What Breast Cancer Screening Program do Rural Women Prefer? A Discrete Choice Experiment in Jiangsu, China.

BACKGROUND: Chinese rural women aged 35-64 years are encouraged to complete breast cancer screening (BCS) free of charge. However, it is challenging to reach a satisfying BCS uptake rate. In this study, rural women's preferences and preferences heterogeneity were measured for the development of strategies to enhance participation in BCS. METHODS: A cross-sectional survey with a discrete choice experiment (DCE) was conducted via convenience sampling via face-to-face interviews in Jiangsu, China. Six DCE attributes were identified through a systematic literature review; our previous study of Chinese rural women's BCS intentions; a qualitative work involving in-depth interviews with rural women (n = 13), medical staff (n = 4), and health care managers (n = 2); and knowledge of realistic and actionable policy. The D-efficient design was generated using Ngene 1.3.0. A mixed logit model (MXL) in Stata 18.0 was used to estimate the main effect of attribute levels on rural women's preferences. The relative importance and willingness to utilize BCS services (WTU) were also estimated. The heterogeneous preferences were analyzed by a latent class model (LCM). Sociodemographic status was used to predict the characteristics of class membership. The WTU for different classes was also calculated. RESULTS: A total of 451 rural women, aged 35-64 years, were recruited. The MXL results revealed that the screening interval (SI) was the most important attribute for rural women with regard to utilizing BCS services, followed by the level of screening, the attitude of medical staff, ways to get knowledge and information, people who recommend screening, and time spent on screening (TSS). Rural women preferred a BCS service with a shorter TSS; access to knowledge and information through multiple approaches; a shorter SI; a recommendation from medical staff or workers from the village or community, and others; the enthusiasm of medical staff; and medical staff with longer tenures in the field. Two classes named "process driven" and "efficiency driven" were identified by the preference heterogeneity analysis of the LCM. CONCLUSION: There is a higher uptake of breast cancer screening when services are tailored to women's preferences. The screening interval was the most important attribute for rural women in China with a preference for a yearly screening interval versus longer intervals.

Combined transcriptome and metabolome analysis reveals breed-specific regulatory mechanisms in Dorper and Tan sheep.

BACKGROUND: Dorper and Tan sheep are renowned for their rapid growth and exceptional meat quality, respectively. Previous research has provided evidence of the impact of gut microbiota on breed characteristics. The precise correlation between the gastrointestinal tract and peripheral organs in each breed is still unclear. Investigating the metabolic network of the intestinal organ has the potential to improve animal growth performance and enhance economic benefits through the regulation of intestinal metabolites. RESULTS: In this study, we identified the growth advantage of Dorper sheep and the high fat content of Tan sheep. A transcriptome study of the brain, liver, skeletal muscle, and intestinal tissues of both breeds revealed 3,750 differentially expressed genes (DEGs). The genes PPARGC1A, LPL, and PHGDH were found to be highly expressed in Doper, resulting in the up-regulation of pathways related to lipid oxidation, glycerophospholipid metabolism, and amino acid anabolism. Tan sheep highly express the BSEP, LDLR, and ACHE genes, which up-regulate the pathways involved in bile transport and cholesterol homeostasis. Hindgut content analysis identified 200 differentially accumulated metabolites (DAMs). Purines, pyrimidines, bile acids, and fatty acid substances were more abundant in Dorper sheep. Based on combined gene and metabolite analyses, we have identified glycine, serine, and threonine metabolism, tryptophan metabolism, bile secretion, cholesterol metabolism, and neuroactive ligand-receptor interaction as key factors contributing to the differences among the breeds. CONCLUSIONS: This study indicates that different breeds of sheep exhibit unique breed characteristics through various physiological regulatory methods. Dorper sheep upregulate metabolic signals related to glycine, serine, and threonine, resulting in an increase in purine and pyrimidine substances. This, in turn, promotes the synthesis of amino acids and facilitates body development, resulting in a faster rate of weight gain. Tan sheep accelerate bile transport, reduce bile accumulation in the intestine, and upregulate cholesterol homeostasis signals in skeletal muscles. This promotes the accumulation of peripheral and intramuscular fat, resulting in improved meat quality. This work adopts a joint analysis method of multi-tissue transcriptome and gut metabolome, providing a successful case for analyzing the mechanisms underlying the formation of various traits.

Prediction of behavioral deficits in acute stroke from lesion and structural disconnection mapping.

Prediction of behavioral deficits in stroke relies on understanding the distribution of focal damage as well as the distribution of the underlying functional anatomy. Using structural or functional magnetic resonance imaging, previous studies investigated the predictive performance of imaging biomarkers for behavioral deficits in stroke patients. However, only focal lesion information or functional connectivity information alone was used in the modelling, with a small sample size and on a specific behavioral deficit domain. In this study, we investigated the prediction of behavioral deficits in acute stroke using both focal lesion patterns and structural disconnection mapping on a cohort of 551 ischemic stroke patients within one week post symptom onset. Five behavioral deficits domains, including motor, cognitive, visual, somatosensory and coordination deficits, were investigated. A probabilistic map of lesion-induced structural "disconnectome" map was created to estimate the degree of structural disconnection due to lesions. In the predictive modelling, both lesion volume and location and distant structural disconnections were included in combination with the clinical information. The results showed that improved prediction performance was achieved when considering both focal lesion patterns and global lesion-induced structural disconnections for all five behavioral deficits groups. Distinct lesion maps were obtained for each behavioral deficit, providing insights into neurobiological mechanisms of stroke functional impairment.

MiR-199a-3p Regulates the PTPRF/ß-Catenin Axis in Hair Follicle Development: Insights into the Pathogenic Mechanism of Alopecia Areata.

Alopecia areata is an autoimmune disease characterized by the immune system attacking self hair follicles, mainly in the scalp. There is no complete cure, and the pathogenesis is still not fully understood. Here, sequencing of skin tissues collected from 1-month-old coarse- and fine-wool lambs identified miR-199a-3p as the only small RNA significantly overexpressed in the fine-wool group, suggesting a role in hair follicle development. MiR-199a-3p expression was concentrated in the dermal papillae cells of sheep hair follicles, along with enhanced ß-catenin expression and the inhibition of PTPRF protein expression. We also successfully constructed a mouse model of alopecia areata by intracutaneous injection with an miR-199a-3p antagomir. Injection of the miR-199a-3p agomir resulted in hair growth and earlier anagen entry. Conversely, local injection with the miR-199a-3p antagomir resulted in suppressed hair growth at the injection site, upregulation of immune system-related genes, and downregulation of hair follicle development-related genes. In vivo and in vitro analyses demonstrated that miR-199a-3p regulates hair follicle development through the PTPRF/ß-catenin axis. In conclusion, a mouse model of alopecia areata was successfully established by downregulation of a small RNA, suggesting the potential value of miR-199a-3p in the study of alopecia diseases. The regulatory role of miR-199a-3p in the PTPRF/ß-catenin axis was confirmed, further demonstrating the link between alopecia areata and the Wnt-signaling pathway.

Deep asymmetric extraction and aggregation for infrared small target detection.

Infrared small target detection is widely applied in military and civilian fields. Due to the small size of infrared targets, textural detail is missing. Common target detection methods extract semantic feature by narrowing down the feature map several times, which may lead to the small targets lost in deep layers and are not effective for infrared small target detection. To solve this problem, we propose a novel network called deep asymmetric extraction and aggregation. The network mainly consists of two processes - the vertical feature extraction and the horizontal feature aggregation, both of which are enhanced by an asymmetric attention mechanism. In the vertical process, the use of asymmetric attention mechanism combined with the reduction of down-sampling makes the small target better retained in the deep layers. Then through the horizontal process, shallow spatial feature and deep semantic feature are aggregated to further highlight the small targets while suppressing background noise. Experiments on the public datasets NUAA-SISRT, NUDT-SISRT and MDvsFA-cGan show that our proposed network outperforms the state-of-the-art methods in terms of detection accuracy and parameter efficiency.

Epigenetic mechanism of Gtl2-miRNAs causes the primitive sheep characteristics found in purebred Merino sheep.

BACKGROUND: It is not uncommon for some individuals to retain certain primitive characteristics even after domestication or long-term intensive selection. Wild ancestors or original varieties of animals typically possess strong adaptability to environmental preservation, a trait that is often lacking in highly artificially selected populations. In the case of the Merino population, a world-renowned fine wool sheep breed, a phenotype with primitive coarse wool characteristic has re-emerged. It is currently unclear whether this characteristic is detrimental to the production of fine wool or whether it is linked to the adaptability of sheep. The underlying genetic/epigenetic mechanisms behind this trait are also poorly understood. RESULTS: This study identified lambs with an ancestral-like coarse (ALC) wool type that emerged during the purebred breeding of Merino fine wool sheep. The presence of this primitive sheep characteristic resulted in better environmental adaptability in lambs, as well as improved fine wool yield in adulthood. Reciprocal cross experiments revealed that the ALC phenotype exhibited maternal genetic characteristics. Transcriptomic SNP analysis indicated that the ALC phenotype was localized to the imprinted Gtl2-miRNAs locus, and a significant correlation was found between the ALC wool type and a newly identified short Interstitial Telomeric Sequences (s-ITSs) at this locus. We further confirmed that a novel 38-nt small RNA transcribed from these s-ITSs, in combination with the previously reported 22-nt small RNAs cluster from the Gtl2-miRNAs locus, synergistically inhibited PI3K/AKT/Metabolic/Oxidative stress and subsequent apoptotic pathways in wool follicle stem cells, resulting in the ALC wool type. The necessity of Gtl2-miRNAs in controlling primary hair follicle morphogenesis, as well as the wool follicle type for ALC wool lambs, was verified using intergenic differentially methylated region-knockout mice. CONCLUSION: The ALC wool type of Merino sheep, which does not reduce wool quality but increases yield and adaptability, is regulated by epigenetic mechanisms in the imprinted Gtl2-miRNAs region on sheep chromosome 18, with the maternally expressed imprinted gene responsible for the ALC phenotype. This study highlights the significance of epigenetic regulation during embryonic and juvenile stages and emphasizes the advantages of early adaptation breeding for maternal parents in enhancing the overall performance of their offspring.

MiT family translocation renal cell carcinoma with retroperitoneal metastasis in childhood: a case report.

RCC accounts for only 0.1%-0.3% of all kidney tumors and 2%-6% of malignant kidney tumors in children. Accounting for approximately one-third of the total number of cases in children and adolescents with RCC, Xp11.2 tRCC is the most common subtype of the MiT family translocation renal cell carcinoma, which is a group of rare childhood and adult tumors, characterized by recurrent gene rearrangements of TFE3. Here we report a rare case of a 6-year-old male patient with MiT family translocation renal cell carcinoma (MiTF tRCC) where the patient developed retroperitoneal metastasis. The patient underwent partial nephrectomy (PN), radical nephrectomy (RN), abdominal lymph node resection, and intestinal adhesion lysis. Microscopically, we detected focal and nest clump-shaped clusters of tumor cells whose cytoplasm was bright and clear. Immunohistochemistry (IHC) showed tumor cells diffusely expressed TFE3, and fluorescence in situ hybridization (FISH) demonstrated disruption of the TFE3 locus, confirming the diagnosis of Xp11.2 tRCC, the most common subtype of MiTF tRCC. Eventually, the patient obtained a good therapeutic result. This case can provide a good reference and guidance for pediatric urologists and oncologists to recognize and diagnose rare renal cell carcinoma in children.

Genome-wide DNA methylation and transcriptome analyses reveal the key gene for wool type variation in sheep.

BACKGROUND: Wool fibers are valuable materials for textile industry. Typical wool fibers are divided into medullated and non-medullated types, with the former generated from primary wool follicles and the latter by either primary or secondary wool follicles. The medullated wool is a common wool type in the ancestors of fine wool sheep before breeding. The fine wool sheep have a non-medullated coat. However, the critical period determining the type of wool follicles is the embryonic stage, which limits the phenotypic observation and variant contrast, making both selection and studies of wool type variation fairly difficult. RESULTS: During the breeding of a modern fine (MF) wool sheep population with multiple-ovulation and embryo transfer technique, we serendipitously discovered lambs with ancestral-like coarse (ALC) wool. Whole-genome resequencing confirmed ALC wool lambs as a variant type from the MF wool population. We mapped the significantly associated methylation locus on chromosome 4 by using whole genome bisulfite sequencing signals, and in turn identified the SOSTDC1 gene as exons hypermethylated in ALC wool lambs compare to their half/full sibling MF wool lambs. Transcriptome sequencing found that SOSTDC1 was expressed dozens of times more in ALC wool lamb skin than that of MF and was at the top of all differentially expressed genes. An analogy with the transcriptome of coarse/fine wool breeds revealed that differentially expressed genes and enriched pathways at postnatal lamb stage in ALC/MF were highly similar to those at the embryonic stage in the former. Further experiments validated that the SOSTDC1 gene was specifically highly expressed in the nucleus of the dermal papilla of primary wool follicles. CONCLUSION: In this study, we conducted genome-wide differential methylation site association analysis on differential wool type trait, and located the only CpG locus that strongly associated with primary wool follicle development. Combined with transcriptome analysis, SOSTDC1 was identified as the only gene at this locus that was specifically overexpressed in the primary wool follicle stem cells of ALC wool lamb skin. The discovery of this key gene and its epigenetic regulation contributes to understanding the domestication and breeding of fine wool sheep.

A newly identified small tRNA fragment reveals the regulation of different wool types and oxidative stress in lambs.

Novel small RNAs derived from tRNAs are continuously identified, however, their biological functions are rarely reported. Here, we accidentally found the reads peak at 32nt during statistical analysis on the miRNA-seq data of lamb skin tissue, and found that it was related to the wool type of lambs. This 32nt peak was composed of small tRNA fragments. The main component sequence of this peak was a novel small tRNA derived from Glycyl tRNA (tRNAGly), the expression level of tRNAGly-derived tRNA fragments (tRFGly) was 5.77 folds higher in the coarse wool lambs than that in the fine wool lambs. However, in contrast, the expression of tRNAGly in the skin of fine wool lambs is 6.28 folds more than that in coarse wool lambs. tRNAGly promoted the synthesis of high glycine protein including KAP6 in fine wool lamb skin. These proteins were reported as the major genes for fine curly wool. Integrative analysis of target gene prediction, proteomics and metabolomics results revealed that tRFGly reduced the level of reactive oxygen species (ROS) in the skin of coarse wool lambs by targeted inhibition of the Metabolic signal and the corresponding Glutathione metabolic pathway, on the contrary, the level of oxidative stress in the skin of fine wool lambs was significantly higher. This study revealed for the first time the relationship between tRNAGly and its derived tRFGly and animal traits. tRFGly has the function of targeting and regulating protein synthesis. At the same time, tRFGly can reduce the expression of its resource complete tRNA, thereby reducing its ability to transport specific amino acid and affecting the expression of corresponding proteins.

Investigation of the Rheological Properties and Storage Stability of Waste Polyethylene/Ethylene-Vinyl Acetate-Modified Asphalt with Crosslinking and a Silicone Coupling Agent.

As the market for polyethylene consumption continues to expand, the amount of waste polyethylene is also increasing. Modifying asphalt with waste polyethylene (PE) is economical and environmentally friendly. The low-temperature performance and storage stability of PE-modified asphalt has long been an insurmountable problem. The high vinyl acetate (VA) content of ethylene-vinyl acetate (EVA) and PE blended into asphalt can improve the compatibility of PE and asphalt. It compensates for the high VA content of EVA brought about by the lack of high-temperature resistance to permanent deformation but is still not conducive to the stable storage of PE at high temperatures. The effect of furfural extraction oil, a crosslinking (DCP) agent, a silicone coupling agent (KH-570), and calcium carbonate (CaCO3) on the rheological properties and compatibility of PE/EVA-modified asphalt was investigated in this study. The conventional physical properties of PE/EVA-modified asphalt were tested after introducing furfural extraction oil, DCP, KH570, and CaCO3 to determine the correlations of these materials. In addition, frequency sweep, multiple stress creep and recovery (MSCR), and linear amplitude sweep (LAS) were utilized to characterize the rheological properties and fatigue behavior. The results reveal that the addition of suitable ratios of furfural extract oil, DCP, KH-570, and CaCO3 to PE/EVA-modified asphalt produces a remarkable improvement in the viscoelastic characteristics and viscosity compared with PE/EVA-modified asphalt. Furthermore, fluorescence microscopy (FM) was utilized to evaluate the modification mechanism, which shows that PE/EVA undergoes significant crosslinking in asphalt, forming a three-dimensional network structure that dissolves in the asphalt. The storage stability of the PE-modified bitumen was fully determined, and its high-temperature rheology was substantially improved.

Label-free impedimetric immunosensor for point-of-care detection of COVID-19 antibodies.

The COVID-19 pandemic has posed enormous challenges for existing diagnostic tools to detect and monitor pathogens. Therefore, there is a need to develop point-of-care (POC) devices to perform fast, accurate, and accessible diagnostic methods to detect infections and monitor immune responses. Devices most amenable to miniaturization and suitable for POC applications are biosensors based on electrochemical detection. We have developed an impedimetric immunosensor based on an interdigitated microelectrode array (IMA) to detect and monitor SARS-CoV-2 antibodies in human serum. Conjugation chemistry was applied to functionalize and covalently immobilize the spike protein (S-protein) of SARS-CoV-2 on the surface of the IMA to serve as the recognition layer and specifically bind anti-spike antibodies. Antibodies bound to the S-proteins in the recognition layer result in an increase in capacitance and a consequent change in the impedance of the system. The impedimetric immunosensor is label-free and uses non-Faradaic impedance with low nonperturbing AC voltage for detection. The sensitivity of a capacitive immunosensor can be enhanced by simply tuning the ionic strength of the sample solution. The device exhibits an LOD of 0.4 BAU/ml, as determined from the standard curve using WHO IS for anti-SARS-CoV-2 immunoglobulins; this LOD is similar to the corresponding LODs reported for all validated and established commercial assays, which range from 0.41 to 4.81 BAU/ml. The proof-of-concept biosensor has been demonstrated to detect anti-spike antibodies in sera from patients infected with COVID-19 within 1 h. Photolithographically microfabricated interdigitated microelectrode array sensor chips & label-free impedimetric detection of COVID-19 antibody.

Soy isoflavone-specific biotransformation product S-equol in the colon: physiological functions, transformation mechanisms, and metabolic regulatory pathways.

Epidemiological data suggest that regular intake of soy isoflavones may reduce the incidence of estrogen-dependent and aging-associated disorders. Equol is a metabolite of soy isoflavone (SI) produced by specific gut microbiota and has many beneficial effects on human health due to its higher biological activity compared to SI. However, only 1/3 to 1/2 of humans are able to produce equol in the body, which means that not many people can fully benefit from SI. This review summarizes the recent advances in equol research, focusing on the chemical properties, physiological functions, conversion mechanisms in vitro and vivo, and metabolic regulatory pathways affecting S-equol production. Advanced experimental designs and possible techniques in future research plan are also fully discussed. Furthermore, this review provides a fundamental basis for researchers in the field to understand individual differences in S-equol production, the efficiency of metabolic conversion of S-equol, and fermentation production of S-equol in vitro.

Contribution of gut microbiomes and their metabolomes to the performance of Dorper and Tan sheep.

Background: Livestock is an excellent source of high nutritional value protein for humans; breeding livestock is focused on improving meat productivity and quality. Dorper sheep is a distinguished breed with an excellent growth performance, while Tan sheep is a Chinese local breed famous for its delicious meat. Several studies have demonstrated that the composition of gut microbiome and metabolome modulate host phenotype. Methods: In the present study, we performed 16S amplicon sequencing and metabolomic analyses of the rumen and hindgut microbiome of 8-month-old Dorper and Tan sheep, raised under identical feeding and management conditions, to explore the potential effects of gut microbiome and its metabolites on growth performance and meat quality. Results: Our study identified Lactobacillus, a marker genus in the rumen, to be significantly associated with the levels of fumaric acid, nicotinic acid, and 2-deoxyadenosine (P-value < 0.05). Statistical analysis showed that nicotinic acid was significantly negatively correlated with body weight (P-value < 0.01), while 2-deoxyadenosine was significantly positively correlated with fatty acids content (P-value < 0.05). There was a biologically significant negative correlation between Phascolarctobacterium and deoxycytidine levels in the hindgut. Deoxycytidine was significantly positively correlated with body weight, protein, and amino acid content. Differences in rumen fermentation patterns that are distinctive among breeds were identified. Tan sheep mainly used Lactobacillus and fumaric acid-mediated pyruvic acid for energy supply, while Dorper sheep utilize glycogenic amino acids. The difference of iron metabolism in the hindgut of Dorper sheep affects lipid production, while Phascolarctobacterium in Tan sheep is related to roughage tolerance. The accumulation of nucleosides promotes the growth performance of Dorper sheep. Conclusion: These findings provide insights into how the microbiome-metabolome-dependent mechanisms contribute to growth rate and fat contents in different breeds. This fundamental research is vital to identifying the dominant traits of breeds, improving growth rate and meat quality, and establishing principles for precision feeding.

Cecum microbiome and metabolism characteristics of Silky Fowl and White Leghorn chicken in late laying stages.

Cecal microflora plays a key role in the production performance and immune function of chickens. White Leghorn (WL) is a well-known commercial layer line chicken with high egg production rate. In contrast, Silky Fowl (SF), a Chinese native chicken variety, has a low egg production rate, but good immune performance. This study analyzed the composition of cecal microbiota, metabolism, and gene expression in intestinal tissue of these varieties and the correlations among them. Significant differences were observed in the cecal microbes: Bacteroides was significantly enriched in WL, whereas Veillonellaceae and Parabacteroides were significantly enriched in SF. Carbohydrate biosynthesis and metabolism pathways were significantly upregulated in WL cecum, which might provide more energy to the host, leading to persistently high levels of egg production. The higher Parabacteroides abundance in SF increased volicitin content, enhanced α-linolenic acid metabolism, and significantly negatively correlated with metabolites of propanoate metabolism and carbohydrate metabolism. Genes related to lipid metabolism, immunity, and melanogenesis were significantly upregulated in the SF cecum, regulating lipid metabolism, and participating in the immune response, while genes related to glucose metabolism and bile acid metabolism were expressed at higher levels in WL, benefiting energy support. This study provided a mechanism for intestinal microorganisms and metabolic pathways to regulate chicken egg-laying performance and immunity.

m6A Methylation Analysis Reveals Networks and Key Genes Underlying the Coarse and Fine Wool Traits in a Full-sib Merino Family.

In our study, a set of lambs with coarse wool type all over their bodies were discovered within a full-sib family during an embryo transfer experiment of merino fine wool sheep. The difference between coarse and fine wool traits were studied from the perspective of RNA modification-N6-methyladenosine. A total of 31,153 peaks were collected, including 15,968 peaks in coarse skin samples and 15,185 peaks in fine skin samples. In addition, 7208 genes were differentially m6A methylated, including 4167 upregulated and 3041 downregulated in coarse skin samples. Four key genes (EDAR, FGF5, TCHH, KRT2) were obtained by comprehensive analysis of the MeRIP-seq and RNA sequence, which are closely related to primary wool follicle morphogenesis and development. The PI3K/AKT pathway was enriched through different m6A-related genes. These results provided new insights to understand the role of epigenetics in wool sheep domestication and breeding.

Breast and cervical cancer screening adherence in Jiangsu, China: An ecological perspective.

Background: High screening coverage can effectively reduce the mortality in breast and cervical cancer. Further research on extending the coverage of breast and cervical cancer screening in China is required. This study explored factors influencing women's "two-cancer" screening service utilization using an ecological approach. Methods: Data were obtained from the National Health Services Survey (NHSS) conducted in 2018 in Jiangsu, China. A total of 3,500 women aged 18-64 years were included in the analysis. Chi-squared test, hierarchical multiple logistic regression analysis, and binary logistic regression analysis were performed. Results: In total, 44.1% of the women had been screened for breast cancer (BC) and 40.9% for cervical cancer (CC). Breast cancer screening (BCS) and cervical cancer screening (CCS) differed significantly in the following common categories: age, gestational experiences, chronic disease status, body mass index (BMI), exercise, health checkup, marital status, number of children, employment, education, family doctors, and health records. In the results of hierarchical multiple logistic regression analysis, the explanatory power of the final model was 37.5% and the area under the receiver operating characteristic curve was 0.812. The results showed that being in the age group of 35-64 years, having gestational experiences, having chronic diseases, exercising, having a health checkup, being married, having children, and being employed were statistically significant positive predictors of "two-cancer" screening adherence. The household size was a barrier. For BCS, obesity was also a negative factor, and a higher overall self-related health status was a positive factor. Being married and living in households of three or more families were not predictors. For CCS, having health records was also positively significant, while having chronic disease did not influence adherence. Conclusion: The findings provide an ecological explanation for women's BCS and CCS service utilization. Both proximal and distal factors should be considered to achieve a high coverage rate.

A gold nanoparticle-protein G electrochemical affinity biosensor for the detection of SARS-CoV-2 antibodies: a surface modification approach.

As COVID-19 waves continue to spread worldwide, demand for a portable, inexpensive and convenient biosensor to determine community immune/infection status is increasing. Here we describe an impedance-based affinity biosensor using Interdigitated Electrode (IDE) arrays to detect antibodies to SARS-CoV-2 in serum. We created the biosensor by functionalizing the IDEs' surface with abaculaovirus-expressed and purified Spike (S) protein to bind anti-SARS CoV-2antibodies. Gold nanoparticles (GNP) fused to protein G were used to probe for bound antibodies. An ELISA assay using horseradish peroxidase-protein G to probe for bound IgG confirmed that the purified S protein bound a commercial source of anti-SARS-CoV-2 antibodies specifically and bound anti-SARS-CoV-2 antibodies in COVID-19 positive serum. Then we demonstrated that our biosensor could detect anti-SARS-CoV-2 antibodies with 72% sensitivity in 2 h. Using GNP-protein G, the affinity biosensor had increased impedance changes with COVID-19positive serum and minimal or decreased impedance changes with negative serum. This demonstrated that our biosensor could discriminate between COVID-19 positive and negative sera, which were further improved using poly(vinyl alcohol)as a blocking agent.

Improving immunoassay detection accuracy of anti-SARS-CoV-2 antibodies through dual modality validation.

A novel test strategy is proposed with dual-modality detection techniques for COVID-19 antibody detection. The full-length S protein of SARS-CoV-2 was chemically immobilized on a glass surface to capture anti-SARS-CoV-2 IgG in patient serum and was detected through either Electrochemical Impedance Spectroscopy (EIS) or fluorescence imaging with labeled secondary antibodies. Gold nanoparticles conjugated with protein G were used as the probe and the bound GNP-G was detected through EIS measurements. Anti-human-IgG conjugated with the fluorescent tag Alexa Fluor 488 was used as the probe for fluorescence imaging. Clinical SARS-CoV-2 IgG positive serum and negative controls were used to validate both modalities. For fluorescence-based detection, a high sensitivity was noticed with a quantification range of 0.01-0.1 A.U.C. and a LOD of 0.004 A.U.C. This study demonstrates the possibility of utilizing different measurement techniques in conjunction for improved COVID-19 serology testing.

An impedimetric biosensor for COVID-19 serology test and modification of sensor performance via dielectrophoresis force.

Coronavirus disease 2019 (COVID-19) has caused significant global morbidity and mortality. The serology test that detects antibodies against the disease causative agent, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has often neglected value in supporting immunization policies and therapeutic decision-making. The ELISA-based antibody test is time-consuming and bulky. This work described a gold micro-interdigitated electrodes (IDE) biosensor for COVID antibody detection based on Electrochemical Impedance Spectroscopy (EIS) responses. The IDE architecture allows easy surface modification with the viral structure protein, Spike (S) protein, in the gap of the electrode digits to selectively capture anti-S antibodies in buffer solutions or human sera. Two strategies were employed to resolve the low sensitivity issue of non-faradic impedimetric sensors and the sensor fouling phenomenon when using the serum. One uses secondary antibody-gold nanoparticle (AuNP) conjugates to further distinguish anti-S antibodies from the non-specific binding and obtain a more significant impedance change. The second strategy consists of increasing the concentration of target antibodies in the gap of IDEs by inducing an AC electrokinetic effect such as dielectrophoresis (DEP). AuNP and DEP methods reached a limit of detection of 200 ng/mL and 2 µg/mL, respectively using purified antibodies in buffer, while the DEP method achieved a faster testing time of only 30 min. Both strategies could qualitatively distinguish COVID-19 antibody-positive and -negative sera. Our work, especially the impedimetric detection of COVID-19 antibodies under the assistance of the DEP force presents a promising path toward rapid, point-of-care solutions for COVID-19 serology tests.

Examining Primary Care Physicians' Intention to Perform Cervical Cancer Screening Services Using a Theory of Planned Behavior: A Structural Equation Modeling Approach.

Background: Promoting cervical cancer screening (CCS) is undoubtedly effective in combating severe public health problems in developing countries, but there are challenges to its implementation. Understanding the factors influencing primary care physicians' intentions to provide CCSs to rural women is crucial for the future implementation of screening programs. The aim of this study was to assess the intentions of primary care physicians to provide cervical cancer screening services (CCSSs) to rural women and their determinants. Methods: This cross-sectional study included 1,308 primary care physicians in rural primary health care, and the data collection tool was developed based on the theory of planned behavior (TPB), which included demographic characteristics, the basic constructs of TPB, and the degree of knowledge of CCSSs as an extended variable of the TPB model. Structural equation modeling was used to analyze the relationships between each factor. Results: Pathway analysis found that TPB is an appropriate theoretical basis for predicting primary care physicians' intent to provide CCSSs (χ2/df = 2.234 < 3, RMSEA = 0.035, and SRMR = 0.034). Meanwhile, the structural equation model showed that attitude (ß = 0.251, p < 0.001), subjective norm (ß = 0.311, p < 0.001), perceived behavioral control (ß = 0.162, p < 0.001), and knowledge level (ß = 0.152, p < 0.01) positively predicted primary care physicians' intention to provide CCSSs. Conclusions: TPB model, with the addition of knowledge, was useful in predicting primary care physicians' intention to provide CCSSs for rural Chinese women. The findings of this study provide a reference for the government and hospitals to develop strategies to improve the intent of primary care physicians to provide CCSSs.