113 research outputs found
The room temperature phosphine-free synthesis of near-infrared emitting HgSe quantum dots
Luminescent mercury selenide (HgSe) quantum dots have been synthesised by a phosphine-free method using oleic acid as a capping agent. The modification of experimental conditions such as temperature resulted in particles of various sizes (15–100 nm) and morphologies not previously seen in HgSe, with emission tuneable between 1000 nm and 1350 nm
Investigation of thermal behavior of α-PbO and β-PbO in O2 atmosphere
The compounds α-lead oxide (α-PbO) and β-lead oxide (β-PbO) were purchased from Merck co. and used for thermal investigations in laboratory. The compound was heated in a thermogravimeter at different temperature, from 25 to 400 °C. The used gas atmosphere was O2. The received products were investigated by X-ray diffraction (XRD) technique. The received product Pb3O4 was confirmed by XRD. The textures of two different morphologies of α-PbO, β-PbO and the product Pb3O4 is investigated by scanning electron microscope (SEM) and transmission electron microscope (TEM) techniques
An improved mosquito electrocuting trap that safely reproduces epidemiologically relevant metrics of mosquito human-feeding behaviours as determined by human landing catch
Background:
Reliable quantification of mosquito host—seeking behaviours is required to determine the efficacy of vector control methods. For malaria, the gold standard approach remains the risky human landing catch (HLC). Here compare the performance of an improved prototype of the mosquito electrocuting grid trap (MET) as a safer alternative with HLC for measuring malaria vector behaviour in Dar es Salaam, Tanzania.
Methods:
Mosquito trapping was conducted at three sites within Dar es Salaam representing a range of urbanicity over a 7-month period (December 2012–July 2013, 168 sampling nights). At each site, sampling was conducted in a block of four houses, with two houses being allocated to HLC and the other to MET on each night of study. Sampling was conducted both indoors and outdoors (from 19:00 to 06:00 each night) at all houses, with trapping method (HLC and MET) being exchanged between pairs of houses at each site using a crossover design.
Results:
The MET caught significantly more Anopheles gambiae sensu lato than the HLC, both indoors (RR [95 % confidence interval (CI)]) = 1.47 [1.23–1.76], P < 0.0001 and outdoors = 1.38 [1.14–1.67], P < 0.0001). The sensitivity of MET compared with HLC did not detectably change over the course of night for either An. gambiae s.l. (OR [CI]) = 1.01 [0.94–1.02], P = 0.27) or Culex spp. (OR [CI]) = 0.99 [0.99–1.0], P = 0.17) indoors and declined only slightly outdoors: An. gambiae s.l. (OR [CI]) = 0.92 [0.86–0.99], P = 0.04), and Culex spp. (OR [CI]) = 0.99 [0.98–0.99], P = 0.03). MET-based estimates of the proportions of mosquitoes caught indoors (P i ) or during sleeping hours (P fl ), as well as the proportion of human exposure to bites that would otherwise occurs indoors (π i ), were statistically indistinguishable from those based on HLC for An. gambiae s.l. (P = 0.43, 0.07 and 0.48, respectively) and Culex spp. (P = 0.76, 0.24 and 0.55, respectively).
Conclusions:
This improved MET prototype is highly sensitive tool that accurately quantifies epidemiologically-relevant metrics of mosquito biting densities, behaviours and human exposure distribution
High Energy Proton Induced X-Ray Emission and its Applications
High energy protons of energies between 30 and 60 MeV are particularly valuable in particle induced X-ray analysis of elements in the rare earth region and above. Transmission samples of thickness up to 100 μm can be used, and damage to both biological and mineral samples is minimal. Detection limits are estimated, and the use of Fourier transformation techniques in the analysis of data is discussed in some detail. The quality of the raw data from mineralogical and biological experiments is such as to permit immediate identification of all elements above Germanium present at the part per million level or above in a sample. Particle induced K X-ray spectra from Au ore, sperrylite, rutheniridosmine and autonite are shown, indicating that all elements from As to U are readily identified when K X-rays are generated by protons of appropriately high energy
Development and evaluation of mosquito-electrocuting traps as alternatives to the human landing catch technique for sampling host-seeking malaria vectors
Background
The human landing catch (HLC) is the gold standard method for sampling host-seeking malaria vectors. However, the HLC is ethically questionable because it requires exposure of humans to potentially infectious mosquito bites.
Methods
Two exposure-free methods for sampling host-seeking mosquitoes were evaluated using electrocuting surfaces as potential replacements for HLC: (1) a previously evaluated, commercially available electrocuting grid (CA-EG) designed for killing flies, and (2) a custom-made mosquito electrocuting trap (MET) designed to kill African malaria vectors. The MET and the CA-EG were evaluated relative to the HLC in a Latin Square experiment conducted in the Kilombero Valley, Tanzania. The sampling consistency of the traps across the night and at varying mosquito densities was investigated. Estimates of the proportion of mosquitoes caught indoors (P i ), proportion of human exposure occurring indoors (π i ), and proportion of mosquitoes caught when most people are likely to be indoors (P fl ) were compared for all traps.
Results
Whereas the CA-EG performed poorly (<10 % of catch of HLC), sampling efficiency of the MET for sampling Anopheles funestus s.l. was indistinguishable from HLC indoors and outdoors. For Anopheles gambiae s.l., sampling sensitivity of MET was 20.9 % (95 % CI 10.3–42.2) indoors and 58.5 % (95 % CI 32.2–106.2) outdoors relative to HLC. There was no evidence of density-dependent sampling by the MET or CA-EG. Similar estimates of P i were obtained for An. gambiae s.l. and An. funestus s.l. from all trapping methods. The proportion of mosquitoes caught when people are usually indoors (P fl ) was underestimated by the CA-EG and MET for An. gambiae s.l., but similar to the HLC for An. funestus. Estimates of the proportion of human exposure occurring indoors (π i ) obtained from the CA-EG and MET were similar to the HLC for An. gambiae s.l., but overestimated for An. funestus.
Conclusions
The MET showed promise as an outdoor sampling tool for malaria vectors where it achieved >50 % sampling sensitivity relative to the HLC. The CA-EG had poor sampling sensitivity outdoors and inside. With further modification, the MET could provide an efficient and safer alternative to the HLC for the surveillance of mosquito vectors outdoors.
Keywords: Mosquito electrocuting trap; Human landing catch; Mosquito behaviour; Vector sampling tools; Outdoor biting; Malaria; Anopheles arabiensis ; Anopheles gambiae s.l.; Anopheles funestus s.l
Hepatosteatoz olgularında elastografi bulguları
OBJECTIVE: This study evaluates whether dynamic elastography could better
characterize and differentiate the non-alcoholic fatty liver disease (NAFLD) and
patient pool for biopsy.
MATERIALS AND METHODS: 18 patients with NAFLD were examined by ultrasound
(US) and elastography at the Department of Radiology. The patients,
none of whom had any chronic liver disease, were 54±9.5 (35-71) years old (8
men; 10 women). Biochemical markers were evaluated. Patients with high liver
echogenicity were classified as Stage III NAFLD. B-mode US equipment includes
a Hitachi HI VISION Preirus system with an embedded elastography (EL) module
(Hitachi Medical Systems Europe) and 6.5 MHz linear probe.
RESULTS: Of the cases, 55.6% were female and 44.4% were male. All cases with
Stage I NAFLD were female (n:5). Only 33.3% of the cases with Stage III NAFLD
were female (n:2). According to the results of elastography, no intergroup difference
was differentiated when the stages of NAFLD were compared. When
biochemical and hepatomegaly values were considered, differences were only
detected in GGT and hepatomegaly values among the NAFLD groups (p:0.015).
CONCLUSION: In the study, the stages of hepatosteatosis could not be differentiated
with the EL examination. Therefore, it was thought to be of no benefit
to the selection.AMAÇ: Bu çalışma alkolik olmayan yağlı karaciğer (NAFLD) olgularının biopsi
öncesi değerlendiriminde elastografinin etkinliğini araştırmak için planlandı.
GEREÇ VE YÖNTEMLER: Radyoloji bölümünde 18 NAFLD hastası B mod ultrason
ile incelendikten sonra elastografi ile değerlendirildi . Olguların hiçbirinde
kronik karaciğer hastalığı yoktu. Yaşları 35 ila 71 arasında değişen 8 erkek hasta
ile 10 kadın hasta çalışmaya dahil edildi ( ortalama 54±9.5). Son 6 ay içerisindeki
biyokimyasal değerlendirmeleri de kayıt altına alındı. Karaciğer dalak ile karşılaştırılarak
ekojenite artışına göre I., II. ve III. derecelerde ile sınıflandıırldı. B mod ve
elastografi değerlendirilmesi Hitachi HI VISION Preirus sistemi ile 6.5 MHz lineer
prob ile yapıldı.
BULGULAR: Olguların %55,6’sı kadın, %44’ ü erkek idi. Evre I NAFLD olgularının
tümü kadın idi (n:5). Evre III olgularının sadece %33,3’ü kadın idi (n:2). Gruplar
arası hepatosteatoz evresi göz önüne alındığında elastografi sonuçları arasında
fark saptanmadı. Biyokimyasal değerler ve hepatomegali ölçüm değerleri göz
önüne alındığında GGT ve hepatomegali ölçümleri gruplar arası farklılık göstermekte
idi (p:0.015).
SONUÇ: Bu çalışmada, B mod ultrasonda sıklıkla kullanılan hepatosteatoz evreleme
sistemi elastografi tekniği ile doğrulanamadı. Böylelikle NAFLD tanısı ile
biyopsi gereken ile gerekmeyen takipteki olgular arasında ayrım yapılamadı. Bu
veri transient elastografi bulgularından oldukça farklı idi
Low-coverage whole-genome sequencing of extracellular vesicle-associated DNA in patients with metastatic cancer
© 2021, The Author(s). Low-coverage whole-genome sequencing (LC-WGS) can provide insight into oncogenic molecular changes. Serum extracellular vesicles (EV) represent a novel liquid biopsy source of tumoral DNA. This study compared copy number alteration (CNA) profiles generated from LC-WGS of formalin-fixed paraffin-embedded (FFPE) tumoral DNA and EV-DNA obtained from cancer patients. Patients with squamous cell carcinoma of the base of tongue (n = 3) and cutaneous squamous cell carcinoma (n = 2) were included. LC-WGS (0.5-1X coverage) was performed on FFPE-DNA and serum EV-DNA. Similarity between CNA profiles was analysed using QDNAseq. FFPE samples had a mean CNA of 31 (range 17–50) over 1.9 × 109 (range 1.0–2.6 × 109) bp in length, and EV samples had a mean CNA value of 17 (range 7–19) over 7.6 × 108 (range 2.9–15 × 108) bp in length. A mean of 8 (range 0–21) CNA over 5.9 × 108 (range 1.6–14 × 108) bp in length was found to overlap between EV and FFPE-derived samples per patient. Although the mean correlation efficient between samples was r = 0.34 (range − .08 to 0.99), this was not statistically significant (p \u3e 0.05). Regions of highest deletion and duplication in FFPE samples were not well reflected in the EV-DNA. Selected CNA regions in EV-associated DNA were reflective of the primary tumor, however appreciation of global CNA and areas of most significant change was lost. The utility of LC-WGS of EV-derived DNA is likely limited to molecular alterations of known interest
Starve to Sustain - An Ancient Syrian Landrace of Sorghum as Tool for Phosphorous Bio-Economy?
Phosphorus (P) is an essential macronutrient, playing a role in developmental and metabolic processes in plants. To understand the local and systemic responses of sorghum to inorganic phosphorus (Pi) starvation and the potential of straw and ash for reutilisation in agriculture, we compared two grain (Razinieh) and sweet (Della) sorghum varieties with respect to their morpho-physiological and molecular responses. We found that Pi starvation increased the elongation of primary roots, the formation of lateral roots, and the accumulation of anthocyanin. In Razinieh, lateral roots were promoted to a higher extent, correlated with a higher expression of SbPht1 phosphate transporters. Infrared spectra of straw from mature plants raised to maturity showed two prominent bands at 1371 and 2337 cm−1, which could be assigned to P-H(H2) stretching vibration in phosphine acid and phosphinothious acid, and their derivates, whose abundance correlated with phosphate uptake of the source plant and genotype (with a higher intensity in Razinieh). The ash generated from these straws stimulated the shoot elongation and root development of the rice seedlings, especially for the material derived from Razinieh raised under Pi starvation. In conclusion, sorghum growing on marginal lands has potential as a bio-economy alternative for mineral phosphorus recycling
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