Since late December 2019, the coronavirus pandemic (COVID-19; previously
known as 2019-nCoV) caused by the severe acute respiratory syndrome
coronavirus 2 (SARS-CoV-2) has been surging rapidly around the world.
With more than 1,700,000 confirmed cases, the world faces an unprecedented
economic, social, and health impact. The early, rapid, sensitive,
and accurate diagnosis of viral infection provides rapid responses
for public health surveillance, prevention, and control of contagious
diffusion. More than 30% of the confirmed cases are asymptomatic,
and the high false-negative rate (FNR) of a single assay requires
the development of novel diagnostic techniques, combinative approaches,
sampling from different locations, and consecutive detection. The
recurrence of discharged patients indicates the need for long-term
monitoring and tracking. Diagnostic and therapeutic methods are evolving
with a deeper understanding of virus pathology and the potential for
relapse. In this Review, a comprehensive summary and comparison of
different SARS-CoV-2 diagnostic methods are provided for researchers
and clinicians to develop appropriate strategies for the timely and
effective detection of SARS-CoV-2. The survey of current biosensors
and diagnostic devices for viral nucleic acids, proteins, and particles
and chest tomography will provide insight into the development of
novel perspective techniques for the diagnosis of COVID-19.
The ribose 2'-hydroxyl group at the cleavage site has little role in transition-state stabilization by group II ribozymes. Substrate 2'-hydroxyl groups are not involved in substrate binding, suggesting that only base-pairing is required for substrate recognition.
A quantum dot-based lateral flow immunoassay system (QD-LFIAS) was developed to simultaneously detect both influenza A virus subtypes H5 and H9. Water-soluble carboxyl-functionalized quantum dots (QDs) were used as fluorescent tags. The QDs were conjugated to specific influenza A virus subtype H5 and H9 antibodies via an amide bond. When influenza A virus subtype H5 or H9 was added to the QD-LFIAS, the QD-labeled antibodies specifically bound to the H5 or H9 subtype viruses and were then captured by the coating antibodies at test line 1 or 2 to form a sandwich complex. This complex produced a bright fluorescent band in response to 365 nm ultraviolet excitation. The intensity of fluorescence can be detected using an inexpensive, low-maintenance instrument, and the virus concentration directly correlates with the fluorescence intensity. The detection limit of the QD-LFIAS for influenza A virus subtype H5 was 0.016 HAU, and the detection limit of the QD-LFIAS for influenza A virus subtype H9 was 0.25 HAU. The specificity and reproducibility were good. The simple analysis step and objective results that can be obtained within 15 min indicate that this QD-LFIAS is a highly efficient test that can be used to monitor and prevent both Influenza A virus subtypes H5 and H9.
Introduction. Posttraumatic stress disorder (PTSD) is accompanied by poor general psychological status (GPS). In the present study, we investigated the effects of a Chinese herbal formula on GPS in earthquake survivors with PTSD. Methods. A randomized, double-blind, placebo-controlled trial compared a Chinese herbal formula, Xiao-Tan-Jie-Yu-Fang (XTJYF), to placebo in 2008 Sichuan earthquake survivors with PTSD. Patients were randomized into XTJYF (n = 123) and placebo (n = 122) groups. Baseline-to-end-point score changes in the three global indices of the Symptom Checklist-90-Revised (SCL-90-R) and rates of response in the SCL global severity index (GSI) were the primary endpoints. A subanalysis of the nine SCL factors and the sleep quality score were secondary endpoints. Results and Discussion. Compared to placebo, the XTJYF group was significantly improved in all three SCL global indices (P = 0.001~0.028). More patients in the XTJYF group reported “much improved” than the placebo group (P = 0.001). The XTJYF group performed significantly better than control in five out of nine SCL factors (somatization, obsessive-compulsive behavior, depression, anxiety, and hostility (P = 0.001~0.036)), and in sleep quality score (P < 0.001). XTJYF produced no serious adverse events. These findings suggest that XTJYF may be an effective and safe treatment option for improving GPS in patients with PTSD.
Highly photoluminescent (PL) CuInZn x S 1+x nanocrystals (NCs) and CuInZn x S 1+x /ZnS core/shell NCs were successfully synthesized by a facile colloidal method. First, a facile and reliable non-injection method for the synthesis of photoluminescent CuInZn x S 2+x NCs was developed with inexpensive reagents. The relative PL quantum yields (QYs) of CuInZn x S 2+x NCs could reach up to 30%, with tunable emissions in the range 580-780 nm. Then, CuInZn x S 2+x /ZnS core/shell NCs were synthesized and showed greatly improved optical properties, the PL QY of the CuInZn x S 2+x /ZnS NCs can reach up to 60%. Even in the near-infrared region, the PL QY still can achieve up to 45% due to the successful controlled red shift of PL during the ZnS shell growth process. More importantly, such core/shell NCs can be transferred into water successfully using amphiphilic oligomer (polymaleic acid n-hexadecanol ester) as a surface coating agent by an organic-aqueous phase transfer method and the PL QYs can be well controlled over 40%. Furthermore, a biosensor system (lateral flow immunoassays system, LFIA) for the detection of C-reactive protein (CRP) was developed by using this water-soluble CuInZn x S 2+x / ZnS core/shell NCs as fluorescent label and a nitrocellulose filter membrane for lateral flow. The results showed that such CuInZn x S 2+x /ZnS core/shell NCs were excellent fluorescent labels to detect CRP. The detection sensitivity for CRP could reach 1 ng mL À1 .
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