Highly sensitive alkane odour sensors based on functionalised gold nanoparticles

We deposit dense, ordered, thin films of Au-dodecanethiol core/shell nanoparticles by the Langmuir-Schafer (LS) printing method, and find that their resistance at ambient temperature responds selectively and sensitively to alkane odours. Response is a rapid resistance increase due to swelling, and is strongest for alkane odours where the alkane chain is similar in length to the dodecane shell. For decane odours, we find a response to concentrations as low as 15 ppm, about 600 times below the lower explosive limit. Response is weaker, but still significant, to aromatic odours (e.g. Toluene, Xylene), while potential interferants such as polar and/or hydrogen-bonding odours (e.g. alcohols, ketones, water vapour) are somewhat rejected. Resistance is weakly dependent on temperature, and recovers rapidly and completely to its original value within the error margin of measurement. (C) 2011 Elsevier B.V. All rights reserved

Two Weeks of Ischemic Conditioning Improves Walking Speed and Reduces Neuromuscular Fatigability in Chronic Stroke Survivors

This pilot study examined whether ischemic conditioning (IC), a noninvasive, cost-effective, and easy-to-administer intervention, could improve gait speed and paretic leg muscle function in stroke survivors. We hypothesized that 2 wk of IC training would increase self-selected walking speed, increase paretic muscle strength, and reduce neuromuscular fatigability in chronic stroke survivors. Twenty-two chronic stroke survivors received either IC or IC Sham on their paretic leg every other day for 2 wk (7 total sessions). IC involved 5-min bouts of ischemia, repeated five times, using a cuff inflated to 225 mmHg on the paretic thigh. For IC Sham, the cuff inflation pressure was 10 mmHg. Self-selected walking speed was assessed using the 10-m walk test, and paretic leg knee extensor strength and fatigability were assessed using a Biodex dynamometer. Self-selected walking speed increased in the IC group (0.86 ± 0.21 m/s pretest vs. 1.04 ± 0.22 m/s posttest, means ± SD; P\u3c 0.001) but not in the IC Sham group (0.92 ± 0.47 m/s pretest vs. 0.96 ± 0.46 m/s posttest; P= 0.25). Paretic leg maximum voluntary contractions were unchanged in both groups (103 ± 57 N·m pre-IC vs. 109 ± 65 N·m post-IC; 103 ± 59 N·m pre-IC Sham vs. 108 ± 67 N·m post-IC Sham; P = 0.81); however, participants in the IC group maintained a submaximal isometric contraction longer than participants in the IC Sham group (278 ± 163 s pre-IC vs. 496 ± 313 s post-IC, P = 0.004; 397 ± 203 s pre-IC Sham vs. 355 ± 195 s post-IC Sham; P = 0.46). The results from this pilot study thus indicate that IC training has the potential to improve walking speed and paretic muscle fatigue resistance poststroke

Strategies for the production of long-acting therapeutics and efficient drug delivery for cancer treatment

Protein therapeutics play a significant role in treating many diseases. They, however, suffer from patient's proteases degradation and antibody neutralization which lead to short plasma half-lives. One of the ways to overcome these pitfalls is the frequent injection of the drug albeit at the cost of patient compliance which affects the quality of life of patients. There are several techniques available to extend the half-life of therapeutics. Two of the most common protocols are PEGylation and fusion with human serum albumin. These two techniques improve stability, reduce immunogenicity, and increase drug resistance to proteases. These factors lead to the reduction of injection frequency which increases patient compliance and improve quality of life. Both techniques have already been used in many FDA approved drugs. This review describes many technologies to produce long-acting drugs with the attention of PEGylation and the genetic fusion with human serum albumin. The report also discusses the latest modified therapeutics in the field and their application in cancer therapy. We compare the modification methods and discuss the pitfalls of these modified drugs

Studies on vascular response to full superantigens and superantigen derived peptides:Possible production of novel superantigen variants with less vasodilation effect for tolerable cancer immunotherapy

Superantigens (SAgs) are a class of antigens that cause non-specific activation of T-cells resulting in polyclonal T cell activation and massive cytokine release and causing symptoms similar to sepsis, e.g. hypotension and subsequent hyporeactivity. We investigated the direct effect of SAgs on vascular tone using two recombinant SAgs, SEA and SPEA. The roles of Nitric Oxide (NO) and potentially hyperpolarization, which is dependent on the K + channel activation, were also explored. The data show that SEA and SPEA have direct vasodilatory effects that were in part NO-dependent, but completely dependent on activation of K + channels. Our work also identified the functional regions of one of the superantigens, SPEA, that are involved in causing the vasodilation and possible hypotension. A series of 20 overlapping peptides, spanning the entire sequence of SPEA, were designed and synthesized. The vascular response of each peptide was measured, and the active peptides were identified. Our results implicate the regions, (61–100), (101–140) and (181–220) which cause the vasodilation and possible hypotension effects of SPEA. The data also shows that the peptide 181–220 exert the highest vasodilation effect. This work therefore, demonstrates the direct effect of SAgs on vascular tone and identify the active region causing this vasodilation. We propose that these three peptides could be effective novel antihypertensive drugs. We also overexpressed, in E.coli, four superantigens from codon optimized genes

Transorbital transnasal endoscopic combined approach to the anterior and middle skull base: a laboratory investigation

Orbital approaches provide significant trajectory to the skull base and are used with differently designed pathways. The aim of this study is to investigate the feasibility of a combined transorbital and transnasal approach to the anterior and middle cranial fossa. Cadaveric dissection of five silicon-injected heads was used. A total of 10 bilateral transorbital approaches and 5 extended endonasal approaches were performed. Identification of surgical landmarks, main anatomical structures, feasibility of a combined approach and reconstruction of the superior orbital defect were examined. Rod lens endoscope (with 0° and 45° lenses) and endoscopic instruments were used to complete the dissection. The transorbital approach showed good versatility and provides the surgeon with a direct route to the anterior and middle cranial fossa. The transorbital avascular plane showed no conflict with major nerves or vessels. Large exposure area from crista galli to the third ventricle was demonstrated with significant control of different neurovascular structures. A combined transorbital transnasal approach provides considerable value in terms of extent of exposure and free hand movement of the two surgeons, and allows better visualisation and control of the ventral skull base, thus overcoming the current surgical limits of a single approach. Combination of these two minimally invasive approaches should reduce overall morbidity. Clinical trials are needed to evaluate the virtual applications of this approach

Sub-nanomolar detection of Cesium with water-gated transistor

Caesium (Cs + ) cations are rare in nature but the β - active radioisotope 137 Cs can be released in nuclear incidents and find its way into the water supply, where it is harmful to humans and animals drinking it. We here report a water-gated thin film transistor (WGTFT) which allows the detection of Cs + in drinking water at very low concentrations. The transistor channel is formed from spray pyrolysed tin dioxide, SnO 2 which gives WGTFTs with near- zero initial threshold. When the WGTFT is sensitised with a plasticised PVC membrane containing the Cs + - selective zeolite ‘mordenite’, it displays a threshold shift when exposed to drinking water samples carrying traces of Cs + . The response characteristic is given by the Langmuir adsorption isotherm instead of the NikolskyEisenman law commonly found for ion- sensitive WGTFTs sensitised with organic ionophores. We find a complex stability constant K = (3.9 +/- 0.4) x 10 9 L / mole and a limit-of detection (LoD) of 33 pM. Our LoD is far lower than the Cs + potability limit of 7.5 nM, which cannot be met by organicsensitised membranes where LoD is typically in the order of 100 nM or more

Design and Development of a Web Extension to Help Facilitate the Learning of a Foreign Language

Learning a foreign language is a time consuming task that requires perseverance, commitment and hard work. The time required to learn a foreign language can range from hundreds to thousands of hours, depending on the language being learnt and the native language of the learner. Two major barriers to learning a language are lack of motivation and time. Spending increasing amounts of time online also has a detrimental effect on learning a language. The global digital language learning industry is growing and the market has more than doubled in size in the last decade due to the world becoming increasingly interconnected. There is a need to provide users with a web browser extension that is both interactive and continuous for learning a language. This paper presents the design and development of a web browser extension that will help facilitate the learning of foreign languages. The web extension overrides the default content when either a new tab or window is opened with interactive language learning material. The web extension is compatible with the desktop version of the Chrome web browser. Each time a new tab or window is opened, a range of language learning material are presented at random, which can be read, understood and completed in 30 seconds or less with immediate feedback. Overriding the web browser’s functionality ensures the user is exposed to language learning material

Stimulation of insulin secretion by 5-methylcoumarins and its sulfur analogues isolated from Clutia lanceolata Forssk

Clutia lanceolata Forssk. (C. lanceolata) is a medicinal plant native to sub-Saharan Africa and the Arabian Peninsula. Phytochemical investigation of the aerial parts of C. lanceolata yielded twenty-one coumarins including methylthio and methylsulfinyl-coumarins. Thirteen of these compounds are reported here for the first time, named as cluteolin A to M. The remaining eight compounds are known but have not been associated previously with C. lanceolata. The structures of the undescribed compounds were elucidated from their 2D NMR and MS spectra. Single crystal X-ray analyses confirmed the structures of eleven compounds. As, in Saudi Arabian tradition, C. lanceolata has been reported to have anti-diabetic and anti-fungal properties, the coumarins were examined for their biological activity. Seven compounds strongly enhanced the glucose-triggered release of insulin by murine pancreatic islets, with two compounds showing more than two-fold enhancement of insulin secretion, compared with the standard drug glimepiride.</p

Stimulation of insulin secretion by 5-methylcoumarins and its sulfur analogues isolated from Clutia lanceolata Forssk

Clutia lanceolata Forssk. (C. lanceolata) is a medicinal plant native to sub-Saharan Africa and the Arabian Peninsula. Phytochemical investigation of the aerial parts of C. lanceolata yielded twenty-one coumarins including methylthio and methylsulfinyl-coumarins. Thirteen of these compounds are reported here for the first time, named as cluteolin A to M. The remaining eight compounds are known but have not been associated previously with C. lanceolata. The structures of the undescribed compounds were elucidated from their 2D NMR and MS spectra. Single crystal X-ray analyses confirmed the structures of eleven compounds. As, in Saudi Arabian tradition, C. lanceolata has been reported to have anti-diabetic and anti-fungal properties, the coumarins were examined for their biological activity. Seven compounds strongly enhanced the glucose-triggered release of insulin by murine pancreatic islets, with two compounds showing more than two-fold enhancement of insulin secretion, compared with the standard drug glimepiride