549 research outputs found
Spectral diffusion of single semiconductor nanocrystals: the influence of the dielectric environment
We have explored the influence of different matrices on the emission line
shape of individual homogeneously coated CdSe/CdS/ZnS nanocrystals. The results
obtained corroborate previous observations of a correlation between blinking
events and spectral diffusion but in addition we have found that the extent of
spectral diffusion is almost independent of the dielectric environment of the
NC. Additionally, we report the observation of a correlation between the line
width and emission energy which is not expected to occur in the spherical -
symmetric NCs employed in this work. The implications of these results are
discussed.Comment: 3 pages, 3 figure
Mycobacterium canettii, the smooth variant of M. tuberculosis, isolated from a Swiss patient exposed in Africa.
An exceptionally smooth and glossy morphotype of Mycobacterium tuberculosis complex was isolated from a 56-year-old Swiss patient with mesenteric tuberculosis. Direct 16S rRNA sequence analysis of the hypervariable signature gene regions revealed a 100% homology to the specific M. tuberculosis complex sequence. Spoligotyping and restriction fragment length polymorphism analyses using the insertion sequences IS6110 and IS1081 and the polymorphic GC-rich sequence as additional genetic markers identified the isolate as the novel taxon M. canettii. Like a Somali child with a similar case, this patient probably contracted the infection in Africa, which raises questions about the geographic distribution of M. canettii
Multidrug-resistant tuberculosis in prison inmates, Azerbaijan.
In a tuberculosis (TB) program in the Central Penitentiary Hospital of Azerbaijan, we analyzed 65 isolates of Mycobacterium tuberculosis by IS6110-based restriction fragment-length polymorphism (RFLP) and spoligotyping. From 11 clusters associated with 33 patients, 31 isolates had an IS6110-based banding pattern characteristic of the Beijing genotype of M. tuberculosis. In addition, 15 M. tuberculosis isolates with similar RFLP patterns constituted a single group by spoligotyping, matching the Beijing genotype. Multidrug resistance, always involving isoniazid and rifampin, was seen in 34 (52.3%) of 65 isolates, with 28 belonging to the Beijing genotype
Long-term musculoskeletal function after Open Pelvic ring fractures in Children (OPEC); a multicentre, retrospective case series with follow-up measurement
Background: The proportion of Open Pelvic fractures in the paediatric population is relatively high. While operative fixation is the primary approach for managing Open Pelvic fractures in adults, there is limited literature on treatment outcomes in Children, particularly regarding long-term musculoskeletal, neurological, and urogenital function. Methods: This multicentre case series included paediatric patients (<18 years old) with Open Pelvic ring fractures treated at one of two major trauma centres in the Netherlands between January 1, 2001 and December 31, 2021. Data collection involved clinical records and long-term assessments, including musculoskeletal function, growth disorders, urogenital function, sexual dysfunction, and sensory motor function. Results: A total of 11 patients were included, primarily females (73 %), with a median age at trauma of 12 years (P25–P75 7–14). Most patients had unstable Pelvic ring fractures resulting from high-energy trauma. Surgical interventions were common, with external fixation as the main initial surgical approach (n = 7, 70 %). Complications were observed in eight (73 %) patients. Musculoskeletal function revealed a range of issues in the lower extremity, daily activities, and mental and emotional domain. Long-term radiologic follow-up showed high rates of Pelvic malunion (n = 7, 64 %). Neurological function assessment showed motor and sensory function impairment in a subset of patients. Urogenital function was moderately affected, and sexual dysfunction was limited with most respondents reporting no issues. Conclusion: Paediatric Open Pelvic fractures are challenging injuries associated with significant short-term complications and long-term musculoskeletal and urogenital issues. Further research is needed to develop tailored treatment strategies and improve outcomes of these patients.</p
Global Origin of Mycobacterium tuberculosis in the Midlands, UK
DNA fingerprinting data for 4,207 Mycobacterium tuberculosis isolates were combined with data from a computer program (Origins). Largest population groups were from England (n = 1,031) and India (n = 912), and most prevalent strains were the Euro-American (45%) and East African–Indian (34%) lineages. Combining geographic and molecular data can enhance cluster investigation
Molecular Differentiation of Mycobacterium tuberculosis Strains without IS6110 Insertions
By using standard restriction fragment length polymorphism, 6 zero-copy IS6110
Mycobacterium tuberculosis isolates were identified from 1,180 Maryland isolates as part of the National Tuberculosis Genotyping Surveillance Network Project. By using various genotyping methods, we demonstrated that this zero band cluster can be differentiated into six genotypes
A Geographically-Restricted but Prevalent Mycobacterium tuberculosis Strain Identified in the West Midlands Region of the UK between 1995 and 2008
Background: We describe the identification of, and risk factors for, the single most prevalent Mycobacterium tuberculosis strain in the West Midlands region of the UK.Methodology/Principal Findings: Prospective 15-locus MIRU-VNTR genotyping of all M. tuberculosis isolates in the West Midlands between 2004 and 2008 was undertaken. Two retrospective epidemiological investigations were also undertaken using univariable and multivariable logistic regression analysis. The first study of all TB patients in the West Midlands between 2004 and 2008 identified a single prevalent strain in each of the study years (total 155/3,056 (5%) isolates). This prevalent MIRU-VNTR profile (32333 2432515314 434443183) remained clustered after typing with an additional 9-loci MIRU-VNTR and spoligotyping. The majority of these patients (122/155, 79%) resided in three major cities located within a 40 km radius. From the apparent geographical restriction, we have named this the "Mercian" strain. A multivariate analysis of all TB patients in the West Midlands identified that infection with a Mercian strain was significantly associated with being UK-born (OR = 9.03, 95% CI = 4.56-17.87, p 65 years old (OR = 0.25, 95% CI = 0.09-0.67, p < 0.01). A second more detailed investigation analyzed a cohort of 82 patients resident in Wolverhampton between 2003 and 2006. A significant association with being born in the UK remained after a multivariate analysis (OR = 9.68, 95% CI = 2.00-46.78, p < 0.01) and excess alcohol intake and cannabis use (OR = 6.26, 95% CI = 1.45-27.02, p = .01) were observed as social risk factors for infection.Conclusions/Significance: The continued consistent presence of the Mercian strain suggests ongoing community transmission. Whilst significant associations have been found, there may be other common risk factors yet to be identified. Future investigations should focus on targeting the relevant risk groups and elucidating the biological factors that mediate continued transmission of this strain
Molecular Typing of Mycobacterium tuberculosis Strains with a Common Two-Band IS6110 Pattern
We conducted a population-based molecular typing of all Mycobacterium tuberculosis isolates obtained in Alabama since 1994. Of 2,452 isolates, 1,013 (41%) had fewer than 6 bands of IS6110; 348 (14%) had a single two-band pattern (JH2). With conventional epidemiologic methods, we identified three groups of related patients with JH2 isolates. Spoligotyping and pattern of variable number of tandem repeats identified 10 molecular groups; two found by conventional methods were subdivided
High-performance field effect transistors using electronic inks of 2D molybdenum oxide nanoflakes
Planar 2D materials are possibly the ideal channel candidates for future field effect transistors (FETs), due to their unique electronic properties. However, the performance of FETs based on 2D materials is yet to exceed those of conventional silicon based devices. Here, a 2D channel thin film made from liquid phase exfoliated molybdenum oxide nanoflake inks with highly controllable substoichiometric levels is presented. The ability to induce oxygen vacancies by solar light irradiation in an aqueous environment allows the tuning of electronic properties in 2D substoichiometric molybdenum oxides (MoO3-x). The highest mobility is found to be approximate to 600 cm(2) V-1 s(-1) with an estimated free electron concentration of approximate to 1.6 x 10(21) cm(-3) and an optimal I-On/I-Off ratio of >10(5) for the FETs made of 2D flakes irradiated for 30 min (x = 0.042). These values are significant and represent a real opportunity to realize the next generation of tunable electronic devices using electronic inks
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