14 research outputs found
Chemometrics and Spectroscopic Analyses of Peganum harmala Plantās Seeds by LaserāInduced Breakdown Spectroscopy
In the present work, the rapid identification of elements and their relative chemical comā position in various Peganum harmala seed samples were investigated using a calibrationāfree laserā induced breakdown spectroscopy technique (CFāLIBS). A pulsed Nd:YAG laserāsource with a 5 ns pulseāduration, and 10 Hz pulse repetition rates providing 400 and 200 mJ energy at 1064 and 532 nm wavelength, respectively, was focused on the Peganum harmala seed samples for ablation. A LIBS 2000+ spectrometer within the wavelength range (200 to 720 nm), emissionāspectra were recorded. The measured spectra of the Peganum harmala sample gives spectral lines of Carbon (C), Magnesium (Mg), Lithium (Li), Sodium (Na), Calcium (Ca), Silicon (Si), Iron (Fe), Strontium (Sr), Copper (Cu), Potassium (K), and Lead (Pb). A CFāLIBS technique has been employed for the compositional study of the elements exist in the Peganum harmala seed samples. The measured results demonstrate that C, Mg, and Ca are found to be major elements in the Peganum harmala seed samples with composiā tions of ~36.64%, ~24.09%, and ~19.03%, respectively. Along with the major elements, the elements including Li, Na, Si, K, Fe, and Sr were identified as minor elements with compositions of ~2.87%, ~2.33%, ~3.72%, ~7.17%, ~2.83%, and ~1.14%, respectively. Besides Cu (~8.07 Ī¼g/g), and Pb (~1.10 Ī¼g/g) elements were observed as trace elements exist in the Peganum harmala seed samples. Furtherā more, the electron number density including the plasma excitationātemperature were calculated using the starkābroadening line profile method and the SahaāBoltzmann plot method, respectively. The plasma parameters versus laserāirradiance and the distance from the sample were further inā vestigated. Moreover, a principal component analysis (PCA) method was also utilized to the specā tral data obtained by using LIBS to discriminate various seed samples with four classes, namely, Ī±, Ī², Ī³, and Ī. Three principalācomponents (PCs) calculated from eigenvalues of score matrix deā scribed 87.6%, 4.6%, and 2.5% of total variance for PC1, PC2, and PC3, respectively. The LIBS specā tral data variance covered by the initial 3 PCS was found as ~94.7% of total variance. The PCA results have successfully demonstrated the different classes of the Peganum harmala seed samples based on the different doping compositional ratios of the Zn element. This study confirmed the feasibility and ability of LIBS and PCA for the rapid analysis of Peganum harmala seed samples. Finally, the results achieved using CFāLIBS were incorporated with those obtained from the XRF and EDX anā alytical techniques
The Prevalence and Clinical Characteristics of Multidrug-resistant Hospital-acquired Staphylococcus aureus in Medina, Saudi Arabia
Hospital acquired-Staphylococcus aureus (HA-Staphylococcus aureus), particularly methicillin-resistant Staphylococcus aureus (MRSA), are an important source of nosocomial infections with high morbidity and mortality rates. Few reports showed that infections due to HA-Staphylococcus aureus in Saudi Arabia is increasing, particularly infections attributed to HA-MRSA. The study aimed to explore the prevalence and clinical characteristics of HA-Staphylococcus aureus for the first time in Medina, Saudi Arabia. A total of 1262 clinical samples of hospitalized patients were examined for the presence of Staphylococcus aureus through selective culturing on mannitol salt agar. Vitek Compact System and conventional methods were followed to confirm the isolates. Vitek Compact System tested the antimicrobial susceptibility of isolates whereas the standard PCR was employed to detect the genes encoding antimicrobial resistance (mecA and vanA) and virulence factors (tst, et, and LukS-PV). The overall HA-Staphylococcus aureus prevalence was low (6.58%, n = 1262) of which 84.34% (n = 83) were MRSA. Approximately, 57 samples of the 70 MRSA (81.5%) exhibited a multidrug-resistance (MDR) pattern. All the 83 HA-Staphylococcus aureus isolates were negative for the genes encoding toxic shock syndrome toxin, exfoliative toxin, and Panton-Valentine leukocidin. The study was conducted during the Covid-19 pandemic under partial lockdown, restricted hospitalization, and increased disinfection and infection control measures. Therefore, the low prevalence of HA-Staphylococcus aureus should be carefully interpreted and further multicenter investigations could reveal its true incidence in the city. The high prevalence of MDR HA-MRSA is alarming as it highlights inappropriate antibiotic prescriptions to counter staphylococcal infections. HA-Staphylococcus aureus investigated in this study might lack certain virulence factors. However, their MDR traits and invasive nature could worsen the situation if not properly handled
Turning Evidence into Digital policy in Sri Lanka, India and Myanmar : final technical report
The research aims to articulate to policy makers and practitioners the priorities that must be set in order to continue the momentum achieved so far in the ICT sector. This report outlines activities and outputs of the research objectives and provides a synthesis of project results, including dissemination of research, modelling the impact of digitization in developing country jobs, women in the ICT labour force, and reform of broadcasting policy
First Report of Multi-drug Resistant Staphylococcus haemolyticus in Nosocomial Infections in North Western Saudi Arabia
We report in this study for the first time the prevalence of multiple resistant Staphylococcus haemolyticus in clinical settings in Saudi Arabia. A total of 1060 clinical specimens of hospitalized patients were screened for the presence of S. haemolyticus in the period between September and December 2020. Primary identification of the isolates was carried out by colonial characteristics on mannitol salt agar and clumping factor test, confirmation of presumptive isolates and antimicrobial susceptibility testing was performed by VitekĀ® 2, while PCR was employed to detect mecA and vanA genes. A total of 20 S. haemolyticus isolates were recovered from 20 samples (blood cultures, urine, nasal swab, wound swab, groin swab, and axilla swab), 90% (P <0.001, x2) of the isolates were multiple resistant to three antimicrobial agents and more. Resistance to oxacillin was exhibited in 95% of the isolates, while none of the isolates were resistant to vancomycin and linezolid, yet resistance to rifampicin was observed in 30 % of the isolates. The findings of this study highlights the emerging trends of Staphylococcus haemolyticus as potential drug resistant pathogen in hospital settings in Saudi Arabia, which requires in depth investigation on molecular understanding on antimicrobial resistance and virulence traits of the strains
Quantification of Aluminum Gallium Arsenide (AlGaAs) Wafer Plasma Using Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS)
In this work, we report the results of the compositional analysis of an aluminum gallium arsenide (AlGaAs) sample using the calibration-free laser-induced breakdown spectroscopy (CF-LIBS) technique. The AlGaAs sample was doped with three various concentrations of gallium (Ga), arsenic (As), and aluminum (Al), as reported by the manufacturer, and the CF-LIBS technique was employed to identify the doping concentration. A pulsed Q-switched Nd: YAG laser capable of delivering 200 and 400 mJ energy at 532 and 1064 nm, respectively, was focused on the target sample for ablation, and the resulting emission spectra were captured using a LIBS 2000+ spectrometer covering the spectral range from 200 to 720 nm. The emission spectra of the AlGaAs sample yielded spectral lines of Ga, As, and Al. These lines were further used to calculate the plasma parameters, including electron temperature and electron number density. The Boltzmann plot method was used to calculate the electron temperature, and the average electron temperature was found to be 5744 Ā± 500 K. Furthermore, the electron number density was calculated from the Stark-broadened line profile method, and the average number density was calculated to be 6.5 Ć 1017 cmā3. It is further observed that the plasma parameters including electron temperature and electron number density have an increasing trend with laser irradiance and a decreasing trend along the plume length up to 2 mm. Finally, the elemental concentrations in terms of weight percentage using the CF-LIBS method were calculated to be Ga: 94%, Al: 4.77% and As: 1.23% for sample-1; Ga: 95.63%, Al: 1.15% and As: 3.22% for sample-2; and Ga: 97.32%, Al: 0.69% and As: 1.99% for sample-3. The certified concentrations were Ga: 95%, Al: 3% and As: 2% for sample-1; Ga: 96.05%, Al: 1% and As: 2.95% for sample-2; and Ga: 97.32%, Al: 0.69% and As: 1.99% for sample-3. The concentrations measured by CF-LIBS showed good agreement with the certified values reported by the manufacturer. These findings suggest that the CF-LIBS technique opens up an avenue for the industrial application of LIBS, where quantitative/qualitative analysis of the material is highly desirable
Understanding digital access and use in the Global South
The project works to build an evidence base for digital policymaking in the Global South, through coordinated nationally representative surveys, using common methodology and common research instruments in order to better understand household and individual ICT usage. Data collection was conducted through face to face surveys of the 15-65 demographic in each country, with sample sizes of 2,000 each in Pakistan, Bangladesh and Cambodia and 5,000 in India. LIRNEasia is a regional digital policy and regulation think tank active across the Asia Pacific
Role of 18F-FluorodeoxyglucoseāPositron Emission Tomography/Computed Tomography Imaging in the Prediction of Prognosis in Patients With Indolent Lymphoma: Prospective Study
BackgroundThe role of fluorodeoxyglucoseāpositron emission tomography/computed tomography (FDG-PET/CT) in indolent lymphoma has been minimally studied.
ObjectiveThis study aims to assess the value of FDG-PET/CT in predicting the prognosis of indolent lymphoma.
MethodsWe prospectively recruited 42 patients with indolent lymphoma. A total of 2 patients were excluded, and 40 underwent baseline PET/CT and follow-up at various time points. A total of 9 patients were observed only, 7 received 4 doses of rituximab alone, and 24 received chemoimmunotherapy. Metabolic response on follow-up PET/CT was assessed using the maximum standardized uptake value (SUVmax) and Deauville criteria (DC). We aimed to obtain the best SUVmax and DC to predict optimal survival rates, risk stratification, and optimize therapeutic strategies. The mean follow-up from the initial diagnosis was 33.83 months.
ResultsSUVmax <4.35 at interim PET/CT provided the best discrimination, with a progression-free survival (PFS) of 100% and a median survival time of 106.67 months compared with SUVmax ā„4.35 (P=.04), which had a PFS of 43.8% and a median survival time of 50.17 months. This cutoff was also valuable in predicting overall survival at baseline, that is, 100% overall survival with baseline SUVmax <4.35, versus 58.4% for SUVmax ā„4.35 (P=.13). The overall survival of patients with a baseline DC score <3.0 was 100%, with a median overall survival of 106.67 months.
ConclusionsWe demonstrated the utility of PET/CT in indolent lymphomas. SUVmax (<4.35 vs ā„4.35) on interim PET/CT performed best in predicting PFS