Biological Elements Research Articles

PTEX helps efficiently traffic haemoglobinases to the food vacuole in Plasmodium falciparum.

A key element of Plasmodium biology and pathogenesis is the trafficking of ~10% of the parasite proteome into the host red blood cell (RBC) it infects. To cross the parasite-encasing parasitophorous vacuole membrane, exported proteins utilise a channel-forming protein complex termed the Plasmodium translocon of exported proteins (PTEX). PTEX is obligatory for parasite survival, both in vitro and in vivo, suggesting that at least some exported proteins have essential metabolic functions. However, to date only one essential PTEX-dependent process, the new permeability pathways, has been described. To identify other essential PTEX-dependant proteins/processes, we conditionally knocked down the expression of one of its core components, PTEX150, and examined which pathways were affected. Surprisingly, the food vacuole mediated process of haemoglobin (Hb) digestion was substantially perturbed by PTEX150 knockdown. Using a range of transgenic parasite lines and approaches, we show that two major Hb proteases; falcipain 2a and plasmepsin II, interact with PTEX core components, implicating the translocon in the trafficking of Hb proteases. We propose a model where these proteases are translocated into the PV via PTEX in order to reach the cytostome, located at the parasite periphery, prior to food vacuole entry. This work offers a second mechanistic explanation for why PTEX function is essential for growth of the parasite within its host RBC.

Experiences of Veteran and Civilian Patients in Exploratory Yoga Sessions for Chronic Pain: A Qualitative Study

ABSTRACT Background Yoga integrates all aspects of self, with biological, mental, intellectual, and spiritual elements. The practice of yoga aligns with the biopsychosocial model of health and, as such, it can be instrumental in pain treatment. Aims The purpose of this qualitative study was to explore perceptions regarding the yoga sessions for chronic pain through thematic content analysis with comparison of gender, veteran or civilian status, and delivery methods. Methods Patients with chronic pain attended a 5-week intensive interdisciplinary chronic pain management program at the Michael G. DeGroote Pain Clinic. Participants were asked to complete six open-ended questions following four weekly 1-h yoga classes, through in-person or virtual delivery. Survey responses were thematically and separately analyzed by reviewers. Results Forty-one (N = 41) participants (56% males, 71% veterans) with an average age of 50.87 (SD 10.10) years provided comments. Nine themes emerged: (1) mind and body are one through yoga practices; (2) meaningful practice of yoga basics is productive for range of motion/movement, tension in joints, and chronic pain; (3) yoga classes provide an enjoyable process of learning; (4) yoga reminds patients of their physical capabilities; (5) routine practices lead to improvements; (6) yoga improved on strategies for chronic pain; (7) yoga can be adapted for each patient; (8) mindset improves to include positive thinking, better focus, and willingness to try new things; and (9) improvements exist for the current yoga programming. Conclusion Findings of the current study were nine qualitative themes that present the experience of patients with chronic pain in the yoga sessions.

Use of random forest for assessing the effect of water quality parameters on the biological status of surface waters

The Water Framework Directive aims to reach good status in European surface waters by 2027. Despite the efforts taken already, the ecological status of surface waters has hardly improved during the last decades. In order to find efficient measures, there is an urgent need to improve our knowledge in understanding the linkage between the anthropogenic factors and the indicators of the ecological status assessment. Due to the complexity of the ecosystems, basic statistical methods (such as linear regression) cannot help in finding relationships between the biological quality elements and the supporting water chemistry parameters. The paper demonstrates that in these cases a machine learning data-driven method can be a promising tool for supporting biological classification. With random forest, the Gini index was used for ranking physico-chemical variables based on their influence on biological elements. Variables that have the biggest Gini index were selected for predicting the biological status of phytoplankton, phytobenthos and macrophytes. Binary classification and predictions were performed on a five-class scale. Predictions tended to be fairly good (errors varied within 8–60%, median 33.3%). A comparative analysis was also made with logistic regression, however, in some cases it led to slightly worse or slightly better predictions. We concluded that due to significant errors, the biological status assessment cannot be replaced completely by model predictions, but the method is sufficient to fill in certain gaps in the data and can help in the planning of biological monitoring systems. The evaluation was performed with Hungarian river and water quality database.

Biological features and elements of the technology of seed production of marigolds (<i>Tagetes patula</i> L.) in the conditions of the Southern Urals

Relevance. One of the priority areas of research at Heterosis Selection LLC is the creation of varieties and the development of regional agricultural technology for growing seed material of flower crops. The article represents the results of the study of intravarietal variability according to 7 structural features of marigolds (Tagetes patula L.) cv. Elena Prekrasnaya under the conditions of the Southern Urals. To develop a methodology of seed production of marigolds in the conditions of the Southern Urals, it is necessary to study a complex of morphological features and identify those that more fully contribute to the preservation and maintenance of the variety.Results. As a result of the study of intravarietal variability, it was found that the most stable traits of the variety of marigolds cv. Elena Prekrasnaya are the height of the plant, the diameter of the inflorescence, and the number of seeds in the inflorescence. Efficient selection when obtaining original seeds of marigolds cv. Elena Prekrasnaya will be when focusing on the signs of plant height and inflorescence diameter. In order to obtain high-quality seeds in the industrial seed production of marigold in the conditions of the Southern Urals, it should be kept in mind that in the period from August 20 to September 1, half of the potential seed yield ripens – 49.4%. The greatest uniformity of seed ripening (37.3% of the total yield) was noted on September 1. The harvesting of inflorescences during this period provided the production of seeds with high sowing qualities.

Smartphone-Based Electrochemical Biosensor for On-Site Nutritional Quality Assessment of Coffee Blends.

This work aimed to develop an easy-to-use smartphone-based electrochemical biosensor to quickly assess a coffee blend's total polyphenols (Phs) content at the industrial and individual levels. The device is based on a commercial carbon-based screen-printed electrode (SPE) modified with multi-walled carbon nanotubes (CNTs) and gold nanoparticles (GNPs). At the same time, the biological recognition element, Laccase from Trametes versicolor, TvLac, was immobilized on the sensor surface by using glutaraldehyde (GA) as a cross-linking agent. The platform was electrochemically characterized to ascertain the influence of the SPE surface modification on its performance. The working electrode (WE) surface morphology characterization was obtained by scanning electron microscopy (SEM) and Fourier-transform infrared (FT-IR) imaging. All the measurements were carried out with a micro-potentiostat, the Sensit Smart by PalmSens, connected to a smartphone. The developed biosensor provided a sensitivity of 0.12 μA/μM, a linear response ranging from 5 to 70 μM, and a lower detection limit (LOD) of 2.99 μM. Afterward, the biosensor was tested for quantifying the total Phs content in coffee blends, evaluating the influence of both the variety and the roasting degree. The smartphone-based electrochemical biosensor's performance was validated through the Folin-Ciocâlteu standard method.

Designing Regenerative Bioadhesives for Tissue Repair and Regeneration

AbstractTissue loss through injury, surgery, and disease motivates the development of new biomaterials to enable tissue repair and regeneration. Emerging at the interface between bioadhesives and regenerative medicine, a new generation of regenerative bioadhesives is created to possess dual functions of seamless tissue adhesion and effective tissue repair. This bioadhesive innovation has wide clinical applications, ranging from wound management to the regeneration of musculoskeletal tissues such as tendons and intervertebral discs. This perspective covers the design principles of regenerative bioadhesives in considering both mechanical and biological elements. Case studies of regenerative bioadhesives for load‐bearing organs such as skin, tendon, and intervertebral discs are presented here. Finally, immediate opportunities and future perspectives are outlined to further advance the field of regenerative bioadhesives.

Deconstructing Eurocentrism in skin pigmentation research via the incorporation of diverse populations and theoretical perspectives.

The evolution of skin pigmentation has been shaped by numerous biological and cultural shifts throughout human history. Vitamin D is considered a driver of depigmentation evolution in humans, given the deleterious health effects associated with vitamin D deficiency, which is often shaped by cultural factors. New advancements in genomics and epigenomics have opened the door to a deeper exploration of skin pigmentation evolution in both contemporary and ancient populations. Data from ancient Europeans has offered great context to the spread of depigmentation alleles via the evaluation of migration events and cultural shifts that occurred during the Neolithic. However, novel insights can further be gained via the inclusion of diverse ancient and contemporary populations. Here we present on how potential biases and limitations in skin pigmentation research can be overcome with the integration of interdisciplinary data that includes both cultural and biological elements, which have shaped the evolutionary history of skin pigmentation in humans.

Auerbach, Lotka, and Zipf: pioneers of power-law city-size distributions

Power-law city-size distributions are a statistical regularity researched in many countries and urban systems. In this history of science treatise we reconsider Felix Auerbach’s paper published in 1913. We reviewed his analysis and found (i) that a constant absolute concentration, as introduced by him, is equivalent to a power-law distribution with exponent approx 1, (ii) that Auerbach describes this equivalence, and (iii) that Auerbach also pioneered the empirical analysis of city-size distributions across countries, regions, and time periods. We further investigate his legacy as reflected in citations and find that important follow-up work, e.g. by Lotka (Elements of physical biology. Williams & Wilkins Company, Baltimore, 1925) and Zipf (Human behavior and the principle of least effort: an introduction to human ecology, Martino Publishing, Manfield Centre, CT (2012), 1949), does give proper reference to his discovery—but others do not. For example, only approximately 20% of city-related works citing Zipf (1949) also cite Auerbach (Petermanns Geogr Mitteilungen 59(74):74–76, 1913). To our best knowledge, Lotka (1925) was the first to describe the power-law rank-size rule as it is analyzed today. Saibante (Metron Rivista Internazionale di Statistica 7(2):53–99, 1928), building on Auerbach and Lotka, investigated the power-law rank-size rule across countries, regions, and time periods. Zipf’s achievement was to embed these findings in his monumental 1949 book. We suggest that the use of “Auerbach–Lotka–Zipf law” (or “ALZ-law”) is more appropriate than “Zipf’s law for cities”, which also avoids confusion with Zipf’s law for word frequency. We end the treatise with biographical notes on Auerbach.

Pathogenesis of cancers derived from thyroid follicular cells.

The genomic simplicity of differentiated cancers derived from thyroid follicular cells offers unique insights into how oncogenic drivers impact tumour phenotype. Essentially, the main oncoproteins in thyroid cancer activate nodes in the receptor tyrosine kinase-RAS-BRAF pathway, which constitutively induces MAPK signalling to varying degrees consistent with their specific biochemical mechanisms of action. The magnitude of the flux through the MAPK signalling pathway determines key elements of thyroid cancer biology, including differentiation state, invasive properties and the cellular composition of the tumour microenvironment. Progression of disease results from genomic lesions that drive immortalization, disrupt chromatin accessibility and cause cell cycle checkpoint dysfunction, in conjunction with a tumour microenvironment characterized by progressive immunosuppression. This Review charts the genomic trajectories of these common endocrine tumours, while connecting them to the biological states that they confer.

The tradition and prospects of studying the mechanism of criminal behavior from the standpoint of modern biosocial interpretation of the phenomenology of human aggression

In recent decades, there has been an increasing interest in the biopsychophysiological side of the criminal's nature in foreign criminology. The representatives of the biosocial trend are focused on advanced developments in the field of studying the biological side of aggressive human behavior. Serious progress has been made in this direction over the past thirty years, primarily due to the discoveries of cognitive neuroscientists, endocrinologists and molecular geneticists. In addition, specialists in the field of human physiology and nutrition have also made some progress in understanding the patterns of interaction of biological and social elements in the formation of the mechanism of aggression. Discoveries in the field of epigenetics can also give a significant impetus to the development of social sciences, which have fundamentally changed researchers' ideas about the role and relationship of the genetic base and the external environment in the mechanism of heredity. All relevant information on this subject is analyzed and summarized in a timely manner by foreign biosocial specialists, expanding, among other things, the criminological discourse in terms of studying the patterns of formation of the mechanism of criminal behavior, as well as individual crime prevention (primarily violent). This article is an attempt to review advanced research in the field of today's biology of human behavior, as well as those measures that are already being implemented (taking into account current scientific information about the socio-biological side of the criminal's nature) abroad in order to minimize the scale of criminal aggression.

Current Status of Omics in Biological Quality Elements for Freshwater Biomonitoring.

Freshwater ecosystems have been experiencing various forms of threats, mainly since the last century. The severity of this adverse scenario presents unprecedented challenges to human health, water supply, agriculture, forestry, ecological systems, and biodiversity, among other areas. Despite the progress made in various biomonitoring techniques tailored to specific countries and biotic communities, significant constraints exist, particularly in assessing and quantifying biodiversity and its interplay with detrimental factors. Incorporating modern techniques into biomonitoring methodologies presents a challenging topic with multiple perspectives and assertions. This review aims to present a comprehensive overview of the contemporary advancements in freshwater biomonitoring, specifically by utilizing omics methodologies such as genomics, metagenomics, transcriptomics, proteomics, metabolomics, and multi-omics. The present study aims to elucidate the rationale behind the imperative need for modernization in this field. This will be achieved by presenting case studies, examining the diverse range of organisms that have been studied, and evaluating the potential benefits and drawbacks associated with the utilization of these methodologies. The utilization of advanced high-throughput bioinformatics techniques represents a sophisticated approach that necessitates a significant departure from the conventional practices of contemporary freshwater biomonitoring. The significant contributions of omics techniques in the context of biological quality elements (BQEs) and their interpretations in ecological problems are crucial for biomonitoring programs. Such contributions are primarily attributed to the previously overlooked identification of interactions between different levels of biological organization and their responses, isolated and combined, to specific critical conditions.

Disaggregated monthly SWAT+ model versus daily SWAT+ model for estimating environmental flows in Peninsular Spain

The Water Framework Directive requires all water bodies in EU countries to ensure the ecological integrity of freshwater ecosystems in all water bodies. A “good” status in water bodies leads to their biological elements to reproduce reference conditions, so quantity and timing should be considered in describing environmental flows. However, the availability of daily natural flow data is one of the major drawbacks, especially in highly water-regulated countries, such as Spain, and hydrological models, such as the Soil and Water Assessment Tool (SWAT+) model, can be used to generate them. This work evaluated three different approaches for obtaining daily flows used to characterise the natural regime and to estimate environmental flows in the Piloña River (northern Spain) and Tagus River (centre Spain) basins: Scenario 1) daily flows simulated by the SWAT+ model calibrated on a monthly scale; Scenario 2) daily flows estimated by applying monthly-to-daily disaggregation techniques from the monthly series obtained from the SWAT+ model calibrated on a monthly scale using Water Rights Analysis Package (WRAP) software; and Scenario 3) daily flows simulated by the SWAT+ model calibrated on a daily scale. The Kling–Gupta efficiency (KGE), percent bias (PBIAS), Nash–Sutcliffe efficiency (NSE), root mean square error (RMSE) and standard deviation ratio (RSR) were used to evaluate the model’s performance. Furthermore, the indicators of hydrologic alteration in rivers (IAHRIS) and the basic flow methods were assessed and compared with those obtained directly using the real data observed at the gauging station. Our results indicated that Scenario 2 outperformed the rest of the approaches for all the statistics used. KGE and NSE varied between 0.78 and 0.92 for both basins in Scenario 2 while these values decreased to 0.50–0.60 for KGE and 0.20–0.40 for NSE in Scenarios 1 and 3. Moreover, PBIAS ranged between 3.24 and 4.47% in validation periods in Scenario 2, while it decreased to −14.64% in Scenario 3. Likewise, Scenario 2 was also observed to show better performance related to both the patterns of the natural regime and the basic flow values, which were generally underestimated by the other scenarios. The methodology proposed provides a valuable tool for evaluating and managing the hydrological and environmental status of river basins.

Loading and Transportation Issues in Horses

Abstract Refusal to load into a trailer or horsebox is a commonly seen behaviour in equines and one which is experienced by laypersons and professionals alike. Transportation of equines is highlighted as a prevalent welfare problem facing UK equines during a recent study. Problems with loading and travelling may occur in any equine at any life stage and may appear as significant issues from the first performance or develop gradually over time, increasing in frequency and intensity of their performance. These issues are likely to be maintained or worsened by repeated exposure to the travelling process and the use of inappropriate methods to attempt to resolve them. Behaviourally these problems present in a variety of ways including signs of stress, displacement and high levels of negative arousal. To fully understand the motivation for the behaviours identified, it is important that social, biological, psychological and functional analyses of the behavioural performance should be considered. Within this, there is also the element of learning, which is a constant aspect of the antecedent, behaviour and consequence continuum. Treatment protocols for travelling related issues should be holistic in nature to address the environmental, social, biological and psychological elements of the behavioural response. Information © The Author 2023

Gemcitabine drug intercalation with ds-DNA at surface of ds-DNA/Pt–ZnO/SWCNTs/GCE biosensor: A DNA-biosensor for gemcitabine monitoring confirmed by molecular docking study

Herein, a facile and highly sensitive electroanalytical tool for monitoring and quantifying the antineoplastic drug gemcitabine in real sample was provided. In this regard, a novel DNA-biosensor based on Pt-doped ZnO decorated single walled carbon nanotubes (Pt–ZnO/SWCNTs) hybrid nanomaterial modification of glassy carbon electrode (GCE) was fabricated. Ds-DNA (Calf Thymus), as a biological recognition element, was decorated onto nanomaterial-modified GCE via layer-by-layer fabrication strategy to attain ultimate biosensor ds-DNA/Pt–ZnO/SWCNTs/GCE. The characterizations confirmed the successful fabrication of hybrid nanomaterial, as well as the modification of electrode surface by fabricated nanomaterial. The electrochemical impedance spectroscopy (EIS) analysis revealed that the nanomaterial modification of GCE surface enhanced the electrical conductivity thanks to the synergistic effects of Pt–ZnO and SWCNTs structures, thereby boosted the electrocatalytic activity of the resultant biosensor. The electrochemical characterization results showed that the suggested biosensor is capable of detecting gemcitabine in a wide concentration range of 0.01–30.0 μM, with a detection limit of 5.0 nM. The intercalation binding mode of Gemcitabine inside guanine and cytosine rich region of DNA receptor was approved by molecular docking study. The results of the experimental data were well congruent with the molecular docking analysis, which showed that the binding mode of gemcitabine drug with ds-DNA was intercalation.

Macrophyte- and Macrozoobenthic-Based Assessment in Rivers: Specificity of the Response to Combined Physico-Chemical Stressors

The importance of adequate biological assessments of rivers based on aquatic assemblages is essential to establish recovery measures. Macrophyte and macroinvertebrate communities react differently in time and in response strength to diverse stressors. Our hypothesis was that each group response is a result of specific and combined abiotic factors and each stressor’s impact. To address the above, both biological quality elements (BQEs) and values of the ecological quality ratio (EQR) were studied in relation to four abiotic parameters and five physico-chemical stressors. Discrepancies of more than one degree between the ecological status assessments of Bulgarian river sites determined using macrophytes and macrozoobenthos were discussed. The RDA analysis showed that altitude had a determining role in shaping the abundance of macrophyte and macrozoobenthos communities. Aquatic flora richness positively correlated with nitrogen enrichment and macroinvertebrate fauna—with altitude and biochemical oxygen demand (BOD). Nutrients and shading were most significant for the ecological status evaluation defined with both macrophytes and macrozoobenthos. Macrophyte-based EQR was related to oxygen concentration and shading, while macroinvertebrate-based EQR was better at sites with coarser substrates. Among tested stressors, mainly total nitrogen and BOD explained the lower macrophyte-based assessment at half of the studied sites. In conditions of increased nitrogen and BOD, but remaining in the range of good status, macrophytes as primary producers gave a faster and stronger response. Despite the differences in the assessment, both BQEs have higher values in conditions of lower BOD and total phosphorus.

Climate change impact on the ecological status of rivers: The case of Albaida Valley (SE Spain)

Understanding the effects of environmental stressors (e.g., potential changes in climate and land use) on ecological status is essential for freshwater management. The ecological response of rivers to stressors can be evaluated by several physico-chemical, biological, and hydromorphological elements as well as computer tools. In this study, an ecohydrological model based on SWAT (Soil and Water Assessment Tool) is used to investigate climate change impact on the ecological status of Albaida Valley Rivers. The predictions of five General Circulation Models (GCMs) each with four Representative Concentration Pathways (RCPs) are employed as input to the model for simulating several chemical and biological quality indicators (nitrate, ammonium, total phosphorus, and the IBMWP (Iberian Biological Monitoring Working Party) index) in three future periods (Near Future: 2025–2049, Mid Future: 2050–2074, and Far Future: 2075–2099). Based on chemical and biological status predicted with the model, the ecological status is determined at 14 representative sites. As a result of increased temperatures and decreased precipitations from most of GCMs projections, the model predicts decreased river discharge, increased concentrations of nutrients, and decreased values of IBMWP for future compared to the baseline period (2005–2017). While most representative sites have poor ecological status (10 sites with poor ecological status and four sites with bad ecological status) in the baseline, our model projects bad ecological status for most representative sites (four sites with poor ecological status and 10 sites with bad ecological status) under most emission scenarios in the future. It should be noted that the bad ecological status is projected for all 14 sites under the most extreme scenario (i.e., RCP8.5) in the Far Future. Despite the different emission scenarios, and all possible changes in water temperature and annual precipitation, our findings emphasize the urgent need for scientifically informed decisions to manage and preserve freshwaters.

#5987 EPIDEMIOLOGICAL AND CLINICAL PROFILE OF PATIENTS REQUIRING EMERGENCY HEMODIALYSIS

Abstract Background and Aims Dialysis can be either programmed or performed in an emergency context, which complicates the management of patients. Our objective was to study the indications as well as the epidemiological, clinical and biological elements of dialysis emergencies. Method This is a retrospective study conducted over a period of 5 months from March 2022 to September 2022 in the nephrology department of the Mongi Slim Hospital La Marsa including patients having had emergency hemodialysis sessions Results We collected a total of 32 cases with an average age of 65 years, ranging from 30 years to 93 years and a sex ratio at 1.06. The majority of patients were transferred from the emergency department (69%) and secondarily from the nephrology (6%) and cardiology (6%) departments. Sixty-five percent of the patients had arterial hypertension, 53% were diabetic, 37% had chronic kidney disease, 28% had cardiovascular complications, and 41% had an active infection with a biological inflammatory syndrome. Emergency hemodialysis was indicated for severe metabolic acidosis in 50% of the cases, threatening hyperkalemia in 41% of the cases, uremic syndrome in 28% of cases, anuria in 28% of cases, and acute lung edema resistant to medical treatment in 19% of cases. Indeed, 47% of the patients had a single dialysis emergency and 53% of them were dialyzed for several interrelated indications. The vascular approach was mainly femoral catheter in 84% of the cases followed by arteriovenous fistula in 13% and jugular catheter in 3%. The average session duration was 3.5 hours with good hemodynamic tolerance for the majority of patients. Five patients required a blood transfusion. Conclusion Severe metabolic acidosis and threatening hyperkalemia were the main indications for emergency hemodialysis. Unfortunately, the majority of our patients were dialyzed via a femoral catheter. It is therefore recommended to insist on the necessity of early preparation of patients for dialysis as early as stage 4 of chronic kidney disease if the patient obviously chooses hemodialysis as the preferred method of epuration.

An axisymmetric metal and metal-oxide grating-structured self-reference fiber optic SPR sensor

An optical-fiber-based surface plasmon resonance (SPR) sensing probe consisting of axisymmetrical grating is proposed and studied theoretically for the detection of the refractive index (RI). The sensing probe is formed by depositing a plasmonic metal layer on a bare core of optical fiber, followed by an axisymmetric grating layer and an analyte. The grating consists of metal and metal oxide in an alternate manner. The proposed structure of a single channel provides two resonance modes in the transmission SPR spectra. It is found that the mode present at the lower wavelength remains fixed, and the mode present at the higher wavelength is varied when the RI of the analyte is varied, so that the previous one works as a reference mode while the latter one works as a sensing mode. These properties provide the self-referencing capability of the proposed RI sensor in ambient conditions. We have calculated the sensitivity, detection accuracy (DA) and signal to width ratio (SWR) using the SPR spectra of various probes of different combinations of plasmonic metal and metal-oxide gratings to enhance the study. The best performing probe is found to be Ag/Cu-ITO. This optimum probe attained a maximum SWR of 42, sensitivity of 5400 nm RIU−1 and DA of 0.08 nm−1 with the self-referencing capability. The optimum probe also works well for a dispersive analyte within the spectral range. The use of metal oxide provides better adsorption of the analyte as well as high sensitivity. The cumulative properties of self-referencing and the metal oxide of the designed probe make it accurate and useful for the detection of biological elements in the ambient atmosphere.

Biofunctionalized Silicon Carbide-Titanium (SiC-Ti) Platforms for the Determination of Enteropathogenic Escherichia coli by an Infrared Biosensor

Escherichia coli (E. coli) may be harmful to humans. Hence, a rapid, low cost, and easy detection method is needed, and optical biosensors are an excellent option. Here a new platform based upon silicon carbide and titanium (SiC-Ti) was used to determine enteropathogenic E. coli by Fourier transform infrared (FTIR) spectroscopy. Self-assembly monolayer (SAM) approach was used to modify the platform. Antibody anti-E. coli flagella were obtained and utilized as the biological recognition element. Three concentrations of bacteria (10, 100, and 1000 CFU/mL) were determined. The detection region was from 1330 to 1480 cm−1, where characteristic bands associated with E. coli were determined. An increase in the absorption intensity was observed with the bacteria concentration, demonstrating suitability for quantitative analysis.

The designation, synthesis, and affinity determination of affinity peptide for anthrax protective antigen.

Detection of anthrax protective antigen is an effective way to diagnose anthracnose, and it plays an important part in the treatment of anthracnose. Affinity peptides, as a miniature biological recognition element, can quickly and effectively detect anthrax protective antigens. Based on computer-aided design technology (CAD), we have herein developed an affinity peptide design strategy for the detection of anthrax protective antigens. Firstly, six high-value mutation sites were determined based on the molecular docking between the template peptide and the receptor, and then the multi-site mutation of amino acids was carried out in order to establish a virtual peptide library. The library was selected by using molecular dynamics simulation and the best designed affinity peptide (code: P24) was found. The theoretical affinity with P24 peptide has increased by 19.8% compared with template peptide. Finally, the affinity with P24 peptide was measured by SPR technology to reach the nanomole level, which verified the effectiveness of the design strategy. The newly designed affinity peptide is expected to be used in the diagnosis of anthracnose.