Measurement of energy and directional distribution of neutron ambient dose equivalent for the 7Li(p,n)7Be reaction.

Double differential neutron fluence distributions were measured in the 7Li(p,n)7Be reaction for proton beam energies 7, 9 and 12 MeV. Seven liquid scintillator based detectors were employed to measure neutron fluence distributions using the Time of Flight technique. Neutron ambient dose equivalents were determined from the measured fluence distribution using ICRP (International Commission on Radiological Protection) recommended fluence to dose equivalent conversion coefficients. Neutron dose equivalents were also measured using a conventional BF3 detector based REM counter. Ambient dose equivalent measured by the REM counter is found to be in agreement with that determined from the neutron fluence spectra within their uncertainties. Angular distributions of the ambient dose equivalents were also determined from the measured fluence distributions at different angles.

Green synthesis of Cu-doped ZnO nanoparticles and its application for the photocatalytic degradation of hazardous organic pollutants.

In recent times, the synthesis of metal nanoparticles (NPs) using plant extracts has recently emerged as an intriguing issue in the field of nanoscience and nanobiotechnology, with numerous advantages over conventional physicochemical approaches. In the current study, ZnO NPs were synthesized from Synadium grantii leaf extricate with varying Cu-dopant concentrations. In order to the synthesis of the pure and Cu-doped ZnO NPs, zinc nitrate hexahydrate and copper nitrate trihydrate were used as a precursor in leaf extracts of the plant. XRD, TEM, FTIR, XPS, and PL measurements were carried out to examine the physical and optical properties of the synthesized samples. The photocatalytic studies of the prepared samples were studied using Methylene blue (MB), Indigo Carmine (IC), and Rhodamine B (RhB) organic pollutants. The wurtzite crystal structure of synthesized samples was confirmed by XRD and TEM analysis. Further, the presence of functional groups in the prepared samples was confirmed by FTIR analysis. XPS analysis confirmed that the binding energies of a host material and dopant ions. The emission peaks identified at 424, 446 and 573 nm are associated with the electron movement from the deep donor level, zinc interstitial to the zinc vacancy and oxygen vacancy. 3% and 5% Cu-doped samples exhibited superior photocatalytic activity for MB, IC, and RhB dyes. The green synthesized ZnO NPs showed enriched photocatalytic performance, signifying that bio-synthesis can be an outstanding approach to develop versatile and environmental products.

Ultrasound-Assisted Aqueous Extraction of Phenolic, Flavonoid Compounds and Antioxidant Activity of Mucuna macrocarpa Beans: Response Surface Methodology Optimization.

OBJECTIVE: This investigation was undertaken to optimize the effective extraction of total phenolics content (TPC), total flavonoids content (TFC), and antioxidant activity from the Mucuna macrocarpa (MM) beans. An ultrasound-assisted extraction (UAE) technique with water as an effective solvent was proposed for the response surface methodology (RSM) optimization. METHODS: A three-level, two-factor central composite design (CCD) was employed to reveal the optimal points of variables. Different extraction times (5, 10, 15 minutes) and ultrasonic power levels (10, 20, 30 W) were used for the optimization. The experimental runs given by the RSM were evaluated for TPC, TFC, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (RSA), and N,N-dimethyl-p-phenylenediamine (DMPD) RSA and ferric reducing antioxidant power (FRAP). RESULTS: The predicted times for maximum extraction of TPC (186.61 mg GAE g-1), TFC (148.87 mg QUE g-1), and DPPH RSA (99.37%), and DMPD RSA (50.58%) and FRAP (2.38 O.D. at 593 nm) were 12.57, 12.84, 12.43, 12.97, and 13.24 min, and ultrasonic power levels were found to be 27.30, 26.76, 26.22, 27.03, and 27.84 W, respectively. Reverse-phase high-performance liquid chromatography (RP-HPLC) analysis of phenolics compounds from the RSM optimized sample showed tannic acid (48.09 ± 1.92 mg/g), gallic acid (1.17 ± 0.19 mg/g), p-coumaric acid (0.56 ± 0.03 mg/g), and p-hydroxybenzoic acid (0.049 ± 0.01 mg/g) content. CONCLUSION: Water and ultrasonication were found to be an effective extraction solvent and technique. RSM was effectively employed to investigate the optimal process conditions for the maximum extraction of TPC, TFC, and antioxidant compounds from the MM beans. Further, MM beans can be explored as a prominent antioxidant source for the treatment of several disorders.

Response surface methodology optimization for sorption of malachite green dye on sugarcane bagasse biochar and evaluating the residual dye for phyto and cytogenotoxicity.

In the present study, sorption and detoxification of malachite green (MG) dye was executed using biochar resulting after pyrolysis of agro-industrial waste at 400, 600 and 800 °C. Maximum sorption of MG dye (3000 mg/L) was observed on the sugarcane bagasse biochar (SCB) prepared at 800 °C. The interactive effects of different factors like dye concentration, time, pH and temperature on sorption of MG dye were investigated using response surface methodology (RSM). Optimum MG dye concentration, contact time, temperature and pH predicted through Box-Behnken based RSM model were 3000 mg/L MG dye, 51.89 min, 60 °C and 7.5, respectively. ANOVA analysis displayed the non-significant lack of fit value (0.4566), whereas, the predicted correlation coefficient values (R2 0.8494) were reasonably in agreement with the adjusted value (R2 0.9363) demonstrating highly significant model for MG dye sorption. The applicability of this model was also checked through F- test (30.39) with lower probability (0.0001) value. Furthermore, the characterization of SCB was performed using fourier transform infra-red spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM), Brunauer-Emmett-Teller surfaces (BET), total organic carbon (TOC) and atomic absorption spectroscopy (AAS). Phyto-toxicity and cytogenotoxicity studies showed successful removal of MG dye using SCB. In addition, the batch sorption studies for reutilization of SCB revealed that the SCB was effective in removal of MG for five repeated cycles. This technology would be effective for treating the toxic textile effluent released from the textile industries.

Optimization of beam dump shielding for K-130 cyclotron at VECC.

A compact and efficient beam dump shield has been designed using Monte Carlo simulation code FLUKA to facilitate low background measurement of neutron and gamma rays using K130 cyclotron at Variable Energy Cyclotron Centre, Kolkata (VECC). Iron, lead and high density Polyethylene (HDPE) were considered in the design of the beam dump shield. Representative FLUKA simulation results have been validated using in-beam experiment performed on the same beam dump constituents. Experimental neutron and gamma-rays energy spectra have been found to be in fair agreement with the simulation results. Activation of various beam dump shield components were also carried out.

Aspergillus fischeri Mediated Biosynthesis of Gold Nanoparticles and their Beneficially Comparative Effect on Normal and Cancer Cell Lines.

BACKGROUND: Along with the intensified use of metal nanoparticles, growing concern of their adverse outcome on human health has also expanded, indicating that this work is an integral part of nanobioscience study. OBJECTIVE: The aim of this study was to evaluate varied effect of biosynthesized gold nanoparticles (AuNPs) on normal and cancerous mammalian cells. METHODS: AuNP synthesized and characterized by different characterization methods, here are produced by specifically isolated Aspergillus species, which is hardly explored in precious scientific findings. These bio-synthesized AuNP are then tested by MTT assay and further confirmed by different fluorescent staining methods. RESULTS: The AuNPs synthesized here are fairly monodispersed and uniform in shape as confirmed by the relatively tall and dominant UV spectroscopy peak at 540 nm and TEM images showing round shaped particles at a magnification of 20 and 50 nm size ranges. The crystalline powder formed peaks at 2θ angles specific for AuNPs verifying their presence and FT-IR validates presence of side groups which help in stabilization of particulates. We have clearly proved that the less toxic nature of these AuNPs on mouse fibroblasts cells and comparatively elevated inhibiting effect on cancer cells at as low as 1 µg/mL concentration of AuNP. Condensation of nucleus and damage of cells seen in fluorescent images also substantiates the results. CONCLUSION: This conclusion is encouraging to the nanoscientists to study elaborately their system pathways which might be responsible for varied toxicity levels of these AuNPs in mammalian cells and pursue different methods in biomedical applications.

Antimicrobial, Biofilm Inhibitory and Anti-infective Activity of Metallic Nanoparticles Against Pathogens MRSA and Pseudomonas aeruginosa PA01.

BACKGROUND: The emergence of drug resistant pathogens is a major concern to the scientific community. Novel approaches such as the use of functionalized nanomaterials with antimicrobial activity is required to treat infectious diseases. OBJECTIVE: In the present study, the metallic nanoparticles (iron, gold, zinc oxide and copper oxide) were evaluated for the antimicrobial, biofilm inhibitory and anti-infective activity against human pathogens methicillin resistant Staphylococcus aureus and Pseudomonas aeruginosa PA01. METHODS: The efficacy of nanoparticles on the planktonic growth of clinically relevant pathogens was determined by MIC. Further, the effect of nanoparticles was studied on their biofilms using crystal violet microtiter plate assay and fluorescent microscopy. The cytotoxicity of nanoparticles was studied in HT29 cell line. RESULTS: The nanoparticles of copper and zinc oxide (size < 50 nm) were more effective against Grampositive and Gram-negative pathogens in comparison to gold and iron nanoparticles. The ZnO nanoparticles had an MIC in the range of 3.125 µg/ ml and 6.25 µg/ ml against the tested pathogens. The nanoparticles at the tested concentration reduced biofilm burden by > 75% in the pathogens. The nanoparticles showed cytotoxicity in HT 29 at 20 µg/ ml. CONCLUSION: The results of the study showed that of all the tested nanoparticles, ZnO nanoparticles had significant antimicrobial activity against the drug resistant pathogens and could be used at concentrations less toxic to mammalian cells. Hence, ZnO nanoparticles have the potential for the design of novel antibacterial agents and therapeutics.

Mucuna pruriens Protects against MPTP Intoxicated Neuroinflammation in Parkinson's Disease through NF-κB/pAKT Signaling Pathways.

Till date, drugs that have been used to manage Parkinson's disease (PD) have only shown symptomatic relief with several adverse effects besides their inability to prevent neurodegeneration. Neuroinflammation plays an important role in the advancement of PD and can be targeted for its effective treatment. Researchers have suggested that herbal plants exhibiting the anti-inflammatory and anti-oxidant properties are therefore beneficial to human health. Conventionally, Mucuna pruriens (Mp) seeds are used for maintaining male virility in India. Reportedly, Mp is used as a rejuvenator drug having neuroprotective property. Our study aimed to investigate effects of aqueous extract of Mp (100 mg/kgbwt) on neuroinflammation, orally administered to mice intoxicated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) as well as the molecular mechanism involved in the progression of PD. In this study, we have observed significant behavioral abnormalities beside decreased antioxidant defense in MPTP intoxicated mice. We have also observed significant increase in inflammatory parameters like Glial Fibrillary Acidic Protein, Inducible Nitric Oxide Synthase, Intercellular Cell Adhesion Molecule, and Tumor Necrosis Factor alpha in substantia nigra pars compacta (SNpc) of parkinsonian mice, while Mp treatment has notably reduced these inflammatory parameters. Mp also inhibited the MPTP induced activation of NF-κB and promoted pAkt1 activity which further prevented the apoptosis of the dopaminergic neurons. Moreover, Mp exhibited significant antioxidant defense by inhibiting the lipid peroxidation and nitrite level, and by improving catalase activity and enhancing GSH level in nigrostriatal region of mouse brain. Mp also recovered the behavioral abnormalities in MPTP treated mice. Additionally, Mp treatment considerably increased the immunoreactivity of Tyrosine Hydroxylase and Dopamine Transporter in SNpc of parkinsonian mice. Our high performance liquid chromatography analysis of the Mp seed extract have shown L-DOPA, gallic acid, phytic acid, quercetin, and catechin equivalents as the major components which might cause neuroprotection in PD mice. Our result suggested that Mp extract treatment containing L-DOPA and a mixture of rich novel phytochemicals significantly alleviates the MPTP induced neurotoxicity by NF-κB and pAkt pathway. The findings observed thereby indicate that Mp extract have suggestively ameliorated MPTP induced neuroinflammation, restored the biochemical and behavioral abnormalities in PD mouse and thus provided a scientific basis for its traditional claim.

A genome wide dosage suppressor network reveals genomic robustness.

Genomic robustness is the extent to which an organism has evolved to withstand the effects of deleterious mutations. We explored the extent of genomic robustness in budding yeast by genome wide dosage suppressor analysis of 53 conditional lethal mutations in cell division cycle and RNA synthesis related genes, revealing 660 suppressor interactions of which 642 are novel. This collection has several distinctive features, including high co-occurrence of mutant-suppressor pairs within protein modules, highly correlated functions between the pairs and higher diversity of functions among the co-suppressors than previously observed. Dosage suppression of essential genes encoding RNA polymerase subunits and chromosome cohesion complex suggests a surprising degree of functional plasticity of macromolecular complexes, and the existence of numerous degenerate pathways for circumventing the effects of potentially lethal mutations. These results imply that organisms and cancer are likely able to exploit the genomic robustness properties, due the persistence of cryptic gene and pathway functions, to generate variation and adapt to selective pressures.

Assessment of genetic diversity in Mucuna species of India using randomly amplified polymorphic DNA and inter simple sequence repeat markers.

Genus Mucuna which is native to China and Eastern India comprises of perennial climbing legume with long slender branches, trifoliate leaves and bear green or brown pod covered with soft or rigid hairs that cause intense irritation. The plants of this genus are agronomically and economically important and commercially cultivated in India, China and other regions of the world. The high degrees of taxonomical confusions exist in Mucuna species that make authentic identification and classification difficult. In the present study, the genetic diversity among the 59 accessions of six species and three varieties of M. pruriens has been assessed using DNA fingerprinting based molecular markers techniques namely randomly amplified polymorphic DNA (RAPD), inter simple sequence repeats (ISSR) and combined dataset of RAPD and ISSR. Also, genetic relationship among two endemic species of Mucuna namely M. imbricata and M. macrocarpa and two varieties namely IIHR hybrid (MHR) and Dhanwantari (MD) with other species under study was investigated by using cluster analysis and principal coordinate analysis. The cluster analysis of RAPD, ISSR and combined dataset of RAPD and ISSR clearly demonstrated the existence of high interspecific variation than intra-specific variation in genus Mucuna. The utility and efficacy of RAPD and ISSR for the study of intra species and interspecies genetic diversity was evident from AMOVA and PCoA analysis. This study demonstrates the genetic diversity in Mucuna species and indicates that these markers could be successfully used to assess genetic variation among the accessions of Mucuna species.

Radiation mapping inside the bunkers of medium energy accelerators using a robotic carrier.

The knowledge of ambient and peak radiation levels prevailing inside the bunkers of the accelerator facilities is essential in assessing the accidental human exposure inside the bunkers and in protecting sensitive electronic equipments by minimizing the exposure to high intensity mixed radiation fields. Radiation field mapping dynamically, inside bunkers are rare, though generally dose-rate data are available in every particle accelerator facilities at specific locations. Taking into account of the fact that the existing neutron fields with a spread of energy from thermal up to the energy of the accelerated charged projectiles, prompt photons and other particles prevailing during cyclotron operation inside the bunkers, neutron and gamma survey meters with extended energy ranges attached to a robotic carrier have been used. The robotic carrier movement was controlled remotely from the control room with the help of multiple visible range optical cameras provided inside the bunkers and the wireless and wired protocols of communication helped its movement and data acquisition from the survey meters. Variable Energy Cyclotron Centre, Kolkata has positive ion accelerating facilities such as K-130 room Temperature Cyclotron, K-500 Super Conducting Cyclotron and a forthcoming 30 MeV Proton Medical Cyclotron with high beam current. The dose rates data for K-130 Room Temperature Cyclotron, VECC were collected for various energies of alpha and proton beams losing their total energy at different stages on different materials at various strategic locations of radiological importance inside the bunkers. The measurements established that radiation levels inside the machine bunker dynamically change depending upon the beam type, beam energy, machine operation parameters, deflector condition, slit placement and central region beam tuning. The obtained inference from the association of dose rates with the parameters like beam intensity, type and energy of projectiles, helped in improving the primary beam transmission and minimizing the ambient radiation fields inside the bunkers.

Note: Neutron shutter for Kolkata superconducting cyclotron.

In particle accelerator facilities, experimental areas are isolated from active accelerator area with thick concrete walls. A neutron shutter is used to isolate the experimental areas from the active accelerator area in the beam line. These shutters are provided primarily to reduce the secondary radiations like neutrons in the experimental areas to permissible limit when the primary beam is blocked in the accelerator area. The reduced radiation level in the experimental areas makes the experimental areas accessible. The shutters should allow the primary beam to pass to the experimental caves when they retracted from the beam line. A new neutron shutter has been designed and fabricated. This shutter incorporates compact features with considerable reduction in length, surface area and volume. The attenuation of secondary radiations is evaluated using Monte-Carlo radiation transport code FLUKA. It is found that the features of the shutter are sufficiently good enough to reduce the diffused secondary radiations well within the permissible levels.

Sunlight-enhanced calcareous deposition on cathodic stainless steel in natural seawater.

In replicate series of experiments in natural seawater, one in full darkness and the other in a 1:1 diurnal cycle with as little as ~5% of natural solar illumination, sunlight promoted calcareous deposition on cathodic stainless steel surfaces. As exemplified by scanning electron microscopy, the deposit that formed under the natural diurnal cycle, in the presence of photosynthetic biofilms, was composed of finer calcareous crystals that provided more compact and more uniform surface coverage than the one formed in the dark. The light-enhanced deposit also possessed better scale properties, as suggested by X-ray analysis and electrochemical measurements. Sunlight enhancement of calcareous deposition looked all the more conspicuous when day and night regimes were examined independently. These results not only bear important implications for cathodic protection in marine waters, but also provide an intriguing analogy to coral reef calcification.

Functional outcome of diaphyseal fractures of femur managed by closed intramedullary interlocking nailing in adults.

OBJECTIVE: To study the effectiveness, advantages, disadvantages and failure rates of closed intramedullary interlocking nailing of daiphyseal fractures of the femur in adults. MATERIALS AND METHODS: A total of 30 cases of diaphyseal femur fractures in adults, who have been treated with closed intramedullary interlocking nailing were studied from 2008 - 2010. Data was analyzed both with regards to the clinical and radiological outcome to evaluate the effectiveness, functional outcome and morbidity associated with the procedure. RESULTS: Average age of the patient was 27.4 years with male preponderance. Road traffic accidents were the most common mode of injury; middle third shaft fractures were most commonly seen (56.66%); comminuted and transverse fractures (63.33%) were the commonest fracture pattern. The union rate was 96.6%. Five patients had superficial infection, four had shortening of limb, and in two cases union was delayed. Excellent to good results were seen in 86.6% cases as per modified Klaus and Klemm criteria. CONCLUSION: Closed intramedullary interlocking nailing has now become the treatment of choice for closed diaphyseal fractures of femur in adults, especially those with high comminution, long spiral, and segmental fractures. Interlocking nail offers the added advantages of early joint mobilization, early weight bearing, early muscle rehabilitation, shortened hospital stay, and most importantly early return to work and prefracture state.

Bone tumors in a tertiary care hospital of south India: A review 117 cases.

BACKGROUND: Bone tumors remain a daunting challenge to orthopedic surgeons. The challenge is heightened in developing countries due to limited diagnostic and therapeutic facilities as well as due to ignorance. The published literature on this subject is sparse in our environment. OBJECTIVE: To determine the pattern of bone tumors including their relative frequencies, age and sex distributions, anatomical sites of occurrence and clinico-pathological characteristics as seen in a tertiary care hospital of south India. MATERIALS AND METHODS: This is a retrospective review of all the histologically confirmed bone tumors seen at JSS Medical College and Hospital, Mysore over an 8 year period: 2002 to 2009. RESULTS: A total of 117 patients (aged 5 to 82 years) with a mean of age of 26.87 years were studied. Seventy-six patients (64.96%) were males and 41 (35.04%) were females. The peak age incidence for primary bone tumors was in the age group of 11-20 years and that for metastatic bone tumors was more than 60 years. Sixty-seven (57.26%) of the tumors were benign. Among these, osteochondroma was the most common, accounting for 26 cases (22.22%) followed by Giant cell tumor (24 cases, 20.51%). Osteosarcoma accounted for 35.14% (13 cases) of all the primary malignant tumors in the study. Lower end of femur was the most common site for primary bone tumors and accounted for 30 cases (25.64%) followed by upper end of tibia and fibula (24 cases, 20.51%). The most common site for metastatic bone tumors was upper end of femur including hip joint followed by spine. CONCLUSION: This study showed that primary bone tumors are mainly benign, occurred predominantly in the second decade of life with a male preponderance. Osteochondroma and osteosarcoma are the most common benign and primary malignant bone tumors, respectively. The most common primary foci for metastatic bone tumor are from the respiratory tract.

Outcome of closed proximal phalangeal fractures of the hand.

BACKGROUND: The proximal phalanx (PP) of the fingers is fractured more frequently than the middle or even distal phalanges. The problems of malunion, stiffness and sometimes loss of skin or other soft tissues associated with PP fracture increases the disability. The optimum treatment depends on fracture location, fracture geometry and fracture stability. The objective of the study was to analyse the treatment outcome in a series of closed proximal phalangeal fractures of the hand. MATERIALS AND METHODS: Eighty-four proximal phalangeal fractures in 68 patients were enrolled from 2007 to 2009. The treatment modalities were broadly categorised into two groups, Group A consisted of conservative treatment, and Group B consisted of surgical treatment. Group A included 47 digits treated with closed reduction (CR) with immobilization (n=43), extension block cast and dynamic traction (n=4), while 37 digits were treated in Group B, which included closed or open reduction (OR) and internal fixation (IF) with K-wires (n=31), OR and IF with stainless-steel wiring (n=2), and mini external-fixator (n=4). Belsky's criteria and Gingrass' criteria were used for assessment of finger injuries and to assess the efficacy of conservative and surgical modalities for closed proximal phalangeal fractures of the hand. RESULTS: Average period of follow-up was 1 year (range 10-14 months). The excellent to good results seen in Groups A and B were 89% and 92%, respectively. Six complications were seen in Group A, which included four cases with malunion and two cases with digital stiffness. Three complications were seen in Group B, which included one each of malunion, digital stiffness and extensor lag. Overall, maximum poor results (n=4) were seen with CR and buddy strapping. CONCLUSION: Conservative treatment is an inexpensive method, particularly suitable for stable fractures, and in patients who are poor candidates for surgery, Surgical modalities have distinct advantage of stable fixation, but with added risk of digital stiffness. Percutaneous pinning is a reliable, most commonly used surgical modality and technically easier. Both conservative and surgical modalities have good efficacy when used judiciously.

Automated refinement and inference of analytical models for metabolic networks.

The reverse engineering of metabolic networks from experimental data is traditionally a labor-intensive task requiring a priori systems knowledge. Using a proven model as a test system, we demonstrate an automated method to simplify this process by modifying an existing or related model--suggesting nonlinear terms and structural modifications--or even constructing a new model that agrees with the system's time series observations. In certain cases, this method can identify the full dynamical model from scratch without prior knowledge or structural assumptions. The algorithm selects between multiple candidate models by designing experiments to make their predictions disagree. We performed computational experiments to analyze a nonlinear seven-dimensional model of yeast glycolytic oscillations. This approach corrected mistakes reliably in both approximated and overspecified models. The method performed well to high levels of noise for most states, could identify the correct model de novo, and make better predictions than ordinary parametric regression and neural network models. We identified an invariant quantity in the model, which accurately derived kinetics and the numerical sensitivity coefficients of the system. Finally, we compared the system to dynamic flux estimation and discussed the scaling and application of this methodology to automated experiment design and control in biological systems in real time.