139 research outputs found

    Numerical simulation of circulating tumor cell separation in a dielectrophoresis based Y-Y shaped microfluidic device

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    Efficient and effective separation of circulating tumor cells from biological samples to promote early diagnosis of cancer is important but challenging, especially for non-small cell lung cancer (NSCLC). In this article, a Y-Y shaped microfluidic device was designed to isolate NSCLC cells with a dielectrophoresis approach. Numerical simulations were conducted that the trajectories of cells were traced by solving the electric potential distribution and the flow field in a microchannel. The effects of inlet flow rate ratio of blood sample and buffer on separation performance were studied and optimized by the numerical investigation. Under optimal operating conditions, the separation efficiency can reach around 99%, which is achieved with 100 kHz AC, electrodes potential ranging from 1.6 V to 2.2 V, and flow rate ratio from 1.9 to 2.5. This study presents a potentially efficient, facile and low-cost route for circulating tumor cell separation

    Ambient air pollution and adverse birth outcomes: a natural experiment study

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    Background Radical regulations to improve air quality, including traffic control, were implemented prior to and during the 2008 Beijing Olympic Games. Consequently, ambient concentrations of nitrogen dioxide (NO 2 ) and particular matter 10 micrometers or less (PM 10 ), were reduced in a distinct and short window of time, which presented a natural experiment for testing the relationships between maternal exposure to PM 10 and NO 2 during pregnancy and adverse birth outcomes. Methods We estimated the effect of PM 10 and NO 2 exposure during each trimester of gestation on the risk of preterm birth among live births and the birth weight among term babies. The data were based on 50,874 live births delivered between January 1, 2006 and December 31, 2010 at the Beijing Haidian Maternal and Child Health Hospital. Air monitoring data for the same period were obtained from the Beijing Municipal Environmental Monitoring Center. Results Among full-term births, maternal exposure to NO 2 in the third trimester predicted birth weight, with each 10-unit increment (per 10 ug/m 3 ) in NO 2 concentration associated with a 13.78 g (95 % confidence interval: βˆ’21.12, βˆ’6.43; p \u3c 0.0001) reduction in birth weight. This association was maintained after adjusting for other pollutants, including carbon monoxide (CO), sulfur dioxide (SO 2 ), and PM 10 . No relationship was found between the concentration of PM 10 and low birth weight among full-term births. Neither PM 10 nor NO 2 concentrations predicted the risk of premature birth. Conclusions Exposure to ambient air pollution during certain periods of pregnancy may decrease birth weight, but the effect size is small

    Preplanned Studies: Orofacial Clefts in High Prevalence Area of Birth Defects β€” Five Counties, Shanxi Province, China, 2000–2020

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    What is already known on this topic?: The prevalence of structural birth defects, especially neural tube defects, decreased after national folic acid (FA) supplementation initiation. / What is added by this report?: The prevalence of orofacial clefts (OFCs) in five counties of Shanxi Province in northern China, including most subtypes except cleft palate, showed a downward trend in the past two decades. In this study, pre-perinatal prevalence increased due to earlier detection. / What are the implications for public health practice?: Periconceptional supplementation with FA may contribute to the decline in OFCs prevalence, while the effect on the OFCs subtype needs further investigation. Continuing to advocate for earlier supplementation (3 months before conception) and increased supplementation frequency (daily consumption) could promote further reduction in the prevalence of OFCs. Specific surveillance of this effect in the era of universal three-child policy is warranted

    Non-Isolated Neural Tube Defects with Comorbid Malformations Are Responsive to Population-Level Folic Acid Supplementation in Northern China

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    Objective: Comorbid congenital malformation of multiple organs may indicate a shared genetic/teratogenic causality. Folic acid supplementation reduces the population-level prevalence of isolated neural tube defects (NTDs), but whether complex cases involving independent malformations are also responsive is unknown. We aimed to describe the epidemiology of NTDs with comorbid malformations in a Chinese population and assess the impact of folic acid supplementation. Study Design: Data from five counties in Northern China were obtained between 2002 and 2021 through a population-based birth defects surveillance system. All live births, stillbirths, and terminations because of NTDs at any gestational age were recorded. NTDs were classified as spina bifida, anencephaly, or encephalocele. Isolated NTDs included spina bifida cases with presumed secondary malformations (hydrocephalus, hip dislocation, talipes). Non-isolated NTDs were those with independent concomitant malformations. Results: A total of 296,306 births and 2031 cases of NTDs were recorded from 2002–2021. A total of 4.8% of NTDs (97/2031) had comorbid defects, which primarily affected the abdominal wall (25/97), musculoskeletal system (24/97), central nervous system (22/97), and face (15/97). The relative risk of cleft lip and/or palate, limb reduction defects, hip dislocation, gastroschisis, omphalocele, hydrocephalus, and urogenital system defects was significantly greater in infants with NTDs than in the general population. Population-level folic acid supplementation significantly reduced the prevalence of both isolated and non-isolated NTDs. Conclusion: Epidemiologically, non-isolated NTDs follow similar trends as isolated cases and are responsive to primary prevention by folic acid supplementation. Various clinically-important congenital malformations are over-represented in individuals with NTDs, suggesting a common etiology

    Ambient outdoor air pollutants and sex ratio of singletons born after in vitro fertilization: the effect of single blastocyst transfer.

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    OBJECTIVE(#br)To evaluate the impact of air pollution on the sex ratio in singletons after IVF treatment and to evaluate the influence of the number of and the developmental stage of transferred embryos on the sex ratio.(#br)DESIGN(#br)Retrospective cohort study.(#br)SETTING(#br)University-affiliated IVF unit.(#br)PATIENT(S)(#br)A total of 7,004 singletons born after fresh transfer or frozen-thawed embryo transfer (FET) between January 2013 and December 2017.(#br)INTERVENTION(S)(#br)None.(#br)MAIN OUTCOME MEASURE(S)(#br)Male-to-female ratio in live-born singletons.(#br)RESULT(S)(#br)The estimated medians (interquartile range) of particle matter (PM)10, PM2.5, CO, NO2, O3, and SO2 at the IVF site were 51.4 (39.5-64.6), 27.7 (20.7-37.4), 0.62 (0.5-0.72), 32.5 (25.4-40.1), 79.6 (63.3-96.6), and 11.9 (9.3-15.9) ΞΌg/m3, respectively. Multivariate analysis indicated that SO2 was the only pollutant clearly associated with sex ratio. In singletons from single blastocyst transfer (SBT), as indicated by the generalized additive model, the SO2 concentration and sex ratio showed an inverted-U-shape association. In singletons after non-SBT, a monotonic decreasing in the sex ratio was observed with increased SO2 concentration. Compared with the referent category (SO2 < 7.57 ΞΌg/m3), the sex ratio at the 5th decile of SO2 (10.81-11.94 ΞΌg/m3) was increased by 2.1-fold (95% confidence interval [CI], 1.3-3.14) after adjusting covariates. In singletons born from non-SBT, the sex ratio significantly decreased only in the 9th (odds ratio = 0.69; 95% CI, 0.53-0.90) and 10th (OR = 0.74, 95% CI, 0.56-0.98) deciles.(#br)CONCLUSION(S)(#br)Low concentrations of SO2 showed an association with increased sex ratio in singletons of SBT, while in singletons born from another ET system the sex ratios did not show an association at low concentrations of SO2

    Public-health-driven microfluidic technologies: from separation to detection

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    Separation and detection are ubiquitous in our daily life and they are two of the most important steps toward practical biomedical diagnostics and industrial applications. A deep understanding of working principles and examples of separation and detection enables a plethora of applications from blood test and air/water quality monitoring to food safety and biosecurity; none of which are irrelevant to public health. Microfluidics can separate and detect various particles/aerosols as well as cells/viruses in a cost-effective and easy-to-operate manner. There are a number of papers reviewing microfluidic separation and detection, but to the best of our knowledge, the two topics are normally reviewed separately. In fact, these two themes are closely related with each other from the perspectives of public health: understanding separation or sorting technique will lead to the development of new detection methods, thereby providing new paths to guide the separation routes. Therefore, the purpose of this review paper is two-fold: reporting the latest developments in the application of microfluidics for separation and outlining the emerging research in microfluidic detection. The dominating microfluidics-based passive separation methods and detection methods are discussed, along with the future perspectives and challenges being discussed. Our work inspires novel development of separation and detection methods for the benefits of public health

    Temporal and Spatial Expression of Muc1 During Implantation in Sows

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    Recent evidence points to an important role for Muc1 in embryo implantation. In this study, Real-time PCR and immunohistochemistry were used to study mRNA and protein levels at, and between, the attachment sites of the endometrium of Day 13, 18 and 24 pregnant sows. The results indicate that Muc1 mRNA expression was higher between attachment sites than at attachment sites during implantation and this effect was significant on Day 13 (P < 0.01) and 24 (P < 0.01). Intense Muc1 immunostaining was observed in luminal epithelium and stroma and the staining between attachment sites was stronger than at attachment sites on Days 13 and 18. Collectively, these results suggest the crucial role of Muc1 in successful implantation and embryo survival

    Reemerging superconductivity at 48 K across quantum criticality in iron chalcogenides

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    Pressure plays an essential role in the induction1 and control2,3 of superconductivity in iron-based superconductors. Substitution of a smaller rare-earth ion for the bigger one to simulate the pressure effects has surprisingly raised the superconducting transition temperature Tc to the record high 55 K in these materials4,5. However, Tc always goes down after passing through a maximum at some pressure and the superconductivity eventually tends to disappear at sufficiently high pressures1-3. Here we show that the superconductivity can reemerge with a much higher Tc after its destruction upon compression from the ambient-condition value of around 31 K in newly discovered iron chalcogenide superconductors. We find that in the second superconducting phase the maximum Tc is as high as 48.7 K for K0.8Fe1.70Se2 and 48 K for (Tl0.6Rb0.4)Fe1.67Se2, setting the new Tc record in chalcogenide superconductors. The presence of the second superconducting phase is proposed to be related to pressure-induced quantum criticality. Our findings point to the potential route to the further achievement of high-Tc superconductivity in iron-based and other superconductors.Comment: 20 pages and 7 figure
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