Palladium nanoparticles/wool keratin-assisted carbon composite-modified flexible and disposable electrochemical solid-state pH sensor

Several p H-dependent processes and reactions take place in the human body;hence,the p H of body fluids is the best indicator of disturbed health conditions.However,accurate and real-time diagnosis of the p H of body fluids is complicated because of limited commercially available p H sensors.Hence,we aimed to prepare a flexible,transparent,disposable,userfriendly,and economic strip-based solid-state p H sensor using palladium nanoparticles(Pd NPs)/N-doped carbon(NC)composite material.The Pd NPs/NC composite material was synthesized using wool keratin(WK)as a precursor.The insitu prepared Pd NPs played a key role in the controlled switching of protein structure to the N-doped carbon skeleton withπ–πarrangement at the mesoscale level,which mimics the A–B type polymeric structure,and hence,is highly susceptible to H+ions.The optimized carbonization condition in the presence of Pd NPs showed that the material obtained using a modified Ag/Ag Cl reference electrode had the highest p H sensitivity with excellent stability and durability.The optimized p H sensor showed high specificity and selectivity with a sensitivity of 55 m V/p H unit and a relative standard deviation of 0.79%.This study is the first to synthesize Pd NPs using WK as a stabilizing and reducing agent.The applicability of the sensor was investigated for biological samples,namely,saliva and gastric juices.The proposed protocol and material have implications in solid-state chemistry,where biological material will be the best choice for the synthesis of materials with anticipated performance.     

Protective effect of Rubia cordifolia on reserpine-induced orofacial dyskinesia

In this study, the neuroprotective potential and in vivo antioxidant status of extract of roots and rhizomes of Rubia cordifolia L (MERC) in reserpine-induced orofacial dyskinesia was studied. Reserpine (1 mg/kg, s.c.) on day 1, 3 and 5 was used to induce orofacial dyskinesia. At the end of treatment schedule, MERC significantly inhibited reserpine-induced vacuous chewing movements, tongue protrusions, orofacial bursts, catalepsy. MERC significantly increased locomotion and rearing in open field test. MERC exhibited significant elevation in the levels of superoxide dismutase, catalase, glutathione reductase and inhibition of lipid peroxidation in forebrain region, compared with the reserpine treated group. It significantly elevated dopamine levels in the forebrain region. GCMS revealed the presence of anthraquinones, having strong antioxidant activity. It is concluded that oxidative stress might play an important role in reserpine-induced abnormal oral movements and MERC significantly protected animals against reserpine-induced orofacial dyskinesia and has great potential in treatment of neuroleptic induced orofacial dyskinesia.     

Chirality Transfer and Memory of Chirality in Gold‐Catalyzed Reactions

Over the last few years, gold‐catalyzed reactions that involved chirality transfer and memory of chirality (MOC) have emerged as a powerful tool in enantioselective synthesis. This technique has allowed for the single‐step synthesis of enantioenriched compounds from readily available starting materials. This Focus Review discusses this emerging field with an emphasis on mechanistic aspects and their applications in synthetic organic chemistry.     

Preparation of α-oxygenated ketones by the dioxygenation of alkenyl boronic acids

Two in two: Dioxygenation of alkenyl boronic acids has been achieved with N-hydroxyphthalimide. The two-step process involves etherification of an alkenyl boronic acid with N-hydroxyphthalimide followed by a [3,3] rearrangement. The dioxygenated product can then be hydrolyzed to form either the corresponding α-hydroxy ketone or the α-benzoyloxy ketone.     

Coherent crosstalk in passive microring based Optical Networks-on-Chip

Optical Networks-on-Chip (ONoC) is emerging technology for future optical interconnects used in all optical networks. The electrical interconnects face lot of problems due to their inability to support higher data rates used in the System-on-Chip (SoC) technologies. Integrated optical interconnects based on SoC avoid this bottleneck with their support to higher data rates. In this paper for the first time we have studied and analyzed ONoC at physical level for the system performance based on crosstalk, BER, throughput, system frequency, and other related parameters. The investigation of ONoC performance is carried out for the multistage microring optical crossconnect on SoC for coherent WDM signals. The analysis can be used in the design of ultra-high speed photonic routers for reliable data communication and processing. The results show the dependency of a coherent crosstalk on the system frequency of SoC and also illustrate the reduction in throughput with increase in number of WDM signals due to higher probability of packet transmission. Minimum 2 dB signal to noise ratio can be obtained when crosstalk is ?25 dB with 60 wavelengths for probability of packet transmission is 0.5.     

Fluoranthene based fluorescent chemosensors for detection of explosive nitroaromatics

A novel fluoranthene based fluorescent chemosensor for the detection of picric acid (PA) at the parts per billion (ppb) level was evaluated. Static fluorescence quenching was the dominant process by intercalative π-π interaction between fluoranthene (S(1)) and nitroaromatics.     

FTIR and thermal studies on gel grown neodymium tartrate crystals

The growth of neodymium tartrate crystals was achieved in silica gel by single diffusion method. Optimum conditions were established for the growth of good quality crystals. Fourier transform infrared (FT-IR) spectroscopic study indicates the presence of water molecules and tartrate ligands and suggests that tartrate ions are doubly ionised. The thermal behaviour of the material was studied using thermogravimetry (TG), differential thermal analysis (DTA), derivative thermogravimetry (DTG) and differential scanning calorimetry (DSC). Thermogravimetric analysis support the suggested chemical formula of the grown crystal to be Nd₂(C₄H₄O₆)₃·7H₂O, and the presence of seven water molecules as water of hydration. It is shown that the material is thermally stable up 45 °C beyond which it decomposes through many stages till the formation of neodymium oxide (Nd₂O₃) at 995 °C. The decomposition pattern is reported to be typical of a hydrated metal tartrate.     

New Cu-based catalysts supported on TiO2 films for Ullmann S(N)Ar-type C-O coupling reactions

New routes for the preparation of highly active TiO(2)-supported Cu and CuZn catalysts have been developed for C-O coupling reactions. Slurries of a titania precursor were dip-coated onto glass beads to obtain either structured mesoporous or non-porous titania thin films. The Cu and CuZn nanoparticles, synthesized using a reduction by solvent method, were deposited onto calcined films to obtain a Cu loading of 2 wt%. The catalysts were characterized by inductively coupled plasma (ICP) spectroscopy, temperature-programmed oxidation/reduction (TPO/TPR) techniques, (63)Cu nuclear magnetic resonance (NMR) spectroscopy, X-ray diffraction (XRD), scanning and transmission electron microscopy (S/TEM-EDX) and X-ray photo-electron spectroscopy (XPS). The activity and stability of the catalysts obtained have been studied in the C-O Ullmann coupling of 4-chloropyridine and potassium phenolate. The titania-supported nanoparticles retained catalyst activity for up to 12 h. However, catalyst deactivation was observed for longer operation times due to oxidation of the Cu nanoparticles. The oxidation rate could be significantly reduced over the CuZn/TiO(2) catalytic films due to the presence of Zn. The 4-phenoxypyridine yield was 64% on the Cu/nonporous TiO(2) at 120 °C. The highest product yield of 84% was obtained on the Cu/mesoporous TiO(2) at 140 °C, corresponding to an initial reaction rate of 104 mmol g(cat) (-1) s(-1). The activation energy on the Cu/mesoporous TiO(2) catalyst was found to be (144±5) kJ mol(-1), which is close to the value obtained for the reaction over unsupported CuZn nanoparticles (123±3 kJ mol(-1)) and almost twice the value observed over the catalysts deposited onto the non-porous TiO(2) support (75±2 kJ mol(-1)).     

A one-pot catalysis: the strategic classification with some recent examples

In this "Emerging Area", the strategic classification of one-pot catalysis, i.e. cooperative, relay and sequential catalysis, is described. In order to illustrate this classification, we take the readers through a series of recent examples which utilize either metal-metal, metal-organo and organo-organo catalysts. The compilation clearly demonstrates the explosive growth and power of this field, which has become, in the last few years, an important technique particularly in the case of enantioselective catalysis.