A multiplex recombinase polymerase amplification assay combined with CRISPR/Cas12a for the detection of respiratory syncytial virus and respiratory adenovirus.

OBJECTIVE: Respiratory syncytial virus (RSV) and respiratory adenovirus (ADV) are two common pathogens that cause acute respiratory tract infections in children. We aimed to develop a rapid method for detecting both pathogens simultaneously. METHODS: The recombinase polymerase isothermal amplification (RPA) method was combined with the CRISPR/Cas detection system. The assay's specificity and sensitivity were explored by designing RPA primers and CRISPR RNAs (crRNAs) through multi-sequence comparisons, optimizing the reaction conditions, and using a fluorescent reading device. The consistency of the test results of 160 clinical pharyngeal swab samples was studied using quantitative polymerase chain reaction (qPCR) results as a comparative control. RESULTS: RSV and ADV could be detected at levels as low as 104 copies/mL and 103 copies/mL, respectively, within 50 minutes with no cross-reactivity with other similar pathogens. For the clinical samples, compared with the qPCR method, the sensitivities for RSV and ADV were 98.1% and 91.4%, respectively, and the detection specificities were both 100%. The Kappa values were greater than 0.95, suggesting a high degree of consistency. CONCLUSION: This method for detecting RSV and ADV is rapid, sensitive, and specific. It can accurately detect mixed infections in a timely manner, making it suitable for use in areas with scarce healthcare resources.

Enantioselective Palladium-Catalyzed Domino Carbonylative Heck Esterification of o-Iodoalkenylbenzenes with Arylboronic Acids.

The current investigation presents an innovative palladium-catalyzed asymmetric carbonylative Heck esterification method. This approach facilitates the efficient synthesis of various chiral γ-ketoacid esters by utilizing o-alkenyliodobenzenes and arylboronic acids as primary substrates. This reaction achieves the creation of three carbon-carbon bonds, two carbon-oxygen bonds, and the establishment of a quaternary carbon center within a single step. The α-chiral γ-ketoacid esters were obtained in yields ranging from good to high yields, displaying enantiomeric excesses (ee's) levels up to 92% under mild reaction conditions.

C(alkyl)-C(vinyl) bond cleavage enabled by Retro-Pallada-Diels-Alder reaction.

Activation and cleavage of carbon-carbon (C-C) bonds is a fundamental transformation in organic chemistry while inert C-C bonds cleavage remains a long-standing challenge. Retro-Diels-Alder (retro-DA) reaction is a well-known and important tool for C-C bonds cleavage but less been explored in methodology by contrast to other strategies. Herein, we report a selective C(alkyl)-C(vinyl) bond cleavage strategy realized through the transient directing group mediated retro-Diels-Alder reaction of a six-membered palladacycle, which is obtained from an in situ generated hydrazone and palladium hydride species. This unprecedented strategy exhibits good tolerances and thus offers new opportunities for late-stage modifications of complex molecules. DFT calculations revealed that an intriguing retro-Pd(IV)-Diels-Alder process is possibly involved in the catalytic cycle, thus bridging both Retro-Diels-Alder reaction and C-C bond cleavage. We anticipate that this strategy should prove instrumental for potential applications to achieve the modification of functional organic skeletons in synthetic chemistry and other fields involving in molecular editing.

Breastfeeding in Mothers with COVID-19: Insights from Laboratory Tests and Follow-Up from Early Outbreak of the Pandemic in China.

Objective: The outbreak of Coronavirus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) threatens a surging number of community groups within society, including women actively breastfeeding. Breastfeeding involves intimate behaviors, a major transmission route of SARS-CoV-2, and is integral to the close mother-baby relationship highly correlated with maternal psychological status. Materials and Methods: Twenty-three pregnant women and puerperae with either confirmed or suspected diagnoses of COVID-19 were enrolled in the study. The clinical characteristics and outcomes of the mothers and neonates were recorded. The presence of SARS-CoV-2, IgG, and IgM in breast milk, maternal blood, and infant blood, together with feeding patterns, was assessed within 1 month after delivery. Feeding patterns and maternal psychological status were also recorded in the second follow-up. Results: No positive detection of SARS-CoV-2 was found in neonates. All breast milk samples were negative for the detection of SARS-CoV-2. The presence of IgM for SARS-CoV-2 in breast milk was correlated with IgM presence in the maternal blood. The results of IgG detection for SARS-CoV-2 were negative in all breast milk samples. All infants were in a healthy condition in two follow-ups, and antibody tests for SARS-CoV-2 were negative. The rate of breast milk feeding increased during two follow-ups. All mothers receiving a second follow-up experienced negative psychological factors and status. Conclusions: Our findings support the feasibility of breastfeeding in women infected with SARS-CoV-2. The additional negative psychological status of mothers due to COVID-19 should also be considered during the puerperium period.

Neutrophil-lymphocyte ratio predicts short term mortality in patients with hepatitis B virus-related acute-on-chronic liver failure treated with an artificial liver support system.

AIM: Hepatitis B virus-related acute-on-chronic liver failure has high short-term mortality. Artificial liver support systems (ALSS) may improve outcome and avoid liver transplantation, but predicting short-term prognosis in such patients is difficult. This study aimed to determine whether the neutrophil-lymphocyte ratio (NLR), an inflammation marker, predicted mortality in patients treated with ALSS. METHODS: A total of 560 patients with hepatitis B virus-related acute-on-chronic liver failure were enrolled, 338 were treated with ALSS and the others treated with standard of care(SOC). Clinical variables and the NLR were evaluated for prognostic value. RESULTS: Thirty-day mortality was 28.4% in ALSS and 55.4% in SOC patients. The NLR was lower in survivors than in ALSS or SOC patients who died. Univariate and multivariate analysis found that NLR and the chronic liver failure sequential organ failure assessment scores(CLIF-SOFA) were independently associated with 30-day mortality. Among patients with NLRs ≤ 3, 3-6, and >6, 30-day mortality was 7.7%,23.1%, and 69.2% in ALSS and 25.5%, 50.0%, and 75.0% in SOC patients. Among patients with NLRs ≤ 3 or 3-6, mortality was lower in ALSS than in SOC patients (P < 0.01). Mortality rates of ALSS and SOC patients with NLRs > 6 did not different (P >0.05). The area under curve of NLR and CLIF-SOFA was 0.82 and 0.88 in ALSS group, 0.78 and 0.86 in SOC group. The results suggest that liver function in most patients with NLRs ≤ 3 recovered with ALSS treatment, and patients with NLRs > 6 needed emergency liver transplantation. CONCLUSION: NLR was an independent predictor of mortality in ALSS patients and may assist physicians in determining treatment options.