Enhanced optoelectronic reservoir computation using semiconductor laser with double delay feedbacks.

We numerically explored the enhanced performance and physical mechanism of semiconductor laser (SL) based reservoir computation (RC) with double optoelectronic feedback (DOEF). One-step and multistep Santa Fe time series predictions were used as standard test benchmarks in this work. We found that in the optimized parameter region the normalized mean square error (NMSE) of an SL-based RC under DOEF is smaller than an SL-based RC with single optoelectronic feedback (SOEF). In addition, the performance improvement is more obvious for multistep prediction, which is particularly suitable for more complex tasks that requires a higher memory capability (MC). The enriched node states (optical intensity of the virtual nodes for each sample) and the enhanced MC of the proposed DOEF were verified by a comparison to SOEF under the optimized feedback strength. The influence of the feedback strength and the delay difference on the NMSE and the MC was also investigated. Our study should be helpful in the design of a high-performance optoelectronic RC based on an SL.

Towards fast sensing along ultralong BOTDA: flatness enhancement by utilizing injection-locked dual-bandwidth probe wave.

Brillouin optical time-domain analysis (BOTDA) using distributed Brillouin amplification (DBA) only requires a milliwatt-level pump to achieve a sensing range beyond 100 km, which provides a powerful tool for temperature/strain sensing. However, similar to the majority of other long-range BOTDAs, the state-of-the-art reports require > 1000 times average, severely restricting the sensing speed. The blind area over tens of kilometers caused by the nonuniform Brillouin response and parasitic amplitude modulation (AM) are crucial factors affecting the signal-to-noise ratio (SNR). Here, a comprehensive performance optimization and substantial enhancement for BOTDA sensors was presented by the direct demodulation of an injection-locked dual-bandwidth probe wave. Injection locking (IL) can completely eliminate the impact of AM noise; dual-bandwidth probe enables self-adaptive pulse loss compensation, thereby intensifying the SNR flatness along the ultralong fiber, and direct probe demodulation can overcome nonlocal effects and allows ∼19.7 dB enhancement of probe input power. Therefore, using only 100 times average, ∼148.3 km sensing, and ∼5 m spatial resolution were achieved with < ∼0.8 MHz standard deviation of Brillouin frequency shift (BFS) over a broad range (∼131.7 km). The reduction in averages was more than 10 times that of the reported majority of long-range BOTDAs. Such performances were achieved without using time-consuming or post-processing techniques, such as optical pulse coding and image denoising. Because this approach is compatible with optical chirp chain technique without frequency sweeping, fast acquisition (0.3 s) was also realized, which has the potential for fast sensing at 3.3 Hz along a ∼150 km fiber.

Effects of combined calcium and vitamin D supplementation on osteoporosis in postmenopausal women: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: The aim of the present study was to explore whether combined calcium and vitamin D supplementation is beneficial for osteoporosis in postmenopausal women. METHODS: We searched the PubMed, Cochrane library, Web of science and Embase databases and reference lists of eligible articles up to Feb, 2020. Randomized controlled trials (RCTs) evaluating the effect of combined calcium and vitamin D on osteoporosis in postmenopausal women were included in the present study. RESULTS: Combined calcium and vitamin D significantly increased total bone mineral density (BMD) (standard mean differences (SMD) = 0.537; 95% confidence interval (CI): 0.227 to 0.847), lumbar spine BMD (SMD = 0.233; 95% CI: 0.073 to 0.392; P < 0.001), arms BMD (SMD = 0.464; 95% CI: 0.186 to 0.741) and femoral neck BMD (SMD = 0.187; 95% CI: 0.010 to 0.364). It also significantly reduced the incidence of hip fracture (RR = 0.864; 95% CI: 0.763 to 0.979). Subgroup analysis showed that combined calcium and vitamin D significantly increased femoral neck BMD only when the dose of the vitamin D intake was no more than 400 IU d-1 (SMD = 0.335; 95% CI: 0.113 to 0.558), but not for a dose more than 400 IU d-1 (SMD = -0.098; 95% CI: -0.109 to 0.305), and calcium had no effect on the femoral neck BMD. Subgroup analysis also showed only dairy products fortified with calcium and vitamin D had a significant influence on total BMD (SMD = 0.784; 95% CI: 0.322 to 1.247) and lumbar spine BMD (SMD = 0.320; 95% CI: 0.146 to 0.494), but not for combined calcium and vitamin D supplement. CONCLUSION: Dairy products fortified with calcium and vitamin D have a favorable effect on bone mineral density. Combined calcium and vitamin D supplementation could prevent osteoporosis hip fracture in postmenopausal women.

Dietary patterns and anemia morphology in young men and women in Shandong province, China.

BACKGROUND AND OBJECTIVES: The association between diet and macrocytic and hypochromic anemia in young Chinese men and women remains unclear. The present study aimed to investigate the relationship between dietary pattern and macrocytic and hypochromic microcytic anemia in young Chinese men and women. METHODS AND STUDY DESIGN: Some 4,840 first-year students (2,385 men and 2,455 women) were recruited for this study from Qingdao University, China. Biochemical and hematological parameters, and food frequency questionnaires were obtained from the subjects. Based on dietary intake, participants were divided into three dietary patterns: seafood dietary pattern (SDP), vegan dietary pattern (VDP) and omnivorous dietary pattern (ODP). The risks for macrocytic and microcytic hypochromic anemia in three dietary patterns were assessed. RESULTS: Macrocytic and hypochromic anemia were less common in participants who adhered to the omnivorous dietary pattern than to the vegan or seafood dietary patterns (p<0.05). Adhering to an omnivorous dietary pattern was negatively associated with macrocytic anemia in men [odds ratio (95% CI): 0.74 (0.62, 0.89), p<0.001] and microcytic, hypochromic anemia in both genders [men: odds ratio (95% CI): 0.64 (0.45, 0.92), p=0.01; women: odds ratio (95% CI): 0.71 (0.51, 0.99), p=0.04]. CONCLUSIONS: Adhering to an omnivorous dietary pattern was associated with less common macrocytic anemia in young men and microcytic, hypochromic anemia. Dietary diversity is important in preventing macrocytic anemia in men and also microcytic, hypochromic anemia in young men and women. Excessive alcohol intake is the most plausible explanation for macrocytosis in the young men.

The combination effect of vitamin K and vitamin D on human bone quality: a meta-analysis of randomized controlled trials.

BACKGROUND: Previous studies did not draw a consistent conclusion about the effects of vitamin K combined with vitamin D on human skeletal quality. METHOD AND FINDINGS: A comprehensive search on Web of Science, PubMed, Embase and the Cochrane Library (from 1950 to February 2020) and bibliographies of relevant articles was undertaken, with the meta-analysis of eight randomized controlled trials (RCTs) including a total of 971 subjects. Vitamin K combined with vitamin D significantly increased the total bone mineral density (BMD): the pooled effect size was 0.316 [95% CI (confidence interval), 0.031 to 0.601]. A significant decrease in undercarboxylated osteocalcin (-0.945, -1.113 to -0.778) can be observed with the combination of vitamin K and D. Simultaneously, subgroup analysis showed that K2 or vitamin K (not specified) supplement was less than 500 µg d-1, which when combined with vitamin D can significantly increase the total BMD compared with the control group fed a normal diet or the group with no treatment (0.479, 0.101 to 0.858 and 0.570, 0.196 to 0.945). CONCLUSIONS: The combination of vitamin K and D can significantly increase the total BMD and significantly decrease undercarboxylated osteocalcin, and a more favorable effect is expected when vitamin K2 is used.

Relationship between retinol and risk of diabetic retinopathy: a case-control study.

BACKGROUND AND OBJECTIVES: The aim of the present study was to evaluate the relationship between retinol and risk of diabetic retinopathy in Chinese adults. METHODS AND STUDY DESIGN: Eighty-six subjects with type 2 diabetes mellitus (T2DM) and 40 healthy subjects (healthy comparison group, HCG) were recruited in Beijing Luhe Hospital. Of the 86 T2DM subjects, 43 subjects were diagnosed with diabetic retinopathy (DRG), and 43 subjects had no retinopathy (DNRG). RESULTS: Dietary intake of retinol (p<0.001) and retinol equivalent (p<0.05) was significantly higher but serum retinol and (p<0.001) retinol binding protein 4 (RBP4) (p<0.05) were significantly lower in DNRG compared with HCG. Dietary intake of retinol (p<0.05) and retinol equivalent (p<0.05) was significantly lower, and serum retinol and (p<0.01) retinol binding protein 4 (RBP4) (p<0.01) were significantly higher in DRG compared with DNRG. In T2DM subjects, per 100 µg/day higher dietary retinol intake was associated with 17% lower risk of diabetic retinopathy (odds ratio (OR), 0.83; 95% CI, 0.70 to 0.98; p=0.032), and after adjusting for potential confounding factors, the OR was 0.82 (95% CI, 0.69 to 0.99; p=0.036); per 100 µg/day higher in dietary retinol equivalent intake was associated with 12% lower risk of diabetic retinopathy (OR, 0.88; 95% CI, 0.79 to 0.97; p=0.010), and after adjusting for potential confounding factors, the OR was 0.88 (95% CI, 0.79 to 0.98; p=0.025). CONCLUSIONS: Higher dietary intake of retinol or retinol equivalent is associated with lower risk of diabetic retinopathy.

Effects of Multivitamin and Multimineral Supplementation on Blood Pressure: A Meta-Analysis of 12 Randomized Controlled Trials.

Previous studies have not drawn a consistent conclusion about effect of multivitamin and multimineral supplementation (MVMS) on blood pressure. A comprehensive search of PubMed, Embase and Cochrane Library (up to May 2018) and references of relevant articles was undertaken. The present meta-analysis included 12 randomized controlled trials (RCTs), of which eight RCTs in 2011 subjects evaluated the effect of MVMS on blood pressure and four RCTs in 21,196 subjects evaluated the effect of MVMS on the risk of hypertension. MVMS had a lowering effect on systolic blood pressure (SBP) and diastolic blood pressure (DBP): the weighted mean difference (WMD) was -1.31 mmHg (95% CI, -2.48 to -0.14 mmHg) and -0.71 mmHg (95% CI, -1.43 to 0.00 mmHg), respectively. Subgroup analysis indicated that the lowering effect of MVMS on blood pressure was only significant in 134 subjects with chronic disease but not in 1580 healthy subjects, and the WMD for systolic blood pressure (SBP) and DBP in subjects with chronic disease was -6.29 mmHg (95% CI, -11.09 to -1.50 mmHg) and -2.32 mmHg (95% CI, -4.50 to -0.13 mmHg), respectively. The effect size of MVMS on SBP in 58 hypertensive subjects (WMD, -7.98 mmHg; 95% CI, -14.95 to -1.02 mmHg) was more than six times of that in 1656 normotensive subjects (WMD, -1.25 mmHg; 95% CI, -2.48 to -0.02 mmHg). However, no significant effect on DBP was observed in both hypertensive and normotensive subgroups. There was no significant effect of MVMS on risk of hypertension in 22,852 subjects with a normal blood pressure at baseline. In conclusion, although MVMS had a significant lowering effect on blood pressure in normotensive subjects, the lowering effect was too small to effectively prevent future hypertension. MVMS may be an effective method for blood pressure control in subjects with chronic disease including hypertension, but the sample size of subjects with hypertension or other chronic disease was too small, and more well-designed RCTs are needed to confirm this result.