32 research outputs found
Room-temperature biphoton source with a spectral brightness near the ultimate limit
The biphotons, generated from a hot atomic vapor via the process of
spontaneous four-wave mixing (SFWM), have the following merits: stable and
tunable frequencies as well as linewidth. Such merits are very useful in the
applications of long-distance quantum communication. However, the hot-atom SFWM
biphoton sources previously had far lower values of generation rate per
linewidth, i.e., spectral brightness, as compared with the sources of biphotons
generated by the spontaneous parametric down conversion (SPDC) process. Here,
we report a hot-atom SFWM source of biphotons with a linewidth of 960 kHz and a
generation rate of 3.7 pairs/s. The high generation rate,
together with the narrow linewidth, results in a spectral brightness of
3.8 pairs/s/MHz, which is 17 times of the previous best result
with atomic vapors and also better than all known results with all kinds of
media. The all-copropagating scheme together with a large optical depth (OD) of
the atomic vapor is the key improvement, enabling the achieved spectral
brightness to be about one quarter of the ultimate limit. Furthermore, this
biphoton source had a signal-to-background ratio (SBR) of 2.7, which violated
the Cauchy-Schwartz inequality for classical light by about 3.6 folds. Although
an increasing spectral brightness usually leads to a decreasing SBR, our
systematic study indicates that both of the present spectral brightness and SBR
can be enhanced by further increasing the OD. This work demonstrates a
significant advancement and provides useful knowledge in the quantum technology
using photons
Patients with chronic kidney disease are at an elevated risk of dementia: A population-based cohort study in Taiwan
Women with endometriosis have higher comorbidities: Analysis of domestic data in Taiwan
AbstractEndometriosis, defined by the presence of viable extrauterine endometrial glands and stroma, can grow or bleed cyclically, and possesses characteristics including a destructive, invasive, and metastatic nature. Since endometriosis may result in pelvic inflammation, adhesion, chronic pain, and infertility, and can progress to biologically malignant tumors, it is a long-term major health issue in women of reproductive age. In this review, we analyze the Taiwan domestic research addressing associations between endometriosis and other diseases. Concerning malignant tumors, we identified four studies on the links between endometriosis and ovarian cancer, one on breast cancer, two on endometrial cancer, one on colorectal cancer, and one on other malignancies, as well as one on associations between endometriosis and irritable bowel syndrome, one on links with migraine headache, three on links with pelvic inflammatory diseases, four on links with infertility, four on links with obesity, four on links with chronic liver disease, four on links with rheumatoid arthritis, four on links with chronic renal disease, five on links with diabetes mellitus, and five on links with cardiovascular diseases (hypertension, hyperlipidemia, etc.). The data available to date support that women with endometriosis might be at risk of some chronic illnesses and certain malignancies, although we consider the evidence for some comorbidities to be of low quality, for example, the association between colon cancer and adenomyosis/endometriosis. We still believe that the risk of comorbidity might be higher in women with endometriosis than that we supposed before. More research is needed to determine whether women with endometriosis are really at risk of these comorbidities
Slow-paced inspiration regularizes alpha phase dynamics in the human brain
[[abstract]]The phase of low-frequency, rhythmic cortical activity is essential for organizing brain processes because it provides a recurrent temporal frame for information coding. However, the low-frequency cortical phase exhibits great flexibility in response to external influences. Given that brain rhythms have been found to track respiratory inputs, we hypothesized that slow breathing, commonly associated with mental regulation, could reorganize the relationship between these two rhythmic systems through the adjustment of the cortical phase to such a slow train of inputs. Based on simultaneous magnetoencephalography and respiratory measurements, we report that while participants performed paced breathing, slow relative to normal breathing modulated cortical phase activity in the alpha range across widespread brain areas. Such modulation effects were specifically locked to the middle of the inspiration stage and exhibited a well-structured pattern. At the single-subject level, the phase angles underlying the effects became more likely to be diametrically opposed across breaths, indicating unique and consistent phase adjustment to slow inspiratory inputs. Neither cardiac fluctuations nor breathing-unrelated task effects could account for the findings. We suggest that slow-paced inspiration could organize the cortical phase in a regularized phase pattern, revealing a rhythmic but dynamic neural network integrated with different neurophysiological systems through volitional control.NEW & NOTEWORTHY Breathing is more complicated than a simple gas exchange, as it is integrated with numerous cognitive and emotional functions. Controlled slow breathing has often been used to regulate mental processes. This magnetoencephalography study demonstrates that slow-paced relative to normal-paced inspiration could organize the timing of alpha rhythmic activities across breathing cycles in a structured manner over widespread brain areas. Our results reveal how a volitionally controlled change in respiratory behavior could systematically modulate cortical activity
Population study evaluating fracture risk among patients with chronic osteomyelitis.
BACKGROUND:Studies investigating the fracture risk in patients with chronic osteomyelitis (COM) limited to case reports. This study evaluated the association between COM and subsequent fracture risk using population-based data. METHODS:A subset claims data of the Taiwan National Health Insurance was used to identify 7,147 patients with COM newly diagnosed in 1999-2005 without fracture history and 28,588 general population controls, frequency matched by sex, age and diagnosis date. The incident fractures was measured by the end of 2013. RESULTS:The incidence density of fracture was 1.94-fold greater in the COM cohort than in controls (21.5 vs. 11.1 per 1000 person-years), with the adjusted hazard ratio (HR) of 1.81 (95% CI: 1.67-1.95) for COM patients compared to controls after controlling for sex, age, and comorbidities of diabetes, osteoporosis, depression and end-stage renal disease in Cox proportional hazards regression. The fracture risk increased with age and women were at greater risk than men. The fracture incidence increased substantially in those with osteoporosis, 40.2 per 1000 person-years in COM patients. Site specific analysis showed a higher portion of incident fractures for lower limbs, 52.7% in COM cohort and 46.3% in controls. CONCLUSION:Findings in this 15-year follow-up observation support our hypothesis that patients with COM are at an elevated risk of subsequent fracture. COM patients and the elderly deserve adequate consultation and awareness for fracture prevention
Stroke risks in women with dysmenorrhea by age and stroke subtype.
BackgroundDysmenorrhea and stroke are health problems affecting women worldwide in their day-to-day lives; however, there is limited knowledge of the stroke risk in women with dysmenorrhea, and there have been no studies assessing the specific distribution of stroke subtypes. This case-control study assessed stroke subtypes by age and the role of comorbidities in women with dysmenorrhea.Methods and findingsData obtained between 1997 and 2013 from Taiwan's health insurance database identified 514 stroke cases and 31,201 non-stroke controls in women with dysmenorrhea aged 15-49 years. Proportional distributions of subtypes and odds ratios (ORs) of stroke associated with comorbidities by age and subtype were measured. We found that the stroke risk in dysmenorrheal patients increased with age, and that hypertension was nine-fold more prevalent in the stroke cases than in the controls and was associated with an adjusted OR of 4.53 (95% confidence interval (CI) = 3.46-5.92) for all stroke cases. Moreover, the proportion of hemorrhagic stroke was greater than that of ischemic stroke in younger dysmenorrheal patients between 15-24 years old (50.5% vs. 11.4%), whereas this was reversed in those aged 30-49 years old (16.1% vs. 21.0%). Overall, 25.3% of the stroke cases consisted of transient cerebral ischemia and 31.3% were other acute but ill-defined cerebrovascular diseases, in which the prevalence increased with age for both types of strokes. Hypertension was the comorbidity with the highest OR associated with each subtype stroke; diabetes, hyperlipidemia, arrhythmia, and thyroid disease were also comorbidities that were significantly associated with ill-defined cerebrovascular diseases.ConclusionsThe stroke type varies by age in dysmenorrheal patients, and hypertension is the most important comorbidity associated with all types of stroke; therefore, more attention for stroke prevention must be paid to women with dysmenorrhea, particularly when combined with comorbidities
Patients with chronic kidney disease are at an elevated risk of dementia: A population-based cohort study in Taiwan
Abstract Background Chronic kidney disease (CKD) is more prevalent in Taiwan than in most countries. This population-based cohort study evaluated the dementia risk associated with CKD. Methods Using claims data of 1,000,000 insured residents covered in the universal health insurance of Taiwan, we selected 37049 adults with CKD newly diagnosed from 2000–2006 as the CKD cohort. We also randomly selected 74098 persons free from CKD and other kidney diseases, frequency matched with age, sex and the date of CKD diagnosed. Incidence and hazard ratios (HRs) of dementia were evaluated by the end of 2009. Results Subjects in the CKD cohort were more prevalent with comorbidities than those in the non-CKD cohort (p Conclusions Patients with CKD could have an elevated dementia risk. CKD patients with comorbidity deserve attention to prevent dementia.</p
Population based retrospective cohort study on risk of retinopathy of prematurity in twins.
BACKGROUND:Twin infants are likely at great risk for ROP, but studies reported conflicting findings and population studies examining the risk of retinopathy of prematurity (ROP) in twins is limited. We aimed to evaluate the ROP risk in the cohort of one of twins, comparing to singletons. MATERIAL AND METHODS:Using insurance claims data of a half of children in Taiwan ages 18 and less, we established a twin cohort (N = 27830) born in 1998-2009 and a randomly selected singleton cohort (N = 111080) frequency matched by sex, birth year, residential area and parental occupation and followed up to 2012 years. RESULTS:The overall incidence rate of ROP was 13.6-fold greater in the twin cohort than in the singleton cohort (35.1 vs. 2.58 per 10,000 person-years; adjusted HR = 13.4, 95% CI = 11.7-15.3; p <0.0001). The ROP incidence was slightly higher in boys than in girls, higher in children in more urbanized areas and born to mothers without works. The incident ROP increased with decreasing birthweight. For children with birthweight <1000 grams, the ROP incidence was 1.2-fold greater in the twin cohort than in the singleton cohort (1243.2 vs. 1016.3 per 10,000 person-years). The use of mechanical ventilation was associated with increased ROP risk for both cohorts, particularly for infants who were under invasive treatment. CONCLUSION:Infants who were born as twins or born with low birthweight were at an elevated risk of developing ROP. Extreme cautious and close monitor are required for new born with low birthweight and have undergone with mechanical ventilation
Risk of Glaucoma Associated with Components of Metabolic Disease in Taiwan: A Nationwide Population-Based Study
Purpose: This retrospective cohort study was conducted to determine the glaucoma risk associated with metabolic disease (MetD) using insurance claims data of Taiwan. Methods: From the database, we identified patients with newly diagnosed hypertension, diabetes and/or hyperlipidemia from the years 2000 to 2002 as the MetD cohort (N = 42,036) and an age-gender-diagnosis-date matched control cohort without MetD with a two-fold sample size than that of the MetD cohort. Both cohorts were followed until the development of glaucoma, death, or withdrawal, until 31 December 2013. The incidence of glaucoma, and the Cox method estimated hazard ratio (HR) of glaucoma were calculated. Results showed that the incidence of glaucoma was two-fold higher in the MetD cohort than in the controls (1.99 versus 0.99 per 1000 person-years), with an adjusted HR of 1.66 (95% CI: 1.50–1.85). The glaucoma incidence was higher in patients with diabetes than those with hypertension and hyperlipidemia (2.38 versus 1.95 and 1.72 per 1000 person-years, respectively). The incidence increased to 5.67 per 1000 person-years in patients with all three comorbidities, with an aHR of 4.95 (95% CI: 2.35–10.40). We also found higher incidence rates of primary open-angle glaucoma and primary angle-closure glaucoma with aHRs of 2.03 and 1.44, respectively. It was concluded that glaucoma risk increased with the number of MetD. Health providers need to monitor patients with MetD to prevent glaucoma
Roles of Ambient Temperature and PM<sub>2.5</sub> on Childhood Acute Bronchitis and Bronchiolitis from Viral Infection
Studies have associated the human respiratory syncytial virus which causes seasonal childhood acute bronchitis and bronchiolitis (CABs) with climate change and air pollution. We investigated this association using the insurance claims data of 3,965,560 children aged ≤ 12 years from Taiwan from 2006–2016. The monthly average incident CABs increased with increasing PM2.5 levels and exhibited an inverse association with temperature. The incidence was 1.6-fold greater in January than in July (13.7/100 versus 8.81/100), declined during winter breaks (February) and summer breaks (June–August). The highest incidence was 698 cases/day at 2.5 > 37.0 μg/m3, with an adjusted relative risk (aRR) of 1.01 (95% confidence interval [CI] = 0.97–1.04) compared to 568 cases/day at 2.5 3 (reference). The incidence at ≥30 °C decreased to 536 cases/day (aRR = 0.95, 95% CI = 0.85–1.06) with PM2.5 > 37.0 μg/m3 and decreased further to 392 cases/day (aRR = 0.61, 95% CI = 0.58–0.65) when PM2.5 was 3. In conclusion, CABs infections in children were associated with lowered ambient temperatures and elevated PM2.5 concentrations, and the high PM2.5 levels coincided with low temperature levels. The role of temperature should be considered in the studies of association between PM2.5 and CABs