168 research outputs found
The Indigenization Of Business Ownership In An Emerging Market: Doing Business In South Africa
Black economic empowerment (BEE) has transformed the South African economic and business environment, and continues to be one of the most important issues a company has to deal with in doing business in South Africa. The indigenization of ownership is also developing as a concern in several other emerging markets particularly in Latin America. This research focuses on BEE issues within the small medium enterprises (SMEs) sector of the engineering industry. The research set out to identify the issues which were considered to be important for the successful implementation of BEE. A significant finding was the importance of upfront planning and setting of objectives prior to implementation of BEE initiatives. The research also found a very low level of satisfaction with the outcomes of BEE initiatives. The findings of this research can prove to be valuable for policymakers and business as they review the progress made towards achieving the broader objectives of indigenization and the costs of doing business in such an environment
Mixed Hepatoblastoma in a Young Male Adult: A Case Report and Literature Review
Hepatoblastoma (HB) is a rare malignant tumour of the liver and usually occurs in the first three years of life. Most of these tumours arise in the embryo; hence it seems to be unusual that hepatoblastoma occurs in adults and is an exceptional cause of primary malignant liver tumour in adult patients. The diagnosis is often overlooked, and patients might be diagnosed at late stages of the disease at risk of increased mortality. In this paper we report a case of a 30-year-old man with mixed hepatoblastoma and abdominal pain, hepatomegaly and fever. The patient under went noninvasive diagnostic methods: duplex scanning, Computed Tomography (CT), and Magnetic Resonance imaging (MRI). In our experience, despite the important role of histological sample provided by biopsy in defining the diagnosis, very important was the role of MRI, more than ultrasonography and enhanced CT. The MRI detects tumor features as size, margins, and ratio with neighboring organs in order to get the best surgical approach
Free energy calculations offer insights into the influence of receptor flexibility on ligand-receptor binding affinities
Docking algorithms for computer-aided drug discovery and design often ignore or restrain the flexibility of the receptor, which may lead to a loss of accuracy of the relative free enthalpies of binding. In order to evaluate the contribution of receptor flexibility to relative binding free enthalpies, two host-guest systems have been examined: inclusion complexes of α-cyclodextrin (αCD) with 1-chlorobenzene (ClBn), 1-bromobenzene (BrBn) and toluene (MeBn), and complexes of DNA with the minor-groove binding ligands netropsin (Net) and distamycin (Dist). Molecular dynamics simulations and free energy calculations reveal that restraining of the flexibility of the receptor can have a significant influence on the estimated relative ligand-receptor binding affinities as well as on the predicted structures of the biomolecular complexes. The influence is particularly pronounced in the case of flexible receptors such as DNA, where a 50% contribution of DNA flexibility towards the relative ligand-DNA binding affinities is observed. The differences in the free enthalpy of binding do not arise only from the changes in ligand-DNA interactions but also from changes in ligand-solvent interactions as well as from the loss of DNA configurational entropy upon restrainin
A Rare Case of Popliteal Venous Aneurysm
We report a case of a 21-year-old man with a popliteal venous aneurysm of the left popliteal fossa, with local symptoms and pain during palpation. Early diagnosis is fundamental in order to prevent the thromboembolic events or other major complications. Duplex scanning, Computed Tomography scanning, and Magnetic Resonance imaging are considered to be important non-invasive diagnostic methods for the diagnosis of PVA. The Angio Computed Tomography acquisition confirmed a 36 mm × 17 mm oval mass in the left popliteal fossa continuous with the popliteal veins. This lesion had presented contrast enhancement only in delayed acquisition (180 sec) and so appeared to be a true venous aneurysm and no arterial. The PVA was repaired surgically via a posterior approach to the popliteal fossa. A 4 × 2 aneurysm was identified. In the same time open tangential aneurysmectomy and lateral vein reconstruction were realised. This case is interesting because the Angio Computed Tomography study, in delayed acquisition, has allowed a correct diagnostic assessment of PVA and the surgical treatment
Influence of the Ion Coordination Number on Cation Exchange Reactions with Copper Telluride Nanocrystals
Cu2-xTe nanocubes were used as starting seeds to access metal telluride
nanocrystals by cation exchanges at room temperature. The coordination number
of the entering cations was found to play an important role in dictating the
reaction pathways. The exchanges with tetrahedrally coordinated cations (i.e.
with coordination number 4), such as Cd2+ or Hg2+, yielded monocrystalline CdTe
or HgTe nanocrystals with Cu2-xTe/CdTe or Cu2-xTe/HgTe Janus-like
heterostructures as intermediates. The formation of Janus-like architectures
was attributed to the high diffusion rate of the relatively small tetrahedrally
coordinated cations, which could rapidly diffuse in the Cu2-xTe NCs and
nucleate the CdTe (or HgTe) phase in a preferred region of the host structure.
Also, with both Cd2+ and Hg2+ ions the exchange led to wurtzite CdTe and HgTe
phases rather than the more stable zinc-blende ones, indicating that the anion
framework of the starting Cu2- xTe particles could be more easily deformed to
match the anion framework of the metastable wurtzite structures. As hexagonal
HgTe had never been reported to date, this represents another case of
metastable new phases that can only be accessed by cation exchange. On the
other hand, the exchanges involving octahedrally coordinated ions (i.e. with
coordination number 6), such as Pb2+ or Sn2+, yielded rock-salt polycrystalline
PbTe or SnTe nanocrystals with Cu2-xTe@PbTe or Cu2-xTe@SnTe core@shell
architectures at the early stages of the exchange process. In this case, the
octahedrally coordinated ions are probably too large to diffuse easily through
the Cu2-xTe structure: their limited diffusion rate restricts their initial
reaction to the surface of the nanocrystals, where cation exchange is initiated
unselectively, leading to core@shell architectures.Comment: 11 pages, 7 figures in J. Am. Chem. Soc, 13 May 201
A shear cell study on oral and inhalation grade lactose powders
Abstract Shear cell tests have been conducted on twenty different lactose powders, most of which commercially available for oral or inhalation purposes, spanning a wide range of particle sizes, particle morphologies, production processes. The aims of the investigation were: i) to verify the reliability of the technique in evaluating and classifying the flowability of powders; ii) to understand the connection between the flowability of a powder and the morphological properties of its particles; iii) to find a general mathematical relationship able to predict the yield locus shape given the particle size, shape and consolidation state of a lactose powder. These aspects and their limitations are detailed in the manuscript together with other interesting findings on the stick-slip behavior observed in most of the lactose powders examined
Aluminium and iron record for the last 28 kyr derived from the Antarctic EDC96 ice core using new CFA methods
AbstractSpectrofluorimetric and spectrophotometric continuous flow analysis (CFA) methods were developed and applied to the determination of aluminium and iron in EPICA Dome C (East Antarctica) ice-core samples (6–585m depth). The methods are able to measure the fraction of Al and Fe which can be detected once the sample is filtered on a 5.0 μm membrane and acidified to pH 2. Both the methods present high sensitivity (detection limit of 10 ng L–1 for Al and 50 ng L–1 for Fe) and reproducibility (5% at sub-ppb level). The Fe and Al profiles show sharp decreases in concentrations in the last glacial/interglacial transition, reflecting the decreasing dust aerosol load. The two elements show a different pattern during the Antarctic Cold Reversal (ACR) climatic change, with high iron concentrations (similar to the glacial period) and low but increasing Al content during the ACR minimum. In order to interpret the Al and Fe data obtained by CFA, a comparison with Al and Fe composition, as measured by inductively coupled plasma sector field mass spectrometry (ICP-SFMS), was performed for Holocene, ACR and glacial periods. The percentage of CFA-Al with respect to ICP-SFMS-Al in the three periods shows a lower variability than CFA-Fe (3% in the glacial period and 64% in the ACR). This pattern may be explained by the different dominant iron sources in the different climatic periods. During the Last Glacial Maximum, Fe is proposed to arise mainly from insoluble continental dust, while a variety of ocean-recycled Fe, mainly distributed in fine particles and as more soluble species, shows a higher contribution in the ACR and, to a lesser extent, in the Holocene
A Derivative of the Thiopeptide GE2270A Highly Selective against Propionibacterium acnes
A chemical derivative of the thiopeptide GE2270A, designated NAI003, was found to possess a substantially reduced antibacterial
spectrum in comparison to the parent compound, being active against just a few Gram-positive bacteria. In particular,
NAI003 retained low MICs against all tested isolates of Propionibacterium acnes and, to a lesser extent, against Enterococcus
faecalis. Furthermore, NAI003 showed a time- and dose-dependent killing of both a clindamycin-resistant and a clindamycinsensitive
P. acnes isolate. Gel shift experiments indicated that, like the parent compound, NAI003 retained the ability to bind to
elongation factors Tu (EF-Tus) derived from Escherichia coli, E. faecalis, or P. acnes, albeit with reduced efficiency. In contrast,
EF-Tus derived from the NAI003-insensitive Staphylococcus aureus or Streptococcus pyogenes did not bind this compound.
These results were confirmed by in vitro studies using a hybrid translation system, which indicated that NAI003 can inhibit most
efficiently protein synthesis driven by the P. acnes EF-Tu. P. acnes mutants resistant to NAI003 were isolated by direct plating.
With one exception, all analyzed strains carried mutations in the tuf gene, encoding EF-Tu. Because of its selective effect on P.
acnes in comparison to resident skin flora, NAI003 represents a promising candidate for the topical treatment of acne, which has
already completed a phase 1 clinical study
Visits to Sexually Transmitted Infection Clinics in Italy from January 2016 to November 2021: A Multicenter, Retrospective Study
There is no evidence of seasonal variation in visits to clinics dedicated to sexually transmitted infections (STIs) in Italy, nor of changes after the advent of the COVID-19 pandemic. An observational, retrospective, multicentric study was conducted to record and analyze all the visits to the STI clinics of the Dermatology Units of the University Hospitals of Ferrara and Bologna and of the Infectious Disease Unit of Ferrara, Italy, between January 2016 and November 2021. Overall, 11.733 visits were registered over a 70-month study period (63.7% males, mean age 34.5 ± 12.8 yrs). The mean number of monthly visits significantly decreased from the advent of the pandemic (136) compared to before (177). In the pre-pandemic period, visits to STI clinics increased in the autumn/winter months when compared to spring/summer, while the trend was the opposite in the pandemic period. Thus, during the pandemic, both an overall significant reduction in visits to STI clinics and a reversal in their seasonality were observed. These trends affected males and females equally. The marked decrease, mostly found in the pandemic winter months, can be linked to the “lockdown”/self-isolation ordinances and social distancing measures during the colder months, coinciding with the spread of the COVID-19 infection, which limited the opportunities for meeting and socializing
Colloidal CuFeS2 Nanocrystals: Intermediate Fe dBand Leads to High Photothermal Conversion Efficiency
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