Possible charge ordering and anomalous transport in graphene/graphene quantum dot heterostructure

Observations of superconductivity and charge density waves (CDW) in graphene have been elusive thus far due to weak electron-phonon coupling (EPC) interactions. Here, we report a unique observation of anomalous transport and multiple charge ordering phases at high temperatures (T1∼213K,T2∼325K) in a 0D-2D van der Waals (vdW) heterostructure comprising of single layer graphene (SLG) and functionalized (amine) graphene quantum dots (GQD). The presence of functionalized GQD contributed to charge transfer with shifting of the Dirac point ∼ 0.05 eV above the Fermi level (ab initio   simulations) and carrier densityn∼-0.3×1012 cm-2confirming p-doping in SLG and two-fold increase in EPC interaction was achieved. Moreover, we elucidate the interplay between electron-electron and electron-phonon interactions to substantiate high temperature EPC driven charge ordering in the heterostructure through analyses of magnetotransport and weak anti-localization (WAL) framework. Our results provide impetus to investigate strongly correlated phenomena such as CDW and superconducting phase transitions in novel graphene based heterostructures.

Clinical and ultrasonographic assessment of airway indices among non-pregnant, normotensive pregnant and pre-eclamptic patients: a prospective observational study

BACKGROUND

Prediction of a difficult airway is of paramount importance for an anaesthesiologist. Various anatomical and physiological factors contribute to a difficult airway in pregnant females, especially those with pre-eclampsia. The aim of the study was to assess airway indices using both routinely used clinical methods and ultrasound.

METHODS

Fifty-five non-pregnant females, 55 normotensive pregnant females and 55 females with pre-eclampsia were included in this prospective study. Clinical airway assessment was the modified Mallampati score, thyromental distance, hyomental distance, hyomental distance ratio, chest circumference, neck circumference and chest-to-neck circumference ratio. Sonographic assessment included tongue width, tongue volume, anterior neck soft tissue thickness at the level of hyoid, epiglottis and vocal cords, subglottic diameter, ratio of pre-epiglottic space to anterior, posterior and midpoint of anterior and posterior vocal folds.

RESULTS

Several significant differences were observed between pregnant and non-pregnant females, with additional changes in pre-eclamptic females. These included clinical parameters such as the modified Mallampati score and sonographic measurements of tongue width, tongue volume, subglottic diameter, anterior neck soft tissue thickness at the level of hyoid, epiglottis and vocal cords, and the ratio of pre-epiglottic space to anterior, posterior and midpoint of anterior and posterior vocal folds.

CONCLUSION

Routinely used clinical methods of airway assessment lack sensitivity and specificity. Ultrasound can visualise anatomical structures in the supraglottic and subglottic views and is encouraging as an airway assessment tool.

Assessment of Urinary Biomarkers for Infectious Diseases Using Lateral Flow Assays: A Comprehensive Overview

Screening of biomarkers is a powerful approach for providing a holistic view of the disease spectrum and facilitating the diagnosis and prognosis of the state of infectious diseases. Unaffected by the homeostasis mechanism in the human body, urine accommodates systemic changes and reflects the pathophysiological condition of an individual. Easy availability in large volumes and non-invasive sample collection have rendered urine an ideal source of biomarkers for various diseases. Infectious diseases may be communicable, and therefore early diagnosis and treatment are of immense importance. Current diagnostic approaches preclude the timely identification of clinical conditions and also lack portability. Point-of-care (POC) testing solutions have gained attention as alternative diagnostic measures due to their ability to provide rapid and on-site results. Lateral flow assays (LFAs) are the mainstay in POC device development and have attracted interest owing to their potential to provide instantaneous results in resource-limited settings. The discovery and optimization of a definitive biomarker can render POC testing an excellent platform, thus impacting unwarranted antibiotic administration and preventing the spread of infectious diseases. This Review summarizes the importance of urine as an emerging biological fluid in infectious disease research and diagnosis in clinical settings. We review the academic research related to LFAs. Further, we also describe commercial POC devices based on the identification of urinary biomarkers as diagnostic targets for infectious diseases. We also discuss the future use of LFAs in developing more effective POC tests for urinary biomarkers of various infections.

Probing the charge transfer and electron-hole asymmetry in graphene-graphene quantum dot heterostructure

In recent years, graphene-based van der Waals (vdW) heterostructures have come into prominence showcasing interesting charge transfer dynamics which is significant for optoelectronic applications. These novel structures are highly tunable depending on several factors such as the combination of the two-dimensional materials, the number of layers and band alignment exhibiting interfacial charge transfer dynamics. Here, we report on a novel graphene based 0D-2D vdW heterostructure between graphene and amine-functionalized graphene quantum dots (GQD) to investigate the interfacial charge transfer and doping possibilities. Using a combination ofab initiosimulations and Kelvin probe force microscopy (KPFM) measurements, we confirm that the incorporation of functional GQDs leads to a charge transfer induced p-type doping in graphene. A shift of the Dirac point by 0.05 eV with respect to the Fermi level (E_F) in the graphene from the heterostructure was deduced from the calculated density of states. KPFM measurements revealed an increment in the surface potential of the GQD in the 0D-2D heterostructure by 29 mV with respect to graphene. Furthermore, we conducted power dependent Raman spectroscopy for both graphene and the heterostructure samples. An optical doping-induced gating effect resulted in a stiffening of theGband for electrons and holes in both samples (graphene and the heterostructure), suggesting a breakdown of the adiabatic Born-Oppenheimer approximation. Moreover, charge imbalance and renormalization of the electron-hole dispersion under the additional influence of the doped functional GQDs is pointing to an asymmetry in conduction and carrier mobility.

Genetic similarities and phylogenetic analysis of Muntjac (Muntiacus spp.) by comparing the nucleotide sequence of 16S rRNA and cytochrome B genome

This study aimed to identify the phylogenetic similarities among the muntjac (Muntiacus spp.). The phylogenetic similarities among seven major muntjac species were studied by comparing the nucleotide sequence of 16s rRNA and cytochrome b genome. Nucleotide sequences, retrieved from NCBI databases were aligned by using DNASTAR software. A phylogenetic tree was created for the selected species of muntjac by using the maximum likelihood method on MEGA7 software. The results of nucleotide sequences (16s rRNA) showed phylogenetic similarities between, the M. truongsonensis and M. rooseveltorum had the highest (99.2%) while the lowest similarities (96.8%) found between M. crinifrons and M. putaoensi. While the results of nucleotide sequences (Cty b) showed the highest similarity (100%) between M. muntjak and M. truongsonensis and the lowest s (91.5%) among M. putaoensis and M. crinifrons. The phylogenetic tree of muntjac species (16s rRNA gene) shows the main two clusters, the one including M. putaoensis, M. truongsonensis, M. rooseveltorum, and M. muntjak, and the second one including M. crinifrons and M. vuquangensis. The M. reevesi exists separately in the phylogenetic tree. The phylogenetic tree of muntjac species using cytochrome b genes shows that the M. muntjak and M. truongsonensis are clustered in the same group.

Evaluation of the Free Radical Scavenging Activities of Ellagic Acid and Ellagic Acid Peracetate by EPR Spectrometry

The purpose of this study was to examine the free radical scavenging and antioxidant activities of ellagic acid (EA) and ellagic acid peracetate (EAPA) by measuring their reactions with the radicals, 2,2-diphenyl-1-picrylhydrazyl and galvinoxyl using EPR spectroscopy. We have also evaluated the influence of EA and EAPA on the ROS production in L-6 myoblasts and rat liver microsomal lipid peroxidation catalyzed by NADPH. The results obtained clearly indicated that EA has tremendous ability to scavenge free radicals, even at concentration of 1 µM. Interestingly even in the absence of esterase, EAPA, the acetylated product of EA, was also found to be a good scavenger but at a relatively slower rate. Kinetic studies revealed that both EA and EAPA have ability to scavenge free radicals at the concentrations of 1 µM over extended periods of time. In cellular systems, EA and EAPA were found to have similar potentials for the inhibition of ROS production in L-6 myoblasts and NADPH-dependent catalyzed microsomal lipid peroxidation.

Cell type specific adhesion to surfaces functionalised by amine plasma polymers

Our previously-obtained impressive results of highly increased C2C12 mouse myoblast adhesion to amine plasma polymers (PPs) motivated current detailed studies of cell resistance to trypsinization, cell proliferation, motility, and the rate of attachment carried out for fibroblasts (LF), keratinocytes (HaCaT), rat vascular smooth muscle cells (VSMC), and endothelial cells (HUVEC, HSVEC, and CPAE) on three different amine PPs. We demonstrated the striking difference in the resistance to trypsin treatment between endothelial and non-endothelial cells. The increased resistance observed for the non-endothelial cell types was accompanied by an increased rate of cellular attachment, even though spontaneous migration was comparable to the control, i.e., to the standard cultivation surface. As demonstrated on LF fibroblasts, the resistance to trypsin was similar in serum-supplemented and serum-free media, i.e., medium without cell adhesion-mediating proteins. The increased cell adhesion was also confirmed for LF cells by an independent technique, single-cell force spectroscopy. This method, as well as the cell attachment rate, proved the difference among the plasma polymers with different amounts of amine groups, but other investigated techniques could not reveal the differences in the cell behaviour on different amine PPs. Based on all the results, the increased resistance to trypsinization of C2C12, LF, HaCaT, and VSMC cells on amine PPs can be explained most probably by a non-specific cell adhesion such as electrostatic interaction between the cells and amine groups on the material surface, rather than by the receptor-mediated adhesion through serum-derived proteins adsorbed on the PPs.

User-adaptive Reminders for Home-based Medical Tasks

Objectives: We present a prototype adaptive reminder system for home-based medical tasks. The system consists of a mobile device for reminder presentation and ambient sensors to determine opportune moments for reminder delivery. Our objective was to study interaction with the prototype under naturalistic living conditions and gain insight into factors affecting the longterm acceptability of context-sensitive reminder systems for the home setting.

Methods: A volunteer participant used the prototype in a residential research facility while adhering to a regimen of simulated medical tasks for ten days. Some reminders were scheduled at fixed times during the day and some were automatically time-shifted based on sensor data. We made a complete video and sensor record of the stay. Finally, the participant commented about his experiences with the system in a debriefing interview.

Results: Based on this case study, including direct observation of individual alert-action sequences, we make four recommendations for designers of context-sensitive adaptive reminder systems. Captured metrics suggest that adaptive reminders led to faster reaction times and were perceived by the participant as being more useful.

Conclusions: The evaluation of context-sensitive systems that overlap into domestic lives is challenging. We believe that the ideal experiment is to deploy such systems in real homes and assess performance longitudinally. This case study in an instrumented live-in facility is a step toward that long-term goal.

Protective effect of Alpinia galanga in STZ induced diabetic nephropathy

The activity of the alcoholic extract of the rhizomes of Alpinia galanga was studied for the treatment of diabetes-induced nephropathy in rats. Wistar rats received a single intraperitoneal streptozotocin injection (60 mg kg(-1) b.wt.) to induce diabetes. Rats were considered diabetic if blood glucose concentration increased up to 200 or more mg dL(-1). The rats were orally administered alcoholic extract of Alpinia galanga (50, 100 and 200 mg kg(-1)), once daily for 40 days. Body weight, blood glucose, urinary albumin, glycosylated haemoglobin, Blood Urea Nitrogen (BUN), creatinine, lipids profile, Malondialdehyde (MDA), Superoxide Dismutase (SOD), Glutathione (GSH) and Catalase (CAT) were then evaluated. After 40 days of treatment, Alpinia galanga significantly (p<0.05) decreased glycaemia, Blood Urea Nitrogen (BUN), urinar albumin and increased body weight in diabetes-nephropathic rats. The extract (200 mg kg(-1)) decreased MDA significantly (p<0.01); GSH (p<0.05), increased SOD (p<0.05) and CAT (p<0.05) in the rats, compared with nephropathic control. The extract (100 and 200 mg kg(-1), respectively) lowered (p<0.05) total cholesterolemia, blood triglycerides (p<0.05), blood LDL cholesterol (p<0.05), but increased blood HDL cholesterol (p<0.01). Overall, atherogenic index was decreased significantly (p<0.05). In the present study, the rhizomes of Alpinia galanga demonstrated significant nephro-protective activities in the tested models. The alcoholic extract of the rhizomes of Alpinia galanga holds promise for the development of a standardized phytomedicine for diabetes mellitus and kidney disease treatment.

Antiretroviral therapy prescribing in hospitalized HIV clinic patients

OBJECTIVES

Antiretroviral therapy (ART) medication prescribing errors in hospitalized patients still remain common. This study aimed to examine the initial prescribing of antiretroviral drug regimens for HIV clinic patients admitted to an urban academic teaching hospital.

METHODS

A retrospective chart review of all patients with a discharge diagnosis of HIV or AIDS was performed. Only patients actively managed by the hospital out-patient HIV clinic at the time of discharge were included in the final analysis. We compared the ART initially prescribed during hospitalization with the clinic records. Medication errors were separated by type and the prescriber's area of specialty was noted.

RESULTS

From 1 January 2009 to 31 December 2009, 90 admissions in 62 patients were included in the final analysis. In 47 of those admissions, the patient had an initial regimen considered to be incorrectly prescribed; in 17 of these 47 admissions, the patient was not prescribed any ART, and in the remainder the errors were related to drug omissions, incorrect frequency/dose, and prescription of the wrong drug. The majority of admissions were by an internal medicine or non-infectious disease (ID) specialist. Average time to ART initiation was comparable among all prescribers. No statistically significant correlation was found between the number of admissions per patient or the prescriber's area of specialty and the percentage of incorrect regimens ordered.

CONCLUSION

Hospital HIV medication management still remains an area of focus because of the complexity of regimens, poor medication reconciliation and limited non-HIV/ID specialist knowledge.

In vitro antibacterial evaluation of Anabaena sp. against several clinically significant microflora and HPTLC analysis of its active crude extracts

The present study was conducted to evaluate the possible antibacterial activity of Anabaena extracts. Anabaena was isolated from a natural source and cultured in vitro. after suitable growth, cyanobacterial culture was harvested using different solvents. Extracts, thus prepared, were evaluated for their antibacterial potential by agar-well diffusion assay against bacterial species of clinical significance. MIC values were determined further to check the concentration ranges for significant inhibition. HPTLC analysis was done to separate the components of active crude extract in an attempt to identify the bio-active chemical entity. Methanol extract exhibited more potent activity than that of hexane and ethyl acetate extracts. No inhibitory effect was found against Pseudomonas aeruginosa, Salmonella typhi, and Klebsiella pneumoniae. Staphylococcus aureus required about 256 µg/ml of the crude methanol extract for effective inhibition. HPTLC evaluation at λ 254 nm was performed for the separation of a complex mixture of the methanol extract. The results provide evidence that Anabaena sp. extracts might indeed be potential sources of new antibacterial agents.

Identification and metabolite profiling of Sitophilus oryzae L. by 1D and 2D NMR spectroscopy

The polyphagous insect Sitophilus oryzae L. (Coleoptera:Curculionidae) has a tremendous adaptability in feeding behaviour, making it a serious invasive pest of stored cereals. The present study identifies the metabolite composition of Sitophilus oryzae (S. oryzae) using Nuclear Magnetic Resonance (NMR) spectroscopy. Assignment of 1D-proton by NMR, 1H-1H COSY, 2D-TOCSY 1H-1H, had been done. Amongst the various biochemically important metabolites isoleucine, valine, leucine, beta-hydroxybutyrate, lysine, glutamate, glutamine, proline, lactate, alanine, di-methylamine, alpha-glucose, beta-glucose, choline, glycerophosphorylcholine and tyrosine are present in S. oryzae. In wheat-fed S. oryzae, the presence of threonine and the absence of lactate is observed. In rice-fed S. oryzae, however, the presence of lactate and the absence of threonine were observed. Barley-fed S. oryzae shows presence of both tyrosine and lactate. It is concluded that the pest S. oryzae has adaptability on different stored cereals and grains, depicting the presence of earlier reported metabolites. The present study aims to identify the key metabolic components and associated enzymes in Sitophilus oryzae fed on different cereals.

In vitro antibacterial activity of laboratory grown culture of Spirulina platensis

The hexane, ethyl acetate, dichloromethane, methanol extracts and spent media (extracellular substances) were tested in vitro for their antibacterial activity for which one Gram-positive bacterium (Staphylococcus aureus) and four Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, and Klebsiella pneumoniae) were used as test organisms. The methanol extract showed more potent activity than other organic extracts, spent medium of the culture exhibited little activity against E. coli only. No inhibitory effect was found against Klebsiella pneumoniae.The broth microdilution assay gave minimum inhibitory concentrations (MIC) values ranging from 1 to 512 μg/ml. The MIC of methanol extract against S. aureus and E. coli were 128 μg/ml and 256 μg/ml, respectively.

User-adaptive reminders for home-based medical tasks. A case study

OBJECTIVES

We present a prototype adaptive reminder system for home-based medical tasks. The system consists of a mobile device for reminder presentation and ambient sensors to determine opportune moments for reminder delivery. Our objective was to study interaction with the prototype under naturalistic living conditions and gain insight into factors affecting the long-term acceptability of context-sensitive reminder systems for the home setting.

METHODS

A volunteer participant used the prototype in a residential research facility while adhering to a regimen of simulated medical tasks for ten days. Some reminders were scheduled at fixed times during the day and some were automatically time-shifted based on sensor data. We made a complete video and sensor record of the stay. Finally, the participant commented about his experiences with the system in a debriefing interview.

RESULTS

Based on this case study, including direct observation of individual alert-action sequences, we make four recommendations for designers of context-sensitive adaptive reminder systems. Captured metrics suggest that adaptive reminders led to faster reaction times and were perceived by the participant as being more useful.

CONCLUSIONS

The evaluation of context-sensitive systems that overlap into domestic lives is challenging. We believe that the ideal experiment is to deploy such systems in real homes and assess performance longitudinally. This case study in an instrumented live-in facility is a step toward that long-term goal.

Development of rabies DNA vaccine using a recombinant plasmid

A recombinant plasmid pTargeT.rabgp containing the glycoprotein (G) gene of Rabies virus (RV) was constructed and produced for immunogenicity studies on mice and dogs. The mice immunized twice with 50 microg or 100 microg of pTargeT.rabgp intramuscularly (i.m.), showed a serum antibody titer of 256 or 64, respectively 14 days post immunization (p.i.). When the vaccinated mice were challenged at 14 days p.i. with RV i.c., they were protected in 81.25% or 87.5%, respectively. A positive cell mediated immune response was observed by lymphocyte proliferation assay and macrophage migration inhibition test. These results indicate that the pTargeT.rabgp plasmid can be used as a rabies DNA vaccine.

Hypergammaglobulinemic purpura of Waldenström: report of 3 cases with a short review

Benign hypergammaglobulinemic purpura of Waldenström (HGPW) is an uncommon cause of non-thrombocytopaenic purpura that may create diagnostic difficulties. The presence of constitutional symptoms associated with prominent immunological abnormalities may raise alarm, leading to extensive and often unnecessary investigations. This report describes 3 young women with HGPW. Clinical features were characterised by recurrent episodes of bilateral asymmetrical palpable purpuric lesions on the lower extremities that were precipitated by a prolonged increase in hydrostatic pressure (e.g. prolonged standing, tight stockings etc.) associated with constitutional features. In one patient the condition was secondary to Sjögren's syndrome with type IV renal tubular acidosis. Laboratory abnormalities included a persistently elevated erythrocyte sedimentation rate, marked polyclonal hypergammaglobulinemia, and high titers of rheumatoid factor and anti-nuclear antibody of the anti-SSA (anti-Ro)/anti-SSB(anti-La) subsets. This topic is reviewed briefly with the emphasis that in its 'primary' form this condition could be considered a 'benign' systemic immunoinflammatory disease that requires neither extensive investigations nor any aggressive form of therapy. Greater awareness of HGPW may increase the frequency of its diagnosis, especially in the patient group with non-thrombocytopenic purpura or the so-called cutaneous vasculitic syndromes with 'palpable purpura'.

Musculoskeletal manifestations with panniculitis--a hospital based study on 62 patients in Kuwait

The study describes 62 patients seen over a period of 4 years mainly presenting with an acute inflammatory ankle arthritis/periarthritis associated with panniculitis. Based upon the clinical characteristics of panniculitis two distinct categories could be defined. These included patients with characteristic lesions of erythema nodosum, seen in 51 (82%), the idiopathic form in 29 (57%), and secondary EN in 22 (43%). Associated conditions included Behçet's disease, oral contraceptive pills, pregnancy and penicillin treatment. Patients clinically not having typical EN was seen in 11 (18%). In this group the histopathology showed erythema induratum in 4, cutaneous-polyarteritis nodosa with minimal panniculitis in 3, Weber-Christian disease, cytophagic histiocytic panniculitis, and 'mixed' lobular and septal variety of panniculitis in 1 each. (In 1 patient the disease was not panniculitis but cutaneous variant of granuloma annulare). It is concluded that in a hospital setting EN associated with acute musculoskeletal symptoms, mainly ankle arthritis/periarthritis or an acute peripheral polyarthritis, was a common rheumatological problem in Kuwait. However, other forms of panniculitides also presented with musculoskeletal manifestations requiring accurate histopathological diagnosis for appropriate treatment.

Infective arthritis in adults--experience at a teaching hospital in Kuwait

Infective arthritis (InfectA) has a variable geographical pattern. A 'Medline' search did not yield any earlier series on epidemiological pattern of InfectA from Kuwait or the Gulf region. Therefore, an observational prospective study of sequential cases seen over a period of 4 years was carried out. Of a total of 2021 patients seen during this period, 36 (1.8%) were diagnosed to have InfectA. There were 6 (16.7%) cases of neisserial and 30 (83.3%) of non-neisserial InfectA. Predisposing factors were seen in 17 (47.2%), all with non-neisserial InfectA. Microbiological diagnosis was proven in 15 (41.7%) cases, and included Neisseria gonorrhoeae in 5, Brucella spp. in 4, Staphylococcus aureus in 3, and Neisseria meningitidis, Salmonella spp. and Mycobacterium tuberculosis in 1 each. In the remaining 21 (58.3%) cases the diagnosis was made on clinical grounds and confirmed on therapeutic response. The most common presentation of neisserial InfectA was acute polyarthritis while that of non-neisserial InfectA was acute monoarthritis. All patients recovered with little disability and no mortality.

Typhoid fever with severe pancytopenia

A patient suffering from typhoid fever with severe pancytopenia is presented. Bone marrow examination revealed extensive haemophagocytosis which possibly contributed to the pancytopenia.

Studies on the determination and degradation of pyrimethamine in mammals

Treatment of pyrimethamine with blood plasma in vitro yields a metabolite which is also produced when the drug is administered through intravenous injection in the rat. A thin layer liquid chromatographic method for quantitative and qualitative determination of pyrimethamine and its metabolite in plasma and biological tissues is described.