Isolation Strategies Research Articles

Bioassay-guided isolation of anti-leukemic steroids from Aglaia abbreviata by inducing apoptosis

The strategy of bioactivity-guided isolation is widely used to obtain active compounds as quickly as possible. Thus, the inhibitory effects on human erythroleukemia cells (HEL) were applied to guide the isolation of the anti-leukemic compounds from Aglaia abbreviata. As a result, 19 compounds (16 steroids, two phenol derivatives, and a rare C12 chain nor-sesquiterpenoid), including 13 new compounds, were isolated and identified based on spectroscopic data analysis, single-crystal X-ray diffraction data, and electronic circular dichroism (ECD) calculations. Among them, 9 steroids exhibited good selective anti-leukemic activity against HEL and K562 (human chronic myeloid leukemia cells) cells with IC50 values between 2.29 ± 0.18 μM and 19.58 ± 0.13 μM. Notably, all the active compounds had relatively lower toxicity on the normal human liver cell line (HL-7702). Furthermore, five compounds (1, 4, 8, 10, and 19) displayed good anti-inflammatory effects, with IC50 values between 7.15 ± 0.16 and 27.1 ± 0.37 μM. An α,β-unsaturated ketone or a 5,6Δ double bond was crucial for improving anti-leukemic effect from the structure–activity relationship analysis. The compound with the most potential, 14 was selected for the preliminary mechanistic study. Compound 14 can induce apoptosis and cause cell cycle arrest. The expression of the marker proteins, such as PARP and caspase 3, were notably effected by this compound, thus inducing apoptosis. In conclusion, our investigation implied that compound 14 may serve as a potential anti-leukemia agent.

An aptamer-based SERS method for rapid screening and identification of pathogens assisted by machine learning technique with robustness evaluation

Pathogen testing is one of the compulsory items for the quality control of pharmaceutical products. Up to now, rapid screening and identification of low-concentration pathogen contaminations is still full of challenge. Herein, an aptamer-coated magnetic beads (Apt-MBs)-based isolation strategy combined with culture medium turbidity observing and label-free SERS detection technique has been developed for rapid screening and detection of Escherichia coli, Salmonella Typhimurium and Staphylococcus aureus. Apt-MBs were employed for capturing and isolation of target pathogens. Then, with a simple enrichment process, the potential pathogens could be screened out by observing the turbidity of liquid culture medium. The presumptive bacteria species was furtherly identified via a silicon-based SERS chip couple with an optimized machine learning model, which was selected by directly evaluating the model’s generalization ability on test data. The results demonstrated that SoftMax classifier had the optimal performance with the recognition accuracy of 100 % for all samples. Finally, the method was successfully applied for identification of pathogens at ∼1 CFU spiked level in drug samples within 24 h, which is much shorter than that of the standard culture-based method (3–5 d). Therefore, the developed method showed a promising application in monitoring pathogen levels in pharmaceutical industries.

New strategies for Helicobacter pylori isolation and sequencing analysis for virulence genes contributing to its pathogenicity.

Helicobacter pylori is a fastidious pathogen that is required a complicated medium for growth. Invading epithelial cells of the stomach. H. pylori virulence factors are classified by function, acidic resistivity, adhesion, chemotaxis and motility, molecular mimicry, immunological invasion and modulation, and toxins formation such as cytotoxin-associated genes A (cagA) and vacuolating cytotoxin A (vacA). This study aims to determine a simple and innovative technique to isolate H. pylori from gastric biopsies and assess pathogenicity by virulence factor gene detection. A total of 200 patients who were suspected of having H. pylori infection had two antral gastric biopsies undertaken. A rapid urease test (RUT) was used for one, and Brain Heart Infusion broth (BHI) was used to cultivate the other. The molecular study included diagnostics utilizing the 16sRNA housekeeping gene along with the identification of the virulence factors genes (cagA, cagT, and vacA) and sequencing, RESULT: Of the 200 antral gastric biopsies collected, 135 were positive rapid urease tests, and 17 H. pylori isolates were successfully obtained from 135 biopsies. The 16SrRNA as a housekeeping gene is confirmed, and about 53%, 70.5%, and 82.3% of the 17 isolates show carrying cagA, cagT, and vacA genes, respectively. All peptic ulcer isolates have the cagA gene, while Gastroesophageal Reflux Disease (GERD) and non-peptic ulcer disease (NPUD) isolates show the lack of the cagA gene. All bacteria, which were isolated from peptic ulcer, nodular gastritis, and gastritis patients, have a vacA gene. The effective method for isolating H. pylori is centrifuging the transport broth after 24h of incubation. The cagA toxin causes peptic ulcer while vacA toxin induces several histopathological changes in the stomach. Three virulence genes were present in all peptic ulcer-causing bacteria, while only one or none were present in the GERD and NPUD biopsy isolates.

Experimental study on a cable-stayed bridge isolated with the combination of elastoplastic cables and fluid viscous dampers in the transverse direction

It is usually challenging to design an effective transverse isolation strategy that needs both large restoring force and large deformation capacity for cable-stayed bridges to meet the requirements under regular operation and earthquakes. The authors proposed a novel transverse isolation device that combines elastoplastic cables and fluid viscous dampers (FVDs) to address this challenge. The elastoplastic cables are adopted to control the relative displacements at the girder-pylon connections in the transverse direction under both regular operation and earthquakes. FVDs are responsible for dissipating input seismic energy. To further validate the effectiveness of the proposed isolation system under both far and near-fault ground motions, shake table tests were conducted for a cable-stayed bridge with a scale ratio of 1/20. Details of the scaled model for the isolated and fixed systems, including dimensions of the components, additional mass arrangement, instrumentations, and boundary conditions, are briefly described. Seismic responses are recorded for each test case, such as accelerations and displacements of the pylons and girder, hysteretic responses of the combined devices, and strain responses of the pylon rebars. The experimental results indicate that the transverse boundary conditions have significant effects on the seismic responses of the girder, and the high-mode content of ground motions mainly dominates the seismic responses of the pylons. In addition, the isolated system effectively reduces the seismic responses at the bottom of the pylons, and the effectiveness of the isolation is becoming more evident with an increase in the PGA of the ground motions.

Advances in Single-Cell Techniques for Linking Phenotypes to Genotypes.

Single-cell analysis has become an essential tool in modern biological research, providing unprecedented insights into cellular behavior and heterogeneity. By examining individual cells, this approach surpasses conventional population-based methods, revealing critical variations in cellular states, responses to environmental cues, and molecular signatures. In the context of cancer, with its diverse cell populations, single-cell analysis is critical for investigating tumor evolution, metastasis, and therapy resistance. Understanding the phenotype-genotype relationship at the single-cell level is crucial for deciphering the molecular mechanisms driving tumor development and progression. This review highlights innovative strategies for selective cell isolation based on desired phenotypes, including robotic aspiration, laser detachment, microraft arrays, optical traps, and droplet-based microfluidic systems. These advanced tools facilitate high-throughput single-cell phenotypic analysis and sorting, enabling the identification and characterization of specific cell subsets, thereby advancing therapeutic innovations in cancer and other diseases.

Target-guided isolation and purification of cyclooxygenase-2 inhibitors from Meconopsis integrifolia (Maxim.) Franch. by high-speed counter-current chromatography combined with ultrafiltration liquid chromatography.

Meconopsis integrifolia (Maxim.) Franch. is used extensively in traditional Tibetan medicine for its potent anti-inflammatory properties. In this study, six cyclooxygenase-2 (COX-2) inhibitors were purified from M. integrifolia using high-speed counter-current chromatography guided by ultrafiltration liquid chromatography (ultrafiltration-LC). First, ultrafiltration-LC was performed to profile the COX-2 inhibitors in M. integrifolia. The reflux extraction conditions were further optimized using response surface methodology, and the results showed that the targeted COX-2 inhibitors could be well enriched under the optimized extraction conditions. Then the six target COX-2 inhibitors were separated by high-speed countercurrent chromatography with a solvent system composed of ethyl acetate/n-butanol/water (4:1:4, v/v/v. Finally, the six COX-2 inhibitors, including 21.2mg of 8-hydroxyluteolin 7-sophoroside, 29.6mg of 8-hydroxyluteolin 7-[6'''-acetylallosyl-(1→2)-glucoside], 42.5mg of Sinocrassoside D3, 54.1mg of Hypolaetin 7-[6'''-acetylallosyll-(l→2)-3''-acetylglucoside, 30.6mg of Hypolaetin 7-[6'''-acetylallosyll-(l→2)-6''-acetylglucoside and 17.8mg of Hypolaetin were obtained from 500mg of sample. Their structures were elucidated by 1 H-NMR spectroscopy. This study reveals that ultrafiltration-LC combined with high-speed counter-current chromatography is a robust and efficient strategy for target-guided isolation and purification of bioactive molecules. It also enhances the scientific understanding of the anti-inflammatory properties of M. integrifolia but also paves the way for its further medicinal applications.

Resource-Efficient Use of Residues from Medicinal and Aromatic Plants for Production of Secondary Plant Metabolites.

Although people's interest in green and healthy plant-based products and natural active ingredients in the cosmetic, pharmaceutical, and food industries is steadily increasing, medicinal and aromatic plants (MAPs) represent a niche crop type.It is possible to increase cultivation and sales of MAPs, by utilizing plant components that are usually discarded. This chapter provides an overview of studies concerning material flows and methods used for sustainable production of valuable metabolites from MAPs between 2018 and 2023. Additionally, it describes new developments and strategies for extraction and isolation, as well as innovative applications. In order to use these valuable resources almost completely, a systematic recycling of the plant material is recommended. This would be a profitable way to increase sustainability in the cultivation and usage of MAPs and provide new opportunities for extraction in plant science.

Validation Strategy for Pulmonary Vein Isolation in Patients With Paroxysmal Atrial Fibrillation in Long-Term Maintaining Sinus Rhythm: A Randomized Controlled Study.

Background: Data comparing the outcomes of loose versus rigorous validation strategies for pulmonary vein isolation (PVI) in patients with paroxysmal atrial fibrillation (PAF) are limited. We aimed to prospectively assess the effectiveness of loose versus rigorous validation for PVI in patients with PAF with a maintained sinus rhythm. Methods: Patients (n = 117) with PAF were randomized to receive either loose validation (n = 59) or rigorous validation (n = 58) after PVI. The presence of dormant conduction in loose validation was assessed only by adenosine administration followed by isoproterenol infusion. The complete absence of pulmonary vein (PV) potentials in rigorous validation was confirmed by the combination of the Lasso catheter with isoproterenol plus adenosine. Dormant conduction, revealed by validation after PVI, was ablated until all reconnections were eliminated. Results: The procedure time in the rigorous validation group was greater than that in the loose validation group (161.3 ± 52.7 min vs. 142.5 ± 37.6 min, p=0.03, respectively). After successful PVI, the detection of dormant PV reconnections in the rigorous validation group was significantly greater than that in the loose validation group (69.0% vs. 37.3%, p=0.001). However, after reisolation of the sites of dormant PV conduction, the postablation recurrence rates in 1.3 years were similar between the groups (79.2% vs. 83.6%, p=0.67). Conclusion: Rigorous validation can reveal dormant conduction in more than two-thirds of patients with PAF undergoing PVI. However, rigorous validation and additional ablation of the resulting connections do not improve long-term outcomes when a protocol that includes electrophysiological confirmation and pharmacological validation is used.

Method of Isolation and In Vitro Culture of Primordial Follicles in Bovine Animal Model.

The mammalian ovary is a substantial source of oocytes arranged into follicles at various stages of folliculogenesis, from the primordial to the ovulatory ones. Primordial follicles constitute the most abundant source of gametes inside the mammalian ovary at any given time.The isolation of a high number of primordial follicles, together with the development of protocols for in vitro follicle growth, would provide a powerful tool to fully exploit the female reproductive potential and boost the rescue and restoration of fertility in assisted reproduction technologies in human medicine, animal breeding, and preservation of threatened species. However, the most significant limitation is the lack of efficient methods for isolating a healthy and homogeneous population of viable primordial follicles suitable for in vitro culture. Here, we provide a fast and high-yield strategy for the mechanical isolation of primordial follicles from limited portions of the ovarian cortex in the bovine animal model.

Optimization strategy for purification and isolation of active lectin from Colocasia esculenta L. Schott rhizome

Lectins are non-enzymatic proteins that attach to carbohydrates and exhibit diverse biological activities and are found in Colocasia esculenta rhizomes. This study determined the optimal conditions for purifying and isolating lectin from C. esculenta rhizome. The methods involved the preparation of crude extracts with variations of salting in, salting in followed by salting out, and precipitation with phosphate buffer saline (PBS), then all extracts were analyzed with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Purification and isolation were carried out using ion exchange chromatography with pH variations of 8.3, 7.2, and 9.6. The isolates were evaluated using the bicinchoninic acid method, SDS-PAGE, and hemagglutination test. The results of SDS-PAGE showed that the best extraction method involved the use of PBS as indicated by the presence of a prominent band at ~12.5kDa. During pH optimization for purification, the best isolate was obtained at pH 9.6. This was observed by the appearance of a single band with ~12.5kDa MW on 12% SDS-PAGE gel and occurrence of an agglutination reaction at the hemagglutination stage. The total protein content of lectins ranged from 1284.83 to 2947.33 μg/mL. The C. esculenta rhizome contains lectins as active protein compounds. The best isolation condition is by extraction with PBS solvent and purification using ion exchange chromatography at pH 9.6.

Full Decoupling High-Order Dynamic Mode Decomposition for Advanced Static and Dynamic Synergetic Fault Detection and Isolation

Real industrial processes often present coupled static and dynamic characteristics, leading to significant challenges for fault detection and isolation. However, traditional dynamic modeling methods may lead to the coupling problem of statics and dynamics, which provide ambiguous process status descriptions and incorrect fault isolation results. In this work, a novel full decoupling high-order dynamic mode decomposition (FDHODMD) method is developed for fault detection and isolation of dynamic processes. Different from the existing dynamic methods, the proposed FDHODMD can separate the high-order dynamic information from static information. First, the static characteristics are separated by discarding the decomposed features corresponding to smaller singular values. Then, a high-order dynamic model is established to present the temporal relationships between variables. In this way, the effect of static characteristics on dynamics analysis can be eliminated. Accordingly, from both static and dynamic perspectives, multiple statistics are designed to comprehensively detect the anomalies and provide an explicit status identification. In addition to the static fault isolation strategy, a dynamic fault isolation strategy is designed to recognize the fault variables after detecting the deviation, which divides the complex dynamic system into several individual dynamic modes to avoid the interaction of dynamic characteristics. Thereupon, the contributions of different variables to each dynamic mode can be clearly presented to recognize the fault variables. Finally, the validity of the proposed method is illustrated through both a numerical case and a real industrial process. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Note to Practitioners</i> —In industrial processes, the static and dynamic characteristics of data are often coupled. This work presents a FDHODMD method, which can be considered the high-order version of DMD, to achieve the decoupling of dynamics and statics while extracting high-order dynamic characteristics. Then the proposed fault detection strategy designs multiple statistics for monitoring the process from both dynamic and static perspectives, which ensures the safe operation of industrial processes. After detecting the anomaly, the proposed fault isolation strategy can recognize the fault variables separately dominating the dynamic and static deviation, which may help engineers locate the fault source.

Enhancing the Conventional Culture: the Evaluation of Several Culture Media and Growth Conditions Improves the Isolation of Ruminal Bacteria

The rumen microbiota is critical in cattle digestion. Still, its low cultivability makes it difficult to study its ecological function and biotechnological potential. To improve the recovery of ruminal microorganisms, this study combined the evaluation of several cultivation parameters with metabarcoding analysis. The parameters tested comprised eight media cultures, three sample dilutions (10−2, 10−6, 10−12), and two incubation times (3 and 7 days). Bacterial populations were determined through Illumina sequencing of 16S rRNA from three biological replicates. The results indicate that none of the culture media recovered all rumen populations and that there was an altered relative abundance of the dominant phyla. In the rumen, Bacteroidetes and Firmicutes comprised 75% and 15% of the relative abundance, respectively, while in the culture media, these were 15% and 60%, respectively. Principal coordinate analysis (PCoA) of the bacterial community revealed significant shifts in population composition due to dilution, with 10−2 and 10−6 dilutions clustered closely while the 10−12 dilution differed markedly. In contrast, incubation duration did not influence population diversity. According to the results, two media, CAN and KNT, were selected based on their ability to recover more similar populations compared to the rumen sample. The metataxonomic study showed that CAN media had consistent reproducibility over time, while KNT showed enrichment of different taxa due to the use of rumen fluid as a substrate. From these, 64 pure cultures were obtained and 54 were identified through 16S rRNA gene sequencing. Being Streptococcus the most frequently isolated genus, this prevalence contrasts with the liquid media composition, underscoring the importance of refining single colony isolation strategies. Although no culture medium could replicate the native rumen bacterial population perfectly, our findings highlight the potential of CAN and KNT media in recovering populations that are more closely aligned to natural rumen conditions. In conclusion, our study emphasizes the importance of integrating molecular approaches in selecting suitable cultivation media and parameters to depict rumen bacteria accurately.

Amplicon-guided isolation and cultivation of previously uncultured microbial species from activated sludge.

Biological wastewater treatment relies on complex microbial communities that assimilate nutrients and break down pollutants in the wastewater. Knowledge about the physiology and metabolism of bacteria in wastewater treatment plants (WWTPs) may therefore be used to improve the efficacy and economy of wastewater treatment. Our current knowledge is largely based on 16S rRNA gene amplicon profiling, fluorescence in situ hybridization studies, and predictions based on metagenome-assembled genomes. Bacterial isolates are often required to validate genome-based predictions as they allow researchers to analyze a specific species without interference from other bacteria and with simple bulk measurements. Unfortunately, there are currently very few pure cultures representing the microbes commonly found in WWTPs. To address this, we introduce an isolation strategy that takes advantage of state-of-the-art microbial profiling techniques to uncover suitable growth conditions for key WWTP microbes. We furthermore demonstrate that this information can be used to isolate key organisms representing global WWTPs.

A novel strategy by combining foam fractionation with high-speed countercurrent chromatography for the rapid and efficient isolation of antioxidants and cytostatics from Camellia oleifera cake

Camellia oleifera cake is a by-product, which is rich in functional chemical components. However, it is typically used as animal feed with no commercial value. The purpose of this study was to isolate and identify compounds from Camellia oleifera cake using a combination of foam fractionation and high-speed countercurrent chromatography (HSCCC) and to investigate their biological activities. Foam fractionation with enhanced drainage through a hollow regular decahedron (HRD) was first established for simultaneously enriching flavonoid glycosides and saponins for further separation of target compounds. Under suitable operating conditions, the introduction of HRD resulted in a threefold increase in enrichment ratio with no negative effect on recovery. A novel elution-extrusion countercurrent chromatography (EECCC) coupled with the consecutive injection mode was established for the successful simultaneous isolation of flavonoid glycosides and saponins. As a result, 38.7 mg of kaemferol-3-O-[2-O-D-glucopyranosyl-6-O-α-L-rhamnopyranosyl]-β-D-glucopyranoside (purity of 98.17%, FI), 70.8 mg of kaemferol-3-O-[2-O-β-D-xylopyranosyl-6-O-α-L-rhamnopyranosyl]-β-D-glucopyranoside (purity of 97.52%, FII), and 560 mg of an oleanane-type saponin (purity of 92.32%, FIII) were separated from the sample (900 mg). The present study clearly showed that FI and II were natural antioxidants (IC50 < 35 μg/mL) without hemolytic effect. FIII displayed the effect of inhibiting Hela cell proliferation (IC50 < 30 μg/mL). Further erythrocyte experiments showed that this correlated with the extremely strong hemolytic effect of FIII. Overall, this study offers a potential strategy for efficient and green isolation of natural products, and is beneficial to further expanding the application of by-products (Camellia oleifera cake) in food, cosmetics, and pharmacy.

The Impact of the COVID-19 Pandemic on Medical Education: a Systematic Review of Distance Learning, Student’s Perceptions, and Mental Health

Introduction: the COVID-19 pandemic has impacted on mortality and several adverse health outcomes. It has also affected education as schools and universities had to adapt to remote learning due to social isolation strategies. Objective: to analyze the pandemic’s impact on medical education including undergraduate and graduate students and lecturers, as follow: i) teaching methods adopted by education institutes during shutdown, ii) students and lecturers’ perceptions and iii) impacts on students’ mental health. Methods: this systematic review includes the following study designs: cross-sectional, surveys, case-control, cohort, and clinical trials. The literature search was performed in four databases: PubMed, Scopus, Embase, and SciELO . The risk of bias and the quality of the evidence were evaluated. Results: a total of 1,576 articles were identified through searching databases, and 40 articles were included. We found the use of several teaching methods such as virtual platforms and social media, pre-recorded videos, discussion forums and others. Student’s challenges related to interference during online study such as family distractions, lack of a study room, challenges with internet connectivity, difficulties in communication between students and lecturers, gaps encountered during clinical skills learning. Lecturers’ challenges were difficulty in grasping students’ progress and learning outcomes and the lack of experience in online teaching. Only five studies explored mental health issues of medical students and found the occurrence of depression, anxiety, and stress. However, their prevalence was not comparable due to the use of different diagnostic instruments. Conclusion: there has been a wide range of teaching methods implemented for distance learning of medical students globally. The perceptions of medical students about these methods and their impact were also varied. Infrastructure, family, and curriculum problems represented the greatest difficulties in adherence and satisfaction with distance learning. However, the flexibility of digital learning was one of the factors that helped reduce these problems. Regarding mental health, the occurrence of anxiety, depression, and stress was reported.

A Compliant Self-Stabilization Nanopositioning Device With Modified Active–Passive Hybrid Vibration Isolation Strategy

Micro/mini light-emitting diodes (LEDs) display panel inspection and repairs have a high demand for vibration isolating devices to protect industrial-level atomic force microscopes (AFM scanning head) against vibrations. The motivation of this work is to combine the advantages of both passive and active vibration isolation strategies to improve inspection performance. The developed self-stabilization device achieves this objective with a design that incorporates a suspension-type passive vibration isolation unit and integrates it with the modified active–passive hybrid (MAPH) vibration isolation strategy using piezoelectric ceramics (PZT) and voice coil motors (VCM) as compensators. First, the design, modeling, and optimization of a self-stabilization device are presented based on the MAPH vibration isolation strategy. To satisfy the requirements of vibration isolation performance and a lightweight design, a multiobjective optimization task was conducted. Next, a tailor-made double compensating PID controller was designed to allow this mechanism to run in the MAPH method to effectively isolate vibrations. Finally, a series of validation experiments, including passive vibration isolation performance tests and MAPH closed-loop tests, were applied. From 1 to 500 Hz, more than 98% frequency domain achieved a vibration isolation rate of 90%, the vibration amplification effect of the passive vibration isolation was significantly suppressed, the steady-state positioning accuracy reached <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm 0.1\;\mu$</tex-math></inline-formula> m, load capacity was up to 2.5 kg, the attenuation ratio of the disturbances reached up to 70%, and the heat of the VCM was effectively reduced. All results comprehensively confirmed that the developed compliant MAPH vibration isolation system has achieved a satisfactory self-stabilization function.

Application Potential of Extracellular Vesicles Derived From Mesenchymal Stem Cells in Renal Diseases.

The high prevalence and complex etiology of renal diseases already impose a heavy disease burden on patients and society. In certain kidney diseases such as acute kidney injury and chronic kidney disease, current treatments are limited to slowing rather than stabilizing or reversing disease progression. Therefore, it is crucial to study the pathological mechanisms of kidney disease and discover new therapeutic targets and effective therapeutic drugs. As cell-free therapeutic strategies are continually being developed, extracellular vesicles derived from mesenchymal stem cells (MSC-EVs) have emerged as a hot topic for research in the field of renal diseases. Studies have demonstrated that MSC-EVs not only reproduce the therapeutic effects of MSCs but also localize to damaged kidney tissue. Compared to MSCs, MSC-EVs have several advantages, including ease of preservation, low immunogenicity, an inability to directly form tumors, and ease of artificial modification. Exploring the detailed mechanisms of MSC-EVs by developing standardized culture, isolation, purification, and drug delivery strategies will help facilitate their clinical application in kidney diseases. Here, we provide a comprehensive overview of studies about MSC-EVs in kidney diseases and discuss their limitations at the human nephrology level.

Bio-SELEX: A Strategy for Biomarkers Isolation Directly from Biological Samples.

Bio-SELEX is a revolutionary method for the discovery of novel biomarkers within biological samples, offering profound insights into diagnosing both infectious and non-infectious diseases. This innovative strategy involves three crucial steps: Traditional SELEX, Pull Down, and mass spectrometry. Firstly, Traditional SELEX involves the systematic selection of specific nucleic acid sequences (aptamers) that bind to the target molecules of interest. These aptamers are generated through iterative rounds of selection, amplification, and enrichment, ultimately yielding highly selective ligands. Secondly, the Pull-Down phase employs these aptamers to capture and isolate the target biomarkers from complex biological samples. This step ensures the specificity of the selected aptamers in binding to their intended targets. Lastly, mass spectrometry is utilized to identify and quantify the captured biomarkers, providing precise information about their presence and concentration in the sample. These quantitative data are invaluable in disease diagnosis and monitoring. Bio-SELEX's significance lies in its ability to discover biomarkers for a wide range of diseases, spanning infectious and non-infectious conditions. This approach holds great promise for early disease detection, personalized medicine, and the development of targeted therapies. By harnessing the power of aptamers and mass spectrometry, Bio-SELEX advances our understanding of disease biology and opens new avenues for improved healthcare.

Cost-effectiveness analysis of isolation strategies for asymptomatic and mild symptom COVID-19 patients

BackgroundManagement of COVID-19 patients with mild and moderate symptoms could be isolated at home isolation (HI), community isolation (CI) or hospitel. However, it was still unclear which strategy was more cost-effective. Therefore, this study was conducted to evaluate this.MethodsThis study used data from patients who initially stayed at HI, CI, and hospitel under supervision of Ramathibodi Hospital between April and October 2021. Outcomes of interest were hospitalisation and mortality. An incremental cost-effectiveness ratios (ICER) was calculated based on hospital perspective using home isolation as the reference.ResultsFrom 7,077 patients, 4,349 2,356, and 372 were admitted at hospitel, HI, and CI, respectively. Most patients were females (57.04%) and the mean age was 40.42 (SD = 16.15). Average durations of stay were 4.47, 3.35, and 3.91 days for HI, CI, and hospitel, respectively. The average cost per day for staying in these corresponding places were 24.22, 63.69, and 65.23 US$. For hospitalisation, the ICER for hospitel was at 41.93 US$ to avoid one hospitalisation in 1,000 patients when compared to HI, while CI had more cost, but less cases avoided. The ICER for hospitel and CI were at 46.21 and 866.17 US$ to avoid one death in 1,000 patients.ConclusionsHI may be cost-effective isolated strategy for preventing hospitalisation and death in developing countries with limited resources.

Structural concept and analysis of the 16- and 14-story base isolated apartment buildings constructed on one stylobate in the multifunctional complex “Arami”

Seismic isolation strategies were developed in Armenia due to the efforts of the author of this paper. Many medium and high-rise base isolated buildings were constructed in different regions of the country. Among them there are multi-story residential and business center complexes with parking floors and with floors envisaged for offices, shopping centers, fitness clubs, etc. Some complexes are briefly mentioned in the paper. However, the main information in this paper is given to describe the 16- and 14-story base isolated apartment buildings constructed on one stylobate in the multifunctional complex “Arami” in the city of Yerevan. The complex has unique structural concept, including the suggested by the author approach on installation by clusters of seismic isolation laminated rubber-steel bearings (SILRSBs) in seismic isolation interfaces of these buildings. Some details of the suggested concepts and construction peculiarities are described. Also, some results of the earthquake response analyses are given. The building was analyzed using several time histories and also according to the requirements of the Armenian Seismic Code.