Analytical study of modified Manashiladi Lepa into Ointment

Lepa Kalpana is one amongst the external application used in Ayurveda. Manashiladi Lepa is a formulation explained in ‘Rasa Tantra Sara Va Siddha Prayoga Sangraha’ for the prevention of scar in the skin surface. The formulation contains Ghrita and Madhu which is to be mixed with the powder of the herbs told in the formulation. In the present scenario, the Lepa Kalpana is not liked by the patients themselves as it leaves behind residual marks on the skin surface and stains the cloth if it comes in contact with it. Hence a modified Lepa in the form of ointment which contains reduced amount of oiliness and good packing is accepted by all. Literary review done through various sources like books, journals and internet revealed that, no modification studies have been carried out on this formulation yet. The Lepa is modified into an ointment for its easy acceptability and usage. The formulation is tested for its analytical values and discussed in the article

Evaluation of polyherbal formulation and synthetic choline chloride on choline deficiency model in broilers: implications on zootechnical parameters, serum biochemistry and liver histopathology

Objective The study was designed to establish choline deficiency model (CDM) in broilers for evaluating efficacy of polyherbal formulation (PHF) in comparison with synthetic choline chloride (SCC). Methods A total of 2,550 one-day-old Cobb 430 broiler chicks were randomly assigned to different groups in three experiments. In experiment 1, G1 and G2 served as normal controls and were fed a basal diet with 100% soybean meal (SBM) as a major protein source supplemented with and without SCC, respectively. In G3, G4, G5, and G6 groups, SBM was replaced at 25%, 50%, 75%, and 100% by soy protein isolate (SPI) to induce a graded level of choline deficiency. In experiment 2, PHF (500 and 1,000 g/ton) in comparison with SCC (1,000 g/ton) were evaluated. In experiment 3, dose-response of PHF (200, 400, and 500 g/ton) with SCC (400 g/ton) was determined. Results Replacement of SBM by SPI produced a linear decrease in body weight gain (BWG) with a poor feed conversion ratio (FCR). 25% SBM replacement by SPI yielded an optimum negative impact on BWG and FCR; hence, it is considered for further studies. In experiment 2, PHF (500 and 1,000 g/ton) and SCC (1,000 g/ton) showed a similar performance in BWG, FCR and relative liver weight. In experiment 3, PHF produced an optimum efficacy at 400 g/ton and was comparable to SCC in the restoration of serum aspartate aminotransferase activity, abdominal fat, breast muscle lipid content and liver histopathological abnormalities. Conclusion Replacement of SBM by SPI caused choline deficiency characterised by worsening of BWG, FCR, elevation in liver enzymes and histopathological changes indicating fatty liver. CDM was found valid for evaluating SCC and PHF. It is concluded that PHF has the potential to mimic biological activities of SCC through the restoration of negative effects caused by CDM

Perceptron learning rule derived from spike-frequency adaptation and spike-time-dependent plasticity

It is widely believed that sensory and motor processing in the brain is based on simple computational primitives rooted in cellular and synaptic physiology. However, many gaps remain in our understanding of the connections between neural computations and biophysical properties of neurons. Here, we show that synaptic spike-time-dependent plasticity (STDP) combined with spike-frequency adaptation (SFA) in a single neuron together approximate the well-known perceptron learning rule. Our calculations and integrate-and-fire simulations reveal that delayed inputs to a neuron endowed with STDP and SFA precisely instruct neural responses to earlier arriving inputs. We demonstrate this mechanism on a developmental example of auditory map formation guided by visual inputs, as observed in the external nucleus of the inferior colliculus (ICX) of barn owls. The interplay of SFA and STDP in model ICX neurons precisely transfers the tuning curve from the visual modality onto the auditory modality, demonstrating a useful computation for multimodal and sensory-guided processing

Phosphorus(V) Porphyrin-Manganese(II) Terpyridine Conjugates: Synthesis, Spectroscopy, and Photo-Oxidation Studies on a SnO₂ Surface

A major challenge in designing artificial photosynthetic systems is to find a suitable mimic of the highly oxidizing photoactive species P₆₈₀ in photosystem II. High-potential phosphorus­(V) porphyrins have many attractive properties for such a mimic but have not been widely studied. Here, we report the synthesis and photophysical characterization of a novel phosphorus­(V) octaethylporphyrin–oxyphenyl–terpyridine conjugate (PPor-OPh-tpy, <b>1</b>) and its corresponding manganese­(II) complex (PPor-OPh-Mn­(tpy)­Cl₂, <b>2</b>). The X-ray structure of <b>2</b> shows that the Mn­(II) and P­(V) centers are 11.783 Å apart and that the phenoxy linker is not fully conjugated with the terpyridine ligand. The porphyrin fluorescence in <b>1</b> and <b>2</b> is strongly quenched and has a shorter lifetime compared to a reference compound without the terpyridine ligand. This suggests that electron transfer from tpy or Mn­(tpy) to the excited singlet state of the PPor may be occurring. However, femtosecond transient absorbance data show that the rate of relaxation to the ground state in <b>1</b> and <b>2</b> is comparable to the fluorescence lifetimes. Thus, if charge separation is occurring, its lifetime is short. Because both <b>1</b> and <b>2</b> are positively charged, they can be electrostatically deposited onto the surface of negatively charged SnO₂ nanoparticles. Freeze-trapping EPR studies of <b>2</b> electrostatically bound to SnO₂ suggest that excitation of the porphyrin results in electron injection from ¹PPor* into the conduction band of SnO₂ and that the resulting PPor^•+ species acquires enough potential to photo-oxidize the axially bound Mn­(II) (tpy) moiety to Mn­(III) (tpy)

Mutagenicity and Acute Oral Toxicity Test for Herbal Poultry Feed Supplements

Herbal products are being used and trusted globally for thousands of years for their health benefits and limited side effects. Globally, a general belief amongst the consumers is that herbal supplements are always safe because they are “natural.” But later, research reveals that they may not be safe. This raises concern on their safety and implications for their use as feed supplement or medicine. Toxicity testing can reveal some of the risks that may be associated with use of herbs, therefore avoiding potential harmful effects. The present study was designed to investigate five poultry feed supplements (PFS), EGMAX® (to revitalize ovarian activity), FEED-X™ (feed efficiency enhancer), KOLIN PLUS™ (natural replacer of synthetic choline chloride), PHYTOCEE® (natural defence enhancer), and STODI® (to prevent and control loose droppings), for their possible mutagenicity and toxicity. Bacterial reverse mutation (BRMT) and acute oral toxicity tests were employed to assess the PFS for their possible mutagenicity and toxicity. Results indicated that the PFS were devoid of mutagenic effects in BRMT and showed higher safety profile in rodent acute oral toxicity test

Fluorinated Antimony(V) Tetraarylporphyrins as High-Valent Electron Acceptors with Unparalleled Reduction Potentials

A series of fluorinated antimony(V) porphyrins, SbTPP(OMe)2·PF6, SbTPP(OTFE)2·PF6, SbT(4F)PP(OMe)2·PF6, SbT(35F)PP(OMe)2·PF6, SbT(345F)PP(OMe)2·PF6, SbT(4CF3)PP(OMe)2·PF6, SbT(35CF3)PP(OMe)2·PF6, and SbT(35CF3)PP(OTFE)2·PF6, have been synthesized with phenyl [P], 4-fluorophenyl [(4F)P], 3,5-difluorophenyl [(35F)P], 3,4,5-difluorophenyl [(345F)P], 4-trifluoromethylphenyl [(4CF3)P], and 3,5-bis(trifluoromethyl)phenyl [(35CF3)P], in the meso-positions. Additionally, the SbTPP(OTFE)2·PF6 and SbT(35CF3)PP(OTFE)2·PF6 carry trifluoroethoxy units in their axial-positions. The fluorination on the porphyrin peripherals ranges from zero fluorine atoms in SbTPP(OMe)2·PF6 to 30 fluorine atoms in SbT(35CF3)PP(OTFE)2·PF6. X-ray crystallography confirmed the structures of the investigated antimony(V) porphyrins. The absorption spectra depend on the number of fluorine atoms as it is blue-shifted with increasing fluorination. The series also exhibited rich redox chemistry with two reduction processes and one oxidation process. Remarkably, these porphyrins manifested the lowest reduction potentials reported among the main-group porphyrins, which are as low as −0.08 V vs SCE for SbT(35CF3)PP(OTFE)2·PF6. On the contrary, the oxidation potentials were found to be very large, that is equal to 2.20 V vs SCE or even higher for SbT(4CF3)PP(OMe)2·PF6 or SbT(35CF3)PP(OMe)2·PF6 and SbT(35CF3)PP(OTFE)2·PF6, respectively. These unprecedented potentials are due to a combination of two factors: (i) the +5-oxidation state of antimony in the porphyrin cavity and (ii) the presence of the strong electron-withdrawing fluorine atoms on the porphyrin peripherals. Density functional theory (DFT) calculations were used to support the experimental results. The systematic study of antimony(V) porphyrins, especially their high potentials, make them ideal for the construction of photoelectrodes and excellent electron acceptors for photoelectrochemical cells and artificial photosynthetic systems, respectively, for solar energy conversion and storage applications

Modulation of Energy Transfer into Sequential Electron Transfer upon Axial Coordination of Tetrathiafulvalene in an Aluminum(III) Porphyrin–Free-Base Porphyrin Dyad

Axially assembled aluminum­(III) porphyrin based dyads and triads have been constructed to investigate the factors that govern the energy and electron transfer processes in a perpendicular direction to the porphyrin plane. In the aluminum­(III) porphyrin–free-base porphyrin (AlPor-Ph-H₂Por) dyad, the AlPor occupies the basal plane, while the free-base porphyrin (H₂Por) with electron withdrawing groups resides in the axial position through a benzoate spacer. The NMR, UV–visible absorption, and steady-state fluorescence studies confirm that the coordination of pyridine appended tetrathiafulvalene (TTF) derivative (TTF-py or TTF-Ph-py) to the dyad in noncoordinating solvents afford vertically arranged supramolecular self-assembled triads (TTF-py→AlPor-Ph-H₂Por and TTF-Ph-py→AlPor-Ph-H₂Por). Time-resolved studies revealed that the AlPor in dyad and triads undergoes photoinduced energy and/or electron transfer processes. Interestingly, the energy and electron donating/accepting nature of AlPor can be modulated by changing the solvent polarity or by stimulating a new competing process using a TTF molecule. In modest polar solvents (dichloromethane and <i>o</i>-dichlorobenzene), excitation of AlPor leads singlet–singlet energy transfer from the excited singlet state of AlPor (¹AlPor*) to H₂Por with a moderate rate constant (<i>k</i>_EnT) of 1.78 × 10⁸ s^–1. In contrast, excitation of AlPor in the triad results in ultrafast electron transfer from TTF to ¹AlPor* with a rate constant (<i>k</i>_ET) of 8.33 × 10⁹–1.25 × 10¹⁰ s^–1, which outcompetes the energy transfer from ¹AlPor* to H₂Por and yields the primary radical pair TTF^+•-AlPor^–•-H₂Por. A subsequent electron shift to H₂Por generates a spatially well-separated TTF^+•-AlPor-H₂Por^–• radical pair

Charge Stabilization in High-Potential Zinc Porphyrin-Fullerene via Axial Ligation of Tetrathiafulvalene

Extending the lifetime of the charge-separated states generated during photoinduced electron transfer in a covalently linked high-potential zinc porphyrin-fullerene dyad, (F₁₅P)­Zn–C₆₀, was accomplished by metal–ligand axial coordination of pyridine-functionalized tetrathiafulvalene (TTF) via a dual-electron-transfer/hole migration mechanism. The <i>meso</i>-aryl positions of the zinc porphyrin carried three penta-fluorophenyl substituents that made the zinc porphyrin ring harder to oxidize by 0.43 V compared with zinc porphyrin with <i>meso</i>-phenyl substituents. Two TTF derivatives, a first with a pyridine directly linked to TTF (Py-TTF) and a second with a phenyl spacer between the pyridine and TTF (Py-phTTF), were employed to vary the distance between the primary photosensitizer/electron donor, zinc porphyrin, and the secondary electron donor, TTF. Both Py-TTF and Py-phTTF coordinated via the pyridine entity to the Zn center with 1:1 molecular stoichiometry and moderate binding constants. The supramolecular triads were characterized by optical absorption and emission, electrochemistry, and computational studies. An energy-level diagram was established to realize the different photochemical events in the triads. Using femtosecond transient absorption spectroscopy, it was possible to show that the coordinated TTF participated in electron transfer from the ¹(F₁₅P)­Zn* in the case of the C₆₀-(F₁₅P)­Zn:TTF triads to produce C₆₀-(F₁₅P)­Zn^•‑:TTF^•+ charge-separated state competitively with the electron transfer from the ¹(F₁₅P)­Zn* to covalently linked C₆₀ to produce C₆₀^•‑-(F₁₅P)­Zn^•+:TTF charge-separated state. The two charge-separated states, C₆₀-(F₁₅P)­Zn^•‑:TTF^•+ and C₆₀^•‑-(F₁₅P)­Zn^•+:TTF, were further involved in electron migration in the former case and hole transfer in the latter case to produce the C₆₀^•‑-(F₁₅P)­Zn:TTF^•+ charge-separated state as the ultimate electron-transfer product. Due to distal separation of the positive and negative radical ions, long-lived charge-separated states persistent for about 0.35 μs was possible to accomplish, as shown by nanosecond transient absorption spectral studies

Interfacial Electron Transfer Followed by Photooxidation in <i>N</i>,<i>N</i>‑Bis(<i>p</i>‑anisole)aminopyridine–Aluminum(III) Porphyrin–Titanium(IV) Oxide Self-Assembled Photoanodes

Two self-assembled photoanodes have been constructed by exploiting the unique optical and structural properties of aluminum­(III) porphyrin (AlPor) in conjunction with TiO₂ nanoparticles as an electron acceptor and bis­(<i>p</i>-anisole)­aminopyridine (BAA–Py) as an electron donor. AlPor is bound to the TiO₂ surface by either: (i) a benzohydroxamic acid bridge, in which the hydroxamic acid acts as an anchor or (ii) direct covalent binding of Al via an ether bond. The open sixth coordination site of the Al center is then used to coordinate BAA–Py through Lewis acid–base interactions, which results in donor–photosensitizer–semiconductor constructs that can be used as photoanodes. The two photoanodes were characterized by steady-state and transient spectroscopic techniques as well as computational methods. Transient-absorption studies show that in the absence of BAA–Py both the photoanodes exhibit electron injection from AlPor to the conduction band of TiO₂. However, the injection efficiencies and kinetics are strongly dependent on the linker with faster and more efficient injection occurring when the porphyrin is directly bound. Kinetic results also suggest that the recombination is faster in directly bound AlPor than benzohydroxamic acid bridged AlPor. When BAA–Py is coordinated to AlPor, electron injection from AlPor to TiO₂ is followed by electron transfer from BAA–Py to the oxidized AlPor. The injection efficiencies modeled using density functional theory and semiempirical tight-binding calculations are consistent with experimentally observed trends