Search

In 2016, Y. Kumar et al. in the paper 'Affine equivalence and non-linearity of permutations over Z n ' conjectured that: For n ≥ 3 , the nonlinearity of any permutation on Z n , the ring of integers modulon, cannot exceed n - 2 . For an odd prime p, we settle the above conjecture when n = 2 p and for p ≡ 3 (mod 4) we prove the above conjecture with an improved upper bound. Further, we derive a lower bound on max N L n when n is an odd prime or twice of an odd prime where max N L n denotes the maximum possible nonlinearity of any permutation on Z n . [ABSTRACT FROM AUTHOR]

Maximum distance separable (MDS) matrices play a crucial role not only in coding theory but also in the design of block ciphers and hash functions. Of particular interest are involutory MDS matrices, which facilitate the use of a single circuit for both encryption and decryption in hardware implementations. In this article, we present several characterizations of involutory MDS matrices of even order. Additionally, we introduce a new matrix form for obtaining all involutory MDS matrices of even order and compare it with other matrix forms available in the literature. We then propose a technique to systematically construct all 4 × 4 involutory MDS matrices over a finite field F 2 m . This method significantly reduces the search space by focusing on involutory MDS class representative matrices, leading to the generation of all such matrices within a substantially smaller set compared to considering all 4 × 4 involutory matrices. Specifically, our approach involves searching for these representative matrices within a set of cardinality (2 m - 1) 5 . Through this method, we provide an explicit enumeration of the total number of 4 × 4 involutory MDS matrices over F 2 m for m = 3 , 4 , ... , 8 . [ABSTRACT FROM AUTHOR]

Security efficiency and hardware efficiency are equally important when designing a block cipher. In this paper, we propose a new block cipher that uses string transformations and requires less memory and fewer computational resources, making it suitable for highly constrained environments. We compare the performance of our design with AES-128 and quasigroup-based block cipher INRU in the cipher block chaining (CBC) mode of operation using the National Institute of Standards and Technology (NIST) test suite. We then analyze our design against the standard linear, differential, and algebraic attacks. Choosing suitable S-boxes and a quasigroup of a smaller order does not compromise the security of the cipher, but the storage space is reduced compared with AES-128 and INRU. [ABSTRACT FROM AUTHOR]

In this paper, we present a new test for stream ciphers named the 'Bit Inclusion Test (BIT)'. This test provides an enhancement to the conventional avalanche test for stream ciphers. This test is efficient and includes the conventional avalanche test. Additionally, it can capture the shortcomings which escape the conventional avalanche test. We also demonstrate, with examples, how BIT is capable of going deeper into the structure of crypto-algorithms and detecting internal biases which make an algorithm susceptible to cryptanalytic attacks. [ABSTRACT FROM AUTHOR]

Background: Pulse beetle, Callosobruchus chinensis L. is a primary pest of stored chickpea which causes 50-60 per cent loss in seed weight and 45.5-66.3 per cent loss in protein content of the seeds and injudicious and indiscriminate use of hazardous synthetic chemicals for preventing storage losses in chickpea may lead to human and animal health issues due to residual hazards. Therefore, the biorational management of the pulse beetle in stored chickpea has been undertaken keeping biology in mind will prevent the loss as well as protect human health hazard. Methodos: The experiments on various non-chemical biorational approaches like effect of elevated levels of CO2 and application of nano particles which control the test insect effectively but have less toxicity to non-target organisms and the environment were studied in the Department of Entomology, College of Agriculture, OUAT, Bhubaneswar, Odisha during 2018-2021. Result: The results showed that elevated levels of CO2 at 60 and 80 per cent for 150 and 30 minutes respectively resulted in cent per cent mortality of the bruchids. Among the nano particles, nano silica and nano zinc applied @1000 ppm and 750 ppm realized the highest mortality of the bruchids. [ABSTRACT FROM AUTHOR]

In this paper, we study the differential δ -uniform property of two position swapped Exponential Welch Costas (EWC) permutations on Z p - 1 and construct permutations with δ = 4 , 6 for different values of p. We calculate the number of swapped EWC permutations with differential uniformity 6 for primes of the form 4 d + 3 . For primes of the form 4 d + 1 , we obtain a lower bound on the number of swapped EWC permutations with differential uniformity 4. [ABSTRACT FROM AUTHOR]

The pulse beetle is a field-to-store pest as its infestation on pulses often begins in the field itself as adults lay eggs on mature pods and when such seed is harvested and stored, the pest population increases rapidly and results in total destruction within a short period of 3-4 months. Keeping in view, varietal screening of fifty chickpea genotypes was carried out in the storage laboratory, Department of Entomology, OUAT, BBSR and the performance of the genotypes was assessed based on various biological parameters of test insect, damage and infestation by C. chinensis. The results indicated that none of the genotypes was completely resistant to pest attack whereas 4 genotypes (Himachal Chana 1, Dheera (NBeG-47), JG-14 and Dilaji) were found moderately resistant, 8 genotypes (Phule Vikram, JG 11, ICCV-181108, ICCV-181107, ICCV-181605, C-18203, C-18205 and C-18252) were moderately susceptible, 11 genotypes (RVG-204, RVG-203, JAKI-9218, Pratap Chana, Bharati, ICCC 4, ICCV-181106, ICCV-181612, C-18206, ICCV-181101 and Radhey) were susceptible and 27 genotypes (NBeG-49, Himachal Chana 2, JG-16, JG-130, CO 4, Vishal, Kranthi, NBeG-3, ICCV-14102, ICCV-171117, C-18175, ICCV-181611, ICCV-14106, Kalahandi Local, ICC 3137, ICCL 86111, C-19162, C-19168, GNG 2207, BG 3043, GG 3, Birsa Chana 3, C 19199, RSG 963, C 19200, KPG 59 and NBeG 119) were noticed to be highly susceptible. The bio-chemical constituents analyzed in the present studies viz., protein, phenol, ash and fibre contents of the genotypes contributed to the resistance / susceptibility of C. chinensis. Among the biochemical parameters, protein exerted significant positive effect whereas phenol, ash and fibre contents exhibited negative influence on pest infestation and development. [ABSTRACT FROM AUTHOR]

'Rotation and shift' based diffusion functions are used in modern ciphers especially in ARX (Addition, Rotation, and XOR) based designs. They are preferred over other alternatives as they are efficient and lightweight. Usually, such diffusion functions map an n-bit block to another n-bit block. One of the requirements for an n-bit to n-bit diffusion function is that, it should be invertible. In this paper, we present mathematical models for different classes of 'rotation and shift' based diffusion functions and explore their invertibility. We derive sufficient conditions under which diffusion functions of these classes are invertible. [ABSTRACT FROM AUTHOR]

In this paper, we report some interesting results on permutations on Z n , the ring of integers modulo n, having full differential uniformity. By full differential uniformity of a permutation f on Z n , we mean that the cardinality of the set { x ∈ Z n : f (x + a) - f (x) = b } is exactly n for some a , b ∈ Z n \ { 0 } . We give a sufficient condition for an arbitrary map on Z n to have full differential uniformity. A necessary and sufficient condition for a permutation to have full differential uniformity over the ring of integers modulo n is also given. Further, we propose an upper bound and two lower bounds on permutations with full differential uniformity on Z n . We prove that these bounds are non-trivial bounds and give the exact number of permutations with full differential uniformity for a certain class of moduli. [ABSTRACT FROM AUTHOR]

The security of block ciphers solely depends on the S-boxes used in their design. Hence, for a secure block cipher, S-boxes should be chosen very thoughtfully. n-ary quasigroups of different orders and for different values of n are being used to design various cryptographic primitives. In the literature, many algorithms based on the quasigroups have been proposed for the generation of S-boxes of order 4. However, in this article, we propose a general method for the construction of symmetric S-boxes of even order using ternary quasigroups of order 4 with certain properties. These S-boxes give strong resistance against linear, differential, algebraic, and DPA attacks and hence provide good cryptographic properties. [ABSTRACT FROM AUTHOR]

The period of a binary sequence generated by feedback with carry shift register (FCSR) depends on the connection integer (q) of the register. We define FCSR primes as primes generating maximum possible period sequences when used as connection integer of an FCSR. Hence, to design good FCSR pseudorandom generators, one needs suitable feedback primes. The authors of this article study some properties about these primes and give algorithms to generate some of them. The first algorithm is somewhat straightforward and is based on the criterion given in Arnault and Berger. We propose two new algorithms for the efficient generation of FCSR primes. Comparison between these algorithms, supported by experimental and analytical results is presented. Further, we address the question of quantification of such primes and derive some explicit bounds. [ABSTRACT FROM AUTHOR]

Groundnut bruchid, Caryedon serratus (Olivier), is the major and most destructive insect pest of groundnut under storage conditions. Eight different essential oils obtained from medicinal plants viz., mentha, palmarosa, neem, citronella, eucalyptus, castor, basil and turmeric were evaluated against C. serratus at two concentrations of 5 and 10 ml/kg. The highest total bruchid mortality was recorded with the treatment of citronella oil at 10 ml/kg and the lowest in castor oil at 5 ml/kg. The least number of eggs laid was found with citronella oil (4.08) and neem oil (4.25) at 10 ml/kg whereas the highest fecundity was recorded with castor oil (21.17) at 5 ml/kg. Groundnut pods treated with neem oil at 10 ml/kg recorded the minimum adult emergence (2.83), whereas the maximum number of adults was emerged (22.33) with castor oil at 5 ml/kg. From the present study, it was also found that none of the treatments had apparently reduced the seed germination even after 120 days of storage, Hence, these essential oils can be used as safer alternatives to chemical insecticides for long-term storage of groundnut. [ABSTRACT FROM AUTHOR]

Background: The pancreas is an exo-endocrine organ that undergoes rapid autolysis soon after death, which limits its utility in academics and research. The timeline of autolytic changes of pancreatic islets and its immunoreactivity is limited in the literature. Decay score has been used to grade the autolytic changes in organs like the brain, lung and liver. However, reports are not available in the pancreas/pancreatic islets. Knowledge regarding the decay score may be used as a torchbearer for the immunoreactivity of human pancreatic islets in autopsy cases. The present study is aimed to provide an optimal cut-off time based on the decay score before which pancreatic specimens should be collected for the purpose of immunohistochemical studies (IHC) of pancreatic islets. Materials and methods: Serial sections of 20 adult human pancreases obtained from the autopsy were subjected to haematoxylin and eosin (H&E) and immunohistochemical staining. Autolytic changes of pancreatic islets were graded by using decay score in H&E sections, which was compared with the results of the immunohistochemical reactivity of pancreatic islets in IHC sections. Results and Conclusions: Pancreatic islets immunoreactivity was found to be well preserved in the samples collected early within 9 hours with a decay score of less than 1.4. There was an inverse relation of decay score and immunoreactivity of pancreatic islets. The decay score of less than 1.4 has better-preserved immunoreactivity than having more than 1.4. This knowledge will help researchers working in the field of the endocrine pancreas. [ABSTRACT FROM AUTHOR]

In this paper, we extend the concepts of Neutrosophy to Boolean function and define ClassicalBalanced, AntiBalanced and NeutroBalanced functions. We consider functions of the form f(x) = Tr(xd), where the exponent d may be Gold exponent, Kasami exponent, Welch exponent or any arbitrary positive integer. We, for different values of d, examine nature of these functions with respect to the above stated three categories. [ABSTRACT FROM AUTHOR]

Recent reports have recommended laparoscopic diverticulectomy for symptomatic Meckel diverticulum (MD) rather than laparoscopic-assisted extracorporeal resection. This technique may risk leaving residual ectopic mucosa leading to complications. This systematic review attempts to quantify the relative risks of both approaches. A systematic review was conducted according to PRISMA guidelines. Articles were eligible for inclusion if they reported data on the laparoscopic management of symptomatic MD in children. Eleven reports were identified, all of which were institutional retrospective studies. Pooled outcome data on 248 children showed no statistically significant difference in complications between laparoscopic diverticulectomy (n = 133) and laparoscopic-assisted segmental resection (n = 115) (3% vs. 6.1%, p = 0.39). One patient from the diverticulectomy group re-presented with recurrent bleeding necessitating segmental small bowel resection. Conclusions are limited by the number of patients and variable follow up. Short, wide MD with a height:base ratio of < 2; diverticula with thickening or ischemia at the base and those complicated by volvulus or small bowel obstruction are probably best treated by laparoscopic-assisted extracorporeal resection. For other symptomatic diverticula laparoscopic diverticulectomy is a reasonable approach with a less than 1% risk of leaving residual ectopic gastric mucosa. [ABSTRACT FROM AUTHOR]

GOST-R 34.11-94 is a Russian standard cryptographic hash function that was introduced in 1994 by the Russian Federal Agency for the purposes of information processing, information security, and digital signature. Mendel et al. (2008) and Courtois and Mourouzis (2011) found attacks on the compression function of the GOST-R structure that were basically weaknesses of the GOST-R block cipher (GOST 28147–89, 1989). Hence in 2012, it was updated to GOST-R 34.11-2012, which replaced the older one for all its applications from January 2013. GOST-R 34.11-2012 is based on a modified Merkle-Damgård construction. Here we present a modified version of GOST-R 34.11-2012 (Modified GOST-R (MGR) hash). The design of the MGR hash is based on wide-pipe construction, which is also a modified Merkle-Damgård construction. MGR is much more secure as well as three times faster than GOST-R 34.11-2012. Advanced Encryption Standard (AES)-like block ciphers have been used in designing the compression function of MGR because AES is one of the most efficient and secure block ciphers and has been evaluated for more than 14 years. A detailed statistical analysis with a few other attacks on MGR is incorporated into this paper. [ABSTRACT FROM AUTHOR]

Background: Migrant labourers living in the slums of urban and industrial patches across India make up a key sub-population so far controlling Tuberculosis (TB) in the country is concerned. This is because many TB patients from these communities- remain under reached by the Revised National Tuberculosis Control Programme (RNTCP) of India. This marginalized community usually seeks early-stage healthcare from “friendly neighbourhood” non-formal health providers (NFHPs). Because, RNTCP has limited capacity to involve the NFHPs, an implementation research project was conceived, whereby an external partner would engage with the NFHPs to enable them to identify early TB symptomatics from this key sub-population who would be then tested using Xpert MTB/RIF technology. Diagnosed TB cases among them would be referred promptly to RNTCP for treatment. This paper aimed to describe the project and its impact. Methods: Adopting a quasi-experimental before-after design, four RNTCP units from two major urban-industrial areas of Odisha were selected for intervention, which spanned five quarters and covered 151,400 people, of which 30% were slum-dwelling migrants. Two similar units comprised the control population. The hypothesis was, reaching the under reached in the intervention area through NFHPs would increase TB notification from these traditionally under-notifying units. RNTCP notification data during intervention was compared with pre-intervention era, adjusted for contemporaneous changes in control population Results: The project detected 488 Xpert+ TB cases, of whom 466 were administered RNTCP treatment. This translated into notification of additional 198 new bacteriologically positive cases to RNTCP, a 30% notification surge, after adjustment for 2% decline in control. This meant an average quarterly increase in notification of 41.20(20.08, 62.31; p<0.001) cases. The increase was immediate, evident from the rise in level in the time series analysis by 50.42(10.28, 90.55; p = 0.02) cases. Conclusion: Engagement with NFHPs contributed to an increase in TB notification to RNTCP from key under reached, slum-dwelling migrant populations. [ABSTRACT FROM AUTHOR]

In this paper, we explore the existence and nonlinearity of affine -cycle permutations on for different values of and . It is proved that a transposition on has nonlinearity for , a -cycle permutation on has nonlinearity for , a prime. The number of affine -cycle permutations on and a bound for their nonlinearity have been obtained. Some results on the cyclic decomposition of a permutation on , a prime, have also been proved. [ABSTRACT FROM AUTHOR]

Cryptographic properties of permutations viz non-linearity, affine equivalence, and mode transform have been studied in the literature, treating them as bijections on ℤn. In this article, the authors consider them as bijection on an arbitrary finite commutative ring with unity. Treating them this way, they achieve a generalization of the above mentioned properties. The authors also propose an algorithm for computing non-linearity in their generalized scenario, which is faster compared to the direct approach in many cases. [ABSTRACT FROM PUBLISHER]

Background and Purpose: The aim of the present study was to evaluate the immunomodulatory and chemotherapeutic potential of alginate-(SA) coated nanocapsule (NCs) loaded with doxorubicin (SA-NCs-DOX) against visceral leishmaniasis in comparison with nano-emulsions containing doxorubicin (NE-DOX).Experimental Approach: NE-DOX was prepared using low-energy emulsification methods. Stepwise addition of protamine sulphate and SA in a layer-by-layer manner was used to form SA-NCs-DOX. SA-NCs-DOX, NE-DOX and Free DOX were compared for their cytotoxicity against Leishmania donovani-infected macrophages in vitro and generation of T-cell responses in infected hamsters in vivo.Key Results: Size and ζ potential of the NE-DOX and SA-NCs-DOX formulations were 310 ± 2.1 nm and (-)32.6 ± 2.1 mV, 342 ± 4.1 nm and (-)29.3 ± 1.2 mV respectively. SA-NCs-DOX was better (1.5 times) taken up by J774A.1 macrophages compared with NE-DOX. SA-NCs -DOX showed greater efficacy than NE-DOX against intramacrophagic amastigotes. SA-NCs-DOX treatment exhibited enhanced apoptotic efficiency than NE-DOX and free DOX as evident by cell cycle analysis, decrease in mitochondrial membrane potential, ROS and NO production. T-cell responses, when assessed through lymphoproliferative responses, NO production along with enhanced levels of iNOS, TNF-α, IFN-γ and IL-12 were found to be up-regulated after SA-NCs-DOX, compared with responses to NE-DOX in vivo. Parasitic burden was decreased in Leishmania-infected hamsters treated with SA-NCs-DOX, compared with NE-DOX.Conclusions and Implications: Our results provide insights into the development of an alternative approach to improved management of leishmaniasis through a combination of chemotherapy with stimulation of the innate immune system. [ABSTRACT FROM AUTHOR]

Background and Purpose The aim of the present study was to evaluate the immunomodulatory and chemotherapeutic potential of alginate-( SA) coated nanocapsule ( NCs) loaded with doxorubicin ( SA- NCs- DOX) against visceral leishmaniasis in comparison with nano-emulsions containing doxorubicin ( NE-DOX). Experimental Approach NE-DOX was prepared using low-energy emulsification methods. Stepwise addition of protamine sulphate and SA in a layer-by-layer manner was used to form SA- NCs- DOX. SA- NCs- DOX, NE-DOX and Free DOX were compared for their cytotoxicity against Leishmania donovani-infected macrophages in vitro and generation of T-cell responses in infected hamsters in vivo. Key Results Size and ζ potential of the NE-DOX and SA- NCs- DOX formulations were 310 ± 2.1 nm and (−)32.6 ± 2.1 mV, 342 ± 4.1 nm and (−)29.3 ± 1.2 mV respectively. SA- NCs- DOX was better (1.5 times) taken up by J774 A.1 macrophages compared with NE-DOX. SA- NCs - DOX showed greater efficacy than NE-DOX against intramacrophagic amastigotes. SA-NCs-DOX treatment exhibited enhanced apoptotic efficiency than NE-DOX and free DOX as evident by cell cycle analysis, decrease in mitochondrial membrane potential, ROS and NO production. T-cell responses, when assessed through lymphoproliferative responses, NO production along with enhanced levels of iNOS, TNF-α, IFN-γ and IL-12 were found to be up-regulated after SA- NCs- DOX, compared with responses to NE-DOX in vivo. Parasitic burden was decreased in Leishmania-infected hamsters treated with SA- NCs- DOX, compared with NE-DOX. Conclusions and Implications Our results provide insights into the development of an alternative approach to improved management of leishmaniasis through a combination of chemotherapy with stimulation of the innate immune system. [ABSTRACT FROM AUTHOR]

Recently, we reported that extract of Dalbergia sissoo made from leaves and pods have antiresorptive and bone-forming effects. The positive skeletal effect attributed because of active molecules present in the extract of Dalbergia sissoo. Caviunin 7-O-[β-Dapiofuranosyl-( 1-6)-β -D-glucopyranoside] (CAFG), a novel isoflavonoid show higher percentage present in the extract. Here, we show the osteogenic potential of CAFG as an alternative for anabolic therapy for the treatment of osteoporosis by stimulating bone morphogenetic protein 2 (BMP2) and Wntβ-catenin mechanism. CAFG supplementation improved trabecular microarchitecture of the long bones, increased biomechanical strength parameters of the vertebra and femur and decreased bone turnover markers better than genistein. Oral administration of CAFG to osteopenic ovariectomized mice increased osteoprogenitor cells in the bone marrow and increased the expression of osteogenic genes in femur and show new bone formation without uterine hyperplasia. CAFG increased mRNA expression of osteoprotegerin in bone and inhibited osteoclast activation by inhibiting the expression of skeletal osteoclastogenic genes. CAFG is also an effective accelerant for chondrogenesis and has stimulatory effect on the repair of cortical bone after drill-hole injury at the tissue, cell and gene level in mouse femur. At cellular levels, CAFG stimulated osteoblast proliferation, survival and differentiation. Signal transduction inhibitors in osteoblast demonstrated involvement of p-38 mitogen-activated protein kinase pathway stimulated by BMP2 to initiate Wnt/β-catenin signaling to reduce phosphorylation of GSK3-β and subsequent nuclear accumulation of β-catenin. Osteogenic effects were abrogated by Dkk1, Wnt-receptor blocker and FH535, inhibitor of TCF-complex by reduction in β-catenin levels. CAFG modulated MSC responsiveness to BMP2, which promoted osteoblast differentiation via Wnt/b-catenin mechanism. CAFG at 1 mg/kg/day dose in ovariectomy mice (human dose ~0.081 mg/kg) led to enhanced bone formation, reduced bone resorption and bone turnover better than well-known phytoestrogen genistein. Owing to CAFG’s inherent properties for bone, it could be positioned as a potential drug, food supplement, for postmenopausal osteoporosis and fracture repair. [ABSTRACT FROM AUTHOR]

The objective of the present investigation was to study the spontaneous self-assembling behavior of stearic acid in the presence of its monoglyceride and to evaluate its potential to be used as drug delivery vehicle. The interesting feature of this system lies in spontaneous formation of vesicles on hydration of molten mixture of stearic acid (SA) and glyceryl monostearate (GMS) without using any solvent. The 1H NMR spectrum of a sample was devoid of signals from fatty acid side chain protons, suggesting that upon interaction between SA and GMS, it adopts an orientation in which fatty acid side chains exists in hydrophobic domains separated from hydrophilic headgroup. A single endothermic event of optimized formulation was obtained as the inflection point of the jump heat capacity at 57°C. To evaluate its feasibility to be used as drug delivery vehicle, ciprofloxacin HCl (CFn) was chosen as a model drug. The entrapment efficiency of CFn was found to be 13 ± 3% and 32 ± 4.2% when the formulation was prepared at pH 5.5 and 9.5, respectively. When viewed through polarizing filter, discernible Maltese cross was observed describing bilayer structure. The viscosity profile demonstrates that the both of the formulation follow Newtonian flow. The size of the vesicles was found to be in the range of 1-3 µm. In a 24 hours study period the VES-1c and VES-2c formulation released 95.8% and 82.3% of the drug, respectively. The formulation was found to be resistant towards osmotic stress. These formulations were found to be biocompatible when studied against J774 macrophages. [ABSTRACT FROM AUTHOR]

The main purpose of the present study was to investigate different cationic submicron emulsions as potential delivery for oral administration. Different submicron emulsion based formulations were prepared by standard procedures incorporating Chitosan, stearylamine, and protamine as charge inducer. Saquinavir (SQ) laden emulsions were characterized in terms of globule size, zeta potential, entrapment efficiency, release profile, cytotoxicity, LDH release, and stability studies. The prepared formulations were stable in terms of mean globule size, drug content, and tended to retain their cationic charge. Pay load efficiency was found to be pretty high (≈ 95–99%) in various formulations prepared. Sustained release phenomenon was more prominent in the case of chitosan emulsions (CE) followed by stearylamine emulsion (SE), Protamine emulsion (PE), and then plain emulsion (E) containing no charge inducer. The total amounts of drug released in 24 hr from CE, SE, PE, and E were 46%, 52%, 56%, and 62%, respectively. The induction of positive charge in emulsions resulted in enhanced absorption of drug through intestinal membrane. The apparent permeability coefficient through the intestinal sac was in the order of CE > SE > PE > E. The permeation flux of SQ through CE (1.0 μg/min) was more than twice compared to plain emulsion (0.46 μg/min) while it was almost three times (0.3 μg/min) compared to control. However, protamine based emulsion didn’t confer significant improvement in absorption when compared to plain emulsion formulation. By this study it can be concluded that induction of positive charge on submicron emulsions can be effective for improving oral absorption of drug safely, as it is evinced with low LDH release into the medium when intestinal tissue is treated with submicron emulsion. [ABSTRACT FROM AUTHOR]

Nanocrystalline semiconducting materials are attracting much attention due to their potential applications in solar energy conversion, nonlinear optics, and heterogeneous photocatalysis. In the present investigation, we have synthesized nanostructured TiO2 photocatalysts, which have been used in the photocatalytic degradation of phenol (one of the most common water pollutants). These catalysts have been prepared through sol-gel technique using titanium tetra-isopropoxide as a raw material for synthesis. Characterization techniques such as XRD, SEM and TEM have been employed for structural/microstructural investigations. XRD results show that the as synthesized TiO2 nanopowder exhibit anatase phase, TiO2. The average sizes of the TiO2 nanopowders are ~ 5-10 nm. The optical properties of the samples were investigated through UVvisible and fluorescence techniques. It has been observed that absorption edge corresponds to ~ 410 nm (bandgap, ~ 3·02 eV). The emission peak in the fluorescence spectrum at ~ 418 nm corresponds to the bandgap energy of ~ 2·97 eV. Concentration of phenol (initial concentration, ~ 100 ppm) with illumination time was monitored by measuring the absorbance of pure and illuminated phenol through UV-visible spectrophotometer. Salient feature of this study relates to the fact that the present sol-gel synthesized TiO2 nanopowders have been found to be better photocatalysts for phenol degradation than the presently employed commercial TiO2 (P-25, Degussa) photocatalyst. Thus, whereas phenol concentration, with the presently synthesized TiO2 nanopowders, the concentration of phenol decreases up to ~ 32% but for commercial TiO2 nanopowder (P-25, Degussa), it decreased only up to ~ 25%. The improved surface area is considered as an important factor for the aforesaid decrease in phenol concentration. [ABSTRACT FROM AUTHOR]

In the present study, we report the synthesis, characterization and application of nanostructured oxide materials. The oxide materials (Cu2O and ZnO) have been synthesized by electrolysis based oxidation and thermal oxidation methods. Cuprous oxide (Cu2O) nanostructures have been synthesized by anodic oxidation of copper through a simple electrolysis process employing plain water (with ionic conductivity, ~ 6 μS/m) as electrolyte. In this method no special electrolytes, chemicals and surfactants are needed. The method is based on anodization pursuant to the simple electrolysis of water at different voltages. Two different types of Cu2O nanostructures have been found. One type got delaminated from copper anode and was collected from the bottom of the electrochemical cell and the other was located on the copper anode itself. The nanostructures collected from the bottom of the cell are either nanothreads embodying beads of different diameters, ~ 10-40 nm or nanowires (length, ~ 600-1000 nm and diameter, ~ 10-25 nm). Those present on the copper anode were nanoblocks with preponderance of nanocubes (nanocube edge, ~ 400 nm). The copper electrode served as a sacrificial anode for the synthesis of different nanostructures. Aligned ZnO nanorod array has been successfully synthesized by simple thermal evaporation catalyst free method. Detailed structural characterizations revealed that the as synthesized aligned ZnO nanorods are single crystalline, with a hexagonal phase, and with growth along the [0001] direction. The room-temperature photoluminescence spectra showed a weak ultraviolet emission at 380 nm, a broad blue band at 435 nm and a strong orange-red emission at 630 nm. Structural/microstructural characterization of these nanomaterials have been carried out employing scanning (XL-20) and transmission electron microscopic (Philips EM, CM-12 and Technai 20G2) techniques and X-ray diffraction techniques having graphite monochromater with CuKa radiation (λ = 1·54439 Å) (X'Pert PRO PAN analytical). The UV-visible absorption spectra were recorded on Model-VARIAN, Cary 100, and Bio UV-visible spectrophotometer. The photoluminescence (PL) measurement was carried out at room temperature with a He-Cd, a laser excited at 325 nm. [ABSTRACT FROM AUTHOR]

The macroscopic coaxial carbon cylinders (dia. ~ 0·5 cm with varying lengths, ~ 7-10 cm) consisting of aligned carbon nanotube (CNT) stacks have been prepared by controlled spray pyrolysis method. The coaxial carbon cylinders of CNT stacks have been formed directly inside the quartz tube. Another study is done on multi-walled CNTs (MWNTs)-polymer (e.g. polyethylene oxide (PEO), polyacrylamide (PAM)) composite films. We have investigated the structural, electrical and mechanical properties of MWNTs-PEO composites. Composites with different wt% (between 0 and 50 wt% of MWNTs) have been prepared and characterized by the scanning electron microscopic technique. Enhanced electrical conductivity and mechanical strength were observed for the MWNTs-PEO composites. We have also studied the electrical property of MWNTs-PAM composite films. [ABSTRACT FROM AUTHOR]

The blood brain barrier (BBB) represents one of the strictest barriers of in vivo therapeutic drug delivery. The barrier is defined by restricted exchange of hydrophilic compounds, small proteins and charged molecules between the plasma and central nervous system (CNS). For decades, the BBB has prevented the use of many therapeutic agents for treating Alzheimer's disease, stroke, brain tumor, head injury, spinal cord injury, depression, anxiety and other CNS disorders. Different attempts were made to deliver the drug across the BBB such as modification of therapeutic agents, altering the barrier integrity, carrier-mediated transport, invasive techniques, etc. However, opening the barrier by such means allows entry of toxins and undesirable molecules to the CNS, resulting in potentially significant damage. An attempt to overcome the barrier in vivo has focused on bypassing the BBB by using a novel, practical, simple and non-invasive approach i.e. intranasal delivery. This method works because of the unique connection which the olfactory and trigeminal nerves (involved in sensing odors and chemicals) provide between the brain and external environments. The olfactory epithelium acting as a gateway for substances entering the CNS and peripheral circulation is well known. Also, it is common knowledge that viral infections such as common cold, smallpox, measles, and chicken pox lake place through the nasopharynx. The neural connections between the nasal mucosa and the brain provide a unique pathway for the non-invasive delivery of therapeutic agents to the CNS. This pathway also allows drugs which do not cross the BBB to enter the CNS and it eliminates the need for systemic delivery and thereby reducing unwanted systemic side effects. Intranasal delivery does not require any modification of therapeutic agents and does not require that drugs be coupled with any carrier. A wide variety of therapeutic agents, including both small molecules and macromolecules can be... [ABSTRACT FROM AUTHOR]

Low entrapment of drugs into liposomes is a serious challenge in their commercial application. 6-Mercaptopurine (6-MP), an antineoplastic agent, is such a drug with low entrapment efficiency (EE). We devised their lipophilic derivatization as a means of enhancing EE by covalently coupling 6-MP with glyceryl monostearate (GMS) via a succinic anhydride spacer. This prodrug had an improved partition coefficient value of 25.16 compared to 1.22 for free drug, confirming higher lipophilicity. A hydrolysis rate study of prodrug indicated 2.90%, 12.5%, 24.1%, and 25.1% hydrolysis in phosphate buffered saline (PBS) (pH 7.4) and 10%, 20%, and 30% serum, respectively. Liposomes of phosphatidylcholine (PC)/sphingomyelin, cholesterol, and dicetyl phosphate bearing drug or prodrug were prepared by shaking by hand and sonication methods. The EE was found to increase from 1.92% for free drug to 91.8% for drug-conjugate. An in vitro cell line toxicity study on L1210 leukemia cells showed improved performance of liposome-encapsulated drug-conjugate compared to free drug. The plasma drug level profile following administration of free drug and the liposomal formulation containing prodrug (HE liposome) manifested a higher sustained level of the latter, which was further improved in case of sphingomyelin-containing liposomes (STHE liposome). The pharmacokinetic parameters revealed an increase in half-life, from 61 min to 120 min for the HE liposomes and 296 min for the STHE liposomes. Therefore, increased entrapment was made possible through lipophilic derivatization, and it was subsequently tested in vivo. [ABSTRACT FROM AUTHOR]

A new derivative of erythrocyte ghosts - reverse biomembrane vesicles (RBVs) - was developed, loaded with doxorubicin HCl (Dox RBVs), and extensively characterized both in vivo and in vitro. The formulation of reverse biomembrane is based on budding of membrane into the ghost interiors (endocytosis) leading to accumulation of small vesicles within each parent ghost. The system was evaluated in vitro for entrapment efficiency, membrane orientation, vesicle size, release profile, and centrifugal stress. The stability studies were performed at 4°C by assessing the effect on vesicle size and leakage after 7, 15, and 21 days. The stability study showed negligible leakage and no appreciable change in vesicle size after storage for several days-an indication of good stability of RBVs formulation. The formulation and process variables were optimized to obtain vesicles of 1.2-1.8 μm. The amount of doxorubicin entrapped in RBVs was 0.75 mg/ml of packed vesicles. The in vitro release profile showed 52.86% of drug release in 16 hr. A membrane orientation study revealed inversion of membrane surface because only 10% of sialic acid was accessible on trypsin treatment. The plasma clearance data revealed an increase in halflife and bioavailability of drug. Tissue concentration data suggest that liver and spleen remain the major organs for clearance of these drug-loaded RBVs, which suggests preferential uptake by the reticuloendothelial system. On the whole, this vesicle system proved to be of potential application in cancer chemotherapy. [ABSTRACT FROM AUTHOR]