Coronavirus Disease 2019 (COVID-19), which is caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), has rapidly spread leading to a global pandemic. Here, we combined m ultiple cross displacement amplification (MCDA) with C RISPR- C as12a-based d etection to develop a novel diagnostic test (MCCD) and applied for the diagnosis of COVID-19, called COVID-19 MCCD. The MCCD protocol conducts reverse transcription MCDA (RT-MCDA) reaction for RNA templates followed by CRISPR-Cas12a/CrRNA complex detection of predefined target sequences after which degradation of a single-strand DNA (ssDNA) molecule confirms detection of the target sequence. Two MCDA primer sets and two CrRNAs were designed targeting the opening reading frame 1a/b (ORF1ab) and nucleoprotein (N) of SARS-CoV-2. The optimal conditions include two RT-MCDA reactions at 63 °C for 35 min and a CRISPR-Cas12a/CrRNA detection reaction at 37 °C for 5 min. The COVID-19 MCCD assay can be visualized on a lateral flow biosensor (LFB) and completed within 1 h including RNA extraction (15 min), RT-MCDA reaction (35 min), CRISPR-Cas12a/CrRNA detection reaction (5 min), and reporting of result (within 2 min). The COVID-19 MCCD assay is very sensitive and detects the target gene with as low as seven copies per test and does not cross-react with non-SARS-CoV-2 templates. SARS-CoV-2 was detected in 37 of 37 COVID-19 patient samples, and nonpositive results were detected from 77 non-COVID-19 patients. Therefore, the COVID-19 MCCD assay is a useful tool for the reliable and quick diagnosis of SARS-CoV-2 infection.

Anisotropic microstructures are widely used by being cleverly designed to achieve important functions. Mammals' respiratory tract is filled with dense cilia that rhythmically swing back and forth in a unidirectional wave to propel mucus and harmful substances out of the lung through larynx. Inspired by the ciliary structure and motion mechanism of the respiratory tract systems, a viscoelastic microsphere transporting strategy based on integration of airway cilium‐like structure and magnetically responsive flexible conical arrays is demonstrated. Under external magnetic fields, the viscoelastic microspheres can be directionally and continuously transported alongside the swing of the cilia‐like arrays that contain magnetic particles. This work provides a promising route for the design of advanced medical applications in directional transport of microspheres, drug delivery systems, ciliary dyskinesia treating, and self‐cleaning without liquid.

Background: The known risk factors of childhood OSAS include tonsillar and adenoidhypertrophy, obesity, craniofacial anomalies, neuromuscular disorders and African-American (AA) ancestry. Whether other factors such as allergic rhinitis (AR), premature, environmental tobacco smoking (ETS) are associated with OSAS are inconsistent in different studies. Our study enrolled children of a broad age range and included potential risk factors of OSAS derived from previous studies and our own experience. Our objective is to identify risk factors of OSAS in children in a clinical setting. Methods: Children between 2 and 15 years of age exhibiting snoring symptoms who visited the sleep center for polysomnography (PSG) were enrolled. All children completed a questionnaire, physical examination and PSG. The questionnaire included demographic data and information related to potential risk factors for sleep disorders. A physical examination included measurements of height, weight, neck circumference, waist and hip ratio, visual evaluation of the tonsils and the degree of adenoid obstruction. Children with obstructive apnea-hypopnea index (OAHI) ≥ 1 were defined as OSAS.Results: A total of 1578 children were enrolled and1009 children exhibited OSAS. Univariate analyses showed that snoring occurring for ≥ 3 months, male gender, preterm birth, breastfeeding, obesity, neck circumference ≥ 30 cm, waist/hip ratio ≥ 0.95, tonsillar hypertrophy, and adenoid hypertrophy were associated with OSAS. The proportion of low educational level was higher in parents who breastfed their babies than those who didn't. Multivariate analysis showed that snoring for ≥ 3 months, male gender, obesity, breastfeeding, tonsillar hypertrophy, and adenoid hypertrophy were associated with OSAS. Confounders such as socioeconomic status, parental occupation, and healthrelated behaviors should be explored further to investigate the relationship between breastfeeding and OSAS. Conclusion: The independent risk factors for OSAS in children included snoring ≥ 3 months, male gender, obesity, breastfeeding, tonsillar and adenoid hypertrophy. The study was registered on Clinical Trials government (NCT02447614). The name of the trial is "Follow-up Studies of Primary Snoring (PS) and Obstructive Sleep Apnea Hypopnea Syndrome (OSAHS) in Chinese Children" and the URL is https://clinicaltrials.gov/.

The existing CRISPR-mediated diagnostic tests require a two-step procedure (DNA or RNA amplification followed by CRISPR-mediated sequence-specific detection) for nucleic acid detection, which increases complexity and the risk of sample cross-contamination. Here, we report a new CRISPR-mediated test, called CRISPR-top ( CRISPR -mediated t esting in o ne- p ot), which integrates simultaneous target pre-amplification with CRISPR/cas12b-mediated detection into a one-pot reaction mixture, performed at a constant temperature. The novel CRISPR-top assay was applied to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent for COVID-19 (coronavirus disease 2019). COVID-19 CRISPR-top targets the ORF1ab (opening reading frame 1a/b) and NP (nucleoprotein) genes of SARS-CoV-2, and operates at 59ºC for 40 min with minimal instrument. The COVID-19 CRISPR-top assay can return results within 60-min and is easily interpreted by visual fluorescence or lateral flow readouts. The analytical limit of detection (LoD) for COVID-19 CRISPR-top is 10 copies (for each detection target) per reaction with no cross-reactivity observed from non-SARS-CoV-2 templates. Among clinically collected non-COVID-19 samples, the assay's specificity was 100% (80/80 oropharynx swab samples). Among 52 COVID-19 positive clinical samples collected, the COVID-19 CRISPR-top assay yielded 38 (73.1%) positive results using fluorescence readout and 35 (67.3%) positive results with lateral-flow readout. These diagnostic results were similar to those obtained using RT-PCR (34 positive (65.4%)). These data indicate that COVID-19 CRISPR-top is a simple, rapid, accurate and highly sensitive method for SARS-CoV-2 detection which can be used in the clinic, field laboratories and primary care facilities in resource-challenged settings.

To control the ongoing coronavirus disease‐2019 (COVID‐19) pandemic, CoronaVac (Sinovac), an inactivated vaccine, has been granted emergency use authorization by many countries. However, the underlying mechanisms of the inactivated COVID‐19 vaccine‐induced immune response remain unclear, and little is known about its features compared to (Severe acute respiratory syndrome coronavirus 2) SARS‐CoV‐2 infection. Here, we implemented single‐cell RNA sequencing (scRNA‐seq) to profile longitudinally collected PBMCs (peripheral blood mononuclear cells) in six individuals immunized with CoronaVac and compared these to the profiles of COVID‐19 infected patients from a Single Cell Consortium. Both inactivated vaccines and SARS‐CoV‐2 infection altered the proportion of different immune cell types, caused B cell activation and differentiation, and induced the expression of genes associated with antibody production in the plasma. The inactivated vaccine and SARS‐COV‐2 infection also caused alterations in peripheral immune activity such as interferon response, inflammatory cytokine expression, innate immune cell apoptosis and migration, effector T cell exhaustion and cytotoxicity, however, the magnitude of change was greater in COVID‐19 patients, especially those with severe disease, than in immunized individuals. Further analyses revealed a distinct peripheral immune cell phenotype associated with CoronaVac immunization (HLA class II upregulation and IL21R upregulation in naïve B cells) versus SARS‐CoV‐2 infection (HLA class II downregulation and IL21R downregulation in naïve B cells from severe disease individuals). There were also differences in the expression of important genes associated with proinflammatory cytokines and thrombosis. In conclusion, this study provides a single‐cell atlas of the systemic immune response to CoronaVac immunization and revealed distinct immune responses between inactivated vaccines and SARS‐CoV‐2 infection.

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Neuroblastoma (NB) is the most common extra-cranial solid tumor in children and the most frequently diagnosed cancer in the first year of life. Previous genome-wide association studies (GWAS) of Caucasian and African populations have shown that common single nucleotide polymorphisms (SNPs) in several genes are associated with the risk of developing NB, while few studies have been performed on Chinese children. Herein, we examined the association between the genetic polymorphisms in candidate genes and the risk of NB in Chinese children. In total, 127 SNPs in nine target genes, revealed by GWAS studies of other ethnic groups and four related lincRNAs, were genotyped in 549 samples (244 NB patients and 305 healthy controls). After adjustment for gender and age, there were 21 SNPs associated with NB risk at the two-sided P < 0.05 level, 11 of which were located in LMO1. After correction for multiple comparisons, only rs204926 in LMO1 remained significantly different between cases and controls (OR = 0.45, 95% CI: 0.31–0.65, adjusted P = 0.003). In addition, 16 haplotypes in four separate genes were significantly different between case and control groups at an unadjusted P value < 0.05, 11 of which were located in LMO1. A major haplotype, ATC, containing rs204926, rs110420, and rs110419, conferred a significant increase in risk for NB (OR = 1.82, 95% CI: 1.41–2.36, adjusted P < 0.001). The major finding of our study was obtained for risk alleles within the LMO1 gene. Our data suggest that genetic variants in LMO1 are associated with increased NB risk in Chinese children.

ZFX (zinc finger protein, X-linked) gene locus on the human X chromosome is structurally similar to the zinc finger protein, Y-linked gene, which may constitute the primary sex-determining signal. However, the pathological roles of the dysfunction of ZFX gene in human disease such as cancer have not been addressed. Here, we analyzed the expression of ZFX in human laryngeal squamous cell carcinoma (LSCC) tissue specimens and found a significant up-regulation compared to corresponding non-tumorous LSCC tissue. Recombinant lentivirus expressing ZFX short hairpin RNA (shZFX) was constructed and infected Hep-2 human LSCC cells. We found that knockdown of ZFX gene resulted in suppression of proliferation and colony-forming ability of Hep-2 cells, and led to S phase cell cycle arrest. In addition, down-regulation of ZFX induced a significant enhancement of cell apoptosis and expression changes of apoptosis-related genes. These results suggest that high expression of ZFX is associated with LSCC progression and knockdown of ZFX may block tumor cell growth mainly by promoting cell apoptosis.