486 research outputs found
A Wide Tuning-Range CMOS VCO with a Tunable Active Inductor
This study describes a wide tuning-range VCO using tunable active inductor (TAI) topology and cross-coupled pair configuration for radio frequency operation. The TAI used two feedback loops to form a cascode circuit to obtain more degrees of freedom for inductance value. The TAI-VCO was fabricated using a 0.18 μm CMOS technology. The coarse frequency tuning is achieved by TAIs while the fine tuning is controlled by varactors. The fabricated circuit provides an output frequency range from 0.6 to 7.2 GHz (169%). The measured phase noise is from −110.38 to −86.01 dBc/Hz at a 1 MHz offset and output power is from −11.11 to −3.89 dBm within the entire frequency range under a 1.8 V power supply
The atypical Gaoligong orocline: Its geodynamic origin and evolution
Various orocline systems around the India–Eurasia collision zone have long been recognized and studied. Different portions of the India–Eurasia boundaries represent various scales and models of orocline-forming processes, such as the Baluchistan orocline formed by multiple deformation events and the Himalayan orocline formed by a mixture of complex structural mechanisms. The curvature from the eastern Himalayan syntaxis through east Burma to west Yunnan showed a unique convex curvature toward the mantle wedge. This is different from the concave Baluchistan orocline and the Himalayan orocline. The unique geometry of the Gaoligong orocline shows an N-S trend for the northern section and a NE-SW trend for the southern section. This curvature also marks the boundary between the Tengchong and Baoshan blocks along the Santaishan suture in western Yunnan, China. Our structural reconstruction identified five deformation events: 1) D1 is km-scale upright folding, which only affected the Neoproterozoic meta-sedimentary unit, 2) D2 recumbent folding, which only developed in the southern section of the Gaoligong orocline, 3) D3 large-scale gently westward-inclined thrust folding, 4) D4 right-lateral shear belt, and 5) the D5 normal faults. Since the D3 structure is the earliest event that shows penetrative foliation development along the orocline, we consider D1 and D2 as pre-orocline-forming events. The geometry of the Gaoligong orocline is controlled by the distribution of the Ordovician basement between the Tengchong and Baoshan blocks. Both north and south sections experienced the same structural evolution since D3 (a fault-propagation fold system occurred between 40 Ma and 28 Ma), D4 (steep right-lateral shear belt occurred between 28 Ma and 15 Ma), and D5 (normal faults after 15 Ma). The curvature first developed as a shovel-like top-to-the-NE thrust plane (S3) that formed under amphibolite-facies conditions between 40 Ma and 28 Ma. The following deformation events (D4 and D5) show orocline parallel foliation development under lower metamorphic conditions, indicating that the curvature of the Gaoligong orocline is not generated by additional rotation along multiple deformation events. However, due to the lack of orocline parallel foliation development for S3, and the lack of a proper position of the indenter, the Gaoligong orocline cannot be classified as a primary orocline nor a rotational orocline. The curved geometry is an interference pattern of topography relief to the shovel-like thrust plane that developed during D3. Our new reconstructed structural evolution concludes that the Gaoligong orocline is an “atypical” orocline
Myopia progression after cessation of atropine in children: a systematic review and meta-analysis
Purpose: To comprehensively assess rebound effects by comparing myopia progression during atropine treatment and after discontinuation.Methods: A systematic search of PubMed, EMBASE, Cochrane CENTRAL, and ClinicalTrials.gov was conducted up to 20 September 2023, using the keywords “myopia," “rebound,” and “discontinue." Language restrictions were not applied, and reference lists were scrutinized for relevant studies. Our study selection criteria focused on randomized control trials and interventional studies involving children with myopia, specifically those treated with atropine or combination therapies for a minimum of 6 months, followed by a cessation period of at least 1 month. The analysis centered on reporting annual rates of myopia progression, considering changes in spherical equivalent (SE) or axial length (AL). Data extraction was performed by three independent reviewers, and heterogeneity was assessed using I2 statistics. A random-effects model was applied, and effect sizes were determined through weighted mean differences with 95% confidence intervals Our primary outcome was the evaluation of rebound effects on spherical equivalent or axial length. Subgroup analyses were conducted based on cessation and treatment durations, dosage levels, age, and baseline SE to provide a nuanced understanding of the data.Results: The analysis included 13 studies involving 2060 children. Rebound effects on SE were significantly higher at 6 months (WMD, 0.926 D/y; 95%CI, 0.288–1.563 D/y; p = .004) compared to 12 months (WMD, 0.268 D/y; 95%CI, 0.077–0.460 D/y; p = .006) after discontinuation of atropine. AL showed similar trends, with higher rebound effects at 6 months (WMD, 0.328 mm/y; 95%CI, 0.165–0.492 mm/y; p < .001) compared to 12 months (WMD, 0.121 mm/y; 95%CI, 0.02–0.217 mm/y; p = .014). Sensitivity analyses confirmed consistent results. Shorter treatment durations, younger age, and higher baseline SE levels were associated with more pronounced rebound effects. Transitioning or stepwise cessation still caused rebound effects but combining optical therapy with atropine seemed to prevent the rebound effects.Conclusion: Our meta-analysis highlights the temporal and dose-dependent rebound effects after discontinuing atropine. Individuals with shorter treatment durations, younger age, and higher baseline SE tend to experience more significant rebound effects. Further research on the rebound effect is warranted.Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=463093], identifier [registration number
Apolipoprotein-induced conversion of phosphatidylcholine bilayer vesicles into nanodisks
AbstractApolipoprotein mediated formation of nanodisks was studied in detail using apolipophorin III (apoLp-III), thereby providing insight in apolipoprotein–lipid binding interactions. The spontaneous solubilization of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) vesicles occured only in a very narrow temperature range at the gel–liquid–crystalline phase transition temperature, exhibiting a net exothermic interaction based on isothermal titration calorimetry analysis. The resulting nanodisks were protected from proteolysis by trypsin, endoproteinase Glu-C, chymotrypsin and elastase. DMPC solubilization and the simultaneous formation of nanodisks were promoted by increasing the vesicle diameter, protein to lipid ratio and concentration. Inclusion of cholesterol in DMPC dramatically enhanced the rate of nanodisk formation, presumably by stabilization of lattice defects which form the main insertion sites for apolipoprotein α-helices. The presence of fully saturated acyl chains with a length of 13 or 14 carbons in phosphatidylcholine allowed the spontaneous vesicle solubilization upon apolipoprotein addition. Nanodisks with C13:0-phosphatidylcholine were significantly smaller with a diameter of 11.7±3.1nm compared to 18.5±5.6nm for DMPC nanodisks determined by transmission electron microscopy. Nanodisk formation was not observed when the phosphatidylcholine vesicles contained acyl chains of 15 or 16 carbons. However, using very high concentrations of lipid and protein (>10mg/ml), 1,2,-dipalmitoyl-sn-glycero-3-phosphocholine nanodisks could be produced spontaneously although the efficiency remained low
DC-SIGN (CD209) Promoter −336 A/G Polymorphism Is Associated with Dengue Hemorrhagic Fever and Correlated to DC-SIGN Expression and Immune Augmentation
Dengue fever (DF) is an arthropod-borne disease that is prevalent in tropical and subtropical regions of the world. DC-SIGN [dendritic cell-specific intercellular adhesion molecule 3 (ICAM-3)-grabbing non-integrin] is a major receptor for dengue infection. DC-SIGN, also called CD209, expresses on dendritic cells (DCs) that bind to ICAM-3, which is expressed on T cells to facilitate the initial interaction between DCs and T cells. Variations in the CD209 promoter (−336 A/G; rs4804803) genotype are involved in the pathogenesis of human infectious diseases. Here we found that patients with dengue hemorrhagic fever (DHF) had a higher frequency of the AG or GG genotype of rs4804803 than DF or controls. Functional studies determined that monocyte-derived DCs (MDDCs) from individuals with AG genotype had significantly higher cell surface DC-SIGN expression, associated with higher TNFα, IL-12p40, and IP-10 production, but lower viral replication than those with AA genotype. An increase in DEN-2 replication in MDDCs was observed following the addition of anti-IP-10 neutralizing antibody. These findings highlight the fact that the rs4804803 SNP in the CD209 promoter is associated with DHF and correlated to DC-SIGN expression and immune augmentation
Northern Hemisphere Urban Heat Stress and Associated Labor Hour Hazard from ERA5 Reanalysis
Increasing surface air temperature is a fundamental characteristic of a warming world. Rising temperatures have potential impacts on human health through heat stress. One heat stress metric is the wet-bulb globe temperature, which takes into consideration the effects of radiation, humidity, and wind speed. It also has broad health and environmental implications. This study presents wet-bulb globe temperatures calculated from the fifth-generation European Centre for Medium-Range Weather Forecasts atmospheric reanalysis and combines it with health guidelines to assess heat stress variability and the potential for reduction in labor hours over the past decade on both the continental and urban scale. Compared to 2010–2014, there was a general increase in heat stress during the period from 2015 to 2019 throughout the northern hemisphere, with the largest warming found in tropical regions, especially in the northern part of the Indian Peninsula. On the urban scale, our results suggest that heat stress might have led to a reduction in labor hours by up to ~20% in some Asian cities subject to work–rest regulations. Extremes in heat stress can be explained by changes in radiation and circulation. The resultant threat is highest in developing countries in tropical areas where workers often have limited legal protection and healthcare. The effect of heat stress exposure is therefore a collective challenge with environmental, economic, and social implications.publishedVersio
Pandemic (H1N1) 2009 Vaccination and Class Suspensions after Outbreaks, Taipei City, Taiwan
In Taipei City, class suspensions were implemented beginning September 1, 2009 when transmission of pandemic (H1N1) 2009 infection was suspected. The uptake rate of pandemic (H1N1) 2009 vaccination (starting on November 16, 2009) among students 7–18 years of age was 74.7%. Outbreaks were mitigated after late November 2009
Validation study of a Chinese version of Partners in Health in Hong Kong (C-PIH HK)
“The final publication is available at Springer via http://dx.doi.org/10.1007/s11136-016-1315-5."Background
The Partners in Health (PIH) scale is a measure designed to assess the generic knowledge, attitudes, behaviors, and impacts of self-management. A cross-cultural adaptation of the PIH for use in Hong Kong was evaluated in this study. This paper reports the validity and reliability of the Chinese version of PIH (C-PIH[HK]).
Method
A 12-item PIH was translated using forward–backward translation technique and reviewed by individuals with chronic diseases and health professionals. A total of 209 individuals with chronic diseases completed the scale. The construct validity, internal consistency, and test–retest reliability were evaluated in two waves.
Results
The findings in Wave 1 (n = 73) provided acceptable psychometric properties of the C-PIH(HK) but supported the adaptation of question 5 to improve the cultural relevance, validity, and reliability of the scale. An adapted version of C-PIH(HK) was evaluated in Wave 2. The findings in Wave 2 (n = 136) demonstrated good construct validity and internal consistency of C-PIH(HK). A principal component analysis with Oblimin rotation yielded a 3-factor solution, and the Cronbach’s alphas of the subscales ranged from 0.773 to 0.845. Participants were asked whether they perceived the self-management workshops they attended and education provided by health professionals as useful or not. The results showed that the C-PIH(HK) was able to discriminate those who agreed and those who disagreed related to the usefulness of individual health education (p < 0.0001 in all subscales) and workshops (p < 0.001 in the knowledge subscale) as hypothesized. The test–retest reliability was high (ICC = 0.818).
Conclusion
A culturally adapted version of PIH for use in Hong Kong was evaluated. The study supported good construct validity, discriminate validity, internal consistency, and test–retest reliability of the C-PIH(HK)
Assessing catastrophic health expenditure and impoverishment in adult asthma care:a cross-sectional study of patients attending six public health clinics in Klang District, Malaysia
BackgroundIn Malaysia, asthma is a common chronic respiratory illness. Poor asthma control may increase out-of-pocket payment for asthma care, leading to financial hardships Malaysia provides Universal Health Coverage for the population with low user fees in the public health system to reduce financial hardship. We aimed to determine out-of-pocket expenditure on outpatient care for adult patients with asthma visiting government-funded public health clinics. We examined the catastrophic impact and medical impoverishment of these expenses on patients and households in Klang District, Malaysia.MethodsThis is a cross-sectional face-to-face questionnaire survey carried out in six government-funded public health clinics in Klang District, Malaysia. We collected demographic, socio-economic profile, and outpatient asthma-related out-of-pocket payments from 1003 adult patients between July 2019 and January 2020. Incidence of catastrophic health expenditure was estimated as the proportion of patients whose monthly out-of-pocket payments exceeded 10% of their monthly household income. Incidence of poverty was calculated as the proportion of patients whose monthly household income fell below the poverty line stratified for the population of the Klang District. The incidence of medical impoverishment was estimated by the change in the incidence of poverty after out-of-pocket payments were deducted from household income. Predictors of catastrophic health expenditure were determined using multivariate regression analysis.ResultsWe found the majority (80%) of the public health clinic attendees were from low-income groups, with 41.6% of households living below the poverty line. About two-thirds of the attendees reported personal savings as the main source of health payment. The cost of transportation and complementary-alternative medicine for asthma were the main costs incurred. The incidences of catastrophic expenditure and impoverishment were 1.69% and 0.34% respectively. The only significant predictor of catastrophic health expenditure was household income. Patients in the higher income quintiles (Q2, Q3, Q4) had lower odds of catastrophic risk than the lowest quintile (Q1). Age, gender, ethnicity, and poor asthma control were not significant predictors.ConclusionThe public health system in Malaysia provides financial risk protection for adult patients with asthma. Although patients benefited from the heavily subsidised public health services, this study highlighted those in the lowest income quintile still experienced financial catastrophe and impoverishment, and the risk of financial catastrophe was significantly greater in this group. It is crucial to ensure health equity and protect patients of low socio-economic groups from financial hardship.<br/
Multiplex sequencing of paired-end ditags (MS-PET): a strategy for the ultra-high-throughput analysis of transcriptomes and genomes
The paired-end ditagging (PET) technique has been shown to be efficient and accurate for large-scale transcriptome and genome analysis. However, as with other DNA tag-based sequencing strategies, it is constrained by the current efficiency of Sanger technology. A recently developed multiplex sequencing method (454-sequencing™) using picolitre-scale reactions has achieved a remarkable advance in efficiency, but suffers from short-read lengths, and a lack of paired-end information. To further enhance the efficiency of PET analysis and at the same time overcome the drawbacks of the new sequencing method, we coupled multiplex sequencing with paired-end ditagging (MS-PET) using modified PET procedures to simultaneously sequence 200 000 to 300 000 dimerized PET (diPET) templates, with an output of nearly half-a-million PET sequences in a single 4 h machine run. We demonstrate the utility and robustness of MS-PET by analyzing the transcriptome of human breast carcinoma cells, and by mapping p53 binding sites in the genome of human colorectal carcinoma cells. This combined sequencing strategy achieved an approximate 100-fold efficiency increase over the current standard for PET analysis, and furthermore enables the short-read-length multiplex sequencing procedure to acquire paired-end information from large DNA fragments
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