Tailored spectroscopic characteristics of a new type of CuO nanoparticles-inserted borate glass system: Samarium concentration tuning effect

The demand for new glass hosts with emergent properties is constantly growing for various miniaturized applications. Thus, some new types of Sm2O3-activated strontium-telluro-alumino-magnesium-borate glasses with copper oxide nanoparticles (CuONps) insertion were made using melt-quenching approach. The obtained glasses were characterized to determine the effects of Sm2O3 concentration changes on their thermal, structural, and luminescence properties. XRD, FTIR, and HRTEM analyses of the samples verified their glassy nature, presence of different functional units and CuONps, respectively. DTA analysis showed excellent thermal stability of these glasses with a stability factor as much as 125 °C. The optical absorption properties of the glasses were highly sensitive to Sm3+ concentrations variation. The Judd-Ofelt intensity parameters of the glasses with and without CuONps followed the trend of Ω6˃Ω4˃Ω2 and Ω4˃Ω6˃Ω2, respectively. These glasses displayed 4 visible luminescence bands at 561, 598, 645, and 705 nm corresponding to 4G5/2 → 6H5/2, 4G5/2 → 6H7/2, 4G5/2 → 6H9/2, and 4G5/2 → 6H11/2 transitions in Sm3+. In addition, branching ratio above 80% and stimulated emission cross-section up to 135.82 × 10-23 cm2 were achieved. The stimulated emission cross-section and optical gain were enhanced due to the inclusion of CuONps in the glasses. These glasses may be useful for solid state laser and optical amplifier development.

Managing Weed-Crop Interactions Enhances Chickpea (Cicer arietinum L.) Chemical Components

Chickpea (Cicer arietinum L.) is a major pulse crop worldwide, renowned for its nutritional richness and adaptability. Weeds are the main biotic factor deteriorating chickpea yield and nutritional quality, especially Asphodelus tenuifolius Cav. The present study concerns a two-year (2018-19 and 2019-20) field trial aiming at evaluating the effect of weed management on chickpea grain quality. Several weed management practices have been here implemented under a factorial randomized complete block design, including the application of four herbicides [bromoxynil (C7H3Br2NO) + MCPA (Methyl-chlorophenoxyacetic acid) (C9H9ClO3), fluroxypyr + MCPA, fenoxaprop-p-ethyl (C18H16ClNO5), pendimethalin (C13H19N3O4)], the extracts from two allelopathic weeds (Sorghum halepense and Cyperus rotundus), two mulches (wheat straw and eucalyptus leaves), a combination of A. tenuifolius extract and pendimethalin, and an untreated check (control). Chickpea grain quality was measured in terms of nitrogen, crude protein, crude fat, ash, and oil content. The herbicides pendimethalin (Stomp 330 EC (emulsifiable concentrate) in pre-emergence at a rate of 2.5 L ha-1) and fenoxaprop-p-ethyl (Puma Super 7.5 EW (emulsion in water) in post-emergence at a rate of 1.0 L ha-1), thanks to A. tenuifolius control, showed outstanding performance, providing the highest dietary quality of chickpea grain. The herbicides Stomp 330 EC, Buctril Super 40 EC, Starane-M 50 EC, and Puma Super 7.5 EW provided the highest levels of nitrogen. Outstanding increases in crude protein content were observed with all management strategies, particularly with Stomp 330 EC and Puma Super 7.5 EW (+18% on average). Ash content was highly elevated by Stomp 330 EC and Puma Super 7.5 EW, along with wheat straw mulching, reaching levels of 2.96% and 2.94%. Crude fat content experienced consistent elevations across all treatments, with the highest improvements achieved by Stomp 330 EC, Puma Super 7.5 EW, and wheat straw mulching applications. While 2018-19 displayed no significant oil content variations, 2019-20 revealed the highest oil content (5.97% and 5.96%) with herbicides Stomp 330 EC and Puma Super 7.5 EW, respectively, followed by eucalyptus leaves mulching (5.82%). The results here obtained are of key importance in the agricultural and food sector for the sustainable enhancement of chickpea grain's nutritional quality without impacting the environment.

Intense up-conversion luminescence from Dy3+-doped multi-component telluroborate glass matrix: Role of CuO nanoparticles embedment

This paper reports an intense up-conversion luminescence from Dy³⁺-doped strontium-telluro-alumino-magnesium-borate glasses for the first time. The samples were made via the melt-quenching method and characterized to determine the influence of various CuO nanoparticles contents change on their up-conversion emission traits. Absorption spectral data were used to calculate the Judd-Ofelt intensity parameters. The sample without CuO nanoparticles revealed two intense photoluminescence up-conversion emission peaks at 478 and 570 nm. In addition, CuO nanoparticles-activated sample displayed about 1.4-fold up-conversion emission intensity improvement due to strong light absorption in the visible to the infrared region at 799 nm excitation. The stimulated emission cross-section of the CuO nanoparticles-activated glasses was increased from 102.4 × 10^-23 to 1301.1 × 10^-23 cm² (nearly 10-fold amplification) while the branching ratio was reduced to 66.9%. Thus, CuO nanoparticles as an additive in the current glass matrix enhanced the up-conversion emission and strengthened the associated nonlinear optical properties. CIE 1931 color matching revealed the influence of CuO in modifying the up-conversion color coordinates, thereby improving the white color purity. The achieved up-conversion emission coupled with the color tunability of the proposed glasses may be advantageous for the up-conversion UV tunable laser making.

Tabulation of organ dose conversion factors for terrestrial radioactivity monitoring program

Terrestrial radioactivity monitoring of ²³⁸U and ²³²Th series, and ⁴⁰K in soil is an essential practice for radioactivity and radiation measurement of a place. In conventional practice, only basic data can be in-situ measured using a survey instrument, for example radioactivity concentration in soil and ambient dose equivalent rate. For other physical quantities, for example organ absorbed dose and organ equivalent dose, the measurement is impossible to be performed and can only be computed using Monte Carlo radiation transport simulations. In the past, most of the works only focused on calculating air-kerma-to-effective dose conversion factors. However, the information on organ dose conversion factors is scarcely documented and reported. This study was conducted to calculate organ absorbed and tissue-weighted equivalent dose conversion factors as a result of exposure from terrestrial gamma radiation. Series of organ dose conversion factors is produced based on computations from Monte Carlo MCNP5 simulations using modelled gamma irradiation geometry and established adult MIRD phantom. The study found out that most of the radiation exposed organs absorb energy at comparable rates, except for dense and superficial tissues i.e., skeleton and skin, which indicated slightly higher values. The good agreement between this work and previous studies demonstrated that our gamma irradiation geometry and modelling of gamma radiation sources are adequate. Therefore, the proposed organ dose conversion factors from this study are reasonably acceptable for dose estimation in environmental radioactivity monitoring practices.

Radiological hazard associated with amang processing industry in Peninsular Malaysia and its environmental impacts

Continuous depletion in tin productions has led to a newly emerging industry that is a tin by-product (amang) processing industry to harness mega tons of tin by-products produced in the past. Amang composed of profitable multi-heavy minerals and rare-earth elements. With poorly established safety and health practices in operating plant, amang poses extremely high radioactivity problem associated with high occupational ionizing radiation exposures to workers and continuously impacting the local environment with radioactive contamination from industrial effluent and solid waste into lithosphere and water bodies. The radioactivity level of ²³⁸U and ²³²Th series in the mineral varies from few hundreds up to ~200,000 and ~400,000 Bq kg^-1 respectively and are potential to yield more than ~ 30,000 nGy h^-1 of gamma (γ) radiation exposure to plant workers. The study found out that for 8 h of work time, a worker is estimated to receive an average effective dose of 0.1 mSv per day from external γ radiation source with a maximum up to 2 mSv per day for extreme exposure situation. Interferences of different exposure routes for examples inhalation of equivalent equilibrium concentration (ECC) of ²²²Rn and ²²⁰Rn progenies and airborne long-lived α particles from the dusty working environment could pose a higher total effective dose as much as 5 mSv per day and 115 mSv per year. The value is 5 times higher than the annual dose limit for designated radiation worker (20 mSv) in Peninsular Malaysia. The study found that 41% of the total received an effective dose received by a worker is contributed by ²²²Rn, 32% of airborne particulates and dust, 23% from external γ exposure and 4% from ²²⁰Rn. Based on radioecological risk assessment, the study found out that the aquatic environment is the highly exposed group to ionizing radiation from industrial effluent discharge and sand residues. With the impotent establishment of radiation protection in the industry, plus the country newly introduced long-term plan to revive tin mining as well as its accessory amang mineral, it is necessary for the government to harmonize current regulation to improve the worker safety and health as well as sustaining local environment.

Perceptions of UK clinicians towards postoperative critical care

Postoperative critical care is a finite resource that is recommended for high‐risk patients. Despite national recommendations specifying that such patients should receive postoperative critical care, there is evidence that these recommendations are not universally followed. We performed a national survey aiming to better understand how patients are risk‐stratified in practice; elucidate clinicians’ opinions about how patients should be selected for critical care; and determine factors which affect the actual provision of postoperative critical care. As part of the second Sprint National Anaesthesia Project, epidemiology of critical care after surgery study, we distributed a paper survey to anaesthetists, surgeons and intensivists providing peri‐operative care during a single week in March 2017. We collected data on respondent characteristics, and their opinions of postoperative critical care provision, potential benefits and real‐world challenges. We undertook both quantitative and qualitative analyses to interpret the responses. We received 10,383 survey responses from 237 hospitals across the UK. Consultants used a lower threshold for critical care admission than other career grades, indicating potentially more risk‐averse behaviour. The majority of respondents reported that critical care provision was inadequate, and cited the value of critical care as being predominantly due to higher nurse: patient ratios. Use of objective risk assessment tools was poor, and patients were commonly selected for critical care based on procedure‐specific pathways rather than individualised risk assessment. Challenges were highlighted in the delivery of peri‐operative critical care services, such as an overall lack of capacity, competition for beds with non‐surgical cases and poor flow through the hospital leading to bed ‘blockages’. Critical care is perceived to provide benefit to high‐risk surgical patients, but there is variation in practice about the definition and determination of risk, how patients are referred and how to deal with the lack of critical care resources. Future work should focus on evaluating ‘enhanced care’ units for postoperative patients, how to better implement individualised risk assessment in practice, and how to improve patient flow through hospitals.

Biology, ecology and management of Raphanus raphanistrum L.: a noxious agricultural and environmental weed

Weeds are a major constraint to crop production and a barrier to human efforts to meet the ever-rising global demand for food, fibre and fuel. Managing weeds solely with herbicides is unsustainable due to the rapid evolution of herbicide-resistant weeds. Precise knowledge of the ecology and biology of weeds is of utmost importance to determine the most appropriate nonchemical management techniques. Raphanus raphanistrum L. is an extremely invasive and noxious weed due to its prolific seed production, allelopathic potential, multiple herbicide resistance and biological potential. R. raphanistrum causes high crop yield losses and thus has become one of the most troublesome agricultural and environmental weeds. R. raphanistrum could exchange pollen with herbicide-tolerant canola and could become an environmental threat. This weed has evolved resistance to many herbicides, and relying exclusively on herbicide-based management could lead to severe crop loss and uneconomical cropping. Although reviews are available on the ecology and biology of R. raphanistrum, significant changes in tillage, weed management and agronomic practices have been occurring worldwide. Therefore, it is timely to review the status of noxious weeds in different agro-ecological zones and management scenarios. This review focuses on the response of R. raphanistrum to different cultural, mechanical, biological, chemical and integrated management strategies practiced in various agro-ecosystems, and its biological potential to thrive under different weed management tactics. In addition, this review facilitates a better understanding of R. raphanistrum and describes how weed management outcomes could be improved through exploiting the biology and ecology of the weed.

Dosimetric features and kinetic parameters of a glass system dosimeter

Lithium borate (LB) glasses doped with dysprosium oxide (Dy₂ O₃ ) have been prepared by utilizing the conventional melt-quench technique. The prepared glass samples were exposed to ⁶⁰ Co to check their dosimetric features and kinetic parameters. These features involve glow curves, annealing, fading, reproducibility, minimum detectable dose (MDD), and effective atomic number (Z_eff ). Kinetic parameters including the frequency factors and activation energy were also determined using three methods (glow curve analysis, initial rise, and peak shape method) and were thoroughly interpreted. In addition, the incorporation of Dy impurities into LB enhanced the thermoluminescence sensitivity ~170 times. The glow from LB:Dy appeared as a single prominent peak at 190°C. The best annealing proceeding was obtained at 300°C for 30 min. Signal stability was reported for a period of 1 and 3 months with a reduction of 26% and 31%, respectively. The proposed glass samples showed promising dosimeter properties that can be recommended for personal radiation monitoring.

The effectiveness of bismuth breast shielding with protocol optimization in CT Thorax examination

BACKGROUND

Numerous techniques had been proposed to reduce radiation exposure in computed tomography (CT) including the use of radiation shielding.

OBJECTIVE

This study aims to evaluate efficacy of using a bismuth breast shield and optimized scanning parameter to reduce breast absorbed doses from CT thorax examination.

METHODS

Five protocols comprising the standard CT thorax clinical protocol (CP1) and four modified protocols (CP2 to CP5) were applied in anthropomorphic phantom scans. The phantom was configured as a female by placing a breast component on the chest. The breast component was divided into four quadrants, where 2 thermoluminescence dosimeters (TLD-100) were inserted into each quadrant to measure the absorbed dose. The bismuth shield was placed over the breast component during CP4 and CP5 scans.

RESULTS

The pattern of absorbed doses in each breast and quadrant were approximately the same for all protocols, where the 4th quadrant > 3rd quadrant > 2nd quadrant > 1st quadrant. The mean absorbed dose value in CP3 was reduced to almost 34% of CP1's mean absorbed dose. It was reduced even lower to 15% of CP1's mean absorbed dose when the breast shield was used in CP5.

CONCLUSION

This study showed that CT radiation exposure on the breast could be reduced by using a bismuth shield and low tube potential protocol without compromising the image quality.

Optically stimulated Al2O3:C luminescence dosimeters for teletherapy: Hp(10) performance evaluation

The performance of optically stimulated luminescence dosimeters (OSLDs, Al₂O₃:C) was evaluated in terms of the operational quantity of H_P(10) in Co-60 external beam teletherapy unit. The reproducibility, signal depletion, and dose linearity of each dosimeter was investigated. For ten repeated readouts, each dosimeter exposed to 50mSv was found to be reproducible below 1.9 ± 3% from the mean value, indicating good reader stability. Meanwhile, an average signal reduction of 0.5% per readout was found. The dose response revealed a good linearity within the dose range of 5-50mSv having nearly perfect regression line with R² equals 0.9992. The accuracy of the measured doses were evaluated in terms of operational quantity H_P(10), wherein the trumpet curve method was used respecting the 1990 International Commission on Radiological Protection (ICRP) standard. The accuracy of the overall measurements from all dosimeters was discerned to be within the trumpet curve and devoid of outlier. It is established that the achieved OSL Al₂O₃:C dosimeters are greatly reliable for equivalent dose assessment.

Regulatory requirements for nuclear power plant site selection in Malaysia-a review

Malaysia has initiated a range of pre-project activities in preparation for its planned nuclear power programme. Clearly one of the first steps is the selection of sites that are deemed suitable for the construction and operation of a nuclear power plant. Here we outline the Malaysian regulatory requirements for nuclear power plant site selection, emphasizing details of the selection procedures and site characteristics needed, with a clear focus on radiation safety and radiation protection in respect of the site surroundings. The Malaysia Atomic Energy Licensing Board (AELB) site selection guidelines are in accord with those provided in International Atomic Energy Agency (IAEA) and United Stated Nuclear Regulatory Commission (USNRC) documents. To enhance the suitability criteria during selection, as well as to assist in the final decision making process, possible assessments using the site selection characteristics and information are proposed.

Photoluminescence and thermoluminescence properties of Li₂O-Na₂O-B₂O₃ glass

Influence of Nd(3+) concentration on the optical and thermoluminescence (TL) properties of melt-annealed synthesized 10 Na2O: 20 Li2O: (70-x) B2O3 : xNd2O3, where 0.1≤ x ≤0.7 (LNB) glasses are determined. The absence of sharp peaks in X-ray diffraction patterns confirms the amorphous nature of the prepared glasses. The photoluminescence spectra under 800 nm laser excitations at room temperature exhibit three prominent peaks centred at 538, 603 and 675 nm corresponding to the transitions of (4)G(7/2) → (4)I(9/2), [(4)G(7/2) → (4)I(11/2), (4)G(5/2) → (4)I(9/2)] and [(4)G(7/2) → (4)I(13/2), (4)G(5/2) → (4)I(11/2)], respectively. The TL glow curve exhibits a prominent peak (T(m)) at 180°C. The best performance of the prepared glass was found at 0.5 mol% of Nd2O3. We achieved a good linearity of TL response against dose between 0.5 to 4.0 Gy. The calculated value of the effective atomic number, Z(eff), is 7.55 which is nearly tissue equivalent (Z(eff) = 7.42). These promising features demonstrate the capability of the aforementioned glass to be used as a radiation dosimeter.

HIGHLIGHTS

The thermoluminescence and optical properties of new compositions of lithium sodium borate glasses doped with Nd(3+) ions were reported. Attractive features were obtained from the TL, PL and UV-Vis light analysis. Three upconversion luminescences permitting green, orange and red emissions were observed.

Thermoluminescence response of dysprosium doped strontium tetraborate glasses subjected to electron irradiations

The paper presents the thermoluminescence (TL) response of strontium tetraborate glass subjected to electron irradiations at various Dy2O3 concentrations ranging from 0.00 to 1.00mol%. All glass samples exhibited single broad peak with maximum peak temperature positioned at 170-215°C. The optimum TL response was found at Dy2O3 concentration 0.75mol%. This glass showed good linearity and higher sensitivity for 7MeV compared to 6MeV electrons. Analysis of kinetic parameters showed that the glasses demonstrate second order kinetic.

SLE presenting as multiple hemorrhagic complications

A 24 year old female with hereditary spastic paraplegia presented with intermittent headache for one year. She also had lower abdominal pain and vomiting for two months. She was pale, had icterus and mild splenomegaly. On diagnostic evaluation she was found to have hemolytic anemia, thrombocytopenia and bilateral adrenal, subdural, soft tissue (scalp and orbit) hemorrhages due to systemic lupus erythematosus (SLE). However, antiphospholipid syndrome (APS) antibodies were negative. Bilateral adrenal hemorrhage without associated APS is a rare phenomenon in SLE. We describe a case of SLE presenting with sequence of rare hemorrhagic complications in concert.

Photon irradiation response of photonic crystal fibres and flat fibres at radiation therapy doses

Radiation effects of photon irradiation in pure Photonic Crystal Fibres (PCF) and Flat fibres (FF) are still much less investigated in thermoluminescense dosimetry (TLD). We have reported the TL response of PCF and FF subjected to 6 MV photon irradiation. The proposed dosimeter shows good linearity at doses ranging from 1 to 4 Gy. The small size of these detectors points to its use as a dosimeter at megavoltage energies, where better tissue-equivalence and the Bragg-Gray cavity theory prevails.

Mutation of alpha-tubulin genes in trifluralin-resistant water foxtail (Alopecurus aequalis)

BACKGROUND

Trifluralin-resistant biotypes of water foxtail (Alopecurus aequalis) have been identified in wheat fields from northern Kyushu, Japan. Water foxtail is a winter-annual grassy weed, causing substantial crop losses. This study reports on mutation in α-tubulin (TUA) genes from water foxtail, the site of action of trifluralin.

RESULTS

Two trifluralin-sensitive (S) Chikugo and Ukiha biotypes and four trifluralin-resistant (R) Asakura-1, Asakura-2, Tamana and Tosu biotypes of water foxtail were used for herbicide resistance analysis. R biotypes showed 5.7-30.7-fold trifluralin resistance compared with the S biotypes. No differences in the uptake and translocation of (14)C-trifluralin were observed between Chikugo (S) biotype and Asakura-1 (R) biotype. Most of the (14)C detected in the plant material was in the root tissue, and no substantial increases were noted in shoot tissues. Comparative TUA sequence analysis revealed two independent single amino acid changes: change of Val into Phe at position 202 in TUA1 and change of Leu into Met at position 125 in TUA3 in Asakura-1 biotype. In the Tamana (R) biotype, two amino acid changes of Leu to Phe at position 136 and Val to Phe at position 202 were observed in the predicted amino acid sequence of TUA1, compared with Chikugo (S) biotype.

CONCLUSION

The results provide preliminary molecular explanation for the resistance of water foxtail to trifluralin, a phenomenon that has arisen as a result of repeated exposure to this class of herbicide. This is the first report of α-tubulin mutation in water foxtail and for any Alopecurus species reported in the literature.

Emergency obstetric care availability, accessibility and utilization in eight districts in Pakistan's North West Frontier Province

BACKGROUND

Reducing maternal mortality is a critical issue in Pakistan. Do public health care centers in Pakistan's North West Frontier Province (NWFP) comply with minimum UN recommendations for availability, use, and quality of basic and comprehensive Emergency Obstetric Care (EmOC) as measured by UN process indicators?

METHODS

All public health facilities providing EmOC (n = 50) in 30% of districts in NWFP province (n = 8 districts) sampled randomly in September 2003 were included in a cross-sectional study. Data came from health facility records.

RESULTS

Almost all indicators were below minimum recommended UN levels. The number of facilities providing basic EmOC services was much too low to be called providing comprehensive coverage. A low percentage of births took place in hospital and few women with complications reached EmOC facilities. Caesarean section was either underutilized or unavailable. The case fatality rate was low, perhaps due to poor record-keeping.

CONCLUSION

The findings of this first needs assessment in NWFP province can serve as a benchmark for monitoring future progress. In resource-poor countries like Pakistan, it is important to upgrade existing facilities, giving special emphasis to facilities that provide basic EmOC services, since many problems can be resolved at the most basic level. Health policy makers and planners need to take immediate, appropriate rectifying measures to, inter alia, improve staffing in rural areas, enhance staff skills through training, upgrade management and supervision, ensure medical supply availability, mandate proper record-keeping, and observe progress by monitoring process indicators regularly.

Poly(β-hydroxybutyrate) production by a moderate halophile,Halomonas boliviensisLC1 using starch hydrolysate as substrate

AIM

The objective of the present work was to enable the use of starch hydrolysate, generated by the action of a recombinant maltooligosaccharide forming amylase from Bacillus halodurans LBK 34, as the carbon source for the production of poly-beta-hydroxybutyrate (PHB) by Halomonas boliviensis LC1.

METHODS AND RESULTS

In this work, different amounts of the alpha-amylase (Amy 34) were utilized for starch hydrolysis, resulting in the production of mixtures of maltooligosaccharides (G1-G6) at varying ratios. The highest PHB accumulation (56 wt%) by H. boliviensis cultivated in shake flasks (with agitation at 160 rev min(-1)) was obtained when 6.4 U ml(-1) of the amylase was used for starch hydrolysis. When H. boliviensis cells were grown in a fermentor with no oxygen limitation the accumulation of PHB was decreased to 35 wt%. Although some improvements in PHB accumulation and cell mass concentration were reached by the addition of peptone and phosphate, respectively, major enhancements were attained when oxygen limitation was induced in the fermentor.

CONCLUSIONS

Halomonas boliviensis uses preferentially maltose for PHB formation from starch hydrolysate. It is also able to hydrolyse higher sugars if no other simpler carbon source is available but with a significantly lower polymer yield. Furthermore, H. boliviensis is able to adjust its metabolism to oxygen limitation, most probably by directing the excess NAD(P)H to PHB accumulation.

SIGNIFICANCE AND IMPACT OF THE STUDY

There have been no reports related to PHB production amongst the members of the genus Halomonas. The use of a maltooligosaccharide forming alpha-amylase, which is active at a temperature and pH close to that required for growth of H. boliviensis, and the versatility of this bacterium in the selection of the carbon source may provide an attractive alternative for the utilization of starch-derived raw materials.