445 research outputs found
Effect of heat treatment on the antioxidant activities of two cultivars of sweet potatoes
Natural sources of antioxidants are derived from fruits, vegetables and wine, whilst artificial supplements are from teas and spices. Sweet potato (Ipomoea batatas) is an excellent natural source of vitamins and minerals, and likely a great source of antioxidant. The objective of this study is to analyze the antioxidant activity of orange sweet potato (Vitato) and purple sweet potato (All purple), prepared as heat dry and moist heat for 30 minutes at 100oC. All the samples were obtained from Pasir Puteh and MARDI Telong, Bachok, Kelantan, respectively. Both samples were soaked into methanol to obtain the crude extract prior to analyzing for antioxidant activity by using 2, 2-diphenyl-1-picryl hydrazyl (DPPH). IC50 values of dry heat and moist heat Vitato were 0.40mg/L and 0.20mg/L while dry heat and moist heat, All purple were 0.32mg/L and 0.19mg/L, respectively. Both moist heat samples enjoyed higher scavenging activities compared to dry heat samples. However, the All purple sample of moist heat is the most superior one. Significant difference of IC50 values between dry heat and moist heat sample differ significantly. Thus, this study clearly demonstrated that moist heat sweet potato exhibited excellent increase in antioxidant activity
Needle-stick injuries and splash exposures among health-care workers at a tertiary care hospital in north-western Tanzania
Background: Needle-stick injuries (NSIs) and splash exposures carry a risk of occupational acquisition of HIV and other blood borne pathogens to healthcare workers (HCWs) involved in clinical care. This study was carried out to determine the frequency and factors contributing to NSIs and splash exposures as well as post-exposure practices among HCWs in our centre. Methods: This was a cross-sectional study among healthcare workers which was conducted at Bugando Medical Centre (BMC) over a one-year period between April 2013 and March 2014. Results: Out of 436 HCWs who participated in this study, 212 (48.6%) reported incidents of NSIs and splash exposures within the previous 12 months. NSIs were reported by 65.1% (n= 138) and splash exposures by 27.4% (n = 58). Sixteen (7.5%) respondents had both NSIs and splash exposures. High rates of NSIs were observed among nurses (71.0%), during procedures (53.6%) and occurred commonly in the Accident and Emergency department (33.3%). Hollow bore needles were responsible for 63.8% of NSIs. Splash exposures occurred more commonly in operating theatre (41.4%). At the time of the exposure, 116 (54.7%) HCWs wore protective equipment. The most common action following exposure was washing the site with soap and water (55.6%). Only 68 (32.1%) reported the incident of exposure to the relevant authority. Healthcare workers aged ≤ 40 years; those with work experience of ≤ 5 years and those not trained on issues related to infection prevention and occupational risk reduction were more likely to be exposed to any type of occupational injuries studied. While male healthcare workers were less likely to be exposed to NSIs, female were more likely to encounter both NSIs and mucocutaneous splashes (p < 0.001). The majority of HCWs, 185 (87.3%) were not adequately immunized for hepatitis B virus and only 17 (8.0%) were fully vaccinated, having received three doses of the vaccine. Only 16.7% of exposed HCWs received post-exposure prophylaxis for HIV. Subsequent six-month follow-up for HIV showed zero seroconversion. Conclusion: NSIs and splash exposures are common among HCWs at our centre and are under-reported. Post-exposure management is generally poor. All HCWs should be trained on issues related to infection prevention and occupational risk reduction. The hospital should establish surveillance system for registering, reporting and management of occupational injuries and exposures.
Graphene nanoribbons and nanoflakes from functionalized carbon precursors
The process of formation of graphene by exfoliation of carbon nanotubes (CNT) or graphite originates graphene nanoribbons (GNR) and graphene nanoflakes (GNF), respectively. These nanoparticles are expected to present interesting electronic properties, depending on their shape, size, and on their edge shape. Several methods for the unzipping of nanotubes were described in the literature [1]. The major limitations to the application of these methods are related to low yield, or to the formation of highly oxidized GNRs. The present work was motivated by the observation of the unzipping of functionalized CNT under ultra-high vacuum scanning tunneling microscopy (UHV STM) [2]. The CNTs under observation were functionalized by the 1,3-dipolar cycloaddition reaction [3], a potential route for the production of GNRs without oxidation. The formation of graphene flakes was observed when functionalized graphite was exfoliated under similar conditions as the CNT. The graphite was functionalized by the same procedure as the CNT.Fundação para a Ciência e a Tecnologia (FCT
Radiative Corrections to the Muonium Hyperfine Structure. I. The Correction
This is the first of a series of papers on a systematic application of the
NRQED bound state theory of Caswell and Lepage to higher-order radiative
corrections to the hyperfine structure of the muonium ground state. This paper
describes the calculation of the radiative correction. Our
result for the complete correction is 0.424(4) kHz, which
reduces the theoretical uncertainty significantly. The remaining uncertainty is
dominated by that of the numerical evaluation of the nonlogarithmic part of the
term and logarithmic terms of order .Comment: 56 pages, Rev.tex V3.0 and epsf.tex. 12 postscript files are called
in the text. Version accepted by Phys. Rev. D. A new table is adde
Conceivable security risks and authentication techniques for smart devices
With the rapidly escalating use of smart devices and fraudulent transaction of users’ data from their devices, efficient and reliable techniques for authentication of the smart devices have become an obligatory issue. This paper reviews the security risks for mobile devices and studies several authentication techniques available for smart devices. The results from field studies enable a comparative evaluation of user-preferred authentication mechanisms and their opinions about reliability, biometric authentication and visual authentication techniques
Status of global fits to neutrino oscillations
We review the present status of global analyses of neutrino oscillations,
taking into account the most recent neutrino data including the latest KamLAND
and K2K updates presented at Neutrino2004, as well as state-of-the-art solar
and atmospheric neutrino flux calculations. We give the two-neutrino solar +
KamLAND results, as well as two-neutrino atmospheric + K2K oscillation regions,
discussing in each case the robustness of the oscillation interpretation
against departures from the Standard Solar Model and the possible existence of
non-standard neutrino physics. Furthermore, we give the best fit values and
allowed ranges of the three-flavour oscillation parameters from the current
worlds' global neutrino data sample and discuss in detail the status of the
small parameters \alpha \equiv \Dms/\Dma as well as ,
which characterize the strength of CP violating effects in neutrino
oscillations. We also update the degree of rejection of four-neutrino
interpretations of the LSND anomaly in view of the most recent developments.Comment: v6: In the last Appendix we provide updated neutrino oscillation
results which take into account the relevant oscillation data released by the
MINOS and KamLAND collaboration
Etiology and factors associated with pneumonia in children under 5 years of age in Mali: A prospective case-control study
Background: There are very limited data on children with pneumonia in Mali. The objective was to assess the etiology and factors associated with community-acquired pneumonia in hospitalized children <5 years of age in Mali. Methods: A prospective hospital-based case-control study
Urogenital pathogens in urine samples of clinically diagnosed urinary tract infected patients in Tanzania : a laboratory based cross- sectional study
This study is part of the Holistic Approach to Unravel Antibacterial Resistance in East Africa (HATUA) project funded by the National Institute for Health Research, Medical Research Council and the Department of Health and Social Care, Award (MR/S004785/1).Background : Urogenital pathogens such as Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium and Trichomonas vaginalis have been reported to cause pyuria, however they are not routinely cultured from urine samples of patients clinically diagnosed to have urinary tract infections (UTI). In this study, pathogen specific PCR was done to identify the urogenital pathogens in the urine samples among clinically diagnosed UTI patients with negative routine urine culture. Methods : A cross-sectional study was conducted involving 227 archived urine samples from clinically diagnosed UTI patients with positive leucocyte esterase but negative urine culture results. The urogenital pathogens were detected using pathogen specific singleplex PCR. Data were cleaned and analyzed using STATA version 15. Results : The median age of patients was 31[IQR 23 – 51] years and the majority (174, 76.7%) were females. Two thirds of patients had history of antibiotic use two weeks prior to recruitment (154, 67.8%). A total of 62(27.3%) urine samples were positive for at least one urogenital pathogen. Of 62 positive samples, 9 had two urogenital pathogens and 1 had three urogenital pathogens. The most predominant urogenital pathogen detected was Neisseria gonorrhoeae 25(34.2%) and Trichomonas vaginalis 24(32.9%). Being female (aOR 2.4; 95% CI: 1.04 – 5.49; p-value 0.039) and having history of using antibiotics in the past two weeks (aOR 1.9; 95%CI: 1.04 – 3.60; p-value 0.036) was independently associated with the presence of urogenital pathogens. Conclusion : More than a quarter of female patients with clinical symptoms of UTI and routine urine culture negative results were infected with urogenital pathogens mainly Neisseria gonorrhoeae and Trichomonas vaginalis. Further research with a larger sample set in a range of settings is required to understand the implications of these finding generally.Publisher PDFPeer reviewe
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