191 research outputs found
Photophysics of some styryl thiazolo quinoxaline dyes in organic media
The photophysics of a new class of styryl dyes, 2-styryl thiazolo quinoxaline (STQ) based structures was investigated in organic solvents and organized molecular assemblies. The absorption, steady state and time-resolved fluorescence characteristics of the STQ dyes in low-viscosity organic solvents are consistent with a single species in the ground and excited state. The one electron electrochemical oxidation and reduction potentials of the dyes are within ±1V vs. NHE. The spectral shifts of the dyes in organic solvents are linearly correlated with the variation of solvent polarity parameters. The dipole moments in the ground and excited state of the dyes were calculated without assuming a value for the cavity radius. The temperature dependence of the nonradiative rate of STQ dye in DMSO indicated an activation barrier (ΔE=10.7 kJ/mol) which is comparable to the activation energy (Ea=13.7 kJ/mol) of viscous friction in DMSO. In dichloromethane, the activation barrier is 34.0 kJ/mol which is very high compared to Ea=6.64 kJ/mol. Formation of a dyeâsolvent complex is suggested in dichloromethane. The fluorescence decay of STQ dye is multiexponential in a viscous solvent (2-octanol) or when bound to a protein (Lysozyme), micelle or lipid membrane. In 2-octanol, the decay parameters are wavelength dependent and the results are consistent with the mechanism of excited state kinetics of solvent relaxation. In other systems, the multiexponential decay is due to multiple sites of solubilization of the dye in the organized molecular assembly
N-Aryl-linked spirocyclic polymers for membrane separations of complex hydrocarbon mixtures
The fractionation of crude-oil mixtures through distillation is a large-scale, energy-intensive process. Membrane materials can avoid phase changes in such mixtures and thereby reduce the energy intensity of these thermal separations. With this application in mind, we created spirocyclic polymers with N-aryl bonds that demonstrated noninterconnected microporosity in the absence of ladder linkages. The resulting glassy polymer membranes demonstrated nonthermal membrane fractionation of light crude oil through a combination of class- and size-based âsortingâ of molecules. We observed an enrichment of molecules lighter than 170 daltons corresponding to a carbon number of 12 or a boiling point less than 200°C in the permeate. Such scalable, selective membranes offer potential for the hybridization of energy-efficient technology with conventional processes such as distillation
A bibliography of parasites and diseases of marine and freshwater fishes of India
With the increasing demand for fish as human food, aquaculture both in freshwater
and salt water is rapidly developing over the world. In the developing countries,
fishes are being raised as food. In many countries fish farming is a very important
economic activity. The most recent branch, mariculture, has shown advances in
raising fishes in brackish, estuarine and bay waters, in which marine, anadromous and
catadromous fishes have successfully been grown and maintained
Saliva microRNA Biomarkers of Cumulative Concussion
Recurrent concussions increase risk for persistent post-concussion symptoms, and may lead to chronic neurocognitive deficits. Little is known about the molecular pathways that contribute to persistent concussion symptoms. We hypothesized that salivary measurement of microribonucleic acids (miRNAs), a class of epitranscriptional molecules implicated in concussion pathophysiology, would provide insights about the molecular cascade resulting from recurrent concussions. This hypothesis was tested in a case-control study involving 13 former professional football athletes with a history of recurrent concussion, and 18 age/sex-matched peers. Molecules of interest were further validated in a cross-sectional study of 310 younger individuals with a history of no concussion (n = 230), a single concussion (n = 56), or recurrent concussions (n = 24). There was no difference in neurocognitive performance between the former professional athletes and their peers, or among younger individuals with varying concussion exposures. However, younger individuals without prior concussion outperformed peers with prior concussion on three balance assessments. Twenty salivary miRNAs differed (adj. p \u3c 0.05) between former professional athletes and their peers. Two of these (miR-28-3p and miR-339-3p) demonstrated relationships (p \u3c 0.05) with the number of prior concussions reported by younger individuals. miR-28-3p and miR-339-5p may play a role in the pathophysiologic mechanism involved in cumulative concussion effects
Diagnosing Mild Traumatic Brain Injury Using Saliva RNA Compared to Cognitive and Balance Testing
BACKGROUND: Early, accurate diagnosis of mild traumatic brain injury (mTBI) can improve clinical outcomes for patients, but mTBI remains difficult to diagnose because of reliance on subjective symptom reports. An objective biomarker could increase diagnostic accuracy and improve clinical outcomes. The aim of this study was to assess the ability of salivary noncoding RNA (ncRNA) to serve as a diagnostic adjunct to current clinical tools. We hypothesized that saliva ncRNA levels would demonstrate comparable accuracy for identifying mTBI as measures of symptom burden, neurocognition, and balance.
METHODS: This caseâcontrol study involved 538 individuals. Participants included 251 individuals with mTBI, enrolled â€14 days postinjury, from 11 clinical sites. Saliva samples (n = 679) were collected at five time points (â€3, 4â7, 8â14, 15â30, and 31â60 days postâmTBI). Levels of ncRNAs (microRNAs, small nucleolar RNAs, and piwiâinteracting RNAs) were quantified within each sample using RNA sequencing. The first sample from each mTBI participant was compared to saliva samples from 287 controls. Samples were divided into testing (n = 430; mTBI = 201 and control = 239) and training sets (n = 108; mTBI = 50 and control = 58). The test set was used to identify ncRNA diagnostic candidates and create a diagnostic model. Model accuracy was assessed in the naĂŻve test set.
RESULTS: A model utilizing seven ncRNA ratios, along with participant age and chronic headache status, differentiated mTBI and control participants with a crossâvalidated area under the curve (AUC) of .857 in the training set (95% CI, .816â.903) and .823 in the naĂŻve test set. In a subset of participants (n = 321; mTBI = 176 and control = 145) assessed for symptom burden (PostâConcussion Symptom Scale), as well as neurocognition and balance (ClearEdge System), these clinical measures yielded crossâvalidated AUC of .835 (95% CI, .782â.880) and .853 (95% CI, .803â.899), respectively. A model employing symptom burden and four neurocognitive measures identified mTBI participants with similar AUC (.888; CI, .845â.925) as symptom burden and four ncRNAs (.932; 95% CI, .890â.965).
CONCLUSION: Salivary ncRNA levels represent a noninvasive, biologic measure that can aid objective, accurate diagnosis of mTBI
The global biopharma industry and the rise of Indian drug multinationals: implications for Australian generics policy
This article provides a synopsis of the new dynamics of the global biopharma industry. The emergence of global generics companies with capabilities approximating those of 'big pharma' has accelerated the blurring of boundaries between the innovator and generics sectors. Biotechnology-based products form a large and growing segment of prescription drug markets and regulatory pathways for biogenerics are imminent. Indian biopharma multinationals with large-scale efficient manufacturing plants and growing R&D capabilities are now major suppliers of Active Pharmaceutical Ingredients (APIs) and generic drugs across both developed and developing countries. In response to generic competition, innovator companies employ a range of life cycle management techniques, including the launch of 'authorised generics'. The generics segment in Australia will see high growth rates in coming years but the prospect for local manufacturing is bleak. The availability of cheap generics in international markets has put pressure on Pharmaceutical Benefits Scheme (PBS) pricing arrangements, and a new policy direction was announced in November 2006. Lower generics prices will have a negative impact on some incumbent suppliers but industrial renewal policies for the medicines industry in Australia are better focused on higher value R&D activities and niche manufacturing of sophisticated products
Radiation Induced Apoptosis of Murine Bone Marrow Cells is Independent of Early Growth Response 1 (EGR1)
An understanding of how each individual 5q chromosome critical deleted region (CDR) gene contributes to malignant transformation would foster the development of much needed targeted therapies for the treatment of therapy related myeloid neoplasms (t-MNs). Early Growth Response 1 (EGR1) is a key transcriptional regulator of myeloid differentiation located within the 5q chromosome CDR that has been shown to regulate HSC (hematopoietic stem cell) quiescence as well as the master regulator of apoptosisâp53. Since resistance to apoptosis is a hallmark of malignant transformation, we investigated the role of EGR1 in apoptosis of bone marrow cells; a cell population from which myeloid malignancies arise. We evaluated radiation induced apoptosis of Egr1+/+ and Egr1-/- bone marrow cells in vitro and in vivo. EGR1 is not required for radiation induced apoptosis of murine bone marrow cells. Neither p53 mRNA (messenger RNA) nor protein expression is regulated by EGR1 in these cells. Radiation induced apoptosis of bone marrow cells by double strand DNA breaks induced p53 activation. These results suggest EGR1 dependent signaling mechanisms do not contribute to aberrant apoptosis of malignant cells in myeloid malignancies
Provider Attitudes and Practice Patterns for Direct-Acting Antiviral Therapy for Patients With Hepatocellular Carcinoma
Background & Aims: Direct-acting antivirals (DAAs) are effective against hepatitis C virus and sustained virologic response is associated with reduced incidence of hepatocellular carcinoma (HCC). However, there is controversy over the use of DAAs in patients with active or treated HCC and uncertainty about optimal management of these patients. We aimed to characterize attitudes and practice patterns of hepatology practitioners in the United States regarding the use of DAAs in patients with HCC. Methods: We conducted a survey of hepatology providers at 47 tertiary care centers in 25 states. Surveys were sent to 476 providers and we received 279 responses (58.6%). Results: Provider beliefs about risk of HCC recurrence after DAA therapy varied: 48% responded that DAAs reduce risk, 36% responded that DAAs do not change risk, and 16% responded that DAAs increase risk of HCC recurrence. However, most providers believed DAAs to be beneficial to and reduce mortality of patients with complete response to HCC treatment. Accordingly, nearly all providers (94.9%) reported recommending DAA therapy to patients with early-stage HCC who received curative treatment. However, fewer providers recommended DAA therapy for patients with intermediate (72.9%) or advanced (57.5%) HCC undergoing palliative therapies. Timing of DAA initiation varied among providers based on HCC treatment modality: 49.1% of providers reported they would initiate DAA therapy within 3 months of surgical resection whereas 45.9% and 5.0% would delay DAA initiation for 3â12 months and >1 year post-surgery, respectively. For patients undergoing transarterial chemoembolization (TACE), 42.0% of providers would provide DAAs within 3 months of the procedure, 46.7% would delay DAAs until 3â12 months afterward, and 11.3% would delay DAAs more than 1 year after TACE. Conclusions: Based on a survey sent to hepatology providers, there is variation in provider attitudes and practice patterns regarding use and timing of DAAs for patients with HCC. Further studies are needed to characterize the risks and benefits of DAA therapy in this patient population
Biogenic silver nanoparticles associated with silver chloride nanoparticles (Ag@AgCl) produced by laccase from Trametes versicolor
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