Simple Approach Research Articles

A reagent-based label free electrochemiluminescence biosensor for ultrasensitive quantification of low-abundant chloramphenicol

Today, great attentions have been attracted on chloramphenicol (CAP) to its nonnegligible biotoxicity to human. It is most important and urgent to quantify the low-abundant chloramphenicol by generating simple and efficient analysis approach for the detection of chloramphenicol. Herein, we proposed a novel reagent-based label free electrochemiluminescence (ECL) biosensor based on AuNPs@CoFe-PBA nanomaterials as highly efficient catalysts for luminol/hydrogen peroxide (H2O2) system and target indirectly induced activation of the CRISPR/Cas 12a amplification system for simple and efficient quantification of the low-abundant chloramphenicol. Typically, AuNPs@CoFe-PBA nanomaterials as a novel catalyst for luminol/H2O2 system were enclosed in the X-type DNA hydrogel to greatly inhibit their catalytic performance due to the blocking effect of DNA hydrogel. In presence of target CAP, it induced DNA structure transformation of the aptamer of chloramphenicol to generate a toehold to present catalyzed hairpin assembly (CHA) amplification with the help of two self-designed hairpin structure DNA to perform the hybridizer of the two hairpins, which could activate the CRISPR/Cas 12a system to carry out the DNA cleavage. Its activity breaks the structure of DNA hydrogels and releases AuNPs@CoFe-PBA nanomaterials, which enhances the ECL signals of the luminol/H2O2 systems for simple and sensitive analysis of chloramphenicol. Most importantly, all of the target induced amplifications were performed in the detection solution and the ECL reactions were generated on the bare electrode without any modification to construct a reagent-based label-free analysis system simply with high efficiency for quantification of the low-abundant chloramphenicol. The results showed that there was a good linear relationship between ECL intensity and CAP concentration in range from 10 pg/mL to 1 ug/mL with a detection limit of 7.75 pg/mL, providing great potentials to quantify the low-abundant chloramphenicol and some other biomarkers for early disease diagnosis, food safety testing and environmental analysis.

Framework confinement of multi-metals within silica hollow spheres by one-pot synthesis process

ABSTRACT The control incorporation of metals in silica hollow spheres (SHSs) may bring new functions to silica mesoporous structures for applications including catalysis, sensing, molecular delivery, adsorption filtration, and storage. However, the strategies for incorporating metals, whether through pre-loading in the hollow interior or post-encapsulation in the mesoporous shell, still face challenges in achieving quantitative doping of various metals and preventing metal aggregation or channel blockage during usage. In this study, we explored the doping of different metals into silica hollow spheres based on the dissolution-regrowth process of silica. The process may promote the formation of more structural defects and functional silanol groups, which could facilitate the fixation of metals in the silica networks. With this simple and efficient approach, we successfully achieved the integration of ten diverse metal species into silica hollow sphere (SHS). Various single-metal, dual-metal, triple-metal, and quadruple-metal doped SHSs have been prepared, with the doped metals being stable and homogeneously dispersed in the structure. Based on the structural characterizations, we analyzed the influence of metal types on the morphology features of SHSs. The synergistic effects of multi-metals on the catalysis applications were also studied and compared.

An efficient and simple approach to remove Cd(II) in aqueous solution by using rice straw biochar: performance and mechanisms.

In recent years, cadmium pollution in water environment has become an environmental problem that could not be ignored. As a porous carbon rich solid material, biochar is an environment-friendly new material because of its ultra-high adsorption capacity and strong chemical stability. In this study, rice straw biochar (RS-Biochar) was successfully prepared at different temperatures for removal of Cd(II) from aqueous solution. Through a series of characterization and adsorption experiments, the adsorption principle of Cd(II) by RS-Biochar was deeply studied. The results showed that RS-Biochar prepared at 600 °C (BioC600) has high specific surface area (232.6 m2/g) and shows high Cd(II) removal rate of 91.23% with the maximum Cd(II) adsorption capacity of 8.62 mg/g. The Langmuir model fit well to describe the adsorption process of Cd(II) on the BioC600. The mechanism analysis showed that hydroxyl and carboxyl groups on the biochar surface were concerned in the removal of Cd(II). The formation of CdCO3 in the adsorption process was also be proven. Importantly, RS-Biochar could be conveniently produced with needed scale, displaying a promising approach for remediating Cd(II)-contaminated water environment and a huge application potential.

Liquid crystal-induced tunable circular dichroism in CdSe and ZnSe nanoplatelets

Induced circular dichroism in CdSe and ZnSe nanoplatelets (NPLs) was demonstrated using chiral thermotropic liquid crystals (LCs). Firstly, NPLs were easily dispersed in cholesteryl oleyl carbonate (COC) LC via a simple intercalation chemistry-based approach. Extensive circular dichroism (CD) studies showed remarkably strong and reversible chiroptical properties for these composites as a function of temperature. NPL-COC composites displayed strong exciton-induced CD as well as high anisotropy g-factor values (in the case of CdSe NPLs). Secondly, induced chirality in CdSe NPLs was also demonstrated using right-handed (RH) and left-handed (LH) blue phase LCs. LC-induced chirality in nanoparticles was corroborated by theoretical studies which revealed coupling between the chiral molecular excitons and nonchiral nanocrystals. The temperature-tunability is a useful tool to switch the chirality on/off. This study presents an alternative approach to realize exciton-induced tunable circular dichroism in nanomaterials.

Pathological response and tumor stroma immunogenic features predict long-term survival in non-small cell lung cancer after neoadjuvant chemotherapy.

Major pathological response (MPR) has become a surrogate endpoint for overall survival (OS) in non-small cell lung cancer (NSCLC) after neoadjuvant therapy, however, the prognostic histologic features and optimal N descriptor after neoadjuvant therapy are poorly defined. We retrospectively analyzed data from 368 NSCLC patients who underwent surgery after neoadjuvant chemotherapy (NAC) from January 2010 to December 2020. The percentage of residual viable tumors in the primary tumor, lymph nodes (LN), and inflammation components within the tumor stroma were comprehensively reviewed. The primary endpoint was OS. Of the 368 enrolled patients, 12.0% (44/368) achieved MPR in the primary tumor, which was associated with significantly better OS (HR, 0.36 0.17-0.77, p = 0.008) and DFS (HR = 0.59, 0.36-0.92, p = 0.038). In patients who did not have an MPR, we identified an immune-activated phenotype in primary tumors, characterized by intense tumor-infiltrating lymphocyte or multinucleated giant cell infiltration, that was associated with similar OS and DFS as patients who had MPR. Neoadjuvant pathologic grade (NPG), consisting of MPR and immune-activated phenotype, identified 30.7% (113/368) patients that derived significant OS (HR 0.28, 0.17-0.46, p < 0.001) and DFS (HR 0.44, 0.31-0.61, p < 0.001) benefit from NAC. Moreover, the combination of NPG and the number of positive LN stations (nS) in the multivariate analysis had a higher C-index (0.711 vs. 0.663, p < 0.001) than the ypTNM Stage when examining OS. NPG integrated with nS can provide a simple, practical, and robust approach that may allow for better stratification of patients when evaluating neoadjuvant chemotherapy in clinical practice.

A framework for automated scalable designation of viral pathogen lineages from genomic data.

Pathogen lineage nomenclature systems are a key component of effective communication and collaboration for researchers and public health workers. Since February 2021, the Pango dynamic lineage nomenclature for SARS-CoV-2 has been sustained by crowdsourced lineage proposals as new isolates were sequenced. This approach is vulnerable to time-critical delays as well as regional and personal bias. Here we developed a simple heuristic approach for dividing phylogenetic trees into lineages, including the prioritization of key mutations or genes. Our implementation is efficient on extremely large phylogenetic trees consisting of millions of sequences and produces similar results to existing manually curated lineage designations when applied to SARS-CoV-2 and other viruses including chikungunya virus, Venezuelan equine encephalitis virus complex and Zika virus. This method offers a simple, automated and consistent approach to pathogen nomenclature that can assist researchers in developing and maintaining phylogeny-based classifications in the face of ever-increasing genomic datasets.

PCR Development for Analysis of Some Type II Toxin-Antitoxin Systems, relJK, mazEF3, and vapBC3 Genes, in Mycobacterium tuberculosis and Mycobacterium bovis.

Toxin-Antitoxin (TA) systems are some small genetic modules in bacteria that play significant roles in resistance and tolerance development to antibiotics. Whole genome sequencing (WGS) is an effective method to analyze TA systems in pathogenic Mycobacteria. However, this study aimed to use a simple and inexpensive PCR-Sequencing approach to investigate the type II TA system. Using data from the WGS of Mycobacterium tuberculosis (M. tuberculosis) strain H37Rv and Mycobacterium bovis (M. bovis) strain BCG, primers specific to the relJK, mazEF3, and vapBC3 gene families were designed by Primer3 software. Following that, a total of 90 isolates were examined using the newly developed PCR assay, consisting of 64M. tuberculosis and 26M. bovis isolates, encompassing both 45 rifampin-sensitive and 45 rifampin-resistant strains. Finally, 28 isolates (including 14 rifampin-resistant isolates) were sent for sequencing, and their sequences were aligned and compared to the mentioned reference sequences. The amplicons size of mazEF3, relJK, and vapBC3 genes were 825, 875, and 934 bp, respectively. Furthermore, all tested isolates showed the specific amplicons for these TA families. To evaluate the specificity of the primers, PCR was performed on S. aureus and E.coli isolates. None of the examined samples had the desired amplicons. Therefore, the primers had acceptable specificity. The results indicated that the developed PCR-Sequencing approach can be used to effectively investigate certain types of TA systems. Considering high costs of WGS and difficulty in interpreting its results, such a simple and inexpensive method is beneficial in the evaluation of TA systems in Mycobacteria.

Facile hydrothermally grown cobalt oxide (Co3O4) nanostructures and their electrochemical performances

Abstract In this study, pure cobalt oxide (Co3O4) nanoparticles were synthesized using a simple hydrothermal approach. The effect of the reducing agent and reaction temperatures of the prepared products were examined. Co3O4 is formed in the as-synthesized sample, at reaction temperature 190 °C was observed in the XRD pattern. The XPS survey scan spectrum showed the distinctive peaks of the Co and O elements and their valence states. FESEM and HRTEM revealed the particles as cubical in nature. Peak associated with the elements Co and O on the EDAX spectrum demonstrated the purity of the nanoparticles. Three electrode setups were used to measure the electrochemical properties of the synthesized nanoparticles. DTA curve corresponding exothermic peak at 225 °C and the crystallization of the final product was attributed for the third weight loss of 1.5 % in the temperature range of 280 °C to 450 °C. Formation of Co3O4 was confirmed by the observed XRD diffraction peaks at 2θ = 36.83°, 59.82°, and 65.30°, which correspond to h k l planes (311), (511) and (440), respectively. The high-resolution Co2p spectra showed two prominent spin-orbital peaks, 2p1/2 and 2p3/2, at 796.37 eV and 781.81 eV, respectively. The increase in temperature causes the particle size to grow ranges between 20 and 70 nm and the average particle size distribution in the TEM image is 42 nm. The integral area of the CV curve was measured during the CV measurement and as the as-prepared Co3O4 electrode displays specific capacitance values of 154, 126, 81, 65, and 49 Fg−1 at various scan rates of 10, 20, 50, 70, and 100 mVs−1, respectively.

Single arterial access technique for simultaneous dual mechanical circulatory support in cardiogenic shock

Temporary mechanical circulatory support is a treatment of choice for patients in severe cardiogenic shock. Combining veno-arterial extracorporeal life support (ECLS) with devices that enable left ventricular unloading emerges as a promising strategy to diminish detrimental effect of elevated left ventricular afterload and to improve survival. However, the need to establish multiple arterial access sites remains a major drawback of this approach due to a significant rate of vascular complications. We describe herein a case of a single arterial access for ECLS and intra-aortic balloon pump using axillary artery that may provide a simple, modular and flexible approach for escalation or de-escalation of mechanical circulatory support.

A Simple Model for Estimating the Hydraulic Conductivity of Unsaturated Soil

Describing the hydraulic conductivity of unsaturated soil is very important in predicting water transport. Most current models have complex forms and generally need to be calibrated by the measured unsaturated hydraulic conductivity curve. A simple model, by which it is possible to conveniently predict the unsaturated hydraulic conductivity, is proposed in this study. The soil–water characteristic curve and hydraulic conductivity curve are separated into three parts. The soil–water characteristic curve is represented by Fredlund and Xing’s equation. A simple model composed of three lines is proposed for estimating the hydraulic conductivity of unsaturated soil. The model parameters can be conveniently calibrated from the measured soil–water characteristic curve and saturated hydraulic conductivity. Finally, the proposed model is validated by the experimental data from different soils. The proposed model provides a simple approach to estimating the hydraulic conductivity of unsaturated soil, which is more convenient for practical application.

Health inequalities for people with learning disabilities: why it matters and what emergency physicians need to know.

People with learning disabilities die on average 16 years earlier than the general population in England. They are a vulnerable group and may have unhealthy lifestyles and multimorbidity that lead to poor health outcomes. Worryingly, premature deaths are also more common and these often have contributory healthcare causes. This may be a result of staff lacking awareness, expertise and experience managing people with learning disabilities, the lack of reasonable adjustments, or discriminatory attitudes. Other issues include polypharmacy and inappropriate prescribing of sedatives, inappropriate use of do not resuscitate orders, and diagnostic overshadowing leading to delayed or misdiagnoses. Emergency physicians need to be aware of subtle or atypical presentations of illnesses such as sepsis. Carers and family can be vital informants, helping clinicians to interpret subtle signs and aid communication with people with learning disabilities. One simple approach to reasonable adjustments, as required by law, is the TEACH mnemonic: people with learning disabilities need more time (T), in a conducive environment (E), with clinicians approaching them with the right attitude (A) and an open mind. Good communication (C) is essential and clinicians must make every attempt to understand their patients and to be understood by their patients. Finally clinicians need to consider what 'help' (H) the patient and their carers or family needs. With the right approach, time and environment, emergency physicians can optimise the care delivered to people with learning disabilities to address their needs.

Privacy-Preserving Deep Learning Framework Based on Restricted Boltzmann Machines and Instance Reduction Algorithms

The combination of collaborative deep learning and Cyber-Physical Systems (CPSs) has the potential to improve decision-making, adaptability, and efficiency in dynamic and distributed environments. However, it brings privacy, communication, and resource restrictions concerns that must be properly addressed for successful implementation in real-world CPS systems. Various privacy-preserving techniques have been proposed, but they often add complexity and decrease accuracy and utility. In this paper, we propose a privacy-preserving deep learning framework that combines Instance Reduction Techniques (IR) and the Restricted Boltzmann Machine (RBM) to preserve privacy while overcoming the limitations of other frameworks. The RBM encodes training data to retain relevant features, and IR selects the relevant encoded instances to send to the server for training. Privacy is preserved because only a small subset of the training data is sent to the server. Moreover, it is sent after encoding it using RBM. Experiments show that our framework preserves privacy with little loss of accuracy and a substantial reduction in training time. For example, using our framework, a CNN model for the MNIST dataset achieves 96% accuracy compared to 99% in a standard collaborative framework (with no privacy measures taken), with training time reduced from 133.259 s to 99.391 s. Our MLP model for MNIST achieves 97% accuracy compared to 98% in the standard collaborative framework, with training time reduced from 118.146 s to 87.873 s. Compared to other studies, our method is a simple approach that protects privacy, maintains the utility of deep learning models, and reduces training time and communication costs.

Compressing Features for Learning With Noisy Labels.

Supervised learning can be viewed as distilling relevant information from input data into feature representations. This process becomes difficult when supervision is noisy as the distilled information might not be relevant. In fact, recent research shows that networks can easily overfit all labels including those that are corrupted, and hence can hardly generalize to clean datasets. In this article, we focus on the problem of learning with noisy labels and introduce compression inductive bias to network architectures to alleviate this overfitting problem. More precisely, we revisit one classical regularization named Dropout and its variant Nested Dropout. Dropout can serve as a compression constraint for its feature dropping mechanism, while Nested Dropout further learns ordered feature representations with respect to feature importance. Moreover, the trained models with compression regularization are further combined with co-teaching for performance boost. Theoretically, we conduct bias variance decomposition of the objective function under compression regularization. We analyze it for both single model and co-teaching. This decomposition provides three insights: 1) it shows that overfitting is indeed an issue in learning with noisy labels; 2) through an information bottleneck formulation, it explains why the proposed feature compression helps in combating label noise; and 3) it gives explanations on the performance boost brought by incorporating compression regularization into co-teaching. Experiments show that our simple approach can have comparable or even better performance than the state-of-the-art methods on benchmarks with real-world label noise including Clothing1M and ANIMAL-10N. Our implementation is available at https://yingyichen-cyy.github.io/CompressFeatNoisyLabels/.

Cerium metal–organic framework composited with polyaniline on carbon cloth for high-sensitively electrochemical sensing of carbendazim

Carbendazim (CBZ) has generated significant attention due to potential harm to human health, thus developing a simple and economy-friendly approach for determining CBZ is vital. Herein, Cerium metal–organic framework (Ce-MOF) and polyaniline (PANI) were composited under mild condition and modified on carbon cloth (CC) to fabricate an electrochemical sensor based on Ce-MOF@PANI/CC for fast and sensitive determination of CBZ. Rod-shaped Ce-MOF facilitated the dispersion of PANI, while the doping of PANI improved conductivity of Ce-MOF to amplify detection signal. Moreover, the modification of Ce-MOF@PANI on CC increased the electrochemical active area of CC by 2.78 times. Under optimized conditions, the method demonstrated a linear range of 0.1–80 μM and a detection limit of 12.6 nM. Additionally, the response value of the sensor to CBZ still maintained 94.32 % of the initial value after 15 days. It also had good reproducibility and anti-interference. The sensor was utilized for detecting CBZ in fruit (apple, pear), vegetables (tomato, cucumber), and water (lake, tap water) with recovery of 92.31 %–105.47 % consistent with those of high-performance liquid chromatography.

A simple fiducial-assisted approach to solve small membrane transporter structures using cryo-EM

A simple fiducial-assisted approach to solve small membrane transporter structures using cryo-EM

Topographic seismic effects and avalanche hazard: A case study of Mount Siella (L’Aquila, Central Italy)

In mountainous areas, snow avalanches could be triggered by the shaking produced by earthquakes. The forces induced by the earthquake can cause an irregular increase of shear strength load down the slope, for the presence of complex surface and buried morphologies. Topographic irregularities generate maximum effects of waves amplification linked to wavelengths comparable to the horizontal dimension of the topographic feature. For this reason, the selected time-histories represent an appropriate input for the two-dimensional numerical response analyses when a dynamic phenomenon produce the resonant motion of a whole mountain. This represents an important earthquake-induced hazard in snow-covered mountain areas with high probability of seismic events. Some valleys are located in regions with scare ground motion data and investments on infrastructures are not always accompanied by adequate protection against earthquake-induced avalanches. The paper points out a simple deterministic approach for selecting a set of real accelerograms applied to a real case of Siella Mountain (Central Italy) where a large avalanche destroying a tourist facility of Rigopiano resort on 18 January 2017. The selected time histories were used as input for the two-dimensional numerical model of the subsoil to evaluate the topographic seismic amplification in ridge and compare it with the results of other authors. These methods suggest that morphology-related inertial effects should be considered as an overload action on snow layers when controlling multi-hazard studies and spatial planning.

Fluoride and caries prevention: a scoping review of public health policies.

Dental caries is the most common infectious disease, affecting approximately 60 to 90% of the world population, especially young children, and disadvantaged communities. Due to the extremely high prevalence and the significant negative impact on general health, well-being, and quality of life it is considered a global public health problem. Despite the improvement of policies to promote oral health care in the past decades, dental caries is still a healthcare challenge, characterized by increasing disparities among different social groups between and within countries. Fluoride-based prevention of dental caries is a cost-effective approach, that has been implemented since 1940's. It includes systemic and topical administrations, through community-based or individual programs. Preventive interventions should be tailored to individual and community caries risk assessment and estimate of cumulative fluoride intake, in order to maximize the preventive effect and avoid the risk of potential adverse effects associated with excessive fluoride exposure. Regulation of public health policies plays a major role in this context. Scoping review. The aim of this scoping review was to report an overview of current guidelines regarding fluoride-based preventive strategies for dental caries and relevant policies on the matter, as well as to address current issues related to public health aspects of dental caries prevention. We searched for the relevant literature on the matter, focusing on policy documents, such as recommendations, position papers and guidelines, issued from the major scientific and regulatory institutions involved in oral health promotion and on publications concerning relevant aspects of public health law. Prevention of dental caries through fluoride can rely on topical fluorides for home-use (toothpastes and mouthrinses), professionally applied topical fluorides (gels, varnishes, silver diamine fluoride, fluoride-releasing restorative materials and sealants), fluoride supplements (tablets and drops), and community-based strategies (community water fluoridation, fluoridated salt and milk). Current relevant guidelines for all these preventive aids are outlined in the paper. A significantly greater preventive effect of topical fluorides has been widely established in the recent past, as compared to systemic effects. Furthermore, increasing concerns have emerged on potential adverse effects on general health associated with early and excessive systemic exposure to fluoride, especially for children, supported by recent meta-analyses. Also, community water fluoridation has raised significant aspects of relevance for health law and policies. In a public health perspective, healthcare policymakers should tackle social iniquities by promoting information and oral health literacy, through community and school-based programs, ensuring access to early dental visits and basic dental care and improving availability and affordability of fluoride topical products. Conclusions. Fluoride-based prevention can provide a simple and cost-effective approach to reduce the incidence of dental caries and the associated social burden. Among fluoride-based preventive strategies, systemic community-based administration of fluoride should be considered with great caution, due to the unfavorable risk-benefit ratio currently established. Topical fluoridated pro-ducts are generally preferred, given the optimal risk-benefit ratio. Further efforts must be made to identify and tackle the barriers to dental caries prevention and related social iniquities from a public health perspective. Policies and laws on oral health should promote access to caries prevention with targeted comprehensive strategies.

Seasonal Wetlands Make a Relatively Limited Contribution to the Dissolved Carbon Pool of a Lowland Headwater Tropical Stream

AbstractWetlands process large amounts of carbon (C) that can be exported laterally to streams and rivers. However, our understanding of wetland inputs to streams remains unclear, particularly in tropical systems. Here we estimated the contribution of seasonal wetlands to the C pool of a lowland headwater stream in the Australian tropics. We measured dissolved organic and inorganic C (DOC and DIC) and dissolved gases (carbon dioxide—CO2, methane—CH4) during the wet season along the mainstem and in wetland drains connected to the stream. We also recorded hourly measurements of dissolved CO2 along a ‘stream–wetland drain–stream’ continuum, and used a hydrological model combined with a simple mass balance approach to assess the water, DIC and DOC sources to the stream. Seasonal wetlands contributed ∼15% and ∼16% of the DOC and DIC loads during our synoptic sampling, slightly higher than the percent area (∼9%) they occupy in the catchment. The riparian forest (75% of the DOC load) and groundwater inflows (58% of the DIC load) were identified as the main sources of stream DOC and DIC. Seasonal wetlands also contributed marginally to stream CO2 and CH4. Importantly, the rates of stream CO2 emission (1.86 g C s−1) and DOC mineralization (0.33 g C s−1) were much lower than the downstream export of DIC (6.39 g C s−1) and DOC (2.66 g g C s−1). This work highlights the need for further research on the role of riparian corridors as producers and conduits of terrestrial C to tropical streams.

“Middle way” in the description of ultrashort electromagnetic interactions: between Fermi’s golden rule and the numerical solution of the Schrödinger equation

A simple efficient approach describing the interaction of various quantum targets with short electromagnetic (EM) pulses firstly proposed in [1] is reviewed. This approach is based on the expression for the photoprocess probability in terms of the cross section and the Fourier transform of the EM pulse. Our method makes it possible to take into account the internal dynamics of the target and the influence of the pulse parameters in a simple way. The proposed approach is used both for the probability for the entire pulse duration, and for its dependence on the current time. In addition, the developed method is applied to generalize the simulation of the population kinetics of a quantum system to take into account the dependence of the photoprocess rate on time. It is also shown that our expression for the probability of excitation of a micro-target corresponds to the formula describing the energy loss of a non-monochromatic field in a dispersive medium and can be generalized on other EM processes.

Consensus Synergizes With Memory: A Simple Approach for Anomaly Segmentation in Urban Scenes

Consensus Synergizes With Memory: A Simple Approach for Anomaly Segmentation in Urban Scenes