A single molecule switch based on two Pd nanocrystals linked by a conjugated dithiol

Tunneling spectroscopy measurements have been carried out on a single molecule device formed by two Pd nanocrystals (dia, $\sim$5 nm) electronically coupled by a conducting molecule, dimercaptodiphenylacetylene. The I-V data, obtained by positioning the tip over a nanocrystal electrode, exhibit negative differential resistance (NDR) on a background M-I-M characteristics. The NDR feature occurs at $\sim$0.67 V at 300 K and shifts to a higher bias of 1.93 V at 90 K. When the tip is held in the middle region of the device, a coulomb blockade region is observed ($\pm\sim$0.3 V).Comment: Accepted in Praman

Offshore Oil Spills: An Evaluation of Recent United States Responses

This Article discusses the responses of the United States to oil spills in Santa Barbara and the Gulf, examining both executive and legislative action. Also, the article analyzes the institutional and procedural aspects of the Unites States\u27 responses and their influence on the international community

Subcutaneous cysticercosis mimicking tenosynovitis: a rare case with radiological revelation

Subcutaneous cysticercosis is a rare manifestation of cysticercosis, caused by the larval stage of Taenia solium. It presents as a swelling or a palpable cystic mass. We describe a 43-year-old female who presented with subcutaneous swelling over her right hand, gradually increasing in size over ten days. Initially, tenosynovitis was suspected clinically. However, an ultrasound of the hand revealed a well-defined, cystic lesion with eccentric echogenic foci and peripheral oedema suggestive of cysticercosis. She was treated with oral albendazole, leading to significant improvement. This case report emphasizes the importance of considering parasitic infections as a potential cause of subcutaneous swelling. It also highlights the significance of utilizing diagnostic imaging for definitive diagnosis and timely treatment

Mediator-free total cholesterol estimation using a bi-enzyme functionalized nanostructured gold electrode

We report the fabrication of a bi-enzyme functionalized nanostructured Au electrode for the mediator-free determination of total cholesterol. A one-step electrochemical route for the synthesis, functionalization and deposition of Au nanostructures via the electroreduction of gold chloride onto indium tin oxide (ITO) coated glass plates has been proposed. The covalent biofunctionalization of the optimized Au electrode was done with cholesterol esterase (ChEt) and cholesterol oxidase (ChOx) to investigate the kinetic parameters and the sensing characteristics. The ChEt-ChOx/Glu-NanoAu/ITO bioelectrode has a surface-controlled electrode reaction with an electron transfer coefficient and a charge transfer rate constant of 0.68 and 7.09 s(-1), respectively. Under the optimal conditions, the bioelectrode undergoes a direct electron transfer reaction and exhibits a high sensitivity of 0.53 mA mM(-1) cm(-2) and a low detection limit of 1.57 mu M for cholesterol ester without the use of any redox mediator. In addition, the kinetic analysis reveals that the bioelectrode exhibits a surface concentration of 8.82 x 10(-12) mol cm(-2). The sensor has also been validated with clinical samples. The proposed biosensor shows good sensitivity, stability and selectivity towards total cholesterol and may thus find implications in the fabrication of biosensing devices

Surfactant-promoted formation of fractal and dendritic nanostructures of gold and silver at the organic-aqueous interface

The effect of surfactants such as tetraoctylammoniumbromide (TOAB) and cetyltrimethylammoniumbromide (CTAB) on the type of nanostructures formed when gold ions present in the organic phase are reduced at the interface by hydrazine in the aqueous phase has been investigated. Extended fractal structures are formed at the liquid-liquid interface, the fractal structures themselves comprising cauliflower type units formed by gold nanorods. Accordingly, the nanostructures exhibit transverse and longitudinal plasmon adsorption bands in the 550 and 800 nm regions, respectively. Dendritic structures of silver are formed at the interface when Ag ions are reduced similarly in the presence of surfactants. The nanostructures consist of nanoparticles or nanorods with five-fold symmetry

Supporting NASA Science with High-Altitude Long-Endurance Aircraft

NASA Earth Science and Aeronautics researchers have been involved in development and use of High Altitude Long Endurance (HALE) unmanned aircraft systems (UAS) since the 1990's. The NASA Environmental Research Aircraft Sensor and Technology Program (ERAST) demonstrated the promise of HALE aircraft for providing observations while also proving the importance of triple-redundant avionics to improve system reliability for large unmanned aircraft. Early efforts to develop an operational HALE capability for earth observations languished for nearly two decades owing to insufficient solar panel efficiency, battery power density, and light-weight, yet strong, materials. During this time NASA researchers focused on using the Global Hawk to demonstrate the utility of providing diurnal measurements over severe storms (ie. HS3) and to track stratospheric water vapor transport (ATTREX). Recent significant commercial investments are now leading to the realization of a long-held goal of week- to month-long sustained observations and measurements from the stratosphere. In addition to a historical review of NASA use and interest in HALE aircraft, this paper will present current concepts for exploiting current and planned HALE aircraft capabilities including in situ characterization of atmospheric composition and dynamics as well as imagery collection. NASA researchers anticipate HALE will provide a useful means to test smallsat instruments and components. Observations from HALE-based instruments might also provide useful gap-filler observations to flagship satellite missions where the repeat time doesn't allow for measurements of quickly changing phenomenon. HALE will likely also provide measurements and communications relay to facilitate other aircraft in multi-aircraft campaigns. We will also report on progress towards a NASA-funded flight test planned for summer 2019 of a solar-electric vehicle designed to carry 7kg (15lbs) for 30 days at 20km altitude

Research on the improvement of mixed titania and Co(Mn) oxide nano-composite coatings

The structure and the properties of the oxide films formed on titanium in the diphosphate based electrolytes by means of plasma electrolytic oxidizing at direct current density of 2-2.5 A·dm⁻² have been studied. Oxide layers of different composition and content of alloying elements were obtained by modification of electrolytes and variation in current density. The interelectrode voltage during PEO, chemical and phase composition, topography and microstructure of the formed layers depend on the electrolyte composition and applied current density. The spark-discharge regime was shown to be reached at inter-electrode voltage 100 to 130 V depending on the composition of electrolyte. The effect of chemical composition and surface morphology formed mixed oxide films on the corrosion resistance and catalytic activity has been discussed

Contemporary and Ancient Review of Mosquitoes - A Review

Indian system of medicine plays an important part in health care system all over India. There are numerous allusions to mosquitoes in Indian writings from the Vedic era. The Atharvaveda makes special reference of mosquito shape, habitat, many varieties, behaviour, and even their presence throughout the year. The 67 different forms of Keet and their genesis were documented by Acharya Susruta in Kalpasthana, while Keet Visha describes five different types of Mashak in which Parvatiya Mashak is the most hazardous to people. There is also Mashak description In Charaka Samhita of chapter Visha Chikitsa. Numerous mosquito species have been identified in contemporary science. Mosquitoes are the most important group of blood sucking insects causing nuisance diseases to humans and other animals.  It follows that our ancestors' seers or philosophers were already aware of this

Diphtheria, pertussis, and tetanus vaccine-induced extensive longitudinally extensive transverse myelitis: A case report

Transverse myelitis (TM) has been reported in association with vaccination, including post-diphtheria, pertussis, and tetanus (DPTw) vaccination. Here, we report the case of a 21-month-old female child presented with loss of neck control with a history of DPTw booster vaccination approximately 4 weeks before this illness. The child was referred to the tertiary care service hospital. Magnetic resonance imaging of the spine revealed longitudinally extensive TM in the cervical segment. Extensive investigation effectively excluded causes other than vaccination-associated TM. Following treatment with corticosteroids and intravenous immune-globulin, the child had a complete recovery. Early diagnosis and prompt treatment with immunotherapy are associated with a good outcome

Expression of TNF-α and Related Signaling Molecules in the Peripheral Blood Mononuclear Cells of Rheumatoid Arthritis Patients

We examined the role of tumor necrosis factor (TNF-α) and its related signaling intermediates leading to apoptosis/proliferation in the peripheral blood mononuclear cells (PBMCs) of RA patients. The constitutive expression of mRNA for TNF-α receptors (TNFR-I and TNFR-II) and the adapter molecules, such as the TNF receptor-associated death domain protein (TRADD), Fas-associated death domain protein (FADD), receptor interacting protein (RIP), and TNF receptor-associated factor 2 (TRAF-2) were analyzed by reverse transcriptase-PCR (RT-PCR) in PBMCs from control and RA cases. PBMCs of RA patients showed a significant increase in TNF-α and TNFR-I expression as compared with that from control subjects along with significantly increased constitutive expression of TRADD, RIP, and TRAF-2 mRNA. There was a decrease in expression of FADD in RA patients, but the difference was not significant as compared to controls. These data suggested enhanced signaling by the TNFR-I-TRADD-RIP-TRAF-2 pathway and suppressed signaling by the TNFR-I-TRADD-FADD pathway in PBMCs of RA patients. However, the regulatory mechanisms for TNF-α induced signaling may not be explained only by these pathways