Nuclear Magnetic Resonance Chemical Shift as a Probe for Single-Molecule Charge Transport.

Existing modelling tools, developed to aid the design of efficient molecular wires and to better understand their charge-transport behaviour and mechanism, have limitations in accuracy and computational cost. Further research is required to develop faster and more precise methods that can yield information on how charge transport properties are impacted by changes in the chemical structure of a molecular wire. In this study, we report a clear semilogarithmic correlation between charge transport efficiency and nuclear magnetic resonance chemical shifts in multiple series of molecular wires, also accounting for the presence of chemical substituents. The NMR data was used to inform a simple tight-binding model that accurately captures the experimental single-molecule conductance values, especially useful in this case as more sophisticated density functional theory calculations fail due to inherent limitations. Our study demonstrates the potential of NMR spectroscopy as a valuable tool for characterising, rationalising, and gaining additional insights on the charge transport properties of single-molecule junctions.

Tinea pseudoimbricata: observations from a clinicoepidemiological and mycological study from eastern India.

The characteristic ring with ring appearance in patients with dermatophytosis should raise the suspicion of application of topical corticosteroids (alone or in combination with topical antifungals). Such patients be counselled about the harmful effects applying such inappropriate combinaiton.

Allyl piperidine-1-carbodiothioate and benzyl 1H-imidazole 1 carbodithioate: two potential agents to combat against mycobacteria.

AIMS: The emergence of multidrug resistant strains of Mycobacterium tuberculosis has made tuberculosis more difficult to manage clinically. With the aim of obtaining new and effective anti-mycobacterial agent(s), this study investigated the anti-mycobacterial activity of several imidazole and piperidine derivatives. METHODS AND RESULTS: Towards obtaining new anti-mycobacterial agents, Mycobacterium smegmatis cells were treated with different compounds for their growth inhibitory activity. Among these, benzyl 1H-imidazole-1-carbodithioate and allyl piperidine-1-carbodiothioate exhibited better inhibition than the others. Thereafter, anti-biofilm property of these two was examined by treating M. smegmatis with these agents before and after the formation of biofilm. The result showed that both the compounds at their sublethal dose inhibited the formation of biofilm as well as dispersed preformed biofilm. Consistently, they augmented the activity of isoniazid or rifampicin against biofilm-encapsulated cells. MTT assay was performed to examine the toxic effects of this combinatorial therapy on different cell lines. Results exhibited a low cytotoxicity for this combinatorial treatment. The activity of these two was also verified against dormant mycobacterial cells and was found to be effective. CONCLUSION: The present study identified two compounds that exhibited anti-mycobacterial activities against both planktonic and dormant cells. These two also exhibited anti-biofilm activity at their sublethal dose and augmented the activity of isoniazid and rifampicin against biofilm encapsulated cells. SIGNIFICANCE AND IMPACT OF THE STUDY: The current study provides two new agents that have the potential to be used in anti-mycobacterial therapy and may help in public health management.

Cell surface hydrophobicity: a key component in the degradation of polyethylene succinate by Pseudomonas sp. AKS2.

AIM: Polyethylene succinate (PES) contains hydrolysable ester bonds that make it a potential substitute for polyethylene (PE) and polypropylene (PP). Towards bioremediation of PES, we have already reported that a new strain of Pseudomonas, Pseudomonas sp. AKS2, can efficiently degrade PES and hypothesized that cell surface hydrophobicity plays an important role in this degradation process. In this study, our efforts were targeted towards establishing a correlation between cell surface hydrophobicity and PES degradation. METHODS AND RESULTS: We have manipulated cell surface hydrophobicity of AKS2 by varying concentrations of glucose and ammonium sulphate in the growth medium and subsequently examined the extent of PES degradation. We observed an increase in PES degradation by AKS2 with an increase in cell surface hydrophobicity. The increased surface hydrophobicity caused an enhanced biofilm formation on PES surface that resulted in better polymer degradation. CONCLUSION: The current study establishes a direct correlation between cell surface hydrophobicity of an organism and its potential to degrade a nonpolar polymer like PES. SIGNIFICANCE AND IMPACT OF THE STUDY: Cell surface hydrophobicity manipulation can be used as an important strategy to increase bioremediation of nonpolar polymer like PES.

Asymmetrical nostril axis angle in the post traumatic nose.

BACKGROUND: Nasal tip reconstruction is a challenging part of septorhinoplasty in post-traumatic patients. Aesthetic appearance of the nose is dependent on adequate tip definition, projection and rotation. Our aim is to establish if caudal septal dislocation (secondary to fracture or subluxation) is a significant factor in causing asymmetry in nostril axis angle (NAA) to effect surgical intervention. In addition, to assess if there is an association between the side of dislocation and the magnitude of NAA. METHODOLOGY: Photographic assessment of NAA was measured in a study group of 26 patients with caudal dislocation of the septum and a control group of 26 patients without caudal septal dislocation. All 52 patients were awaiting a septorhinoplasty procedure due to nasal trauma. RESULTS: Caudal septal dislocation causes a mean difference in NAA of 7.95o compared to 1.38o difference in the control group. We also found there is a greater degree of upward tip rotation on the side of the dislocation resulting in a larger NAA. CONCLUSION: Caudal dislocation of the septum causes a significant asymmetry in NAA, with a greater degree of rotation on the side of the dislocation. We should be aware of this fallacy prior to surgery.

Potentiation by cigarette smoke of macrophage function against Leishmania donovani infection.

OBJECTIVE: Cigarette smoke is able to induce the generation of reactive oxygen species and pro-inflammatory cytokines, which are mediators of macrophage function and therefore, we have investigated the ability of cigarette smoke to activate Leishmania donovani infected peritoneal macrophage. MATERIALS AND METHODS: Cultured peritoneal macrophages were either left untreated or treated with aqueous cigarette smoke extract prior to L. donovani infection. Parasite burden was assessed by giemsa staining. The level of intracellular reactive oxygen species was determined by FACS analysis. PCR was performed to analyze mRNA levels of cytokines. NF- kappaB activity was assessed by EMSA and reporter assay. RESULTS: A pre-treatment with cigarette smoke extract (CSE) causes a decrease in parasite burden, an increase in intracellular ROS level, up-regulation of pro-inflammatory cytokines, reduced expression of immuno-suppressive cytokine and boosting of NF-kappaB activity in L. donovani-infected macrophage. CONCLUSION: Low concentration of cigarette smoke extract (CSE) counteracts L. donovani infection-mediated suppression of macrophage function without affecting host cell viability. This study reveals a new role of cigarette smoke extract (CSE) as an activator of macrophage function.

The Gal3p-Gal80p-Gal4p transcription switch of yeast: Gal3p destabilizes the Gal80p-Gal4p complex in response to galactose and ATP.

The Gal3, Gal80, and Gal4 proteins of Saccharomyces cerevisiae comprise a signal transducer that governs the galactose-inducible Gal4p-mediated transcription activation of GAL regulon genes. In the absence of galactose, Gal80p binds to Gal4p and prohibits Gal4p from activating transcription, whereas in the presence of galactose, Gal3p binds to Gal80p and relieves its inhibition of Gal4p. We have found that immunoprecipitation of full-length Gal4p from yeast extracts coprecipitates less Gal80p in the presence than in the absence of Gal3p, galactose, and ATP. We have also found that retention of Gal80p by GSTG4AD (amino acids [aa] 768 to 881) is markedly reduced in the presence compared to the absence of Gal3p, galactose, and ATP. Consistent with these in vitro results, an in vivo two-hybrid genetic interaction between Gal80p and Gal4p (aa 768 to 881) was shown to be weaker in the presence than in the absence of Gal3p and galactose. These compiled results indicate that the binding of Gal3p to Gal80p results in destabilization of a Gal80p-Gal4p complex. The destabilization was markedly higher for complexes consisting of G4AD (aa 768 to 881) than for full-length Gal4p, suggesting that Gal80p relocated to a second site on full-length Gal4p. Congruent with the idea of a second site, we discovered a two-hybrid genetic interaction involving Gal80p and the region of Gal4p encompassing aa 225 to 797, a region of Gal4p linearly remote from the previously recognized Gal80p binding peptide within Gal4p aa 768 to 881.

Deafness in Vogt-Koyanagi-Harada syndrome.

Sudden onset sensorineural hearing loss is a well recognized entity frequently encountered in otolaryngological practice. However, the combination of such deafness as part of a wider systemic disorder is fortunately rare. Almost 100 years after the syndrome was classified, we describe a case of Vogt-Koyanagi-Harada syndrome occurring unusually in a Caucasian woman and characterized by sudden hearing loss. A brief review of this rare condition is presented.