years old (p=0,0 12) and Sulawesi island where subject live(p=0,163) and In P.vivax malaria is children under 15 years old (p=0,218). Because of other variables are considered biologicaly related to parasite density, therefore all variabel are analyzed with multivariate. From multivariate analysis, there is significant relationship between parasite density and chidren under 15 years old in P.falciparum malaria (OR = 0,4, CI95%= 0,2-1,0). In P.vivax malaria, parasite density is related to children under 15 years old (OR = 0,6, CI 95% =0,2-1,9), haemoglobin level under 11gr/dl (OR= 1,4, CI 95%= 0,5-3,8), non indigenous OR= 0,3, CI 95%= 0,1-1,2) and the sum of clinical symptom <7 (OR=0,7, CI 95%=0,3-1,9). Parasite density is not related with clinical manifestation in P.falciparum malaria.. Parasite density is related to children under 15 years old significantly in P.falciparum malaria. In P.vivax malaria, parasite density are related to children under 15 years old, anemia, non indigenous, and the sum of clinical symptom <7. But the relationship isn\u27t significant
Respon Klinis dan Parasitologis Dihidroartemisinin - Piperakuin pada Subyek Malaria Falsiparum dan Malaria Vivaks pada Hari Ke-3 Kunjungan Ulang
Background: Clinical and parasitological response of malaria treatment on day 3 follow-up (D3) is a crucial condition to predict the successful of treatment. D3 is a period time that Early Treatment Failure may happen which may cause severe or complicated malaria. Moreover, if the asexual parasitemia is still detected more than 10% study subjects, it is assumed parasites resistance against artemisinin. Methods: Analysis used data from Monitoring Drug Resistance In Subject With P.falciparum And P.vivax Malaria In Kalimantan And Sulawesi. Clinical data was gotten from anamnesis to identify clinical symptoms and physical examination including vital and clinical signs that was notified in case report form (CRF). Parasitological data was cross check examination from NIHRD microscopist for parasite density, and PCR examination result for Plasmodium detection and speciation that were recorded in log book and/or CRF. Clinical and parasitological response of DHP was examined with compared the condition of falciparum and vivax malaria on D0 (before treatment) and D3 (after 3 days treatment with completed dose). Result: Total malaria subject that were analyzed 206 subject, that were 119 falciparum malaria and 87 vivax malaria. Proportion subject falciparum and vivax malaria with clinical symptoms deceased significantly on D3 (p<0.05), accepted diarrhea on subject with vivax malaria. Proportion clinical signs also decreased significantly on D3, accepted dyspneu on falciparum malaria subject. From 206 malaria subject, only 1 subject (0,8%) with falciparum malaria that still was found asexual parasite with low density (10/ul). Proportion subject with gametocyte also decreased significantly on falciparum malaria (p=0,000) and vivax malaria (p=0,000). Conclusion: Clinical and parasitological response of DHP in falciparum and vivax subjects was excellent by D3. Only one falciparum malaria subject (0,8%) was still detected asexual parasitemia with the density of 10/ul. DHP has rapid action and no clear signs artemisinin resistance
Cooling of a mirror by radiation pressure
We describe an experiment in which a mirror is cooled by the radiation
pressure of light. A high-finesse optical cavity with a mirror coated on a
mechanical resonator is used as an optomechanical sensor of the Brownian motion
of the mirror. A feedback mechanism controls this motion via the radiation
pressure of a laser beam reflected on the mirror. We have observed either a
cooling or a heating of the mirror, depending on the gain of the feedback loop.Comment: 4 pages, 6 figures, RevTe
High-sensitivity monitoring of micromechanical vibration using optical whispering gallery mode resonators
The inherent coupling of optical and mechanical modes in high finesse optical
microresonators provide a natural, highly sensitive transduction mechanism for
micromechanical vibrations. Using homodyne and polarization spectroscopy
techniques, we achieve shot-noise limited displacement sensitivities of
10^(-19) m Hz^(-1/2). In an unprecedented manner, this enables the detection
and study of a variety of mechanical modes, which are identified as radial
breathing, flexural and torsional modes using 3-dimensional finite element
modelling. Furthermore, a broadband equivalent displacement noise is measured
and found to agree well with models for thermorefractive noise in silica
dielectric cavities. Implications for ground-state cooling, displacement
sensing and Kerr squeezing are discussed.Comment: 25 pages, 8 figure
Optomechanical scheme for the detection of weak impulsive forces
We show that a cooling scheme and an appropriate quantum nonstationary
strategy can be used to improve the signal to noise ratio for the
optomechanical detection of weak impulsive forces.Comment: 4 pages, Revtex, 1 figur
Thermal and back-action noises in dual-sphere gravitational-waves detectors
We study the sensitivity limits of a broadband gravitational-waves detector
based on dual resonators such as nested spheres. We determine both the thermal
and back-action noises when the resonators displacements are read-out with an
optomechanical sensor. We analyze the contributions of all mechanical modes,
using a new method to deal with the force-displacement transfer functions in
the intermediate frequency domain between the two gravitational-waves sensitive
modes associated with each resonator. This method gives an accurate estimate of
the mechanical response, together with an evaluation of the estimate error. We
show that very high sensitivities can be reached on a wide frequency band for
realistic parameters in the case of a dual-sphere detector.Comment: 10 pages, 7 figure
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