This report provides a perspective on metabolic glycoengineering methodology developed over the past two decades that allows natural sialic acids to be replaced with chemical variants in living cells ...and animals. Examples are given demonstrating how this technology provides the glycoscientist with chemical tools that are beginning to reproduce Mother Nature's control over complex biological systems - such as the human brain - through subtle modifications in sialic acid chemistry. Several metabolic substrates (e.g., ManNAc, Neu5Ac, and CMP-Neu5Ac analogs) can be used to feed flux into the sialic acid biosynthetic pathway resulting in numerous - and sometime quite unexpected - biological repercussions upon nonnatural sialoside display in cellular glycans. Once on the cell surface, ketone-, azide-, thiol-, or alkyne-modified glycans can be transformed with numerous ligands via bioorthogonal chemoselective ligation reactions, greatly increasing the versatility and potential application of this technology. Recently, sialic acid glycoengineering methodology has been extended to other pathways with analog incorporation now possible in surface-displayed GalNAc and fucose residues as well as nucleocytoplasmic O-GlcNAc-modified proteins. Finally, recent efforts to increase the "druggability" of sugar analogs used in metabolic glycoengineering, which have resulted in unanticipated "scaffold-dependent" activities, are summarized.
First-principles theoretical studies on the electronic properties and activation energies for the three steps of the Suzuki cross-coupling reaction have been performed on 3d transition-metal clusters ...and Pd/Ni bimetallic clusters supported on defected graphene. The ability of the clusters to effectively donate and accept charge is found to be critical to the activity of the catalysts, and graphene further enhances this ability. Nickel acts as the best replacement for palladium in cross-coupling catalysts for the oxidation steps but is not a good replacement in the transmetallation and reductive elimination steps which require the cluster to serve as a charge acceptor. Reducing the size of the cluster from Ni13 to Ni4 enhances the activity because of the cluster being more positively charged. Bimetallic Pd/Ni clusters were found to offer even lower activation energies for all three steps of the Suzuki reaction because of charge donation from the Ni atoms to the Pd atoms making the bimetallic cluster a highly active co-catalyst. This study reveals that the donor–acceptor concepts that explain the enhanced activity of Pd clusters on defected graphene can also be applied to explain lowered activation energies in bimetallic clusters acting as co-catalysts.
In present study, the development of aerobic consortia and subsequent screening of bacterial isolates were carried out from pesticide-contaminated soil of Rajasthan (India) by selective enrichment ...technique. The biodegradation potential of consortia and bacterial isolates were evaluated using chromatographic analysis. The developed consortia labelled as C1, C2 and C3 were found to degrade chlorpyrifos (100 mg/L) in basal medium to 51, 25, 38 and 43, 61, 68% after 14 and 28 days of incubation, respectively. Six cultures identified as
Alcaligenes sp.
,
Bacillus subtilis
,
Enterobacter sp., Klebsiella sp., Micrococci sp.
and
Pseudomonas aeruginosa
and obtained from these consortia showed degradation of chlorpyrifos (50 mg/L) after 7 and 15 days of incubation to concentration of 34, 38, 23, 38, 26, 43 and 71, 76, 52, 82, 63, 89%, respectively. The success of biodegradation was followed by monitoring the formation and disappearance of 3,5,6-trichloro-2-pyridinol which is a major metabolite of chlorpyrifos biodegradation. The significant findings in present investigation could be a strong potential of soil derived consortia and bacterial isolates. The characterized bacterial strains may be promising candidates for their future applications in the bioremediation of chlorpyrifos-contaminated sites.
In the present study, we have developed an anti-bacterial as well as mechanically-strengthened super protective coating material, which can be used as a marine antifouling paint. In this research, ...silica, titania and silica-titania core-shell nanoparticles were individually prepared
via
sol-gel and peptization processes. The idea behind the synthesis of core-shell nanoparticles was to utilize the mechanical strength of silica and the antimicrobial property of TiO
2
together. These nanoparticles were characterized
via
dynamic light scattering, UV-Visible spectroscopy, X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. Coating formulations were developed with two types of model binders,
i.e.
, solvent-based polyurethane and water-based poly-acrylic, containing all nanoparticles individually at various concentrations for a better comparative study. These coating formulations were applied onto mild steel for anti-bacterial testing that was performed against
Escherichia coli
and
Bacillus
. The nanoparticle concentration was varied from 1% (wt) to 6% (wt). The best anti-bacterial result was obtained with 4% (wt) of silica-titania core-shell nanoparticles prepared
via
the peptization process among all the nanoparticles. The scratch testing was performed successfully using an Erichsen scratch tester; the formulated PU coating passed up-to 20 N load with good adhesion, impact resistance, flexibility and has shown satisfactory anti-corrosion performance.
In the present study, we have developed an anti-bacterial as well as mechanically-strengthened super protective coating material, which can be used as a marine antifouling paint.
Summary
Background
Infectious enteritis is a commonly identified risk factor for irritable bowel syndrome (IBS). The incidence of Clostridium difficile infection (CDI) is on the rise. However, there ...is limited information on post‐infectious IBS (PI‐IBS) development following CDI and the host‐ and infection‐related risk factors are not known.
Aim
To determine the incidence and risk factors for PI‐IBS following CDI.
Methods
A total of 684 cases of CDI identified from September 2012 to November 2013 were surveyed. Participants completed the Rome III IBS questionnaire and details on the CDI episode. Predictive modelling was done using logistic regression to evaluate risk factors for PI‐IBS development.
Results
A total of 315 CDI cases responded (46% response rate) and 205 were at‐risk (no pre‐CDI IBS) for PI‐IBS development. A total of 52/205 (25%) met the Rome III criteria for IBS ≥6 months following CDI. IBS‐mixed was most common followed by IBS‐diarrhoea. In comparison to those without subsequent PI‐IBS, greater percentage of PI‐IBS patients had CDI symptoms >7 days, nausea, vomiting, abdominal pain during CDI, anxiety and a higher BMI. Using logistic regression, CDI symptoms >7 days Odds ratio (OR): 2.96, P = 0.01, current anxiety (OR: 1.33, P < 0.0001) and a higher BMI (OR: 1.08, P = 0.004) were independently associated with PI‐IBS development; blood in the stool during CDI was protective (OR: 0.44, P = 0.06).
Conclusions
In this cohort study, new‐onset IBS is common after CDI. Longer CDI duration, current anxiety and higher BMI are associated with the diagnosis of C. difficile PI‐IBS. This chronic sequela should be considered during active management and follow‐up of patients with CDI.
Marjolin's Ulcer (A Study of 40 Cases) Tripathi, F. M.; Khanna, Mrs. S.; Khanna, N. N. ...
Indian journal of plastic surgery,
03/2024, Letnik:
15, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Summary Present series is based on 40 cases of histologically proved Marjolin's ulcer, attending Plastic Surgery Service of University Hospital B. H. U. over a period of 8 years. This tumour is ...fairly common in this part of India. Adolescents and adult males are commonly affected by this disease. Limbs, especially around joints are the commonest site of involvement. Marjolin's ulcer is rather slow growing malignant tumour mostly over unstable scar of burns, which is not primarily grafted. The lag period in present series is 17 years and lymph node metastasis is less common and distant metastasis is rare. Squamous cell carcinoma is the commonest histologic type and majority of patients have been treated by surgery. Celsus in the first century A.D. was the first man to describe malignant degeneration in a burn scar, however, the term Marjolin's ulcer was given to the carcinoma arising in post traumatic scar which was described for the first time by Jean-Nicholas Marjolin in the year 1828. Since then the term Marjolin's ulcer has been used for the malignant degeneration in chronic ulcers of the skin, sinuses as well as burn scars. Though the lesion described by Marjolin was not thought to be malignant by Marjolin himself, it was identified as malignant by Smith in 1850 and Da Costa (1903) used the term ‘Marjolin's ulcer’ for all such malignant lesions.
The terahertz (THz) frequency quantum cascade laser (QCL) is a compact source of THz radiation offering high power, high spectral purity and moderate tunability. As such, these sources are ...particularly suited to the application of THz frequency imaging across a range of disciplines, and have motivated significant research interest in this area over the past decade. In this paper we review the technological approaches to THz QCL-based imaging and the key advancements within this field. We discuss in detail a number of imaging approaches targeted to application areas including multiple-frequency transmission and diffuse reflection imaging for the spectral mapping of targets; as well as coherent approaches based on the self-mixing phenomenon in THz QCLs for long-range imaging, three-dimensional imaging, materials analysis, and high-resolution inverse synthetic aperture radar imaging.
Skin Cancer in Varanasi Tripathi, F. M.; Khanna, S.; Khanna, N. N. ...
Indian journal of plastic surgery,
02/2024, Letnik:
10, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Summary In present study 100 cases of skin cancer over a period of three years have been studied. Diagnosis of each lesion is comfirmed by histology. Incidence of epithelioma of skin is much more as ...compared with basal cell carcinoma and melanoma. Various sites of these tumours are also noted. Lymph node metastasis is quite early in cases of melanoma.
Context. Herschel observations of water and highly excited CO (J> 9) have allowed the physical and chemical conditions in the more active parts of protostellar outflows to be quantified in detail for ...the first time. However, to date, the studied samples of Class 0/I protostars in nearby star-forming regions have been selected from bright, well-known sources and have not been large enough for statistically significant trends to be firmly established. Aims. We aim to explore the relationships between the outflow, envelope and physical properties of a flux-limited sample of embedded low-mass Class 0/I protostars. Methods. We present spectroscopic observations in H sub(2) O, CO and related species with Herschel HIFI and PACS, as well as ground-based follow-up with the JCMT and APEX in CO, HCO super(+) and isotopologues, of a sample of 49 nearby (d< 500pc) candidate protostars selected from Spitzer and Herschel photometric surveys of the Gould Belt. This more than doubles the sample of sources observed by the WISH and DIGIT surveys. These data are used to study the outflow and envelope properties of these sources. We also compile their continuum spectral energy distributions (SEDs) from the near-IR to mm wavelengths in order to constrain their physical properties (e.g. L sub(bol), T sub(bol) and M sub(env)). Results. Water emission is dominated by shocks associated with the outflow, rather than the cooler, slower entrained outflowing gas probed by ground-based CO observations. These shocks become less energetic as sources evolve from Class 0 to Class I. Outflow force, measured from low-J CO, also decreases with source evolutionary stage, while the fraction of mass in the outflow relative to the total envelope (i.e. M sub(out)/M sub(env)) remains broadly constant between Class 0 and I. The median value of ~1% is consistent with a core to star formation efficiency on the order of 50% and an outflow duty cycle on the order of 5%. Entrainment efficiency, as probed by F sub(CO)/M sub(acc), is also invariant with source properties and evolutionary stage. The median value implies a velocity at the wind launching radius of 6.3kms super(-1), which in turn suggests an entrainment efficiency of between 30 and 60% if the wind is launched at ~1 AU, or close to 100% if launched further out. LOI is strongly correlated with L sub(bol) but not with M sub(env), in contrast to low-J CO, which is more closely correlated with the latter than the former. This suggests that Oi traces the present-day accretion activity of the source while CO traces time-averaged accretion over the dynamical timescale of the outflow. H sub(2) O is more strongly correlated with M sub(env) than L sub(bol), but the difference is smaller than low-J CO, consistent with water emission primarily tracing actively shocked material between the wind, traced by OI, and the entrained molecular outflow, traced by low-J CO. LOi does not vary from Class 0 to Class I, unlike CO and H sub(2) O. This is likely due to the ratio of atomic to molecular gas in the wind increasing as the source evolves, balancing out the decrease in mass accretion rate. Infall signatures are detected in HCO super(+) and H sub(2) O in a few sources, but still remain surprisingly illusive in single-dish observations.
Summary A twenty-two years old patient with a unilateral hyperpiasia of the mandibular condyle has been presented. The clinical and radiological features and the current methods of treatment have ...been discussed.
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