96 research outputs found
Spatial-photonic Boltzmann machines: low-rank combinatorial optimization and statistical learning by spatial light modulation
The spatial-photonic Ising machine (SPIM) [D. Pierangeli et al., Phys. Rev.
Lett. 122, 213902 (2019)] is a promising optical architecture utilizing spatial
light modulation for solving large-scale combinatorial optimization problems
efficiently. However, the SPIM can accommodate Ising problems with only
rank-one interaction matrices, which limits its applicability to various
real-world problems. In this Letter, we propose a new computing model for the
SPIM that can accommodate any Ising problem without changing its optical
implementation. The proposed model is particularly efficient for Ising problems
with low-rank interaction matrices, such as knapsack problems. Moreover, the
model acquires learning ability and can thus be termed a spatial-photonic
Boltzmann machine (SPBM). We demonstrate that learning, classification, and
sampling of the MNIST handwritten digit images are achieved efficiently using
SPBMs with low-rank interactions. Thus, the proposed SPBM model exhibits higher
practical applicability to various problems of combinatorial optimization and
statistical learning, without losing the scalability inherent in the SPIM
architecture.Comment: 7 pages, 5 figures (with a 3-page supplemental
Spatial-photonic Ising machine by space-division multiplexing with physically tunable coefficients of a multi-component model
This paper proposes a space-division multiplexed spatial-photonic Ising
machine (SDM-SPIM) that physically calculates the weighted sum of the Ising
Hamiltonians for individual components in a multi-component model.
Space-division multiplexing enables tuning a set of weight coefficients as an
optical parameter and obtaining the desired Ising Hamiltonian at a time. We
solved knapsack problems to verify the system's validity, demonstrating that
optical parameters impact the search property. We also investigated a new
dynamic coefficient search algorithm to enhance search performance. The
SDM-SPIM would physically calculate the Hamiltonian and a part of the
optimization with an electronics process.Comment: 12 pages, 5 figure
アレルゲンベツ ニ ミタ Iガタ アレルギー ノ ハッショウ ト アレルギー マーチ ニ カンスル ケンキュウ
We studied the onset of allergic diseases and allergy march in 1,029 children aged from 3 months-old to 18-years old.A clinical study showed the close relationship between atopic dermatitis and asthma,and between asthma and allergic rhinitis. Specific IgE to house dust, mites, pets and pollen was recognized to be positive in early infants aged 4- or 5 months-old.This finding is earlier than the previous report, indicate the recent increase of allergic disease. Allergy to food allergens, inhalanted allergens and contact allergens are linked each other, and tend to be IgE-mediated sensitization to multiallergen
Pretreatment serum FGF-23 levels predict the efficacy of calcitriol therapy in dialysis patients
Pretreatment serum FGF-23 levels predict the efficacy of calcitriol therapy in dialysis patients.BackgroundThe predictor for the result of calcitriol therapy would be useful in the clinical practice of secondary hyperparathyroidism. Fibroblast growth factor-23 (FGF-23) is a newly found circulating phosphaturic factor. Its circulating level is elevated in uremia.MethodsDialysis patients with plasma intact parathyroid hormone (iPTH) levels greater than 300 pg/mL were included in the study. Calcitriol was intravenously injected three times a week. The patients whose plasma iPTH levels dropped below 300 pg/mL within 24 weeks were defined as those who had been successfully treated. A sandwich enzyme-linked immunosorbent assay (ELISA) system that detects human FGF-23 was applied.ResultsSixty-two patients were analyzed. The pretreatment FGF-23 levels were related to the iPTH levels, calcium × phosphate product levels, and history of active vitamin D therapy. The pretreatment FGF-23, iPTH, and calcium levels were lower in the patients who would be successfully treated with calcitriol. A logistic regression study revealed that the pretreatment iPTH and FGF-23 levels significantly affected the therapy results. Analyses using a receiver-operated curve revealed that FGF-23 was the best screening test for identifying patients with future refractory response to calcitriol therapy. The treatment would be successful in 88.2% of those with FGF-23 ≤9860 ng/L and iPTH ≤591 pg/mL, while it would be successful in only 4.2% of those with FGF-23 >9860 ng/L and iPTH >591 pg/mL.ConclusionPretreatment serum FGF-23 levels were a good indicator in predicting the response to calcitriol therapy. The measurement of serum FGF-23 levels, especially in combination with iPTH levels, is a promising laboratory examination for the clinical practice of secondary hyperparathyroidism
Boron-doped p-BaSi 2/n-Si solar cells formed on textured n-Si(001) with a pyramid structure consisting of {111} facets
BaSi2 films were fabricated on textured Si(0 0 1) substrates that consisted of {1 1 1} facets using molecular beam epitaxy. The light-trapping effect of these films and their performance when incorporated into solar cells were measured. X-ray diffraction and reflectivity measurements showed that the BaSi2 films were grown epitaxially on the textured Si(0 0 1) substrate and confirmed the light-trapping effect. The critical thickness over which BaSi2 relaxes increased from approximately 50 to 100 nm when comparing the BaSi2 films on a flat Si(1 1 1) substrate and the textured substrate, respectively. p-BaSi2/n-Si solar cells were fabricated with varying BaSi2 layer thickness and with hole concentrations in the range between 2.0 × 1018 and 4.6 × 1018 cm−3. These cells exhibited a maximum energy conversion efficiency of 4.62% with an open-circuit voltage of 0.30 V and a short-circuit current density of 27.6 mA/cm2 when the p-BaSi2 layer was 75 nm-thick. These results indicated that the use of BaSi2 films on textured Si(0 0 1) substrates in solar cells shows great promise
Reduction in interface defect density in p-BaSi2/n-Si heterojunction solar cells by a modified pretreatment of the Si substrate
We have investigated defects that occurred at the interface of p-BaSi2/n-Si heterojunction solar cells that were fabricated by molecular beam epitaxy. X-ray diffraction measurements indicated that BaSi2 (a-axis-oriented) was subjected to in-plane compressive strain, which relaxed when the thickness of the p-BaSi2 layer exceeded 50 nm. Additionally, transmission electron microscopy revealed defects in the Si layer near steps that were present on the Si(111) substrate. Deep level transient spectroscopy revealed two different electron traps in the n-Si layer that were located at 0.33 eV (E1) and 0.19 eV (E2) below the conduction band edge. The densities of E1 and E2 levels in the region close to the heterointerface were approximately 1014 cm−3. The density of these electron traps decreased below the limits of detection following Si pretreatment to remove the oxide layers from the n-Si substrate, which involved heating the substrate to 800 °C for 30 min under ultrahigh vacuum while depositing a layer of Si (1 nm). The remaining traps in the n-Si layer were hole traps located at 0.65 eV (H1) and 0.38 eV (H2) above the valence band edge. Their densities were as low as 1010 cm−3. Following pretreatment, the current versus voltage characteristics of the p-BaSi2/n-Si solar cells under AM1.5 illumination were reproducible with conversion efficiencies beyond 5% when using a p-BaSi2 layer thickness of 100 nm. The origin of the H2 level is discussed
Time definition of reintubation most relevant to patient outcomes in critically ill patients: a multicenter cohort study
Background: Reintubation is a common complication in critically ill patients requiring mechanical ventilation. Although reintubation has been demonstrated to be associated with patient outcomes, its time definition varies widely among guidelines and in the literature. This study aimed to determine the association between reintubation and patient outcomes as well as the consequences of the time elapsed between extubation and reintubation on patient outcomes. Methods: This was a multicenter retrospective cohort study of critically ill patients conducted between April 2015 and March 2021. Adult patients who underwent mechanical ventilation and extubation in intensive care units (ICUs) were investigated utilizing the Japanese Intensive Care PAtient Database. The primary and secondary outcomes were in-hospital and ICU mortality. The association between reintubation and clinical outcomes was studied using Cox proportional hazards analysis. Among the patients who underwent reintubation, a Cox proportional hazard analysis was conducted to evaluate patient outcomes according to the number of days from extubation to reintubation. Results: Overall, 184,705 patients in 75 ICUs were screened, and 1849 patients underwent reintubation among 48,082 extubated patients. After adjustment for potential confounders, multivariable analysis revealed a significant association between reintubation and increased in-hospital and ICU mortality (adjusted hazard ratio [HR] 1.520, 95% confidence interval [CI] 1.359–1.700, and adjusted HR 1.325, 95% CI 1.076–1.633, respectively). Among the reintubated patients, 1037 (56.1%) were reintubated within 24 h after extubation, 418 (22.6%) at 24–48 h, 198 (10.7%) at 48–72 h, 111 (6.0%) at 72–96 h, and 85 (4.6%) at 96–120 h. Multivariable Cox proportional hazard analysis showed that in-hospital and ICU mortality was highest in patients reintubated at 72–96 h (adjusted HR 1.528, 95% CI 1.062–2.197, and adjusted HR 1.334, 95% CI 0.756–2.352, respectively; referenced to reintubation within 24 h). Conclusions: Reintubation was associated with a significant increase in in-hospital and ICU mortality. The highest mortality rates were observed in patients who were reintubated between 72 and 96 h after extubation. Further studies are warranted for the optimal observation of extubated patients in clinical practice and to strengthen the evidence for mechanical ventilation.Tanaka A., Shimomura Y., Uchiyama A., et al. Time definition of reintubation most relevant to patient outcomes in critically ill patients: a multicenter cohort study. Critical Care 27, 378 (2023); https://doi.org/10.1186/s13054-023-04668-3
当院における過去5年間の高齢子宮体がん患者の治療に関する検討
京都府立医科大学附属北部医療センター 産婦人科Department of Obstetrics and Gynecology???? North Medical Center Kyoto Prefectural University of Medicineがん治療において年齢に応じた治療を考慮しなければならない場合がある。当院で初回治療を施行した子宮体がん患者32例に対し高齢群(70歳以上)と若年群(70歳未満)で検討したところ、高齢群で再発中リスク群以上の化学療法未施行率が有意に多かった。既往症や手術内容、有害事象発生率、再発率は同等であった。高齢子宮体がん患者に対しても高齢者機能評価等で患者状態を正しく評価することで標準治療が可能と考えられた。(著者抄録
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