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1.
Integrative Medicine in Nephrology and Andrology ; 8(1):1-6, 2021.
Article in English | EuropePMC | ID: covidwho-1871289

ABSTRACT

Objective: The aim of the study was to analyze the clinical features of elderly patients with coronavirus disease 2019 (COVID-19) and to explore the relationship between COVID-19 patients and kidney injury. Methods: A total of 188 elderly patients with confirmed COVID-19 enrolled in this study were hospitalized for at least 1 week in the Central Theater Command General Hospital of Chinese People's Liberation Army from January 3, 2020 to March 14, 2020. The recorded information included clinical data and results of kidney-related laboratory tests. Retrospective analysis was performed. Results: The median age of the patients was 69 years (interquartile range 65–78, range: 60–97 years);31.4% were 60–74 years old, and 68.6% were over 75 years old. A total of 12.8% and 18.6% of the patients were in critical and severe stages of COVID-19, respectively. The proportions of patients using mechanical ventilators and deaths were 9.5% and 8.5%, respectively. A total of 26.1% and 8.5% of the patients showed mild elevation of blood urea nitrogen (BUN) and serum creatinine (SCr) levels at admission. A total of 18.6% and 5.9% of the patients had elevated BUN and SCr 1 week after admission, respectively. A total of 3.1% of the patients were diagnosed with acute kidney injury, and 75% of those patients had chronic kidney disease before admission. Compared with the patients aged 60–74 years, those over 75 years exhibited significantly increased proportions of elevated BUN levels, critical illness, use of mechanical ventilated, and death. Multivariate logistic regression analysis revealed that an elevated BUN level at admission and 1 week after admission were independent risk factors for death in the elderly patients with COVID-19. Conclusion: There were more critical cases and a high mortality in elderly patients with COVID-19. An increased BUN level was an independent risk factor for death in elderly patients with COVID-19.

2.
Life ; 12(6):793, 2022.
Article in English | MDPI | ID: covidwho-1869690

ABSTRACT

The ACE2 receptor, as the potential entrance site of SARS-CoV-2-affected cells, plays a crucial role in spreading infection. The DX600 peptide is a competitive inhibitor of ACE2. We previously constructed the 68Ga-labeled DOTA-DX600 (also known as 68Ga-HZ20) peptide and confirmed its ACE2 binding ability both in vitro and in vivo. In this research, we aimed to investigate the noninvasive mapping of ACE2 expression in fowl using 68Ga-HZ20 micro-PET. We chose pigeons as an animal model and first studied the administration method of 68Ga-HZ20 by direct site injection or intravenous injection. Then, the dynamic micro-PET scan of 68Ga-HZ20 was conducted at 0–40 min. Additionally, 18F-FDG was used for comparison. Finally, the pigeons were sacrificed, and the main organs were collected for further immunoPET and IHC staining. Micro PET/CT imaging results showed that 68Ga-HZ20 uptake was distributed from the heart at the preliminary injection to the kidneys, liver, stomach, and lungs over time, where the highest uptake was observed in the kidneys (SUVmax = 6.95, 20 min) and lung (SUVmax = 1.11, 20 min). Immunohistochemical experiments were carried out on its main organs. Compared to the SUVmax data, the IHC results showed that ACE2 was highly expressed in both kidneys and intestines, and the optimal imaging time was determined to be 20 min after injection through correlation analysis. These results indicated that 68Ga-HZ20 is a potential target molecule for SARS-CoV-2 in fowl, which is worthy of promotion and further study.

3.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-335520

ABSTRACT

Background: This study aims to described the epidemiology and genotypic diversity of Human metapneumovirus (HMPV) and the impact of SARS-CoV-2 on the prevalence of HMPV in hospitalized children with Acute respiratory tract infections (ARTIs) in Beijing, China. Methods From April 2018 to March 2019 and from September 2020 to August 2021, nasopharyngeal aspirates (NPAs) from hospitalized children with ARTIs in Beijing were collected and subjected to real-time polymerase chain reaction tests for HMPV. Then genotyping, detection of 15 common respiratory viruses and clinical characteristics were analyzed on HMPV positive samples. Results 7.9% (124/1572) enrolled paediatric patients were identified as having HMPV infection, and the majority of children under the age of 5 (78.2%, 92/124), From April 2018 to March 2019. The detection rate of HMPV in spring and winter is significantly higher than that in summer and autumn. The co-infection rate were 37.1% (46/124), the most common co-infected virus were parainfluenza virus type 3 (HPIV-3). The main diagnosis of HMPV infection was pneumonia (92.7%,115/124), most patient have cough and fever. Of 78 HMPV-positive specimens, A2b (82.1%,64/78) were the main epidemic subtypes. .During the COVID-19 outbreak, Among 232 samples, only 4 cases were HMPV-positive. After statistical test, the detection rate of HMPV during the COVID-19 pandemic has decreased significantly compared with that before the epidemic (p=0.001). Conclusions HMPV is an important cause of ARTIs in children under 5 years old. Under the prevention and control of the COVID-19 pandemic, the HMPV infection of hospitalized children with ARTIs has decreased significantly.

4.
J Med Virol ; 94(8): 3801-3810, 2022 Aug.
Article in English | MEDLINE | ID: covidwho-1802451

ABSTRACT

Influenza-like illness (ILI) varies in intensity year by year, generally keeping a stable pattern except for great changes of its epidemic pattern. Of the most impacting factors, urbanization has been suggested as shaping the intensity of influenza epidemics. Besides, growing evidence indicates the nonpharmaceutical interventions (NPIs) to severe acute respiratory syndrome coronavirus 2 offer great advantages in controlling infectious diseases. The present study aimed to evaluate the impact of urbanization and NPIs on the dynamic of ILI in Tongzhou, Beijing, during January 2013 to March 2021. ILI epidemiological surveillance data in Tongzhou district were obtained from Beijing Influenza Surveillance Network and separated into three periods of urbanization and four intervals of coronavirus disease 2019 pandemic. Standardized average incidence rates of ILI in each separate stages were calculated and compared by using Wilson method and time series model of seasonal ARIMA. Influenza seasonal outbreaks showed similar epidemic size and intensity before urbanization during 2013-2016. Increased ILI activity was found during the process of Tongzhou's urbanization during 2017-2019, with the rate difference of 2.48 (95% confidence interva [CI]: 2.44, 2.52) and the rate ratio of 1.75 (95% CI: 1.74, 1.76) of ILI incidence between preurbanization and urbanization periods. ILI activity abruptly decreased from the beginning of 2020 and kept at the bottom level almost in every epidemic interval. The top decrease in ILI activity by NPIs was shown in 5-14 years group in 2020-2021 influenza season, as 92.2% (95% CI: 78.3%, 95.2%). The results indicated that both urbanization and NPIs interrupted the epidemic pattern of ILI. We should pay more attention to public health when facing increasing population density, human contact, population mobility, and migration in the process of urbanization. NPIs and influenza vaccination should be implemented as necessary measures to protect people from common infectious diseases like ILI.


Subject(s)
COVID-19 , Influenza, Human , Virus Diseases , Beijing/epidemiology , COVID-19/epidemiology , COVID-19/prevention & control , Humans , Influenza, Human/epidemiology , Influenza, Human/prevention & control , Pandemics , Seasons , Urbanization , Virus Diseases/epidemiology
5.
Vaccines (Basel) ; 10(4)2022 Apr 12.
Article in English | MEDLINE | ID: covidwho-1786105

ABSTRACT

(1) Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines were developed in only a short amount of time and were widely distributed. We conducted this meta-analysis to understand the safety of SARS-CoV-2 vaccines. (2) Methods: We searched the corresponding literature published from 1 January 2020 to 20 October 2021. Information of adverse events (AEs) of each selected work was collected. The quality and bias of studies was evaluated, and meta-analysis was carried out by using Stata 17.0. (3) Results: Totally, 11,451 articles were retrieved, and 53 of them were included for analysis. The incidence rate of AEs was 20.05-94.48%. The incidence rate of vascular events increased after viral vector vaccination, while the incidence rate of vascular events decreased after mRNA vaccination. Viral vector vaccine had a higher AE rate compared to mRNA vaccines and inactivated vaccines. In most circumstances, the incidence of AEs was higher in older people, female and after the second dose. The sensitivity of meta-analysis was acceptable; however, the literature was subject to a certain publication bias. (4) Conclusions: The safety of SARS-CoV-2 vaccines was acceptable. The incidence of allergic symptoms and cardiovascular and cerebrovascular symptoms was low. Viral vector vaccine had a higher risk of leading to thrombosis events. The understanding of SARS-CoV-2 vaccine AEs should be enhanced, so as to promote the vaccination.

6.
Adv Exp Med Biol ; 1366: 87-100, 2022.
Article in English | MEDLINE | ID: covidwho-1782742

ABSTRACT

The continued HIV/AIDS epidemic worldwide and the battle against emerging infectious diseases caused by coronaviruses underscore the need for the development of an ever-expanding repertoire of antiviral drugs. Entry inhibitors are of particular interest because of their potential to be used as therapeutic or prophylactic treatments for blocking viral invasion. HIV and coronaviruses utilize class I fusion proteins to facilitate their entry and membrane fusion. Discovery of a common hexameric coiled-coil fusion complex resulting from the packing of three C-terminal heptad repeat region from the fusion-mediating subunit of viral fusion proteins against trimeric coiled-coil made up by their N-terminal heptad repeat prompted the search for peptides mimicking the heptad repeat regions that could potentially inhibit viral entry. This has led to the development of effective peptides that are specific to the virus that is developed for. In this review, we focus on peptide-based entry dual inhibitors that block fusion process not only of HIV but also coronaviruses through interrupting their fusogenic six-helical bundle core and which hopefully will help to gain insight into the α-helical secondary structure- and coiled-coil superstructure-based strategies to design entry inhibitors with broad-spectrum antiviral activity against enveloped viruses with class I fusion proteins.


Subject(s)
Antiviral Agents , Coronavirus Infections , Coronavirus , HIV Fusion Inhibitors , HIV Infections , Peptides , Amino Acid Sequence , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Coronavirus Infections/drug therapy , HIV Envelope Protein gp41/metabolism , HIV Envelope Protein gp41/pharmacology , HIV Fusion Inhibitors/pharmacology , HIV Fusion Inhibitors/therapeutic use , Humans , Peptides/pharmacology , Protein Structure, Secondary
7.
ACS Nano ; 2021 Dec 06.
Article in English | MEDLINE | ID: covidwho-1778567

ABSTRACT

Currently, the quest for highly transparent and flexible fibrous membranes with robust mechanical characteristics, high breathability, and good filtration performance is rapidly rising because of their potential use in the fields of electronics, energy, environment, medical, and health. However, it is still an extremely challenging task to realize transparent fibrous membranes due to serious surface light reflection and internal light scattering. Here, we report the design and development of a simple and effective topological structure to create porous, breathable, and high visible light transmitting fibrous membranes (HLTFMs). The resultant HLTFMs exhibit good optical performance (up to 90% transmittance) and high porosities (>80%). The formation of such useful structure with high light transmittance has been revealed by electric field simulation, and the mechanism of fibrous membrane structure to achieve high light transmittance has been proposed. Moreover, transparent masks have been prepared to evaluate the filtration performance and analyze their feasibility to meet requirement of facial recognition systems. The prepared masks display high transparency (>80%), low pressure drop (<100 Pa) and high filtration efficiency (>90%). Furthermore, the person wearing this mask can be successfully identified by facial recognition systems. Therefore, this work provides an idea for the development of transparent, breathable, and high-performance fibrous membranes.

8.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-329417

ABSTRACT

SARS-CoV-2 has infected more than 400 million people around the globe and caused millions of deaths. Since its identification in November 2021, Omicron, a highly transmissible variant, has become the dominant variant in most countries. Omicron highly mutated spike protein, the main target of vaccine development, significantly compromises the immune protection from current vaccination. We develop an mRNA vaccine (SOmicron-6P) based on an Omicron-specific sequence. In mice, SOmicron-6P shows superior neutralizing antibodies inducing abilities to a clinically approved inactivated virus vaccine, a clinically approved protein subunit vaccine, and an mRNA vaccine (SWT-2P) with the same sequence of BNT162b2 RNA. Significantly, SOmicron-6P induces a 14.4~27.7-fold and a 28.3~50.3-fold increase of neutralizing activity against the pseudovirus of Omicron and authentic Omicron compared to SWT-2P, respectively. In addition, two doses SOmicron-6P significantly protects Syrian hamsters against challenge with SARS-CoV-2 Omicron variant and elicits high titers of nAbs in a dose-dependent manner in macaques. Our results suggest that SOmicron-6P offers advantages over current vaccines, and it will be helpful for those with weak immunity.

9.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-324169

ABSTRACT

Background Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which was first identified in December 2019 in Wuhan. This study mainly analyzed the clinical characteristics, imaging features, and prognosis of patients with COVID-19 in Suining, one of China's fourth-tier cities, and Wuhan in 2019 and compared data between the 2 cities. Methods: A retrospective analysis of the epidemiological history, clinical data, symptom presentation, laboratory test results, chest computed tomography (CT) imaging features, treatment measures and prognosis of 68 patients with COVID-19 diagnosed at Wuhan Red Cross Hospital and 17 patients with COVID-19 diagnosed at Suining Central Hospital from January 23, 2020, to February 27, 2020, was conducted. Results: 1) The incidence rate of COVID-19 in Wuhan was 52.99‱, and the incidence rate in Suining was 0.04‱. The median age of patients with COVID-19 was 40.71 years old in Suining and 56.04 years old in Wuhan. The age of patients with COVID-19 in Wuhan was significantly older than that of patients with COVID-19 in Suining. Among the 68 patients with COVID-19 in Wuhan, 30 (44.1%) had hypertension, and 25 (36.8%) had diabetes. Three out of the 17 patients in Suining (17.6%) had hypertension, and 2 patients (11.8%) had diabetes. The proportion of patients with diabetes or hypertension in Wuhan was significantly higher than that in Suining ( P <0.05). In the clinical classification, there were 1 (5.9%) and 23 (33.8%) patients with severe COVID-19 in Suining and Wuhan, respectively. The proportion of patients with severe COVID-19 in Wuhan was significantly higher than that in Suining ( P <0.05).Fever and cough were the most common clinical symptoms, with 9 cases (52.9%) and 8 cases (47.1%) in Suining, respectively, and 54 cases (79.4%) and 42 cases (61.8%) in Wuhan, respectively. There was 1 patient (5.9%) with COVID-19 with dyspnea in Suining and 23 patients (33.8%) with COVID-19 with dyspnea in Wuhan;the difference was statistically significant ( P <0.05). Chest CT showed that lung consolidation occurred in 2 (11.8%) and 26 (38.2%) patients with COVID-19 in Suining and Wuhan, respectively. The proportion of lung consolidation in patients in Wuhan was significantly higher than that in patients in Suining ( P <0.05). The laboratory tests suggested that percentage ofelevated C-reactive protein (CRP) (58.8%), ALT (33.8%), blood glucose (45.6%), creatine kinase (CK) (33.8%) or D-dimer (47.1%) of patients in Wuhan were significantly increased than those in Suining (29.4%, 5.9%, 17.6%, 5.9%, and 17.7%, respectively). Moreover, the average length of hospital stay of patients in Wuhan was 17.49 days, which was significantly longer than that of patients in Suining (12.29 days). Conclusions: The incidence of COVID-19 in fourth-tier cities, Suining, in China was significantly lower than that in Wuhan, and the disease severity was generally lower than that in Wuhan, with mostly good prognoses. Advanced age, diabetes, and hypertension are important factors that aggravate COVID-19, while elevated CRP, ALT, blood glucose, CK, and D-dimer levels are important indicators for severe disease.

10.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-323540

ABSTRACT

Background: COVID-19, a worldwideinfectious disease, has killed more than 420000 people, whichis extremely harmful. Methods: In this single-center retrospective study, we included the novel coronavirus pneumonia confirmed in our hospital. This study collected the basic information andclinical examination features. Results: The enrolled 704 patients were affirmed infected with 2019-nCoV by the test of throat swabs. There are 334 men and 369 women, and gender, age, combined with basic diseasesare distinct in diverse disease classification (p<0.05). From the symptom analysis, the proportion of fever over 38 degrees, dyspnea, fatigue, poor appetite and other symptoms is diverse in different types of diseases (p<0.05). As the severity of the disease increases, the median lymphocyte count decreases, C-reactive protein increase, erythrocyte sedimentation rateincrease, albumin decrease, pleural effusion increase, D-Dimer and NT-proBNP increase significantly (p<0.05).As the disease severity increases, the average value of MuLBSTA score obviously ascend (p<0.05), MuLBSTA scoring system predicts novel coronavirus pneumonia patients' prognosis is still insufficient, and may require additional indicators including anorexia, fatigue, C reactive protein, etc (p<0.05). Conclusion: The MuLBSTA evaluation system has certain value for the evaluation of the disease, but it needs to be improved.

11.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-312504

ABSTRACT

The COVID-19 pandemic is the most serious catastrophe since the Second World War. To more accurately observe the epidemic under the influence of policies and provide policy adjustments before the official presidential transition in the United States, we use a three-layer superimposed Long-Short-Term-Memory (LSTM) model to predict the epidemic development trend to mid-January, 2021. The proposed model provides more accuracy and stability relative to Susceptible-Exposed-Infective-Recovered (SEIR), modified stacked au-to-encoder, and single-layer LSTM models. The performance effects of the measures in China and five countries with severe epidemics are analysed and summarised. The model shows that the error rate of China, five countries and the world is less than 1.4%. According to forecasts, the epidemic situations in the United States, India, and Brazil, caused by untimely, inappropriate policies, lax regulations and insufficient public cooperation, remain very severe, with cases continuing to increase by tens of thousands. The number of cumulative confirmed cases worldwide will exceed 84.58 million by mid-January, 2021;however, the mortality rate will gradually decrease. Based on analysis of measures (including China’s effective prevention and control policies), we found that there are performed tremendous different efficiency even using same positive policy for different countries because of various cooperation between people and governments. It is essential to maintain self-protection to prevent the epidemic from deterioration or regenerating, especially, wearing mask and maintaining a safe distance.

12.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-305855

ABSTRACT

The sudden rise of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic early 2020 throughout the world has called into drastic action measures to do instant detection and reduce the spread rate. The common diagnostics testing methods has been only partially effective in satisfying the booming demand for fast detection methods to contain the further spread. However, the point-of-risk accurate diagnosis of this new emerging viral infection is paramount as simultaneous normal working operation and dealing with symptoms of SARS-CoV-2 can become the norm for years to come. Sensitive cost-effective biosensor with mass production capability is crucial throughout the world until a universal vaccination become available. Optical label-free biosensors can provide a non-invasive, extremely sensitive rapid detection technique up to ~1 fM concentration along with few minutes sensing. These biosensors can be manufactured on a mass-scale (billions) to detect the COVID-19 viral load in nasal, saliva, urinal, and serological samples even if the infected person is asymptotic. Methods investigated here are the most advanced available platforms for biosensing optical devices resulted from the integration of state-of-the-art designs and materials. These approaches are including but not limited to integrated optical devices, plasmonic resonance and also emerging nanomaterial biosensors. The lab-on-a-chip platforms examined here are suitable not only for SARS-CoV-2 spike protein detection but also other contagious virions such as influenza, and middle east respiratory syndrome (MERS).

13.
Microbiol Spectr ; 10(1): e0155021, 2022 02 23.
Article in English | MEDLINE | ID: covidwho-1685499

ABSTRACT

Mycoplasma pneumoniae is a common pathogen causing respiratory disease in children. We sought to investigate the epidemiology of M. pneumoniae among outpatient children with mild respiratory tract infections (RTIs) during the coronavirus disease 2019 (COVID-19) pandemic. Eligible patients were prospectively enrolled from January 2020 to June 2021. Throat swabs were tested for M. pneumoniae RNA. M. pneumoniae IgM was tested by a colloidal gold assay. Macrolide resistance and the effect of the COVID-19 countermeasures on M. pneumoniae prevalence were assessed. Symptom scores, treatments, and outcomes were evaluated. Eight hundred sixty-two eligible children at 15 centers in China were enrolled. M. pneumoniae was detected in 78 (9.0%) patients. Seasonally, M. pneumoniae peaked in the first spring and dropped dramatically to extremely low levels over time until the next summer. Decreases in COVID-19 prevalence were significantly associated with decreases in M. pneumoniae prevalence (r = 0.76, P = 0.001). The macrolide resistance rate was 7.7%. The overall sensitivity and specificity of the colloidal gold assay used in determining M. pneumoniae infection were 32.1% and 77.9%, respectively. No more benefits for improving the severity of symptoms and outcomes were observed in M. pneumoniae-infected patients treated with a macrolide than in those not treated with a macrolide during follow-up. The prevalences of M. pneumoniae and macrolide resistance in outpatient children with mild RTIs were at low levels in the early stage of the COVID-19 pandemic but may have rebounded recently. The colloidal gold assay for M. pneumoniae IgM may be not appropriate for diagnosis of M. pneumoniae infection. Macrolides should be used with caution among outpatients with mild RTIs. IMPORTANCE This is the first and largest prospective, multicenter, active, population-based surveillance study of the epidemiology of Mycoplasma pneumoniae among outpatient children with mild respiratory tract infections (RTIs) during the COVID-19 pandemic. Nationwide measures like strict face mask wearing and restrictions on population movement implemented to prevent the spread of COVID-19 might also effectively prevent the spread of M. pneumoniae. The prevalence of M. pneumoniae and the proportion of drug-resistant M. pneumoniae isolates in outpatient children with mild RTIs were at low levels in the early stage of the COVID-19 pandemic but may have rebounded recently. The colloidal gold assay for M. pneumoniae IgM may be not appropriate for screening and diagnosis of M. pneumoniae infection. Macrolides should be used with caution among outpatients with mild RTIs.


Subject(s)
Mycoplasma pneumoniae/isolation & purification , Pneumonia, Mycoplasma/microbiology , Respiratory Tract Infections/microbiology , Adolescent , Adult , Anti-Bacterial Agents/therapeutic use , COVID-19/epidemiology , Child , Child, Preschool , China/epidemiology , Drug Resistance, Bacterial , Female , Humans , Infant , Macrolides/therapeutic use , Male , Mycoplasma pneumoniae/genetics , Mycoplasma pneumoniae/physiology , Outpatients/statistics & numerical data , Pneumonia, Mycoplasma/drug therapy , Pneumonia, Mycoplasma/epidemiology , Prospective Studies , Respiratory Tract Infections/drug therapy , Respiratory Tract Infections/epidemiology , Young Adult
14.
International Journal of Production Research ; : 1-21, 2022.
Article in English | Taylor & Francis | ID: covidwho-1665760
16.
SLAS Discov ; 27(1): 8-19, 2022 01.
Article in English | MEDLINE | ID: covidwho-1641663

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 responsible for COVID-19 remains a persistent threat to mankind, especially for the immunocompromised and elderly for which the vaccine may have limited effectiveness. Entry of SARS-CoV-2 requires a high affinity interaction of the viral spike protein with the cellular receptor angiotensin-converting enzyme 2. Novel mutations on the spike protein correlate with the high transmissibility of new variants of SARS-CoV-2, highlighting the need for small molecule inhibitors of virus entry into target cells. We report the identification of such inhibitors through a robust high-throughput screen testing 15,000 small molecules from unique libraries. Several leads were validated in a suite of mechanistic assays, including whole cell SARS-CoV-2 infectivity assays. The main lead compound, calpeptin, was further characterized using SARS-CoV-1 and the novel SARS-CoV-2 variant entry assays, SARS-CoV-2 protease assays and molecular docking. This study reveals calpeptin as a potent and specific inhibitor of SARS-CoV-2 and some variants.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Cysteine Proteinase Inhibitors/pharmacology , Dipeptides/pharmacology , Virus Attachment/drug effects , Virus Internalization/drug effects , Angiotensin-Converting Enzyme 2/metabolism , Animals , Cathepsin L/antagonists & inhibitors , Cell Line , Chlorocebus aethiops , Drug Evaluation, Preclinical , Drug Repositioning , HEK293 Cells , Humans , Molecular Docking Simulation , SARS-CoV-2/drug effects , SARS-CoV-2/growth & development , Serine Endopeptidases/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Vero Cells
17.
Anal Chem ; 94(3): 1626-1636, 2022 01 25.
Article in English | MEDLINE | ID: covidwho-1621191

ABSTRACT

(Mi)RNAs are important biomarkers for cancers diagnosis and pandemic diseases, which require fast, ultrasensitive, and economical detection strategies to quantitatively detect exact (mi)RNAs expression levels. The novel coronavirus disease (SARS-CoV-2) has been breaking out globally, and RNA detection is the most effective way to identify the SARS-CoV-2 virus. Here, we developed an ultrasensitive poly-l-lysine (PLL)-functionalized graphene field-effect transistor (PGFET) biosensor for breast cancer miRNAs and viral RNA detection. PLL is functionalized on the channel surface of GFET to immobilize DNA probes by the electrostatic force. The results show that PGFET biosensors can achieve a (mi)RNA detection range of five orders with a detection limit of 1 fM and an entire detection time within 20 min using 2 µL of human serum and throat swab samples, which exhibits more than 113% enhancement in terms of sensitivity compared to that of GFET biosensors. The performance enhancement mechanisms of PGFET biosensors were comprehensively studied based on an electrical biosensor theoretical model and experimental results. In addition, the PGFET biosensor was applied for the breast cancer miRNA detection in actual serum samples and SARS-CoV-2 RNA detection in throat swab samples, providing a promising approach for rapid cancer diagnosis and virus screening.


Subject(s)
Biosensing Techniques , Breast Neoplasms , COVID-19 , Graphite , MicroRNAs , Breast Neoplasms/diagnosis , Breast Neoplasms/genetics , COVID-19/diagnosis , Female , Humans , Polylysine , RNA, Viral/genetics , SARS-CoV-2
18.
Biosens Bioelectron ; 202: 113971, 2022 Apr 15.
Article in English | MEDLINE | ID: covidwho-1611632

ABSTRACT

Successful control of emerging infectious diseases requires accelerated development of fast, affordable, and accessible assays for wide implementation at a high frequency. This paper presents a design for an in-solution assay pipeline, featuring nanobody-functionalized nanoparticles for rapid, electronic detection (Nano2RED) of Ebola and COVID-19 antigens. Synthetic nanobody binders with high affinity, specificity, and stability are selected from a combinatorial library and site-specifically conjugated to gold nanoparticles (AuNPs). Without requiring any fluorescent labelling, washing, or enzymatic amplification, these multivalent AuNP sensors reliably transduce antigen binding signals upon mixing into physical AuNP aggregation and sedimentation processes, displaying antigen-dependent optical extinction readily detectable by spectrometry or portable electronic circuitry. With Ebola virus secreted glycoprotein (sGP) and a SARS-CoV-2 spike protein receptor binding domain (RBD) as targets, Nano2RED showed a high sensitivity (the limit of detection of ∼10 pg /mL, or 0.13 pM for sGP and ∼40 pg/mL, or ∼1.3 pM for RBD in diluted human serum), a high specificity, a large dynamic range (∼7 logs),and fast readout within minutes. The rapid detection, low material cost (estimated <$0.01 per test), inexpensive and portable readout system (estimated <$5), and digital data output, make Nano2RED a particularly accessible assay in screening of patient samples towards successful control of infectious diseases.


Subject(s)
Antigens, Viral/analysis , Biosensing Techniques , COVID-19 , Metal Nanoparticles , Biosensing Techniques/methods , Ebolavirus , Glycoproteins , Gold/chemistry , Humans , Metal Nanoparticles/chemistry , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Viral Proteins
19.
International Journal of Financial Studies ; 9(4):66, 2021.
Article in English | ProQuest Central | ID: covidwho-1592313

ABSTRACT

E-commerce and FinTech are currently booming in China. The growing consumer market is accompanied by internet finance, by which consumers can easily borrow money from financial institutions online. As a result, the growing risks of financial institutions are of concern to the government and regulatory bodies. Consequently, the securitization market in China is seeing rapid growth that could affect financial stability. Applying FinTech and emerging technologies in securitization might be an effective way to protect against these risks. This paper studies the question of whether China needs a higher standard of information transparency in order to protect against its risks against the background of digital transformation. We analyzed the determinants of securitization in the Chinese banking sector, relying on data on banks for two periods: pre-2017Q4 and post-2017Q4. The main findings of the paper demonstrate that the application of FinTech in China’s banking industry resulted in less information asymmetry. The risk exposure was the most significant determinant in general. Higher risk exposures increased securitization transaction volumes, which reflects securitization with adverse selection problems between the originator and investors. Liquidity and profitability, as important determinants indicating the moral hazard problem, also affected securitization pre-2017Q4, but liquidity and profitability were found to be unimportant determinants after the application of FinTech (the post-2017Q4 period). Moreover, this study finds that the effects of the adverse selection and moral hazard problems varied in different types of banks. Overall, our findings suggest that the Chinese securitization market needs a higher standard of information transparency.

20.
Talanta ; 240: 123197, 2022 Apr 01.
Article in English | MEDLINE | ID: covidwho-1586446

ABSTRACT

The current outbreaking of the coronavirus SARS-CoV-2 pandemic threatens global health and has caused serious concern. Currently there is no specific drug against SARS-CoV-2, therefore, a fast and accurate diagnosis method is an urgent need for the diagnosis, timely treatment and infection control of COVID-19 pandemic. In this work, we developed a field effect transistor (FET) biosensor based on graphene oxide-graphene (GO/Gr) van der Waals heterostructure for selective and ultrasensitive SARS-CoV-2 proteins detection. The GO/Gr van der Waals heterostructure was in-situ formed in the microfluidic channel through π-π stacking. The developed biosensor is capable of SARS-CoV-2 proteins detection within 20 min in the large dynamic range from 10 fg/mL to 100 pg/mL with the limit of detection of as low as ∼8 fg/mL, which shows ∼3 × sensitivity enhancement compared with Gr-FET biosensor. The performance enhancement mechanism was studied based on the transistor-based biosensing theory and experimental results, which is mainly attributed to the enhanced SARS-CoV-2 capture antibody immobilization density due to the introduction of the GO layer on the graphene surface. The spiked SARS-CoV-2 protein samples in throat swab buffer solution were tested to confirm the practical application of the biosensor for SARS-CoV-2 proteins detection. The results indicated that the developed GO/Gr van der Waals heterostructure FET biosensor has strong selectivity and high sensitivity, providing a potential method for SARS-CoV-2 fast and accurate detection.


Subject(s)
Biosensing Techniques , COVID-19 , Graphite , Humans , Pandemics , SARS-CoV-2
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