94 research outputs found

    Improvement of third-order intermodulation product of RF and microwave amplifiers by injection

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    This paper discusses the improvement in the third-order intermodulation product (IM3) performance obtainable from RF and microwave amplifiers by two alternative injection techniques. The first is the addition to the amplifier input of the second harmonics of the input spectrum and the second is the addition to the amplifier input of the difference frequencies between the spectral components of the input signal. Both techniques are considered in theory, by simulation and in practice. Both techniques give useful improvements in two-tone IM3 performance. The second harmonic technique reduced the IM3 level by 43 dB in an amplifier at 835 MHz. The difference-frequency technique gave a reduction of 48 dB in an amplifier at 880 MHz. The difference-frequency technique also gives a greater improvement for complex spectra signal

    Client Satisfaction Towards Quality of Health Services: an Assessment at Primary Healthcare of District Gujranwala

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    This survey designed to evaluate the satisfaction level and the factors that affect the patient satisfaction regarding health care delivery services with the aim to improve the services in the primary health care settings of Gujranwala. A Cross Sectional Study done on randomly selected patients attending the basic health units of Gujranwala, with more than18 years of age. Pretested structured "Liker scale questionnaire" was used for data collection. Out of total respondents, 62 (41.3%) clients were satisfied with the services provided by the basic health units of Gujranwala. The factors identified to determine patient satisfaction were accessibility of services, behavior of staff, health education, level of cleanliness, drug availability and miscellaneous services. Not a single ranked area of satisfaction noticed. Client\u27s occupation and income had significant relationship with the patient satisfaction level. Gender, age, and education of clients were not contributing factors; they not affect the client satisfaction level.Less than half clients were satisfied with the services provided by the basic health units. Management of health facilities needs to improve the services

    Influence of shear flow on vesicles near a wall: a numerical study

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    We describe the dynamics of three-dimensional fluid vesicles in steady shear flow in the vicinity of a wall. This is analyzed numerically at low Reynolds numbers using a boundary element method. The area-incompressible vesicle exhibits bending elasticity. Forces due to adhesion or gravity oppose the hydrodynamic lift force driving the vesicle away from a wall. We investigate three cases. First, a neutrally buoyant vesicle is placed in the vicinity of a wall which acts only as a geometrical constraint. We find that the lift velocity is linearly proportional to shear rate and decreases with increasing distance between the vesicle and the wall. Second, with a vesicle filled with a denser fluid, we find a stationary hovering state. We present an estimate of the viscous lift force which seems to agree with recent experiments of Lorz et al. [Europhys. Lett., vol. 51, 468 (2000)]. Third, if the wall exerts an additional adhesive force, we investigate the dynamical unbinding transition which occurs at an adhesion strength linearly proportional to the shear rate.Comment: 17 pages (incl. 10 figures), RevTeX (figures in PostScript

    Internalization of Formyl Peptide Receptor in Leukocytes Subject to Fluid Stresses

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    Human leukocytes retract pseudopods under normal physiologic levels of fluid shear stress even in the absence of any other mediator. To gain more detailed understanding of the mechanisms that regulate this cell behavior, we exposed leukocytes to a steady state laminar shear field in a flow chamber and computed the fluid stresses distribution on the surface of individual cells with and without pseudopod. The surface fluid stress distribution on such cell is quite inhomogeneous. We hypothesized that the local fluid stresses on the cell surface serve to regulate pseudopod retraction by way of membrane receptors, especially the formyl peptide receptor (FPR). Comparison of the receptor distribution and the stress distribution over the surface of the cells indicates that the membrane fluid stress alone is not directly correlated with the extent of regional pseudopod retraction, giving further support to the hypothesis that membrane receptors are involved in the mechanotransduction of leukocytes. We observed that after exposure to fluid shear the FPR was internalized to a small intracellular compartment. This internalization appears to be independent of the original location of the receptor on the surface of the cell and the FPR appears to be more derived from multiple locations on the cell, with both higher and lower fluid stresses. The evidence suggests that FPR involvement in the pseudopod-retraction process is not limited to cell surface regions with the highest fluid shear stress, but rather a more global occurrence over the majority of the cell membrane

    Contraception and post abortion services: Qualitative analysis of users' perspectives and experiences following Zika epidemic in Honduras

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    Background: Zika virus (ZIKV) infection during pregnancy has severe consequences on the new-born. The World Health Organization declared the Zika outbreak to be a Public Health Emergency of International Concern (PHEIC) in 2016. Health facilities in the regions most affected by Zika lacked the capacity to respond to the increased demand for contraception. The objectives were to explore healthcare users' perceptions regarding contraception, Zika prevention during pregnancy and post-abortion care (PAC) services in the context of a Zika outbreak in Tegucigalpa, Honduras, and to follow these services over time. Methods: This study was part of a broader implementation research study. We used qualitative research consistent with grounded theory approach. Semi-structured interviews and focus groups were performed with women and their partners who used contraceptive services or received PAC services. Data were collected in two stages from December 2017 to July 2018. Themes explored included contraception, Zika and PAC services. Results: Participants had positive attitude towards the use of contraceptive methods and demanded more information on safety, efficacy and on side effects. Health care services were inconsistent in the provision of information on Zika and contraception services. ZIKV vector transmission was known but fewer participants were aware of risk of sexual transmission of Zika. Barriers to access healthcare services included contraceptive and PAC services included distance to healthcare facilities, disorganized admission process, long waiting times and out-of-pocket expenditure to purchase medicines. Furthermore, poor quality, mistreatment and abuse of women seeking PAC was prevalent. Some positive changes were noted over time, such as improvements in infrastructure including improved privacy and cleanliness, removal of fees, requisite to bring clean water to hospital. Conclusions: Our results highlight the challenges and areas for improvement in policy and practice related to contraceptive services and PAC in the context of ZIKV infection. Public policies to prevent epidemics should focus more on providing proper sanitation; removing barriers to access and use of effective contraception as human rights priority. Zika epidemic has highlighted weaknesses in health systems that obstruct access to and use of sexual and reproductive health services. The study results call for increased efforts to improve access, especially for women of low socio-economic status and intervene at different levels to eradicate discrimination and improve equity in the provision of health care. Qualitative methods can capture the community perspectives and can provide useful information to develop interventions to improve services.Fil: Belizan, Maria. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Maradiaga, Edna. Facultad de Ciencias Médicas; HondurasFil: Roberti, Javier Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Epidemiología y Salud Pública. Instituto de Efectividad Clínica y Sanitaria. Centro de Investigaciones en Epidemiología y Salud Pública; ArgentinaFil: Casco Aguilar, Maricela. Facultad de Ciencias Médicas; HondurasFil: Ortez, Alison F.. Facultad de Ciencias Médicas; HondurasFil: Avila Flores, Juan C.. Facultad de Ciencias Médicas; HondurasFil: González, Gloria. Hospital Escuela; HondurasFil: Bustillo, Carolina. Hospital Escuela; HondurasFil: Calderón, Alejandra. Centro de Salud Alonso Suazo; HondurasFil: Bock, Harry. No especifíca;Fil: Cafferata, María L.. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Tavares, Adriano B.. Organizacion Mundial de la Salud; ArgentinaFil: Alger, Jackeline. Facultad de Ciencias Médicas; HondurasFil: Ali, Moazzam. Organizacion Mundial de la Salud; Argentin

    Application of Hazard Functions to Investigate Recurrence After Curative-Intent Resection for Hepatocellular Carcinoma

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    Background: Defining patterns and risk of recurrence can help inform surveillance strategies and patient counselling. We sought to characterize peak hazard rates (pHR) and peak time of recurrence among patients who underwent resection of hepatocellular carcinoma (HCC). Methods: 1434 patients who underwent curative-intent resection of HCC were identified from a multi-institutional database. Hazard, patterns, and peak rates of recurrence were characterized. Results: The overall hazard of recurrence peaked at 2.4 months (pHR: 0.0384), yet varied markedly. The incidence of recurrence increased with Barcelona Clinic Liver Cancer (BCLC) stage 0 (29%), A (54%), and B (64%). While the hazard function curve for BCLC 0 patients was relatively flat (pHR: 400 ng/mL: 36.3%) and Tumor Burden Score (low: 73.7% vs. medium: 50.6% vs. high: 24.2%) (both p < 0.001). Conclusion: Recurrence hazard rates for HCC varied substantially relative to both time and intensity/peak rates. TBS and AFP markedly impacted patterns of hazard risk of recurrence.info:eu-repo/semantics/publishedVersio

    Preliminary study on phosphate solubilizing Bacillus subtilis strain Q3 and Paenibacillus sp. strain Q6 for improving cotton growth under alkaline conditions

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    Background Low phosphorus availability limits crop production in alkaline calcareous soils in semi-arid regions including Pakistan. Phosphate solubilizing bacteria may improve crop growth on alkaline calcareous soils due to their ability to enhance P availability. Methods Twenty rhizobacterial isolates (Q1–Q20) were isolated from rhizosphere of cotton and characterized for their growth promoting attributes in vitro. The selected phosphate solubilizing isolates were further screened for their ability to improve cotton growth under axenic conditions (jar trial). The phosphorus solubilization capacities of selected strains were quantified and these strains were identified through 16S rDNA sequencing. Results Isolates Q2, Q3, Q6, Q7, Q8, Q13 and Q14 were able to solubilize phosphate from insoluble sources. Most of these isolates also possessed other traits including catalase activity and ammonia production. The growth promotion assay showed that Q3 was significantly better than most of the other isolates followed by Q6. Maximum root colonization (4.34 × 106 cfu g−1) was observed in case of isolate Q6 followed by Q3. The phosphorus solubilization capacities of these strains were quantified, showing a maximum phosphorus solubilization by Q3 (optical density 2.605 ± 0.06) followed by the Q6 strain. The strain Q3 was identified as Bacillus subtilis (accession # KX788864) and Q6 as Paenibacillus sp. (accession # KX788865) through 16S rDNA sequencing. Discussion The bacterial isolates varied in their abilities for different growth promoting traits. The selected PGPR Bacillus subtilis strain Q3 and Paenibacillus sp. strain Q6 have multifarious growth promoting traits including ability to grow at higher EC and pH levels, and phosphorus solubilizing ability. These strains can efficiently colonize cotton roots under salt affected soils and help plants in phosphorus nutrition. It is concluded that both strains are potential candidates for promoting cotton growth under alkaline conditions, however further investigation is required to determine their potential for field application

    A Novel Online Calculator to Predict Risk of Microvascular Invasion in the Preoperative Setting for Hepatocellular Carcinoma Patients Undergoing Curative-Intent Surgery

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    Background: The presence of microvascular invasion (MVI) has been highlighted as an important determinant of hepatocellular carcinoma (HCC) prognosis. We sought to build and validate a novel model to predict MVI in the preoperative setting. Methods: Patients who underwent curative-intent surgery for HCC between 2000 and 2020 were identified using a multi-institutional database. Preoperative predictive models for MVI were built, validated, and used to develop a web-based calculator. Results: Among 689 patients, MVI was observed in 323 patients (46.9%). On multivariate analysis in the test cohort, preoperative parameters associated with MVI included α-fetoprotein (AFP; odds ratio [OR] 1.50, 95% confidence interval [CI] 1.23-1.83), imaging tumor burden score (TBS; hazard ratio [HR] 1.11, 95% CI 1.04-1.18), and neutrophil-to-lymphocyte ratio (NLR; OR 1.18, 95% CI 1.03-1.35). An online calculator to predict MVI was developed based on the weighted β-coefficients of these three variables ( https://yutaka-endo.shinyapps.io/MVIrisk/ ). The c-index of the test and validation cohorts was 0.71 and 0.72, respectively. Patients with a high risk of MVI had worse disease-free survival (DFS) and overall survival (OS) compared with low-risk MVI patients (3-year DFS: 33.0% vs. 51.9%, p < 0.001; 5-year OS: 44.2% vs. 64.8%, p < 0.001). DFS was worse among patients who underwent an R1 versus R0 resection among those patients at high risk of MVI (R0 vs. R1 resection: 3-year DFS, 36.3% vs. 16.1%, p = 0.002). In contrast, DFS was comparable among patients at low risk of MVI regardless of margin status (R0 vs. R1 resection: 3-year DFS, 52.9% vs. 47.3%, p = 0.16). Conclusion: Preoperative assessment of MVI using the online tool demonstrated very good accuracy to predict MVI.info:eu-repo/semantics/publishedVersio

    Prevalence and barriers to HIV testing among mothers at a tertiary care hospital in Phnom Penh, Cambodia. Barriers to HIV testing in Phnom Penh, Cambodia

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    <p>Abstract</p> <p>Background</p> <p>One-third of all new HIV infections in Cambodia are estimated to be due to mother-to-child transmission. Although the Ministry of Health adopted a policy of provider-initiated HIV testing and counseling (PITC), nearly a quarter of pregnant mothers were not tested in 2007. Greater acceptance of HIV testing is a challenge despite Cambodia's adoption of the PITC policy.</p> <p>Methods</p> <p>A hospital-based quantitative and cross-sectional survey was conducted to assess the prevalence of and barriers to HIV testing among mothers after delivery at the National Maternal and Child Health Center in Phnom Penh. The Center is one of the largest maternal and child care hospitals in the country to offer PITC services. All 600 eligible mothers who were admitted to the hospital after delivery from October to December 2007 were approached and recruited. Data were collected via a semi-structured questionnaire.</p> <p>Results</p> <p>The prevalence of HIV testing among women who delivered at the hospital was 76%. In multivariate logistic regression, factors such as the perceived need to obtain a partner's permission to be tested (OR=0.27, 95% CI=0.14-0.51, p<0.01), the lack of knowledge about HIV prevention and treatment (OR=0.38, CI=0.22-0.66, p<0.01), and the lack of access to ANC services (OR=0.35, 95% CI=0.21-0.58, p<0.01) were found to be the main barriers to HIV testing.</p> <p>Conclusion</p> <p>To achieve greater acceptance of HIV testing, counseling on HIV prevention and treatment must be provided not only to mothers but also to their partners. In addition, utilization of non-laboratory staff such as midwives to provide HIV testing services in rural health facilities could lead to the greater acceptance of HIV testing.</p
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