Distinguishable Magnetic Reporter Coordination with Buoyancy-Magnetism Separation for Immobilization-Free Dual-Target Electrochemical Immunosensing.

Simultaneous sensitive and precise determination of multibiomarkers is of great significance for improving detection efficiency, reducing diagnosis and treatment expenses, and elevating survival rates. However, the development of simple and portable biosensors for simultaneous determination of multiplexed targets in biological fluids still faces challenges. Herein, a unique and versatile immobilization-free dual-target electrochemical biosensing platform, which combines distinguishable magnetic signal reporters with buoyancy-magnetism separation, was designed and constructed for simultaneous detection of carcinoembryonic (CEA) and α-fetoprotein (AFP) in intricate biological fluids. To construct such distinguishable magnetic signal reporters with signal transduction, amplification, and output, secondary antibodies of CEA and AFP were respectively functionalized on methylene blue (MB) and 6-(ferrocenyl)hexanethiol (FeC) modified Fe3O4@Au magnetic nanocomposites. Meanwhile, a multifunctional flotation probe with dual target recognition, capture, and isolation capability was prepared by conjugating primary antibodies (Ab1-CEA, Ab1-AFP) to hollow buoyant microspheres. The target antigens of CEA and AFP can trigger a flotation-mediated sandwich-type immunoreaction and capture a certain amount of the distinguishable magnetic signal reporter, which enables the conversion of the target CEA and AFP quantities to the signal of the potential-resolved MB and FeC. Thus, the MB and FeC currents of magnetically adsorbed distinguishable magnetic reporters can be used to determine the CEA and AFP targets simultaneously and precisely. Accordingly, the proposed strategy exhibited a delightful linear response for CEA and AFP in the range of 100 fg·mL-1-100 ng·mL-1 with detection limits of 33.34 and 17.02 fg·mL-1 (S/N = 3), respectively. Meanwhile, no significant nonspecific adsorption and cross-talk were observed. The biosensing platform has shown satisfactory performance in the determination of real clinical samples. More importantly, the proposed approach can be conveniently extended to universal detection just by simply substituting biorecognition events. Thus, this work opens up a new promising perspective for dual and even multiple targets and offers promising potential applications in clinical diagnosis.

Dual-potential ratiometric electrochemiluminescence based on single emitter and single coreactant for the sensitive detection of carcinoembryonic antigen.

Dual-potential ratiometric electrochemiluminescence (ECL) is in favor of resistance to environmental interference. However, two kinds of emitters or coreactants, and a wide scan potential range (>2 V) are mandatory. This work developed a new dual-potential ratiometric ECL sensor for detection of carcinoembryonic antigen (CEA) using single emitter (luminol) and single coreactant (H2O2) with a mild potential range from -0.1 to 0.6 V. Luminol could produce a strong cathodic ECL (Ec) induced by hydroxyl radicals (HO‧) from the reduction of H2O2, and a relatively weak anodic ECL (Ea). After the ferrocene modified CEA aptamer (Apt-Fc) was attached, Fc could promote Ea by catalyzing the oxidation of H2O2, and reduce Ec by consuming HO‧. With the cycling amplification of the exonuclease I, CEA could substantially reduce the amount of Apt-Fc, resulting in the decrease of Ea and the rise of Ec. So, the ratio of Ec to Ea (Ec/Ea) was used as the detection signal, realizing the sensitive determination of CEA from 0.1 pg mL-1 to 10 ng mL-1 with a LOD of 41.85 fg mL-1 (S/N = 3). The developed sensor demonstrated excellent specificity, stability and reproducibility, with satisfactory results in practical detection.

The influence of psychotherapy on individuals who have attempted suicide: A systematic review and meta-analysis.

INTRODUCTION: Suicide is a serious global public health issue, and a history of attempted suicide is the most critical indicator of suicide risk. There are limited studies on the effectiveness of psychotherapy in individuals who have attempted suicide, and other outcome measures related to suicide risk in suicide attempts have not been explored. AIM/QUESTION: This study aimed to systematically review and perform a meta-analysis of the effectiveness of psychotherapy on individuals who have attempted suicide. METHODS: This study conducted a comprehensive literature search of five major databases (PubMed, EMBASE, Cochrane, Web of Science, and Ovid). The protocol for this study is registered with PROSPERO (CRD42023464401) and follows the PRISMA guidelines. RESULTS: This meta-analysis included a total of 34 trials from 32 literature sources. The study involved a total of 6600 participants. The results showed that psychotherapy had a positive effect on reducing the suicidal tendencies of individuals who have attempted suicide and effectively reduced the number of repeated suicide attempts as well as the levels of suicidal ideation, depression, anxiety and hopelessness. IMPLICATIONS FOR PRACTICE: This study concludes that psychotherapy is effective in reducing the suicidal tendencies of individuals who have attempted suicide. Psychological therapy for individuals who have attempted suicide are crucial in preventing future suicidal behaviours.

Different biological responses of Skeletonema costatum and Prorocentrum donghaiense to polymetallic nodules from seawaters.

The negative impacts of polymetallic nodules mining on deep-sea benthic organisms have been widely established, but there is still a lack of understanding of the environmental impact on the surface ocean scenario. Phytoplankton growth experiment was conducted to determine the biological effect of polymetallic nodules on Prorocentrum donghaiense and Skeletonema costatum. The results showed that regardless of concentration and particle size, polymetallic nodules show a promoting effect on P. donghaiense (p < 0.05), the cell density in the experimental group increased by 35.2%-46.5% compared to the control at the end of the experiment. While fine particles significantly inhibited the growth of S. costatum (p < 0.05), the maximum inhibition rate on cell density reached 63.1%. Polymetallic nodules significantly enhance the Fv/Fm and the maximum electron transport rate of photosystem II in P. donghaiense, thereby increasing its growth rate. However, polymetallic nodules particles stimulated the antioxidant activity and extracellular polymeric substances secretion of S. costatum, resulting in phytoplankton flocculation and sedimentation, which inhibits its growth. Thus, these discriminatory impacts may cause alterations in biomass and community structure, ultimately affecting the ecological function.

A perylene diimide electrochemical probe with persulfate as a signal enhancer for dopamine sensing.

Dopamine (DA) is an important biomarker related to parkinsonism, schizophrenia and renal disease. Traditional electrochemical sensors for DA were based on the direct electrochemical oxidation of DA. In this paper, we report a new sensing strategy using N,N'-di(trimethylaminoethyl)perylene diimide (TMPDI) as an electrochemical probe and K2S2O8 as a signal enhancer for DA detection between 0 and -0.7 V with the DPV technique. MoS2 nanoflowers prepared by the hydrothermal method were used as a nanocarrier to load TMPDI. The reduction current of TMPDI was found to show a stepwise and significant increase at -0.24 V with the increase of concentration of K2S2O8 due to the continuous cycle of TMPDI molecules' electrochemical reduction and chemical oxidation. The presence of DA caused a large decrease of the reduction current of TMPDI due to the synergistic interaction of the competitive consumption of DA for K2S2O8 and the blocking effect of polyDA adhering to the electrode surface. The decreased current exhibited a linear response for DA from 10 pM to 100 µM with a detection limit of 4.1 pM and the proposed sensor showed high selectivity and excellent feasibility in human urine/serum sample detection.

A smartphone-based electrochemical POCT for CEA based on signal amplification of Zr6MOFs.

Carcinoembryonic antigen (CEA) is a biomarker of high expression in cancer cells. Highly sensitive and selective detection of CEA holds significant clinical value in the diagnosis, monitoring and efficacy evaluation of malignant tumors. In this work, a smartphone-based electrochemical point-of-care testing (POCT) platform for the detection of CEA was developed based on a Zr6MOF signal amplification strategy. Ferrocene labeled DNA strands (Fc-DNA) were immobilized on Zr6MOFs to form a Fc-DNA/Zr6MOF signal probe. Double-stranded DNA (dsDNA) formed by complementary DNA (cDNA) and CEA aptamer was assembled on a screen-printed electrode via an Au-S bond. When CEA was added, the aptamer specifically bound with CEA, resulting in the exposure of cDNA. Then, Fc-DNA/Zr6MOF signal probes were introduced on the electrode surface through hybridization between Fc-DNA and cDNA. The detection of CEA was realized by measuring the electrochemical response of Fc. The POCT device was made by connecting a modified electrode with a smartphone through a Sensit Smart USB flash disk. Due to the signal amplification of Zr6MOFs, this POCT platform exhibited high sensitivity, wide linear range, and low detection limit for CEA detection. The developed POCT platform has been used for the detection of CEA in actual human serum samples with satisfactory results.

Tungsten-based polyoxometalate nanoclusters with remarkable reactive oxygen species-scavenging activity efficiently quenched luminol-based electrochemiluminescence for sensitive detection of Her-2.

This study aimed to develop a quenching-type electrochemiluminescence (ECL) immunosensor for human epidermal growth factor receptor (Her-2) detection. Firstly, Pd/NiFeOx nanoflowers decorated by in situ formation of gold nanoparticles (Au NPs) and 2D Ti3C2 MXene nanosheets were synthesized (AuPd/NiFeOx/Ti3C2) as carriers to load luminol and primary antibodies. Impressively, AuPd/NiFeOx/Ti3C2 with excellent peroxidase-like activity could accelerate the decomposition of the coreactant H2O2 generating more reactive oxygen species (ROSs) under the working potential from 0 to 0.8 V, resulting in highly efficient ECL emission at 435-nm wavelengths. The introduction of tungsten-based polyoxometalate nanoclusters (W-POM NCs) which exhibit remarkable ROSs-scavenging activity as secondary antibody labels could improve the sensitivity of immunosensors. The ZnO nanoflowers were employed to encapsulate minute-sized W-POM NCs, and polydopamine was self-polymerized on the surface of Zn(W-POM)O to anchor secondary antibodies. The mechanism of the quenching strategy was explored and it was found that W-POM NCs could consume ROSs by the redox reaction of W5+ resulting in W6+. The proposed ECL immunosensor displayed a wide linear response range of 0.1 pg·mL-1 to 50 ng·mL-1, and a low detection limit of 0.036 pg mL-1 (S/N = 3). The recoveries ranged from 93.9 to 99.4%, and the relative standard deviation (RSD) was lower than 10%. This finding is promising for the design of detecting new protein biomarkers.

BIRC5 facilitates cisplatin-chemoresistance in a m6 A-dependent manner in ovarian cancer.

Cisplatin-based chemotherapy is the standard treatment for metastatic ovarian cancer (OC). However, chemoresistance continues to pose significant clinical challenges. Recent research has highlighted the baculoviral inhibitor of the apoptosis protein repeat-containing 5 (BIRC5) as a member of the inhibitor of the apoptosis protein (IAP) family. Notably, BIRC5, which has robust anti-apoptotic capabilities, is overexpressed in numerous cancers. Its dysfunction has been linked to challenges in cancer treatment. Yet, the role of BIRC5 in the chemoresistance of OC remains elusive. In our present study, we observed an upregulation of BIRC5 in cisplatin-resistant cell lines. This upregulation was associated with enhanced chemoresistance, which was diminished when the expression of BIRC5 was silenced. Intriguingly, BIRC5 exhibited a high number of N6-methyladenosine (m6 A) binding sites. The modification of m6 A was found to enhance the expression of BIRC5 by recognizing and binding to the 3'-UTR of mRNA. Additionally, the insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) was shown to stabilize BIRC5 mRNA, synergizing with METTL3 and intensifying chemoresistance. Supporting these in vitro findings, our in vivo experiments revealed that tumors were significantly smaller in size and volume when BIRC5 was silenced. This reduction was notably counteracted by co-silencing BIRC5 and overexpressing IGF2BP1. Our results underscored the pivotal role of BIRC5 in chemoresistance. The regulation of its expression and the stability of its mRNA were influenced by m6 A modifications involving both METTL3 and IGF2BP1. These insights presented BIRC5 as a promising potential therapeutic target for addressing cisplatin resistance in OC.

An electrochemical ratiometric biosensor for the detection of dopamine based on an MXene-Au nanocomposite.

Compared with single signal detection, a ratiometric biosensor could offer more accurate and reliable results. Here, a ratiometric electrochemical biosensor for the sensitive and accurate detection of dopamine was developed based on the strong adsorption ability of MXene-Au toward methylene blue, an inner reference element. This ratiometric sensing strategy opened up a new avenue for the development of a ratiometric platform.

Clinical characteristics of abruptly increased paediatric patients with Omicron BF.7 or BA.5.2 in Beijing.

BACKGROUND: The coronavirus disease 2019 outbreak has hit Beijing since mid-Nov, 2022, with soaring growth of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among children. Therefore, it is vital to determine the clinical manifestations of epidemic SARS-CoV-2 strains in paediatric patients. METHODS: In this study, nucleic acid tests (NATs) for SARS-CoV-2 were performed in paediatric outpatients with symptoms of acute respiratory tract infection during 18 Nov-6 Dec, 2022. Half of the outpatients positive for SARS-CoV-2 were randomly selected to screen for other respiratory pathogens, whereas those with low cycle threshold values in SARS-CoV-2 NATs were amplified and sequenced to determine the SARS-CoV-2 variants. Finally, children positive for SARS-CoV-2 with clinical information in detail were enrolled in a follow-up study to identify potential factors significantly associated with long recovery. RESULTS: Among 9625 paediatric outpatients tested for nucleic acid of SARS-CoV-2, 733 (7.62%, 733/9625) were identified as SARS-CoV-2 NAT positive, with only three (0.82%, 3/366) co-infected with other pathogens among 366 randomly selected patients, and 71 (62.83%) determined as Omicron subvariant BF.7 and 42 (37.22%) as BA.5.2 among 113 successfully sequenced. Among the 681 patients with complete clinical information, fever was the most common symptom (96.8%). In a follow-up study of 592 patients, 46.96% became asymptomatic on the third day and 65.71% on the fifth day. Only 1.7% of infected children experienced febrile seizures. Combined with abnormal C-reactive protein, a higher percentage of antibiotics administration was observed. More co-living members and longer duration of first symptoms served as independent risk factors for long-term recovery, especially in children vaccinated for SARS-CoV-2. CONCLUSIONS: BF.7 and BA.5.2 were the dominate Omicron subvariants and caused milder infections during the SARS-CoV-2 outbreak in Beijing. The number of co-living members and duration of first symptoms were independent risk factors for long-term recovery.

Prevalence and genomic analysis of t203-like G9 (G9-VI) rotaviruses circulating in children with gastroenteritis in Beijing, China.

Our previous surveillance revealed that t203-like G9 (tentatively designated subtype G9-VI) rotaviruses re-emerged in 2010 in Beijing and rapidly prevailed over the G9-III subtype (the most common G9 subtype globally) and previously predominant G genotypes over the following two years. G9-VI belongs to the VP7 evolutionary lineage VI, which includes unusual and sporadic human rotaviruses from China (t203) and Japan. To obtain insight into the epidemiology, evolution, and transmission advantages of G9-VI rotavirus, we performed follow-up surveillance (2014-2017) and whole-genome analysis of 12 representative G9 strains. The results showed that the G9 genotype was predominant (77.4%), with a marked increase in prevalence (previously 43.5%). Within the G9 genotype, subtype G9-VI accounted for the majority (98.3%) of cases. The most prevalent P-genotype was P[8] (93.7%), within which subtype P[8]b was rare (0.7%). Phylogenetically, the G9-VI subtype strains in this study clustered closely with contemporary emerging human rotaviruses from many other countries in VP7 lineage VI, indicating that this subtype is capable of spreading globally. These currently emerging G9-VI rotaviruses formed a distinct monophyletic subcluster when compared to early G9-VI rotaviruses. Furthermore, four specific amino acid substitutions and synonymous codon substitutions were observed in the VP7 genes between the current G9-VI and globally common G9-III rotaviruses. The remaining nine genes of all of the analyzed representative G9 strains, whether G9-VI or G9-III, combined with the P[8]a, P[8]b, or P[6] genotype and exhibited the same Wa-like backbone constellation.

A label-free electrochemical aptasensor based on Bi-Sb alloy materials for potential POCT of HER-2.

As a prognostic biomarker for breast cancer, human epidermal growth factor receptor 2 (HER-2) is of crucial diagnostic value. Here, a label-free electrochemical aptasensor was established for the ultrasensitive detection of HER-2 using a modified electrode of Bi-Sb alloy materials (Bi-Sb AMs). The performance of the aptasensor was enhanced greatly due to the introduction of Bi-Sb alloy materials (Bi-Sb AMs) with high conductivity. Furthermore, by integrating the aptasensor with the Sensit Smart U-disk electrochemical analyzer, the point-of-care testing (POCT) for HER-2 was realized. Under the optimal experimental parameters, the POCT analyzer showed a wide linear response from 0.01 pg mL-1 to 100 ng mL-1, with a low detection limit (LOD) of 5.96 fg mL-1 for the detection of HER-2. The presented POCT analyzer exhibited good specificity, stability, and reproducibility. Benefiting from the simple operation and rapid testing, the developed analyzer will have potential application in the prognostic diagnosis and treatment of breast cancer.

Genetic Evolution and Variation of Human Adenovirus Serotype 31 Epidemic Strains in Beijing, China, during 2010-2022.

Human adenovirus serotype 31 (HAdV-31) is closely associated with gastroenteritis in children and can cause fatal systemic disseminated diseases in immunocompromised patients. The lack of genomic data for HAdV-31, especially in China, will greatly limit research on its prevention and control. Sequencing and bioinformatics analyses were performed for HAdV-31 strains from diarrheal children in Beijing, China, during 2010-2022. Three capsid protein genes (hexon, penton, and fiber) were obtained in 37 cases, including one in which the whole genome was sequenced. HAdV-31 strains clustered into three distinct clades (I-III) in a phylogenetic tree constructed based on concatenated genes and the whole genome; the endemic strains only gathered into clade II, and most of the reference strains clustered into clade I. Compared with penton and hexon, fiber had a faster evolutionary rate (1.32 × 10-4 substitutions/site/year), an earlier divergence time (1697), lower homology (98.32-100% at the amino acid level), and greater genetic variation (0.0032). Four out of the six predicted positive selection pressure codons were also in the knob of fiber. These results reveal the molecular evolution characteristics and variations of HAdV-31 in Beijing, and fiber may be one of the main evolution driving forces.

Fascinating Immobilization-Free Electrochemical Immunosensing Strategy Based on the Cooperation of Buoyancy and Magnetism.

Rapid and accurate detection of biomolecules is of vital importance for the diagnosis of disease and for performing timely treatments. The point-of-care analysis of cancer biomarkers in the blood with low cost and easy processing is still challenging. Herein, an advanced and robust strategy, which integrates the buoyant recognition probe with the magnetic reporter probe in one solution, was first proposed for immobilization-free electrochemical immunosensing. The tumor marker of alpha fetoprotein (AFP) can be captured immune-buoyantly, and then a multifunctional magnetic reporter probe in pseudo-homogeneous solution was further captured to fulfill a sandwich-type immunoreaction. The residual magnetic reporter probe can be firmly and efficiently attracted on a magnetic glassy carbon electrode to fulfill the conversion of the target AFP amount into the residual magnetic electrochemical signal indicator. As a result, the electrochemical signal of methylene blue can accurately reflect the original level of target antigen AFP concentration. By integrating buoyancy-driven quasi-homogenous biorecognition with magnetism-mediated amplification and signal output, the proposed immobilization-free electrochemical immunosensing strategy displayed a wide range of linear response (100 fg mL-1 to 10 ng mL-1), low detection limit (14.52 fg mL-1), and good reproducibility, selectivity, and stability. The designed strategy manifests remarkable advantages including assay simplicity, rapidness, and high sensitivity owing to the in-solution instead of on-electrode biorecognition that could accelerate and improve the biorecognition efficiency. To the best of our knowledge, this is the first cooperation of buoyancy-driven biorecognition with magnetism-mediated signal output in bioanalysis, which would be attractive for rapid clinic biomedical application. Thus, this work provides a fresh perspective for convenient and favorable immobilization-free electrochemical biosensing of universal biomolecules.

Perylene derivative and persulfate as highly efficient electrochemical system for constructing sensitive amperometric aptasensor.

To design highly efficient electrochemistry system was important for construct simple and sensitive biosensors, which was crucial in clinical diagnosis and therapy. In this work, a novel electrochemistry probe N,N'-di (1-hydroxyethyl dimethylaminoethyl) perylene diimide (HDPDI) with positive charges was reported to show two-electron redox behavior in neutral phosphate buffer solution between 0 and -1.0 V. And K2S2O8 in solution could significantly increase the reduction current of HDPDI at -0.29 V, which was interpreted with cyclic catalysis mechanism of K2S2O8. Moreover, HDPDI as electrochemical probe and K2S2O8 as signal enhancer was used to design aptasensors for protein detection. Thrombin was used as target model protein. Thiolate ssDNA with thrombin-binding sequence was immobilized on gold electrode to selectively capture thrombin and adsorb HDPDI. The thiolate ssDNA without binding with thrombin was with random coil structure and could adsorb HDPDI through electrostatic attraction interaction. However, the thiolate ssDNA binding with thrombin became G-quadruplex structure and hardly adsorbed HDPDI. Thus, with increasing the concentration of thrombin, the current signal stepwisely decreased and was taken as detection signal. Compared with other aptasensors based on electrochemistry molecules without signal enhancer, the proposed aptasensors exhibited wider linear response for thrombin between 1 pg mL-1 and 100 ng mL-1 with lower detection limit 0.13 pg mL-1. In addition, the proposed aptasensor showed good feasibility in human serum samples.

Electrochemiluminescence detection of miRNA-21 based on dual signal amplification strategies: Duplex-specific nuclease -mediated target recycle and nicking endonuclease-driven 3D DNA nanomachine.

DNA nanomachines have shown potential application in the construction of various biosensors. Here, an electrochemiluminescence biosensor for the sensitive detection of miRNA-21 were reported based on three-dimensional (3D) DNA nanomachine and duplex-specific nuclease (DSN)-mediated target recycle amplification strategy. First, the bipedal DNA walkers were obtained by DSN-mediated digestion reaction initiated by target miRNA-21.3D DNA tracks were prepared by modifying Fe3O4 magnetic beads (MBs) with ferrocene-labeled DNA (Fc-DNA). The produced DNA walkers autonomously moved along 3D DNA tracks powered by nicking endonuclease. During the movement, ferrocene-labeled DNA was cleaved, resulting in large amounts of Fc-labeled DNA fragments away from the MBs surface. Finally, the liberated Fc-labeled DNA fragments were dropped on the C-g-C3N4 modified electrode surface, leading to the quenching of C-g-C3N4 electrochemiluminescence (ECL). Benefiting from the dual amplification strategy of 3D DNA nanomachine and DSN-mediated target recycling, the developed ECL biosensor exhibited an excellent performance for miRNA-21 detection with a wide linear range of 10 fM to 10 nM and a low detection limit of 1.0 fM. This work offers a new thought for the application of DNA walkers in the construction of various biosensors.

Nitrogen removal in improved subsurface wastewater infiltration system: Mechanism, microbial indicators and the limitation of phosphorus.

To enhance the nitrogen removal capacity, scrap iron filings and Si-Al porous clay mineral material (PCMW) was used to improve a subsurface wastewater infiltration system (SWIS). The results showed TN and NH4+-N removal efficiencies of improved SWIS were 20.72% and 5.49% higher than those of the control SWIS, respectively. Based on the response of the removal performance, microbial community and function analysis of 16s rRNA amplicon sequencing results, the amending soil matrix substantially enriched the nitrogen removal bacteria (Rhizobiales_Incertae_Sedis and Gemmatimonadaceae), and significantly improved the activities of key enzymes (Hao, NasAB, NarGHI, NirK, NorBC, NirA and NirBD), particularly at co-occurrence zone of nitrification and denitrification (70-130 cm depth). The amending soil matrix not only extended the growth space of microbes, but also provided additional electrons and carbon sources for denitrifying bacteria by regulating the structure and function of the microbial community. In addition, amending soil matrix could enhance phosphate metabolism genes and phosphate solubilizing microbes in the denitrification zone by increasing the phosphorus source, thus strengthening nitrogen metabolism. Nitrospiraceae, Rhizobiales_Incertae_Sedis and Gemmatimonadaceae related to nitrogen removal and Bacillaceae with phosphate-solubilizing ability could be used as microbial indicators of nitrogen removal in SWISs. The reciprocal action of environmental on microbial characteristics exhibited microbial functional were related to DO, Fe2+, TOC, TP, TN, NH4+-N and NO3--N. Those could be used as physicochemical and biological indicators for application and monitoring of SWIS. In conclusion, this study provided a low-cost and efficient enhancement approach for the application of SWIS in decentralized domestic sewage treatment, and furnished theoretical support for subsequent applications.

Human bocavirus 1 and 2 genotype-specific antibodies for rapid antigen testing in pediatric patients with acute respiratory infections.

BACKGROUND: Previous serological studies of human bocavirus (HBoV) 1 could not exclude cross-reactivity with the other three HBoVs, particularly HBoV2. METHODS: To search for genotype-specific antibodies against HBoV1 and HBoV2, the divergent regions (DRs) located on the major capsid protein VP3 were defined through viral amino acid alignment and structure prediction. DR-deduced peptides were used as antigens to harvest corresponding anti-DR rabbit sera. To determine their genotype specificities for HBoV1 and HBoV2, these sera samples were used as antibodies against the antigens VP3 of HBoV1 and HBoV2 (expressed in Escherichia coli) in western blotting (WB), enzyme-linked immunosorbent assay (ELISA), and bio-layer interferometry (BLI) assays. Subsequently, the antibodies were evaluated with clinical specimens from pediatric patients with acute respiratory tract infection by indirect immunofluorescence assay (IFA). RESULTS: There were four DRs (DR1-4) located on VP3 with different secondary and tertiary structures between HBoV1 and HBoV2. Regarding the reactivity with VP3 of HBoV1 or HBoV2 in WB and ELISA, high intra-genotype cross-reactivity of anti-HBoV1 or HBoV2 DR1, DR3, and DR4, but not anti-DR2, was observed. Genotype-specific binding capacity of anti-DR2 sera was confirmed by BLI and IFA, in which only anti-HBoV1 DR2 antibody reacted with HBoV1-positive respiratory specimens. CONCLUSION: Antibodies against DR2, located on VP3 of HBoV1 or HBoV2, were genotype specific for HBoV1 and HBoV2, respectively.

Empathy and Post-Traumatic Growth among Chinese Community Workers during the COVID-19 Pandemic: Roles of Self-Disclosure and Social Support.

Given the prolonged nature of the COVID-19 pandemic and its long-term psychological impacts, this study aimed to explore how empathy leads to post-traumatic growth (PTG) among Chinese community workers. Guided by the revised PTG model, this study identified the relation between empathy and PTG using a multiple mediation model that included self-disclosure and social support as hypothesized mediators. This study utilized data from 414 Chinese adults aged 20 years or older who completed an online survey during the pandemic. Self-disclosure and social support were measured as mediating variables. The study variables were positively correlated with PTG. Empathy was positively correlated with self-disclosure and social support. After controlling for demographic covariates, the results indicated that self-disclosure and social support mediated the link between empathy and PTG in both parallel and sequential fashion. Empathy, self-disclosure, and social support played important roles in the growth of Chinese community workers. The present findings have been useful in increasing our understanding, policy programs, and interventions by governments or regional bodies to ameliorate community workers' PTG.

Thalassiosira weissflogii grown in various Zn levels shows different ecophysiological responses to seawater acidification.

The presence of zinc (Zn), a vital element for algal physiological functions, coupled with the silicification of diatoms implies that it plays an integral role in the carbon and silicon cycles of the sea. In this study, we examined the effects of different pCO2 and Zn levels on growth rate, elemental compositions and silicification by Thalassiosira weissflogii. The results showed that under normal pCO2 (400 µatm), cultures of T. weissflogii were depressed for growth rate and silica incorporation rate, but encouraged for cellular silicon content, Si/C, Si/N, and sinking rate when Zn deficient (0.3 pmol L-1). However, cellular silicon and sinking rate of Zn-deficient and Zn-replete (25 pmol L-1) T. weissflogii were decreased and increased at higher pCO2 (800 µatm), respectively. Thus, acidification may affect diatoms significantly differently depending on the Zn levels of the ocean and then alter the biochemical cycling of carbon and silica.