Treatment of dental biofilm-forming bacterium Streptococcus mutans using tannic acid-mediated gold nanoparticles

Biosynthesized gold nanoparticles (AuNPs) are highly attracted as a biocompatible nanodrug to treat various diseased conditions in humans. In this study, phytochemical tannic acid-mediated AuNPs (TA-AuNPs) are successfully synthesized and tested for antibacterial and antibiofilm activity against dental biofilm-forming Streptococcus mutans biofilm. The synthesized TA-AuNPs are appeared as spherical in shape with an average size of 19 nm. The antibacterial potential of TA-AuNPs was evaluated using ZOI and MIC measurements; while, antibiofilm efficacy was measured by checking the eradication of preformed biofilm on the tooth model. The ZOI and MIC values for TA-AuNPs are 25 mm in diameter and 4 μg/mL, respectively. The MTT assay, CLSM, and SEM results demonstrate that the preformed S. mutans biofilm is completely eradicated at 4xMIC (16 μg/mL) of TA-AuNPs. Finally, the present study reveals that the synthesized TA-AuNPs might be a great therapeutic drug to treat dental biofilm-forming bacterium S. mutans.

A novel fuzzy programming approach for piece selection problem in P2P content distribution network

Piece selection policy in dynamic P2P networks play crucial role and avoid the last piece problem. BitTorrent uses rarest-first piece selection mechanism to deal with this problem, but its efficacy is limited because each peer only has a local view of piece rareness. The problem of piece section is multiple objectives. A novel fuzzy programming approach is introduced in this article to solve the multiple objectives piece selection problem in P2P network, in which some of the factors are fuzzy in nature. Piece selection problem has been prepared as a fuzzy mixed integer goal programming piece selection problem that includes three primary goals such as minimizing the download cost, time, maximizing speed and useful information transmission subject to realistic constraints regarding peer's demand, capacity and dynamicity. The proposed approach has the ability to handle practical situations in a fuzzy environment and offers a better decision tool to each peer to select optimal pieces to download from other peers in dynamic P2P network. Extensive simulations are carried out to demonstrate the effectiveness of the proposed model. It is proved that proposed system outperforms existing with respect to download cost, time and meaningful exchange of useful information.

Antithrombotics prescription pattern and clinical outcomes in atrial fibrillation patients with type 2 diabetes mellitus

Funding Acknowledgements

Type of funding sources: None.

Background

Atrial fibrillation (AF) and Diabetes mellitus (DM) often coexist. As DM is considered while calculating the thromboembolic risk for AF patients, little is known about the prescription pattern of antithrombotic therapies in patients with AF and DM and their clinical outcomes.

Purpose

In this subsidiary study, we examined the prescription patterns of antithrombotic therapies and clinical outcomes of AF patients with type 2 DM.

Methods

We analyzed data from a single-center cohort of patients with a primary diagnosis of AF in a tertiary cardiac referral hospital in Malaysia from 1st January 2018 to 31st December 2020. Patients' clinical data and information related to antithrombotic therapy were traced through electronic Hospital Information system. A data collection form was used for data collection. The primary endpoint of the study was a composite cardiovascular (CV) event which consists of all-cause mortality, acute coronary syndrome (ACS), ischemic stroke and transient ischemic attack (TIA). The safety endpoint of the study was a bleeding event, defined as hemoglobin drop more than 2 g/dl, blood transfusion and bleeding at critical area.

Results

Of the 1006 AF patients (59.2% male; mean age 64.2 (12.1) years), 400 (39.8%) had a history of DM. Of these, 45.8% (n=183) were using warfarin; 46.5% (n=159) used direct oral anticoagulant (DOAC), 54.0% (n=216) used a single antiplatelet, 11.5% (n=46) used a double antiplatelet, 8.0% (n=32) used triple therapy which consists of two antiplatelet agents with one anticoagulant. The use of single antiplatelet agent (54.0% vs 46.4%, p=0.018) and double antiplatelet agents (11.5% vs 7.1%, p=0.016) was significantly associated with AF with DM patients, whereas there was no association between anticoagulant use and AF patients with or without DM (85.5% vs 82.5%, p=0.209). There was no association in composite CV events between AF patients with or without DM (12.0% vs 10.4%, p=0.427). The proportion of subjects who reported having bleeding events were also did not differ by the presence of AF patients with or without DM. (4.5% vs 2.8%, p=0.151).

Conclusion

Diabetes was associated with increased use of antiplatelet agents; however, DM was not associated with increased risk of composite CV events and bleeding events in patients with concurrent AF. The lack of an association between diabetes and CV risk contrasts with previous research, which could be due to improved diabetes treatment in this cohort of patients with relatively low fasting sugar readings. Further study on the degree of blood glucose as measured by glycosylated hemoglobin (HbA1c) is needed to confirm the finding.

Synergistic antibacterial and mosquitocidal effect of Passiflora foetida synthesized silver nanoparticles

Silver nanoparticles are opted to have various applications in different fields ranging from traditional medicines to culinary items. It is toxic and most effective against bacteria, fungi viruses, parasites, parasite carrying vectors such as mosquitoes and their larvae and other eukaryotic microorganisms at low concentration without any side effects and toxicity to humans. In view of these data, the present research has been investigated by synthesizing silver nanoparticles using 1mM silver nitrate and aqueous extract of Passiflora foetida. The variation of nanoparticles in size and shape concerning the concentration of extract prepared were analysed. The formation of silver nanoparticles was confirmed by colour changing from yellowish green to reddish-brown implicating the surface plasmon resonance. Further, it was concluded by obtaining an absorbance peak at 420 nm using UV-Visible spectrophotometer analysis. FTIR analysis was used to identify the capping ligands, which included alkanes, aromatic groups and nitro compounds. The average grain size of ~12 nm to 14 nm with crystalline phase was revealed by X-ray Diffraction studies. The SEM images depicted the surface morphology with agglomeration; TEM studies showed the shape of nanoparticles as spherical and hexagonal with sizes ranging from 40 nm to 100 nm and EDAX analysis confirmed the presence of elemental silver as the principal constituent. The characterized silver nanoparticles were then tested for synergistic antibacterial effects with tetracycline, and the results show that they are more active against E. coli and S. aureus, but moderately effective against B. cereus and K. pneumoniae . It also had a strong larval and pupal toxic effects on the dengue vector, Aedes aegypti with the highest mortality. As a result, silver nanoparticles could be a viable alternative for a variety of applications.

Biosynthesis Of Silver Nanoparticles Using Rose and Jasmine and Its Anti Diabetic Potential

Introduction: Rose (rosa canina) is one of the flowers that are much in demand by the community because besides being an ornamental flower it can also be used as a cosmetic. Traditional medicinal herbs have seen a rebound in recent years, and as a result, pharmaceutical companies are investing heavily in developing natural medications derived from plants. Aim: To study the Anti-diabetic activity of Rose Jasmine formulation mediated silver nanoparticles. Materials and methods: The anti-diabetic activity was tested by the following inhibition of α-glucosidase at different concentrations of the prepared extract mediated with silver nanoparticles. Result: Using rosa and jasminum extract in the manufacture of silver nanoparticles, the nanoparticles showed remarkable anti-diabetic activity. It was discovered that the herbal effect was less harmful. Rosa jasminum extract of AgNps showed good anti-diabetic efficacy in the BSA assays. Conclusion: Result of this study suggest that biosynthesis of silver nano particle using rose and Jasmine showed its anti diabetic activity

In vitro anti-inflammatory and wound healing properties of Andrographis echioides and Andrographis paniculata

Andrographis echioides (L.) is an annual herbaceous plant in the family Acanthaceae. Anti-inflammatory is the property of a substance or treatment that reduces inflammation or swelling. Antioxidants are substances that can prevent or slow damage to cells caused by free radicals, unstable molecules that the body produces as a reaction to environmental and other pressures. They are sometimes called "free-radical scavengers. Therefore, it is of interest to analyse the anti-inflammatory and antioxidant properties of Andrographis echioides and Andrographis paniculata. Protease inhibitor activity was done by bovine serum albumin was added to 100µl of plant sample with increase in concentrations (100-500µg/ml). Invitro antioxidant activity was done by DPPH free radical scavenging assay. 200 µL of 0.1 mM DPPH prepared in methanol was added to 100 µL of the plant extract with increase in concentration. Based on the results from the present study, it can be concluded that A.echioides is found to be a good natural antioxidant source and A. paniculata is found to be a good anti-inflammatory source. However, both the plant A.echioides and A.paniculata have these properties. Data shows that both A.echioides and A. paniculata have potential anti-inflammatory and antioxidant activity which could be due to the presence of bioactive compounds present in the plant extracts.

Low yield but high levels of multidrug resistance in urinary tract infections in a tertiary hospital, Nepal

SETTING

There are concerns about the occurrence of multidrug resistance (MDR) in patients with urine tract infections (UTI) in Nepal.

OBJECTIVE

To determine culture positivity, trends in MDR among Escherichia coli and Klebsiella pneumoniae infections and seasonal changes in culture-positive UTI specimens isolated from 2014 to 2018 at the B P Koirala Institute of Health Sciences, Dharan, Eastern Nepal.

DESIGN

This was a cross-sectional study using secondary laboratory data.

RESULTS

Among 116,417 urine samples tested, 19,671 (16.9%) were culture-positive, with an increasing trend in the number of samples tested and culture positivity. E. coli was the most common bacteria (54.3%), followed by K. pneumoniae (8.8%). Among E. coli and K. pneumoniae isolates, MDR was found in respectively 42.5% and 36.0%. MDR was higher in males and people aged >55 years, but showed a decreasing trend over the years. The numbers of isolates increased over the years, with a peak always observed from July to August.

CONCLUSION

Low culture positivity is worrying and requires further work into improving diagnostic protocols. Decreasing trends in MDR are a welcome sign. Information on seasonal changes that peak in July-August can help laboratories better prepare for this time with adequate buffer stocks to ensure culture and antibiotic susceptibility testing.

Testicular Atrophy and Hypothalamic Pathology in COVID-19: Possibility of the Incidence of Male Infertility and HPG Axis Abnormalities

Coronavirus disease 2019 (COVID-19), which resulted from the pandemic outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causes a massive inflammatory cytokine storm leading to multi-organ damage including that of the brain and testes. While the lungs, heart, and brain are identified as the main targets of SARS-CoV-2-mediated pathogenesis, reports on its testicular infections have been a subject of debate. The brain and testes are physiologically synchronized by the action of gonadotropins and sex steroid hormones. Though the evidence for the presence of the viral particles in the testicular biopsies and semen samples from COVID-19 patients are highly limited, the occurrence of testicular pathology due to abrupt inflammatory responses and hyperthermia has incresingly been evident. The reduced level of testosterone production in COVID-19 is associated with altered secretion of gonadotropins. Moreover, hypothalamic pathology which results from SARS-CoV-2 infection of the brain is also evident in COVID-19 cases. This article revisits and supports the key reports on testicular abnormalities and pathological signatures in the hypothalamus of COVID-19 patients and emphasizes that testicular pathology resulting from inflammation and oxidative stress might lead to infertility in a significant portion of COVID-19 survivors. Further investigations are required to monitor the reproductive health parameters and HPG axis abnormalities related to secondary pathological complications in COVID-19 patients and survivors.

Deterioration of neuroregenerative plasticity in association with testicular atrophy and dysregulation of the hypothalamic-pituitary-gonadal (HPG) axis in Huntington's disease: A putative role of the huntingtin gene in steroidogenesis

Huntington's disease (HD) is an autosomal dominant progressive neurodegenerative disorder mainly affecting the structure and functions of the striatum, cerebral cortex and hippocampus leading to movement disorders, cognitive dysfunctions and emotional disturbances. The onset of HD has been linked to a pathogenic CAG repeat expansion in the huntingtin (HTT) gene that encodes for the polyglutamine (polyQ) stretches in the huntingtin (Htt) protein. Notably, the neuropathogenic events of the mutant HTT gene appear to be primed during adulthood and magnified along the ageing process. While the normal Htt protein is vital for the neuronal differentiation and neuroprotection, experimental HD models and postmortem human HD brains have been characterized by neurodegeneration and defects in neuroregenerative plasticity in the basal ganglia and limbic system including the hippocampus. Besides gonadal dysfunctions, reduced androgen levels and abnormal hypothalamic-pituitary-gonadal (HPG) axis have increasingly been evident in HD. Recently, ageing-related changes in levels of steroid sex hormones have been proposed to play a detrimental effect on the regulation of hippocampal neurogenesis in the adult brain. Considering its adult-onset nature, a potential relationship between dysregulation in the synthesis of sex steroid hormones and the pathogenesis of the mutant HTT gene appears to be an important clinical issue in HD. While the hippocampus and testis are the major sites of steroidogenesis, the presence of Htt in both areas is conclusively evident. Hence, the expression of the normal HTT gene may take part in the steroidogenic events in aforementioned organs in the physiological state, whereas the mutant HTT gene may cause defects in steroidogenesis in HD. Therefore, this review article comprehends the potential relationship between the gonadal dysfunctions and abnormal hippocampal plasticity in HD and represents a hypothesis for the putative role of the HTT gene in the regulation of steroidogenesis in gonads and in the brain.

Diabetes and pre-diabetes among household contacts of tuberculosis patients in India: is it time to screen them all?

SETTING

Pre-diabetes mellitus (pre-DM) and DM increase the risk of developing tuberculosis (TB). Screening contacts of TB patients for pre-DM/DM and linking them to care may mitigate the risk of developing TB and improve DM management.

OBJECTIVE

To measure the prevalence of pre-DM/DM and associated factors among the adult household contacts (HHCs) of pulmonary TB patients.

METHODS

Between August 2014 and May 2017, adult HHCs of newly diagnosed adult PTB patients in Pune and Chennai, India, had single blood samples tested for glycosylated haemoglobin (HbA1c) at enrolment. DM was defined as previously diagnosed, self-reported DM or HbA1c 6.5%, and pre-DM as HbA1c between 5.7% and 6.4%. Latent tuberculous infection (LTBI) was defined as a positive tuberculin skin test (5 mm induration) or QuantiFERON® Gold In-Tube (0.35 international units/ml).

RESULTS

Of 652 adult HHCs, 175 (27%) had pre-DM and 64 (10%) had DM. Forty (64%) HHCs were newly diagnosed with DM and 48 (75%) had poor glycaemic control (HbA1c 7.0%). Sixty-eight (22%) pre-DM cases were aged 18-34 years. Age 35 years, body mass index 25 kg/m2, chronic disease and current tobacco smoking were significantly associated with DM among HHCs.

CONCLUSIONS

Adult HHCs of TB patients in India have a high prevalence of undiagnosed DM, pre-DM and LTBI, putting them at high risk for developing TB. Routine DM screening should be considered among all adult HHCs of TB.

Clinical and equipment-related factors associated with the adequate peripheral blood stem cell collection in autologous transplant at a tertiary cancer center in Kerala - A retrospective cohort study

BACKGROUND

PBSC collection using apheresis is the preferred source of hematopoietic stem cells transplantation. However, apheresis procedures fail to harvest adequate CD34 yield in 5 to 40% of patients during the first collection. Therefore, this study aimed to study both the clinical- and equipmentrelated factors influencing CD34 yield among the autologous patients and to compare the collection efficiency of two apheresis equipments(Haemonetics MCS+ and Terumo Spectra Optia).

METHODS

Retrospective analysis of 69 patients underwent PBSC collection from 2015 to 2018. Frequency, clinical- and equipment-related factors responsible for adequate CD34+ cells (≥2 x106 cells/kg) yield during the first collection was studied. Factors such as collection efficiency, percentage platelet loss and percentage hemoglobin loss were considered to compare the two apheresis system.

RESULTS

Two-third (72%) patients of the study population had adequate CD34 stem cells yield during the first collection. Factors such as exposure to lenalidomide-based pretreatment regimen, peripheral blood WBC count and CD34 count are associated with the adequate CD34 yield. Optia had a slightly better collection efficiency than MCS+ (50 and 44; p=0.37). Optia had lower product volume (237 vs 298 ml) and lesser procedure duration (277 vs 360 min), whereas the median Hb loss (3.0% and 2.3%) and mean platelet loss (49% and 34%) were higher with MCS.

CONCLUSION

This study infers that the collection efficiency of both the equipments in collecting CD34 stem cells was similar. However, during PBSC collection, procedures using Optia can be preferred to MCS+ on the patients with risk of anemia and thrombocytopenia.

Alarming rates of attrition among tuberculosis patients in public-private facilities in Lahore, Pakistan

Setting: All public-private mix (PPM) facilities caring for tuberculosis (TB) patients in Lahore city, Pakistan, under four models: PPM1 (general practitioners), PPM2 (non-governmental organisations), PPM3 (private hospitals) and PPM4 (others). Objective: To assess the pre-treatment loss to follow-up (LTFU), defined as patients documented in the laboratory registers but not in the treatment registers of any PPM facility, among sputum smear-positive TB patients diagnosed during January-March 2015, and unfavourable treatment outcomes among patients registered for treatment and associated factors. Design: This was a retrospective cohort study reviewing existing programme records. Poisson regression was used to identify factors associated with outcomes. Results: Of 2473 patients diagnosed, 1590 (64%) were lost to follow-up before treatment. This was higher among males (68%) and the elderly (79%), and lower among 'high positives' (smear grading 2+ or 3+, 53%) and in the PPM1 model (34%). Of 883 patients started on treatment, 165 (19%) had unfavourable outcomes: 8% LTFU, 5% treatment failure, 3% died and 3% not evaluated. Previously treated patients (34%) and children (44%) had the worst outcomes. Conclusion: Pre-treatment LTFU was alarmingly high and requires urgent attention, including the development and institution of mechanisms for patient tracking using information and mobile phone technology, and making TB notification mandatory in the private sector.

Potential natural enemies of the invasive rugose spiraling whitefly, Aleurodicus rugioperculatus Martin in India

A invasive rugose spiraling whitefly (RSW) <em>Aleurodicus rugioperculatus</em> Martin (Hemiptera: Aleyrodidae) was found infesting coconut, banana, custard apple and several ornamental plants in Tamil Nadu, Andhra Pradesh and Kerala for the first time in India. The identity of the pest species was determined through morphological and molecular tools. Furthermore cytochrome c oxidase-I gene (658 bp) of RSW was sequenced (GenBank accession number KY209909) which would serve as an ideal molecular diagnostic marker for its identification irrespective of its phenotypic plasticity. During the survey, several natural enemies were recorded and maximum parasitism was recorded by <em>Encarsia guadeloupae</em> Viggiani (Hymenoptera: Aphelinidae) and its COI gene was sequenced and deposited as <em>Encarsia</em> sp. (GenBank accession number KY223606). Per cent parasitism ranged from 20.0 to 60.0 % in different collection locations, highest parasitism being recorded in Kerala as compared to other states. The predators recorded were <em>Mallada</em> sp., few coccinellids and predatory mites. This communication is the first report of the rugose spiraling whitefly, its host plant range and associated natural enemies in India.

Are partners of HIV-infected people being tested for HIV? A mixed-methods research from Gujarat, India

Setting: Four selected antiretroviral therapy (ART) centres of Gujarat State, India, which accounts for 8% of the human immunodeficiency virus (HIV) burden in India. Objectives: 1) To assess the proportion of people living with HIV (PLHIV) whose partners were not tested for HIV; 2) to assess sociodemographic and clinical characteristics of index cases associated with partner testing; and 3) to understand perceived facilitators and barriers to partner testing and make suggestions on how to improve testing from the perspective of the health-care provider. Design: A mixed-method design with a quantitative phase that involved reviewing the programme records of married PLHIV enrolled during 2011-2015, followed by a qualitative phase of key informant interviews. Results: Of 3884 married PLHIV, 1279 (33%) did not have their partners tested for HIV. Factors including index cases being male, illiterate, aged >25 years, belonging to key populations, substance use and being in advanced clinical stages were more likely to be associated with partner non-testing. Non-disclosure of HIV status (due to fear of marital discord) and lack of awareness and risk perception were the key barriers to testing. Conclusion: One third of PLHIV did not have their partners tested for HIV. Several factors were identified as being associated with the non-testing of partners, and solutions were explored that need to be implemented urgently if we are to achieve the 90-90-90 targets and end HIV.

Toxicity and bioefficacy of individual and combination of diversified insecticides against jute hairy caterpillar, Spilarctia obliqua

Toxicity of conventional (profenofos 50 EC and λ-cyhalothrin 5 EC) and non-conventional (flubendiamide 480 SC, chlorantraniliprole 18.5 SC, emamectin benzoate 5 SG) insecticides was determined on the basis of median lethal concentration (LC50) values on third instar larvae of jute hairy caterpillar, Spilarctia obliqua under laboratory conditions. Further, the promising binary insecticides combinations with lesser LC50 values and adequate synergistic activity were evaluated under field conditions. The LC50 values calculated for insecticides viz., chlorantraniliprole, flubendiamide emamectin benzoate, λ-cyhalothrin and profenophos were 0.212, 0.232, 0.511, 0.985 and 3.263 ppm, respectively. Likewise, the LC50 values for flubendiamide with λ-cyhalothrin in 3:1 proportion was most toxic (0.103 ppm) amongst all the other binary combinations with λ-cyhalothrin. Chlorantraniliprole in combination with λ-cyhalothrin at 1:1 proportion (0.209 ppm) was most toxic followed by 3:1 proportion (0.345 ppm). Similarly, emamectin benzoate in combination with λ-cyhalothrin at 1:1 proportion was more toxic (0.271 ppm) than 3:1 ratio (0.333 ppm). Toxicity index of flubendiamide + λ-cyhalothrin (3:1 ratio) was highest (970.87). Bioefficacy of synergistic binary combinations along with individual insecticides established the superiority of profenophos + λ-cyhalothrin (3:1) with 89.12% reduction in infestation and recorded maximum fibre yield 38.67qha' under field condition. Moreover, combination of diverse insecticides group might sustain toxicity against the target insect for longer period with least probability of resistance development.

Greenhouse evaluation of Beauveria bassiana (Balsamo) Vuillemin against Aphis craccivora (Das) on Fenugreek

The bioassay studies were carried out to determine the LC50 and LT50 of Beauveria bassiana against Aphis craccivora on fenugreek under greenhouse conditions. The results revealed that, the cumulative corrected mortality (CCM) was 43.50% at higher concentration (1×1010 spores/ml) and it was 20.85% at lowest concentration (1×104 spores/ml) at one day after treatment (DAT). The CCM decreased with decreasing conidial spore concentration. Likewise, at 2, 3, 4, 5, 6 and 7 DAT, almost same trend was observed. At 7 DAT, the CCM was 85.04% and 55.21% at 1×1010 spores/ml and 1×104 spores/ml, respectively. The LC50 value of B. bassiana against A. craccivora was 1.2×108 spores/ml. Mean lethal time (LT50) values were worked out 73, 89, 97, 112, 126, 138 and 157 hours for 1010, 109, 108, 107, 106, 105 and 104 spores/ml, respectively. By testing the field efficacy of B. bassiana against A. craccivora, this insect pathogenic fungus can be used as potential biocontrol agent for the sustainable management of aphid in fenugreek crop.

Fall Detection with Part-Based Approach for Indoor Environment

In the current scenario, majority of the aged people want to lead independent life, and most of them prefer living at their own home. According to recent case studies, the major cause of casualty among elder people has been due to the accidental falls. Hence, it is eminent to have a fall detection monitoring system at home. The prevailing method for fall detection uses accelerometers to distinguish fall from other day to day activities, these results are more erroneous. In this paper, vision based “Fall detection with part-based approach (FDP)” is proposed to give accurate information about the person activities in the indoor. The proposed scheme uses background subtraction in association with aspect ratio and inclination angle to detect the fall. Moreover, the proposed approach predicts the fall even if the person is occluded by other objects or under self-occluded condition. To detect the person even if only partly visible and occluded by other non-moving objects, part based approach is adapted. To train the system for detection purpose, Cascaded structure of Haar-rectangular features with joint-boosting classifier is utilized. The detection efficiency is measured by precision, recall and accuracy parameters.

Evaluation of a rapid immunochromatographic device for the detection of IgM & IgG antibodies to dengue viruses (DENV) in a tertiary care hospital in south India

This study has evaluated the performance of a rapid immunochromatographic test (ICT) device in detecting antibodies to Dengue virus (DENV) in a tertiary hospital in South India. Sera from hospital attendees, with requests for DENV antibody testing, were tested with the Panbio Dengue Duo Cassette and a reference antibody capture assay for the detection of IgM (Dengue IgM capture ELISA-National Institute of Virology, India) and IgG (Dengue IgG capture ELISA-Panbio Diagnostics Inc., Australia) antibodies. The ICT results were compared with results of antibody capture tests for the detection of the IgM and IgG antibodies, respectively. Accuracy indices for IgM and IgG detection, respectively were -- sensitivity 81.8% and 87.5%, specificity 75.0%, and 66.6%, positive predictive value (PPV) 61.0% and 72.9% and negative predictive value (NPV) 89.6% and 83.9%. The device performs poorly in detection of IgM and IgG antibodies to DENVs and is not recommended for use as a stand-alone diagnostic test.

Structure and microbial synthesis of sub-10 nm Bi2O3 nanocrystals

After the advent of novel chemical and microbial techniques, providing control over grain size and shape of the nanomaterials, several binary-oxide materials have been explored in size less than 10 nm for their tunable physical properties. Bi2O3 nanoparticles have also redrawn attention due to their excellent properties, mostly as optoelectronic material. Here, we report the room-temperature biosynthesis of Bi2O3 nanoparticles in a size range of 5-8 nm by extra-cellularly challenging the plant pathogenic fungus--Fusarium oxysporum with the bismuth nitrate as precursor. The as-synthesized particle-surfaces are inherently functionalized by a robust layer of proteins which provides them very good stability in the aqueous medium. Structural investigation using selected area electron diffraction, high resolution transmission electron microscopy and powder XRD shows that particles are almost perfectly single crystalline and primarily crystallize in alpha-phase with monoclinic structure.

Taiwan's industrial heavy metal pollution threatens terrestrial biota

The bioconcentration levels of essential (Cu, Fe, Mg, Mn, and Zn) and non-essential (As, Cd, Hg, Pb, and Sn) elements have been investigated in different terrestrial biota such as fungi, plant, earthworm, snail, crab, insect, amphibian, lizard, snake, and bat including the associated soil, to investigate the ecosystem health status in Kenting National Park, Taiwan. High bioconcentrations of Cd, Hg, and Sn in snail, earthworm, crab, lizard, snake, and bat indicated a contaminated terrestrial ecosystem. High concentrations of Cd, Hg, and Sn in plant species, effective bioaccumulation of Cd by earthworm, snail, crab and bat, as well as very high levels of Hg found in invertebrates, amphibians, and reptiles revealed a strong influence from industrial pollution on the biotic community. This study for the first time presents data on the impact of heavy metal pollution on various terrestrial organisms in Taiwan.

Evaluation of metal contamination in coastal sediments of the Bay of Bengal, India: geochemical and statistical approaches

Surface sediment samples collected from the inner shelf region of the Bay of Bengal, were analysed for the major elements and total and acetic acid available trace elements (Al, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Si, Zn) to evaluate geochemical processes influencing their distribution. Major elemental analysis showed that the sediments had high concentrations of Si and relatively low concentrations of Al and Fe. Both major elemental and trace metal concentrations indicated that the sediments represent weathered products of granite and charnockite. Normalization of metals to Al indicated relatively high enrichment factors for Pb, Cd, Zn and Cr. The higher proportions of nondetrital Pb (66%), Cd (41%) and Co (28%) reveal metal contamination due to anthropogenic inputs. Factor analysis (FA) identified six possible types of sedimentological and geochemical associations. The dominant factor accounting for 26.9% of the total variance identifies an anthropogenic input and accumulation of nondetrital Cd, Co, Cr, Ni and Pb. Association of these metals with CaCO3 reveals that shell fragments in the surface sediments are likely act as a carrier phase for nondetrital metals. The results are discussed in the context of the sources and pathways of elements in the Bay of Bengal.

Removal of hexavalent chromium using distillery sludge

Batch mode experiments were conducted to study the removal of hexavalent chromium from aqueous and industrial effluent using distillery sludge. Effects of pH, contact time, initial concentration and adsorbent dosage on the adsorption of Cr(VI) were studied. The data obeyed Langmuir and Freundlich adsorption isotherms. The Langmuir adsorption capacity was found to be 5.7 mg/g. Freundlich constants K(f) and n were 2.05 [mg/g(L/mg)(n)] and 3.9, respectively. Desorption studies indicated the removal of 82% of the hexavalent chromium. The efficiency of adsorbent towards the removal of chromium was also tested using chromium-plating wastewater.

Fine structure of human oogonia in the foetal ovary

Foetal ovarian tissue is now being cultured or frozen, to generate oocytes for assisted reproduction, an emerging technology. This study examines the ultrastructure of oogonia at 13-15 weeks of gestation, which could be used as a control for culture and freezing of foetal ovaries. Oogonia are largely located in the ovarian cortex, whilst primordial germ cells (PGC) and somatic follicle cells compose the surface epithelium. Oogonia and PGC have large vesicular nuclei with clear cytoplasm, compared to dense follicle cells, which have polymorphic nuclei. Follicle cells intermingle with oogonia and establish close contacts - beginning of folliculogenesis. Nuclei of oogonia contain one to three highly reticulated nucleoli, reflecting high levels of RNA synthesis at the onset of growth. Rough endoplasmic reticulum (RER) form stacks of cisternae associated with numerous ribosomes. Prominent organelles in the ooplasm are elongated mitochondria with dense matrices and tubular cristate presenting a multilocular appearance. Typical Golgi complexes, dense bodies and clear vacuoles are present and microfilaments are located beneath the plasma membrane. The most remarkable feature of oogonia is that they have typical juxtanuclear centrioles (diplosomes) with dense pericentriolar material, which nucleate microtubules, characteristic of functional centrosomes organizing the cytoskeleton. The mature oocyte has no centrioles, since the maternal centrosome is inactivated or reduced, while the paternal is dominant. Centrioles are most likely involved in mitosis of oogonia.