391 research outputs found

    The Learning Curve of Robot-Assisted Laparoscopic Surgery

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    Nilai Gizi Beras Lima Varitas Padi Unggul

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    Nilai gizi beras lima varitas padi unggul. (The nutritional value of rice of five high-yielding varieties). Presented at the First Asian Congress of Nutrition, Hyderabad, January 28 - February 2, 1971. The protein contents of IRRI rice varieties were: 7% in PB 5 (IRRI 5), 6.4% in PB 8 (IRRI 8) and 9% in C4-63. The Indonesian high-yielding rice varieties had protein contents of 6% in Shinta, and 7.3% in Dewi Ratih, compared to 6% in brown rice. The PER values of PB 5 and PB 8 were 2.3 and 2.5 while that of Shinta and brown rice were 2.2 and 2.1. The PER value of skimmed milk was 2.9. The NPU-op values of those four rice varieties ranged from 52 to 54, but was only 40 for C4-63. Fortification with L-lysine monohydrochloride increased the NPU. Varitas-varitas padi PB 5 dan PB 8 lebih disukai orang karena lebih enak rasanya, terutama jenis Shinta dan C4-63. Menjadi pertanyaan apakah jenis-jenis ini mempunyai kualitas protein yang lebih baik, disamping daya hasil tinggi dan ciri-ciri lain.Penelitian ini ditujukan untuk mencari nilai gizi beras kelima varitas padi

    Ascorbic acid, carotenoid contents and antioxidant properties of Australian summer carrot with different irrigation amounts on a free-draining, sandy soil

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    It is important to reduce the use of water for agricultural production in response to water scarcity and environmental concerns. The nutritive value in fruits and vegetables including carrot (Daucus carota L.), can be influenced by various climatic conditions, such as light intensity, temperature, and irrigation. The effect of differential irrigation treatments on the contents of ascorbic acid and carotenoid as well as antioxidant properties (antioxidant content, antiradical power, and antioxidant capacity) were studied in carrot (cv. Stefano) roots grown on a free-draining, sandy soil (Grey Karrakatta Sand) in the summer period. This soil has water holding capacities as low as 10-13% and requires irrigation up to 150% of class A pan evaporation (Epan) to optimize growth and quality. The irrigation treatments applied in this study consisted of 100% Epan replacement, 150% Epan replacement and crop factor. The soil water stress index calculation showed the soil water tension ranged from -2.4 to -7.6 kPa that was within the range between saturation and field capacity for sandy soil. The reduction of irrigation amount from 150% to 100% Epan did not differentiate the contents of ascorbic acid and total carotenoid, but it slightly decreased antioxidant properties of carrot grown in the free draining sandy soil

    Ventricular structure, function, and mechanics at high altitude: chronic remodeling in Sherpa vs. short-term lowlander adaptation

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    Short-term, high-altitude (HA) exposure raises pulmonary artery systolic pressure (PASP) and decreases left-ventricular (LV) volumes. However, relatively little is known of the long-term cardiac consequences of prolonged exposure in Sherpa, a highly adapted HA population. To investigate short-term adaptation and potential long-term cardiac remodeling, we studied ventricular structure and function in Sherpa at 5,050 m (n = 11; 31 ± 13 yr; mass 68 ± 10 kg; height 169 ± 6 cm) and lowlanders at sea level (SL) and following 10 ± 3 days at 5,050 m (n = 9; 34 ± 7 yr; mass 82 ± 10 kg; height 177 ± 6 cm) using conventional and speckle-tracking echocardiography. At HA, PASP was higher in Sherpa and lowlanders compared with lowlanders at SL (both P < 0.05). Sherpa had smaller right-ventricular (RV) and LV stroke volumes than lowlanders at SL with lower RV systolic strain (P < 0.05) but similar LV systolic mechanics. In contrast to LV systolic mechanics, LV diastolic, untwisting velocity was significantly lower in Sherpa compared with lowlanders at both SL and HA. After partial acclimatization, lowlanders demonstrated no change in the RV end-diastolic area; however, both RV strain and LV end-diastolic volume were reduced. In conclusion, short-term hypoxia induced a reduction in RV systolic function that was also evident in Sherpa following chronic exposure. We propose that this was consequent to a persistently higher PASP. In contrast to the RV, remodeling of LV volumes and normalization of systolic mechanics indicate structural and functional adaptation to HA. However, altered LV diastolic relaxation after chronic hypoxic exposure may reflect differential remodeling of systolic and diastolic LV function. exposure to high altitude (HA) challenges the cardiovascular system to meet the metabolic demand for oxygen (O2) in an environment where arterial O2 content is markedly reduced. The drop in arterial O2 has both direct and indirect consequences for the heart, including depressed inotropy of cardiac muscle (40, 44), changes in blood volume and viscosity, and vasoconstriction of the pulmonary arteries (33). Despite these broad physiological changes, which have been reviewed previously (28, 49), there is evidence that the heart copes relatively well at HA (29, 34). Short-term HA exposure in lowland natives is characterized by a decreased plasma volume (PV), an increased sympathetic nerve activity, and pulmonary vasoconstriction (17, 30, 37), all of which have considerable impact on cardiac function and in time, could stimulate cardiac remodeling. Himalayan native Sherpa, who are of Tibetan lineage and have resided at HA for ∼25,000 yr (2), are well adapted to life at HA, demonstrating greater lung-diffusing capacity (11) and an absence of polycythemia compared with acclimatized lowlanders (4). Previous studies have also reported Sherpa to have higher maximal heart rates (HRs) and only moderate pulmonary hypertension compared with lowlanders at HA (11, 25). Due to their longevity at HA, Sherpa provide an excellent model to investigate the effects of chronic hypoxic exposure. Despite this, neither the acute nor lifelong effects of HA on right- and left-ventricular (RV and LV, respectively) structure and function have been fully assessed in lowlanders or the unique Sherpa population. Due to the unique arrangement of myofibers, cardiac form and function are intrinsically linked, as reflected in the cardiac mechanics (LV twist and rotation and ventricular strain) that underpin ventricular function. In response to altered physiological demand, ventricular mechanics acutely change (16, 41) and chronically remodel (31, 42) to reduce myofiber stress and achieve efficient ejection (5, 47). Therefore, concomitant examination of myocardial mechanics and ventricular structure in both the acute and chronic HA setting will provide novel insight into human adaptation to hypoxia. To investigate the effects of chronic hypoxic exposure, we compared ventricular volumes and mechanics in Sherpa at 5,050 m with lowlanders at sea level (SL). In addition, to reveal potential stimuli for remodeling and to examine the time course of adaptation, we compared Sherpa with lowlanders after short-term HA exposure. We hypothesized that: 1) Sherpa would exhibit smaller LV volumes and a higher RV/LV ratio than lowlanders at SL, 2) LV mechanics in Sherpa will closely resemble those of lowlanders at SL, and 3) following partial acclimatization to HA, LV volumes would be reduced in lowlanders and LV mechanics acutely increased

    Techniques in Analytic Lamb Shift Calculations

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    Quantum electrodynamics has been the first theory to emerge from the ideas of regularization and renormalization, and the coupling of the fermions to the virtual excitations of the electromagnetic field. Today, bound-state quantum electrodynamics provides us with accurate theoretical predictions for the transition energies relevant to simple atomic systems, and steady theoretical progress relies on advances in calculational techniques, as well as numerical algorithms. In this brief review, we discuss one particular aspect connected with the recent progress: the evaluation of relativistic corrections to the one-loop bound-state self-energy in a hydrogenlike ion of low nuclear charge number, for excited non-S states, up to the order of alpha (Zalpha)^6 in units of the electron mass. A few details of calculations formerly reported in the literature are discussed, and results for 6F, 7F, 6G and 7G states are given.Comment: 16 pages, LaTe

    Sixth-Order Vacuum-Polarization Contribution to the Lamb Shift of the Muonic Hydrogen

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    The sixth-order electron-loop vacuum-polarization contribution to the 2P1/2−2S1/22P_{1/2} - 2S_{1/2} Lamb shift of the muonic hydrogen (μ−p+\mu^{-} p^+ bound state) has been evaluated numerically. Our result is 0.007608(1) meV. This eliminates the largest uncertainty in the theoretical calculation. Combined with the proposed precision measurement of the Lamb shift it will lead to a very precise determination of the proton charge radius.Comment: 4 pages, 5 figures the totoal LS number is change

    Improved α4\alpha^4 Term of the Muon Anomalous Magnetic Moment

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    We have completed the evaluation of all mass-dependent α4\alpha^4 QED contributions to the muon g−2g-2, or aμa_\mu, in two or more different formulations. Their numerical values have been greatly improved by an extensive computer calculation. The new value of the dominant α4\alpha^4 term A2(8)(mμ/me)A_2^{(8)} (m_\mu / m_e) is 132.6823 (72), which supersedes the old value 127.50 (41). The new value of the three-mass term A3(8)(mμ/me,mμ/mτ)A_3^{(8)} (m_\mu / m_e, m_\mu / m_\tau) is 0.0376 (1). The term A2(8)(mμ/mτ)A_2^{(8)} (m_\mu / m_\tau) is crudely estimated to be about 0.005 and may be ignored for now. The total QED contribution to aμa_\mu is 116584719.58(0.02)(1.15)(0.85)×10−11116 584 719.58 (0.02)(1.15)(0.85) \times 10^{-11}, where 0.02 and 1.15 are uncertainties in the α4\alpha^4 and α5\alpha^5 terms and 0.85 is from the uncertainty in α\alpha measured by atom interferometry. This raises the Standard Model prediction by 13.9×10−1113.9 \times 10^{-11}, or about 1/5 of the measurement uncertainty of aμa_\mu. It is within the noise of current uncertainty (∼100×10−11\sim 100 \times 10^{-11}) in the estimated hadronic contributions to aμa_\mu.Comment: Appendix A has been rewritten extensively. It includes the 4th-order calculation for illustration. Version accepted by PR

    Robot-assisted laparoscopic surgery of the infrarenal aorta: The early learning curve

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    Background Recently introduced robot-assisted laparoscopic surgery (RALS) facilitates endoscopic surgical manipulation and thereby reduces the learning curve for (advanced) laparoscopic surgery. We present our learning curve with RALS for aortobifemoral bypass grafting as a treatment for aortoiliac occlusive disease. Methods Between February 2002 and May 2005, 17 patients were treated in our institution with robot-assisted laparoscopic aorto-bifemoral bypasses. Dissection was performed laparoscopically and the robot was used to make the aortic anastomosis. Operative time, clamping time, and anastomosis time, as well as blood loss and hospital stay, were used as parameters to evaluate the results and to compare the first eight (group 1) and the last nine patients (group2). Results Total median operative, clamping, and anastomosis times were 365 min (range: 225–589 min), 86 min (range: 25–205 min), and 41 min (range: 22–110 min), respectively. Total median blood loss was 1,000 ml (range: 100–5,800 ml). Median hospital stay was 4 days (range: 3–57 days). In this series 16/18 anastomoses were completed with the use of the robotic system. Three patients were converted (two in group 1, one in group 2), and one patient died postoperatively (group 1). Median clamping and anastomosis times were significantly different between groups 1 and 2 (111 min [range: 85–205 min] versus 57.5 min [range: 25–130 min], p < 0.01 and 74 min [range: 40–110 min] versus 36 min [range: 22–69 min], p < 0.01, respectively) Total operative time, blood loss, and hospital stay showed no significant difference between groups 1 and 2. Conclusions Robot-assisted aortic anastomosis was shown to have a steep learning curve with considerable reduction of clamping and anastomosis times. However, due to a longer learning curve for laparoscopic dissection of the abdominal aorta, operation times were not significantly shortened. Even with robotic assistance, laparoscopic aortoiliac surgery remains a complex procedure
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