Analysis of dual-energy mammography subtraction technique for the dose and image quality evaluation using 3D-printed breast phantom.

This study aimed to quantitatively assess the radiation dose using XR-QA2 and the image quality of the dual-energy subtraction mammography technique on an in-house phantom. The analysis was carried out to investigate the effect of targets/filters on dose value and image quality using an in-house phantom made of PLA + as an object representing compressed breasts. All irradiation parameters were performed in the craniocaudal position with manual mode. Mean glandular dose (MGD) was recorded, followed by the calculation of the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and modulation transfer function (MTF) for image quality assessment parameters. The results showed that the image quality was accepted at dose levels within the IAEA and BAPETEN tolerance limit for 60 mm equivalent compressed breast using dual-energy mammography. Furthermore, the target/filter (W/Rh) reduced the dose by 1.03 mGy compared to the Mo/Mo and Mo/Rh with an enhancement in image quality. This indicated that the target/filter (W/Rh) combination was optimal due to the image quality improvement obtained with lower MGD.

Bat coronavirus was detected positive from insectivorous bats in Krau Wildlife Reserve Forest

@#Bats are flying mammals with unique immune systems that allow them to hold many pathogens. Hence, they are recognised as the reservoir of many zoonotic pathogens. In this study, we performed molecular detection to detect coronaviruses, paramyxoviruses, pteropine orthoreoviruses and dengue viruses from samples collected from insectivorous bats in Krau Reserve Forest. One faecal sample from Rhinolophus spp. was detected positive for coronavirus. Based on BLASTN, phylogenetic analysis and pairwise alignment-based sequence identity calculation, the detected bat coronavirus is most likely to be a bat betacoronavirus lineage slightly different from coronavirus from China, Philippines, Thailand and Luxembourg. In summary, continuous surveillance of bat virome should be encouraged, as Krau Reserve Forest reported a wide spectrum of biodiversity of insectivorous and fruit bats. Moreover, the usage of primers for the broad detection of viruses should be reconsidered because geographical variations might possibly affect the sensitivity of primers in a molecular approach.

Bat coronavirus was detected positive from insectivorous bats in Krau Wildlife Reserve Forest.

Bats are flying mammals with unique immune systems that allow them to hold many pathogens. Hence, they are recognised as the reservoir of many zoonotic pathogens. In this study, we performed molecular detection to detect coronaviruses, paramyxoviruses, pteropine orthoreoviruses and dengue viruses from samples collected from insectivorous bats in Krau Reserve Forest. One faecal sample from Rhinolophus spp. was detected positive for coronavirus. Based on BLASTN, phylogenetic analysis and pairwise alignment-based sequence identity calculation, the detected bat coronavirus is most likely to be a bat betacoronavirus lineage slightly different from coronavirus from China, Philippines, Thailand and Luxembourg. In summary, continuous surveillance of bat virome should be encouraged, as Krau Reserve Forest reported a wide spectrum of biodiversity of insectivorous and fruit bats. Moreover, the usage of primers for the broad detection of viruses should be reconsidered because geographical variations might possibly affect the sensitivity of primers in a molecular approach.

Inhibitor-Induced Wavetrains and Spiral Waves in an Extended FitzHugh-Nagumo Model of Nerve Cell Dynamics.

It is well known that the FitzHugh-Nagumo model is one of the simplified forms of the four-variable Hodgkin-Huxley model that can reflect most of the significant phenomena of nerve cell action potential. However, this model cannot capture the irregular action potentials of sufficiently large periods in a one-parameter family of solutions. Motivated by this, we propose a modified FitzHugh-Nagumo reaction-diffusion system by changing its recovery kinetics. First, we investigate the parameter regime to know the existence of the wavetrains. Second, we conceive the occurrence of Eckhaus bifurcations of solutions that divide the solution region into two parts. The essential spectra at different grid points explore the occurrence of bifurcations of the waves. We find that the wavetrains of sufficiently large periods cross the stability boundary. This characteristic phenomenon is absent in the standard FitzHugh-Nagumo model. Finally, we observe a reasonable agreement between the direct PDE simulations and the solutions in the traveling wave ODEs. Furthermore, the model exhibits spiral wave for monotone and non-monotone cases that agrees with the waves observed in cellular activity.

Metal-on-metal hip resurfacing arthroplasty provides excellent long-term survivorship and function in patients with a good-sized femoral head : results of a single, non-designer surgeon's cohort.

AIMS: To establish the survivorship, function, and metal ion levels in an unselected series of metal-on-metal hip resurfacing arthroplasties (HRAs) performed by a non-designer surgeon. METHODS: We reviewed 105 consecutive HRAs in 83 patients, performed by a single surgeon, at a mean follow-up of 14.9 years (9.3 to 19.1). The cohort included 45 male and 38 female patients, with a mean age of 49.5 years (SD 12.5). RESULTS: At the time of review 13 patients with 15 hips had died from causes unrelated to the hip operation, and 14 hips had undergone revision surgery, giving an overall survival rate of rate of 86.7% (95% confidence interval (CI) 84.2 to 89.1). The survival rate in men was 97.7% (95% CI 96.3 to 98.9) and in women was 73.4% (95% CI 70.6 to 75.1). The median head size of the failed group was 42 mm (interquartile range (IQR) 42 to 44), and in the surviving group was 50 mm (IQR 46 to 50). In all, 13 of the 14 revised hips had a femoral component measuring ≤ 46 mm. The mean blood levels of cobalt and chromium ions were 26.6 nmol/l (SD 24.5) and 30.6 nmol/l (SD 15.3), respectively. No metal ion levels exceeded the safe limit. The mean Oxford Hip Score was 41.5 (SD 8.9) and Harris Hip Score was 89.9 (14.8). In the surviving group, four patients had radiolucent lines around the stem of the femoral component, and one had lysis around the acetabular component; eight hips demonstrated heterotopic ossification. CONCLUSION: Our results confirm the existing understanding that HRA provides good long-term survival and function in patients with adequate-sized femoral heads. This is evidenced by a 97.7% survival rate among men (larger heads) in our series at a mean follow-up of 14.9 years. Failure is closely related to head sizes ≤ 46 cm. Cite this article: Bone Jt Open 2022;3(1):68-76.

Numerical bifurcation analysis and pattern formation in a minimal reaction-diffusion model for vegetation.

Model-aided understanding of the mechanism of vegetation patterns and desertification is one of the burning issues in the management of sustainable ecosystems. A pioneering model of vegetation patterns was proposed by C. A. Klausmeier in 1999 (Klausmeier, 1999) that involves a downhill flow of water. In this paper, we study the diffusive Klausmeier model that can describe the flow of water in flat terrain incorporating a diffusive flow of water. It consists of a two-component reaction-diffusion system for water and plant biomass. The paper presents a numerical bifurcation analysis of stationary solutions of the diffusive Klausmeier model extensively. We numerically investigate the occurrence of diffusion-driven instability and how this depends on the parameters of the model. Finally, the model predicts some field observed vegetation patterns in a semiarid environment, e.g. spot, stripe (labyrinth), and gap patterns in the transitions from bare soil at low precipitation to homogeneous vegetation at high precipitation. Furthermore, we introduce a two-component reaction-diffusion model considering a bilinear interaction of plant and water instead of their cubic interaction. It is inspected that no diffusion-driven instability occurs as if vegetation patterns can be generated. This confirms that the diffusive Klausmeier model is the minimal reaction-diffusion model for the occurrence of vegetation patterns from the viewpoint of a two-component reaction-diffusion system.

Modeling the dispersal effect to reduce the infection of COVID-19 in Bangladesh.

In this paper, we propose a four compartmental model to understand the dynamics of infectious disease COVID-19. We show the boundedness and non-negativity of solutions of the model. We analytically calculate the basic reproduction number of the model and perform the stability analysis at the equilibrium points to understand the epidemic and endemic cases based on the basic reproduction number. Our analytical results show that disease free equilibrium point is asymptotically stable (unstable) and endemic equilibrium point is unstable (asymptotically stable) if the basic reproduction number is less than (greater than) unity. The dispersal rate of the infected population and the social awareness control parameter are the main focus of this study. In our model, these parameters play a vital role to control the spread of COVID-19. Our results reveal that regional lockdown and social awareness (e.g., wearing a face mask, washing hands, social distancing) can reduce the pandemic of the current outbreak of novel coronavirus in a most densely populated country like Bangladesh.

Interaction between C-Tb and PPD given concomitantly in a split-body randomised controlled trial.

SETTING: Seven tuberculosis (TB) clinics in South Africa. OBJECTIVE: As both purified protein derivative (PPD) and a Mycobacterium tuberculosis-specific skin test (C-Tb) contain region of difference 1 (RD1) antigens, we conducted a study to evaluate whether there was any interaction between the two during concomitant and separate administration in patients with newly diagnosed culture-positive TB. DESIGN: Adult patients with active TB (n = 456, 20% human immunodeficiency virus infected) were randomised to receive only C-Tb, only PPD, or concomitant injection of both C-Tb and PPD using the Mantoux technique. Indurations were read after 48-72 h. QuantiFERON®-TB Gold In-Tube (QFT) was performed in tandem. RESULTS: Of the 456 study participants, 154 simultaneously received both C-Tb and PPD, 153 only C-Tb and 149 only PPD. There was no effect of concomitant injection of PPD on the mean C-Tb induration (19 mm, 95%CI 17-22 vs. 18 mm, 95%CI 16-21; P = 0.91). In patients with active TB, C-Tb sensitivity (78%) was similar to PPD (81%) and QFT (84%; excluding 82/429 [19%] indeterminate results). All tests showed reduced sensitivity in participants with CD4 <100 cells/µl. CONCLUSION: In patients with active TB, there was no interaction between C-Tb and PPD during concomitant injection of both agents. Sensitivities were similar for PPD and C-Tb.

Urban-rural and socioeconomic variations in the knowledge of STIs and AIDS among Bangladeshi adolescents.

This study used data from the Bangladesh Adolescents Survey 2005 to identify socioeconomic and urban-rural determinants of knowledge regarding sexually transmitted infections (STIs) including HIV/AIDS transmission. A cluster sampling of 11 986 adolescents was conducted from April to August 2005. Data were analyzed using SPSS applying principle component analysis, multivariate logistic regression analysis, and prevalence ratios (PRs) with 95% confidence intervals (CIs). Overall knowledge of transmission of STIs was poor (4.5%), showing urban adolescents having twice the knowledge of rural adolescents (PR = 1.9; 95% CI = 1.6-2.2). HIV/AIDS knowledge level was high (68%), with a 40% higher knowledge among urban adolescents (PR = 1.4; 95% CI = 1.3-1.4). Probability of knowledge of STIs and HIV/AIDS transmission was lowest in 12- to 14-year-old uneducated female household workers of the poorest socioeconomic status in rural settings (0.0002 and 0.064, respectively). The urban-rural factor was more important than the socioeconomic factor. Health promotion and education programs can play an important role in improving the sexual reproductive health knowledge situation.

Alternans and Spiral Breakup in an Excitable Reaction-Diffusion System: A Simulation Study.

The determination of the mechanisms of spiral breakup in excitable media is still an open problem for researchers. In the context of cardiac electrophysiological activities, spiral breakup exhibits complex spatiotemporal pattern known as ventricular fibrillation. The latter is the major cause of sudden cardiac deaths all over the world. In this paper, we numerically study the instability of periodic planar traveling wave solution in two dimensions. The emergence of stable spiral pattern is observed in the considered model. This pattern occurs when the heart is malfunctioning (i.e., ventricular tachycardia). We show that the spiral wave breakup is a consequence of the transverse instability of the planar traveling wave solutions. The alternans, that is, the oscillation of pulse widths, is observed in our simulation results. Moreover, we calculate the widths of spiral pulses numerically and observe that the stable spiral pattern bifurcates to an oscillatory wave pattern in a one-parameter family of solutions. The spiral breakup occurs far below the bifurcation when the maximum and the minimum excited states become more distinct, and hence the alternans becomes more pronounced.

River-margin habitat of Ardipithecus ramidus at Aramis, Ethiopia 4.4 million years ago.

The nature and type of landscape that hominins (early humans) frequented has been of considerable interest. The recent works on Ardipithecus ramidus, a 4.4 million years old hominin found at Middle Awash, Ethiopia, provided critical information about the early part of human evolution. However, habitat characterization of this basal hominin has been highly contested. Here we present new sedimentological and stable isotopic (carbon and oxygen) data from Aramis, where the in situ, partial skeleton of Ar. ramidus (nicknamed 'Ardi') was excavated. These data are interpreted to indicate the presence of major rivers and associated mixed vegetations (grasses and trees) in adjacent floodplains. Our finding suggests that, in contrast to a woodland habitat far from a river, Ar. ramidus lived in a river-margin forest in an otherwise savanna (wooded grassland) landscape at Aramis, Ethiopia. Correct interpretation of habitat of Ar. ramidus is crucial for proper assessment of causes and mechanisms of early hominin evolution, including the development of bipedalism.

Ultrasound guided percutaneous fine needle aspiration biopsy/automated needle core biopsy of abdominal lesions: effect on management and cost effectiveness.

AIMS: This prospective study was designed to determine whether ultrasound (US)-guided percutaneous fine needle aspiration biopsy (PFNAB)/US-guided percutaneous needle core biopsy (PNCB) of abdominal lesions is efficacious in diagnosis, is helpful in treatment choice, to evaluate whether various other investigations can be avoided, especially invasive ones, its time (shortening hospitalization) and cost-effectiveness. MATERIALS AND METHODS: A total 159 US-guided PFNAB (67) and US-guided automated PNCB (92) of abdominal lesions were performed percutaneously in 150 patients; the youngest patient was a 3-month-old female and eldest was a 75-year-old female. The patient selection was irrespective of age, sex, or location of the abdominal lesion. These patients presented with abdominal mass/lesions, suspected malignancy, jaundice, and in some cases, however, biopsy was performed to determine the nature of indeterminate lesion (malignant / benign versus abscesses). They were 47 hepatobiliary, 6 pancreas, 24 gastrointestinal tract (GIT), 20 kidneys and urinary bladder, 20 prostate, 3 lymph nodes, 4 adrenals, 8 retroperitoneal, 13 ovaries, and 9 other types of lesions. We used free-hand technique (without biopsy attachment) in 129 cases, and transrectal and transvaginal with biopsy attachment was used in 30 cases. RESULTS: In 91.99% of cases, US-guided PFNAB/US-guided PNCB contributed significantly to diagnosis in which US-guided PFNAB/US-guided PNCB was the diagnostic test in 23.33% cases. It confirmed a highly suspected diagnosis in 64% patients, and indicated a specific diagnosis that was not suspected in the remaining 36%. In 57.33% cases, the results of US-guided PFNAB/US-guided PNCB, did not alter treatment choice but increased physician confidence in the choice. US-guided PFNAB/US-guided PNCB was responsible in avoiding 107 planned investigations, including 8 laparotomies, with no significant complications and decreasing length of stay and resulting in 20% cost savings. CONCLUSIONS: Thus, the US-guided PFNAB/US-guided PNCB contributed significantly in diagnosis, and in most of the cases it did not change treatment choice but increased clinicians confidence in the choice. We can avoid the number of investigations, decrease morbidity and mortality, shorten hospitalization and cost by using these methods.

Surface plasmon resonance-enhanced fluorescence implementation of a single-step competition assay: demonstration of fatty acid measurement using an anti-fatty acid monoclonal antibody and a Cy5-labeled fatty acid.

The development of a single-step, separation-free method for measurement of low concentrations of fatty acid using a surface plasmon resonance-enhanced fluorescence competition assay with a surface-bound antibody is described. The assay behavior was unexpectedly complex. A nonlinear coverage-dependent self-quenching of emission from surface-bound fluorescent label was deduced from the response kinetics and attributed to a surface plasmon-mediated energy transfer between adsorbed fluorophores, modified by the effects of plasmon interference. Principles of assay design to avoid complications from such effects are discussed. An anti-fatty acid mouse monoclonal antibody reacting to the alkyl chain was prepared and supported on a gold chip at a spacing appropriate for surface-plasmon field-enhanced fluorescence spectroscopy (SPEFS), by applying successively a self-assembled biotinylated monolayer, then streptavidin, then biotinylated protein A, and then the antibody, which was crosslinked to the protein A. Synthesis of a fluorescently (Cy5) tagged C-11 fatty acid is reported. SPEFS was used to follow the kinetics of the binding of the labeled fatty acid to the antibody, and to implement a competition assay with free fatty acid (undecanoic acid), sensitive at the 1 microM scale, a sensitivity limit caused by the low affinity of antibodies for free fatty acids, rather than the SPEFS technique itself. Free fatty acid concentration in human serum is in the range 0.1-1mM, suggesting that this measurement approach could be applied in a clinical diagnostic context. Finally, a predictive, theoretical model of fatty acid binding was developed that accounted for the observed "overshoot" kinetics.

Poverty status and health equity: evidence from rural Bangladesh.

Many studies have examined the health inequities between different social groups, often measured by individual independent variables, such as education, gender, ethnicity, geography, rich, poor, etc. Although inequities are increasingly widening, a few studies have looked at the health inequity between different poverty groups within the poor. The present study, using equity terms, examined the use of health services in two rural areas of Bangladesh. Using a multistage sampling method, a total of 80 villages were selected from the Bogra and Dinajpur sadar thanas (subdistricts) for the study. A total of 4003 households in these villages were visited for data collection on mortality and fertility, while data related to use of health services was collected from a subsample of 1032 households. A poverty index, constructed using three variables (household landholding, education level of head of household, and self-rated categorization of household's annual food security), categorized the households into three groups: extreme poor, moderate poor and non-poor. Overall, the data revealed considerable inequities in many study indicators between the poor and the non-poor. However, inequities of varying degrees were also found between the extreme poor and the moderate poor. Lower levels of inequities were found between the poor and the non-poor in the use of health services, which were easily accessible and free of charge (immunization, vitamin A capsule, etc.). On the whole, the extreme poor were less likely to use health services than the moderate poor and the non-poor, suggesting the need for a more appropriate programme to address their pressing health needs.

Mapping of a discontinuous and highly conformational binding site on follicle stimulating hormone subunit-beta (FSH-beta) using domain Scan and Matrix Scan technology.

This paper describes the application of two novel screening technologies, i.e. Domain Scan (24- and 30-mer peptides) and Matrix Scan (24-mer peptides) technology, in the mapping of a discontinuous epitope on FSH-beta for a series of 20 monoclonal antibodies. 11 out of 20 mAb's, mapping of which was not successful by conventional Pepscan technology (12-mer peptides), showed selective binding to peptide-constructs corresponding to the beta3-loop of FSH in the Domain and/or Matrix Scan. Systematic replacement analysis studies with peptide-construct 57VYETVRVPGCAC-SAc-ADSLYTYPVATQ81 revealed that for most mAb's the amino acids R62, A70, D71, and L73 form the core of the epitope. A Domain Scan performed in the C-O format showed highly selective binding for mAb's 1 and 2 with only three beta1-beta3 peptide-constructs covering the residues 60TVRVPGCAHHADSLY74 in combination with 10IAIEKEECRFAI21, while for mAb 10 binding was observed with peptide-constructs containing the C-terminal residues 97RGLGPSYCSFGEMKE114 in combination with the residues 10IAIEKEECRFAI21. A Matrix Scan of mAb 17 showed that peptides from four different regions on FSH (1st strand beta3-loop, alpha 1-loop, long alpha2-loop, det. loop) showed enhanced binding in combination with several 70ADSL73-containing peptides. BIACORE measurements with mAb's 1, 2, 13, and 17 using a set of 21 different peptide(-construct)s partially confirmed the Domain and Matrix Scan screening results. Only 24- and 33-mer peptides covering both the 1st and 2nd strand of the beta3-loop showed measurable binding. Cyclic beta3-loop peptide mimics were found to bind significantly stronger (Kd approximately 5 microM) than the lineair analogues, in agreement with the fact that the discontinuous epitope is part of a loop structure. Coupling of the lineair beta1-peptide 1oIAIEKEECRFAI21 to the linear beta3-peptide *52TFKELVYETVRVPGCAHHADSLYTYPVATQAH83# via disulfide bond formation showed a 2-3 fold increase in Kd, thus conforming participation of the beta 1-loop in antibody binding for these mAb's.

[Treatment of incisional hernias]. / Traitement des eventrations post-opratoires.

Several therapeutic processes were proposed in the repair of incisional hernia, on the basis of simple joining suture go to the installation of prosthetic mesh while passing by aponeurotic autoplasty according to Welti-Eudel technique. The aim of this study was to report the results of our experiment in the treatment of incisional hernias. It was a retrospective study carried out of January 11th 1996 to December 31, 2000, concerning 35 cases of incisional hernias operated during the study period. The following parameters were studied: age, sex, diameter, technique of repair, morbidty, mortality and the remote follow-up. Average age of our patients was 33 years with extremes of 13 and 53 years. It include 30 womens and 5 mens. The initial operation were dominated by Caesarean (57%). The diameter of incisional hernia varied between 3 and 5 cm in 22.9% of patients, between 5 and 10 cm in 62.8% of paitents, higher than 10 cm in 14.3% of patients. The simple joining suture was carried out in 22.9% of cases, the Welti-Eudel technique in 42.9% of cases and the installation of prosthetic mesh in 34.2% of the cases. Mortality was 5.1% and the morbidity was 34.2% made exclusively by suppuration including 5.1% on prosthetic material. We noted 14.3% of recurence which has occured after repair by simple joining. The Welti-Eudel procedure gives good results in the repair of incisional hernia with small and average dimensions. The installation of prosthetic mesh constitute the treatment of choice because the rate of recurence is weak even null.

Rapid assessment of the prevalence of lower limb clinical rickets in Bangladesh.

This study attempted to measure the prevalence of lower limb clinical rickets using a rapid assessment methodology in Cox's Bazaar, a coastal district of Bangladesh. The study populations were drawn from 28 random villages representing all seven 'thanas' (subdistricts) of the district. Data were collected on 25,891 children and young people aged 1-20 years in two phases. In the first phase, 30 trained, local, non-medical people listed 490 children suffering from visible signs of any physical disability. To achieve this, they demonstrated a multicolored poster showing the features of lower limb clinical rickets to key informants in the villages. In the second phase, two teams of medically trained people (physicians), each with one male and one female, validated the above cases for rickets. They verified and validated 278 cases in five thanas. Due to inclement weather and floods, they could not visit the other two thanas. Based on these data, the adjusted prevalence rates for lower limb clinical rickets were calculated to be 931 per 100,000 population (95% confidence intervals 795-1067). The prevalence was highest (1215) in children aged 1-4 years and lowest (498) amongst 17-20 year olds. Females had lower prevalence than males. Based on the study experience, a quick investigation using a similar methodology was performed in five other districts (Sunamganj, Noakhali, Bhola, Jessore and Gaibandha), and clinical signs of lower limb rickets were found in Sunamganj and Jessore. It thus indicates that rickets may be endemic, not only in Cox's Bazaar but also in some other parts of Bangladesh. The methodology used for this study was found to be rapid, simple, replicable and inexpensive.

Development and characterization of monoclonal antibodies to chicken riboflavin carrier protein.

Several monoclonal antibodies (MAbs) specific to chicken riboflavin carrier protein (cRCP) were developed and characterized. Of the several MAbs analyzed, four were directed against nonoverlapping epitopes as demonstrated by MAb inhibition assay. Many of these epitopes appeared to be in close proximity and only three were situated at distinct part of the molecule as revealed by sandwich assay. A combination of chemical modification, peptide cleavage by chemical and enzymatic methods, was used to analyze the possible antigenic structure recognized by these MAbs. An assembled epitope spanning the region 22-87 forms the antigenic site recognized by 4999.1; while MAb 5555.3 interacted with the C-terminal peptide 203-219.