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Dengue virus (DENV) causes approximately 390 million dengue infections worldwide every year. There were 22,777 reported DENV infections in Tainan, Taiwan in 2015. In this study, we sequenced the C-prM-E genes from 45 DENV 2015 strains, and phylogenetic analysis based on C-prM-E genes revealed that all strains were classified as DENV serotype 2 Cosmopolitan genotype. Sequence analysis comparing different DENV-2 genotypes and Cosmopolitan DENV-2 sequences prior to 2015 showed a clade replacement event in the DENV-2 Cosmopolitan genotype. Additionally, a major substitution C-A314G (K73R) was found in the capsid region which may have contributed to the clade replacement event. Reverse genetics virus rgC-A314G (K73R) showed slower replication in BHK-21 and C6/36 cells compared to wildtype virus, as well as a decrease in NS1 production in BHK-21-infected cells. After a series of passaging, the C-A314G (K73R) mutation reverted to wildtype and was thus considered to be unstable. Next generation sequencing (NGS) of three sera collected from a single DENV2-infected patient at 1-, 2-, and 5-days post-admission was employed to examine the genetic diversity over-time and mutations that may work in conjunction with C-A314G (K73R). Results showed that the number of haplotypes decreased with time in the DENV-infected patient. On the fifth day after admission, two new haplotypes emerged, and a single non-synonymous NS4A-L115I mutation was identified. Therefore, we have identified a persistent mutation C-A314G (K73R) in all of the DENV-2 isolates, and during the course of an infection, a single new non-synonymous mutation in the NS4A region appears in the virus population within a single host. The C-A314G (K73R) thus may have played a role in the DENV-2 2015 outbreak while the NS4A-L115I may be advantageous during DENV infection within the host. Author summary: Dengue virus (DENV) is an RNA virus which causes many infections worldwide. Taiwan experienced the largest DENV-2 outbreak in 2015 which resulted in many fatalities. Specific reasons for the increase in severity during this outbreak remains unclear. The molecular epidemiology of this outbreak showed that clade replacement may have occurred, with the 2015 isolates forming a new clade and the old clade consisted of sequences from 2001–2004 in Taiwan. A dominant C-A314G (K73R) substitution was found in the 2015 DENV-2 outbreak isolates, which may have resulted in a clade replacement in the DENV-2 Cosmopolitan genotype. Further analysis of genetic variation of the virus population of one DENV-2 infected patient showed a decrease of haplotypes during the progression of infection and an NS4A-L115I mutation that did not appear until a later time-point. These show the difference between the variations found in a population wide analysis compared to an infrapopulation analysis which can influence viral infection. [ABSTRACT FROM AUTHOR]

Purpose: To analyze the composition of abnormal hemoglobin and the relationship between genotype and phenotype by screening abnormal hemoglobin in a subpopulation of Guizhou, China. Patients and Methods: Routine blood evaluation, capillary electrophoresis of hemoglobin, and mutation of α - and β - thalassemia genes were evaluated in 19,976 individuals for thalassemia screening in Guizhou. Sanger sequencing of HBA1, HBA2 and HBB genes was performed in samples with abnormal bands or unexplained increases of normal bands. The types of abnormal hemoglobin were obtained by sequence analysis. Results: Abnormal hemoglobin was detected in 84 individuals (detection rate, 0.42%). Ten types each of α and β globin chain variants were detected, including most commonly Hb E, Hb New York and Hb Port Phillip. In this study, the abnormal Hb Mizuho was identified for the first time in a Chinese population, and a novel abnormal hemoglobin Hb Guiyang (HBA2: c.151C > A) was detected for the first time. Except for Hb Mizuho, other abnormal hemoglobin heterozygotes without thalassemia or iron deficiency had no significant hematological changes. Conclusion: This study enriched the molecular epidemiological data of abnormal hemoglobin in Guizhou, China and provided reference data for genetic counseling and prenatal diagnosis of abnormal hemoglobin. [ABSTRACT FROM AUTHOR]

Coxsackievirus A16 (CVA16) is well known for causing hand-foot-and-mouth disease (HFMD) and outbreaks were frequently reported in Taiwan in the past twenty years. The epidemiology and genetic variations of CVA16 in Taiwan from 1998 to 2021 were analyzed in this study. CVA16 infections usually occurred in early summer and early winter, and showed increased incidence in 1998, 2000–2003, 2005, 2007–2008, and 2010 in Taiwan. Little or no CVA16 was detected from 2017 to 2021. CVA16 infection was prevalent in patients between 1 to 3 years old. A total of 69 isolates were sequenced. Phylogenetic analysis based on the VP1 region showed that CVA16 subgenotype B1 was dominantly isolated in Taiwan from 1998 to 2019, and B2 was identified only from isolates collected in 1999 and 2000. There was a high frequency of synonymous mutations in the amino acid sequences of the VP1 region among CVA16 isolates, with the exception of position 145 which showed positive selection. The recombination analysis of the whole genome of CVA16 isolates indicated that the 5′-untranslated region and the non-structural protein region of CVA16 subgenotype B1 were recombined with Coxsackievirus A4 (CVA4) and enterovirus A71 (EVA71) genotype A, respectively. The recombination pattern of subgenotype B2 was similar to B1, however, the 3D region was similar to EVA71 genotype B. Cross-neutralization among CVA16 showed that mouse antisera from various subgenotypes viruses can cross-neutralize different genotype with high neutralizing antibody titers. These results suggest that the dominant CVA16 genotype B1 can serve as a vaccine candidate for CVA16. [ABSTRACT FROM AUTHOR]

Surgery to correct severe heart arrhythmias usually requires detailed maps of the cardiac activation wave prior to ablation. The pinpoint electrical mapping procedure is laborious and limited by its spatial resolution (5-10 mm). We propose ultrasound current source density imaging (UCSDI), a direct 3-D imaging technique that potentially facilitates existing mapping procedures with superior spatial resolution. The technique is based on a pressure-induced change in resistivity known as the acoustoelectric (AE) effect, which is spatially confined to the ultrasound focus. AE-modulated voltage recordings are used to map and reconstruct current densities. In this preliminary study, we tested UCSDI under controlled conditions and compared it with conventional electrical mapping techniques. A 2-D dipole field was produced by a pair of electrodes in a bath of 0.9% NaCl solution. Boundary electrodes detected the AE signal while a 7.5-MHz focused ultrasound transducer was scanned across the bath. UCSDI located the current source and sink to within 1 mm of their actual positions. A future UCSDI system potentially provides real-time 3-D images of the cardiac activation wave coregistered with anatomical ultrasound and would greatly facilitate corrective procedures for heart abnormalities. Index Terms--Acoustics, acoustoelectric effect, bioelectric phenomena, electrocardiography.

Thermal strain imaging (TSI) is demonstrated in two model systems mimicking two potential clinical applications. First, a custom ultrasound (US) microscope produced high-resolution TSI images of an excised porcine coronary artery. Samples were placed in a temperature-controlled water chamber and scanned transversely and longitudinally. Phase-sensitive, correlation-based speckle tracking was applied to map the spatial distribution of temporal strain across the sample. TSI differentiated fatty tissue from water-based arterial wall and muscle with high contrast and a spatial resolution of 60 [micro]m for a 50-MHz transducer. Both transverse and longitudinal TSI images compared well with B-scans of arterial wall structures, including intima, media, adventitia, and overlying fatty tissue. A second model system was used to test the hypothesis that US can produce the heating pattern required for TSI of internal structures. A 2-D phased array with independent drive electronics was combined with a conventional US scanner (iU22, Philips, Bothell, WA) for these studies. This 513-element array, originally designed for the US therapy, acted as the US heat source. To quantify the temporal strain induced by this system, TSI was performed on a homogeneous rubber phantom. TSI temperature estimates were within 3% error for a 3.2[degrees]C temperature rise produced within 2 s using a specially designed beamformer and pulse sequencer. The system was then used to produce TSI scanning of an excised kidney containing an intact piece of fat below the collecting system. These images were validated using an magnetic resonance imaging (MRI) pulse sequence designed for lipid quantification. TSI scans matched well MRI scans and histology both anatomically and quantitatively. Finally, to test the potential of US-induced TSI for a significant clinical problem, images were obtained on an excised canine aorta with fatty tissue inside the lumen. Both longitudinal and transversal TSI agreed well with anatomy. These in vitro results demonstrate the potential of high-resolution US-induced TSI with a small temperature change ( Index Terms--Thermal strain imaging, ultrasound-induced thermal strain imaging, cardiovascular plaque characterization.

A method for incorporating the segmentation of a B-mode image into the process of sound velocity reconstruction with limited-angle transmission tomography is proposed. This approach is shown to be both feasible and accurate and thus can be used to complement conventional B-mode imaging to further enhance the detection of breast cancer.

Dengue virus, a positive-sense single-stranded RNA virus, continuously threatens human health. Although several criteria for evaluation of severe dengue have been recently established, the ability to prognose the risk of severe outcomes for dengue patients remains limited. Mutant spectra of RNA viruses, including single nucleotide variants (SNVs) and defective virus genomes (DVGs), contribute to viral virulence and growth. Here, we determine the potency of intrahost viral population in dengue patients with primary infection that progresses into severe dengue. A total of 65 dengue virus serotype 2 infected patients in primary infection including 17 severe cases were enrolled. We utilized deep sequencing to directly define the frequency of SNVs and detection times of DVGs in sera of dengue patients and analyzed their associations with severe dengue. Among the detected SNVs and DVGs, the frequencies of 9 SNVs and the detection time of 1 DVG exhibited statistically significant differences between patients with dengue fever and those with severe dengue. By utilizing the detected frequencies/times of the selected SNVs/DVG as features, the machine learning model showed high average with a value of area under the receiver operating characteristic curve (AUROC, 0.966 ± 0.064). The elevation of the frequency of SNVs at E (nucleotide position 995 and 2216), NS2A (nucleotide position 4105), NS3 (nucleotide position 4536, 4606), and NS5 protein (nucleotide position 7643 and 10067) and the detection times of the selected DVG that had a deletion junction in the E protein region (nucleotide positions of the junction: between 969 and 1022) increased the possibility of dengue patients for severe dengue. In summary, we demonstrated the detected frequencies/times of SNVs/DVG in dengue patients associated with severe disease and successfully utilized them to discriminate severe patients using machine learning algorithm. The identified SNVs and DVGs that are associated with severe dengue will expand our understanding of intrahost viral population in dengue pathogenesis. [ABSTRACT FROM AUTHOR]

Abstract Background Enterovirus 71 (EV71) is a major causative agent of hand-foot-and-mouth disease (HFMD), and infection of EV71 to central nerve system (CNS) may result in a high mortality in children less than 2 years old. Although there are two highly glycosylated membrane proteins, SCARB2 and PSGL-1, which have been identified as the cellular and functional receptors of EV71, the role of glycosylation in EV71 infection is still unclear. Results We demonstrated that the attachment of EV71 to RD and SK-N-SH cells was diminished after the removal of cell surface sialic acids by neuraminidase. Sialic acid specific lectins, Maackia amurensis (MAA) and Sambucus Nigra (SNA), could compete with EV71 and restrained the binding of EV71 significantly. Preincubation of RD cells with fetuin also reduced the binding of EV71. In addition, we found that SCARB2 was a sialylated glycoprotein and interaction between SCARB2 and EV71 was retarded after desialylation. Conclusions In this study, we demonstrated that cell surface sialic acids assist in the attachment of EV71 to host cells. Cell surface sialylation should be a key regulator that facilitates the binding and infection of EV71 to RD and SK-N-SH cells.

Mosquito-borne Zika virus (ZIKV) was considered an obscure virus causing only mild or self-limited symptoms until the explosive outbreaks in French Polynesia in 2013–2014 and in the Americas in 2015–2016, resulting in more than 700,000 cases of the disease, with occasional miscarriage and severe congenital birth defects, such as intrauterine growth restriction, fetal microcephaly, and other neurodevelopmental malformations. In this review, we summarized the evolution of ZIKV from a mundane virus to an epidemic virus. ZIKV has acquired a panel of amino acid substitutions during evolution when the virus spread from Africa, Asia, Pacific, through to the Americas. Robust occurrence of mutations in the evolution of ZIKV has increased its epidemic potential. Here we discussed the contributions of these evolutionary mutations to the enhancement of viral pathogenicity and host-mosquito transmission. We further explored the potential hypotheses for the increase in ZIKV activity in recent decades. Through this review, we also explored the hypotheses for the occurrence of the recent ZIKV epidemics and highlighted the potential roles of various factors including pathogen-, host-, vector-related, and environmental factors, which may have synergistically contributed to the ZIKV epidemics. [ABSTRACT FROM AUTHOR]

The physical investigation of surfaces and their properties crucially depends on their quality. Such investigations are commonly performed in an ultra-high vacuum environment. Thereby, the transfer of samples among different setups and under ambient conditions is desirable. The usage of a capping layer for the protection of surfaces against contaminations during long-time storage and transfer, and the subsequent temperature-controlled decapping is an established approach. However, a residual-free removal of the capping layer may present a challenge. Here, we systematically investigate the decapping process of a tellurium protected topological insulator Bi2Te3. We give evidence for the material segregation from the contaminated capping layer surface to the substrates. Therefore, a simple, temperature controlled decapping is not sufficient. We demonstrate that near perfect surfaces can be reliably obtained even after long-time storage through a combination of an initial argon ion sputtering process and a following heating for decapping. This approach is suitable for dedicated analysis systems as well as for industrial applications, large throughput of samples of arbitrary shapes, and is easily implemented in existing setups. [ABSTRACT FROM AUTHOR]

Background: Dengue virus causes a wide spectrum of disease, which ranges from subclinical disease to severe dengue shock syndrome. However, estimating the risk of severe outcomes using clinical presentation or laboratory test results for rapid patient triage remains a challenge. Here, we aimed to develop prognostic models for severe dengue using machine learning, according to demographic information and clinical laboratory data of patients with dengue. Methodology/Principal findings: Out of 1,581 patients in the National Cheng Kung University Hospital with suspected dengue infections and subjected to NS1 antigen, IgM and IgG, and qRT-PCR tests, 798 patients including 138 severe cases were enrolled in the study. The primary target outcome was severe dengue. Machine learning models were trained and tested using the patient dataset that included demographic information and qualitative laboratory test results collected on day 1 when they sought medical advice. To develop prognostic models, we applied various machine learning methods, including logistic regression, random forest, gradient boosting machine, support vector classifier, and artificial neural network, and compared the performance of the methods. The artificial neural network showed the highest average discrimination area under the receiver operating characteristic curve (0.8324 ± 0.0268) and balance accuracy (0.7523 ± 0.0273). According to the model explainer that analyzed the contributions/co-contributions of the different factors, patient age and dengue NS1 antigenemia were the two most important risk factors associated with severe dengue. Additionally, co-existence of anti-dengue IgM and IgG in patients with dengue increased the probability of severe dengue. Conclusions/Significance: We developed prognostic models for the prediction of dengue severity in patients, using machine learning. The discriminative ability of the artificial neural network exhibited good performance for severe dengue prognosis. This model could help clinicians obtain a rapid prognosis during dengue outbreaks. However, the model requires further validation using external cohorts in future studies. Author summary: Dengue virus infects millions of people annually and is associated with a high mortality rate. When outbreaks occur, hospitals are often overcrowded with patients. Thus, novel approaches are required to accelerate patient triage for hospitalization, or further intensive care. Machine learning is being widely applied for resolving various problems, including medical diagnosis and outcome prediction. Here, we combined information from patients, including age, sex, and rapid virus test results, to develop a machine learning model for severe outcome prediction. The developed machine learning model displayed good performance for severe dengue disease prediction, and all information required for the model could be easily obtained. We also found that patients who were over 60 years old, who had detectable nonstructural protein-1 from dengue virus, or who had both detectable anti-dengue IgM and IgG antibodies in their sera, had a greater risk of progression to severe dengue. This study established a new approach to predict dengue disease outcomes by applying machine learning and defined the risk factors for severity prediction. [ABSTRACT FROM AUTHOR]

Two ultrastable luminescent covalent organic frameworks (COFs), PyTA‐BC and PyTA‐BC‐Ph, are synthesized through polycondensations of 4,4′,4″,4′″‐pyrene‐1,3,6,8‐tetrayl)tetraaniline (PyTA‐4NH2) with two carbazole‐based derivatives having different degrees of conjugation. The PyTA‐BC and PyTA‐BC‐Ph COFs exhibit ultrahigh thermal stabilities (up to 421 °C), excellent crystallinity, and high Brunauer–Emmett–Teller surface areas (up to 1445 m2 g−1). These COFs display strong fluorescence emissions in various solvents, with their emission maxima gradually red‐shifting upon increasing the polarity of the solvent (solvatochromism). Upon exposure to HCl, they respond very rapidly and sensitively in terms of changing their colors and fluorescence emission maxima. In the presence of a sacrificial electron donor, these COFs mediate the highly efficient photocatalytic evolution of H2 from water. In the absence of a noble metal cocatalyst, the COFs and ascorbic acid provide a photocatalytic H2 production of up to 1183 µmol g−1 h−1 (λ ≥ 420 nm); this value is the highest reported to date for a COF. Such COFs appear to be potentially useful as chemosensors for the naked‐eye and sensitive spectroscopic detection of HCl and as cocatalysts for the sustainable photocatalytic production of H2 from water. [ABSTRACT FROM AUTHOR]

We describe an inexpensive alternative to conventional hydrophones for measuring ultrasonic fields. The hydrophone, composed of common laboratory supplies, depends on the acoustoelectric (AE) effect, a well-known interaction between electrical current and pressure. Beam patterns of a 540 kHz annular transducer captured using a bowtie-graphite hydrophone were consistent with patterns obtained using conventional, more expensive hydrophones. The AE signal was proportional to both the applied bias current (1.83 μV/mA) and pressure (13.3 μV/MPa) with sensitivity better than 50 kPa. Disposable AE hydrophones may be an attractive alternative for clinical applications that require close monitoring of high intensity acoustic fields. [ABSTRACT FROM AUTHOR]

Enterovirus A71 (EV-A71) is a non-enveloped virus possessing 4 capsid proteins: VP1-VP4. The outermost capsid protein, VP1, plays roles in both antigenicity and virulence of the virus. The concept of generating other EV-A71 genotypes of reverse genetics (rg) viruses by replacing VP1 can be made possible with synthetic biotechnology, allowing us to redesign organisms, creating unavailable ones. To determine suitable vaccine candidates against EV-A71 infections, we combined synthetic biotechnology, rg-virus production and high-fidelity determinants to produce genetically stable viruses. With the use of antigenic cartography, we are able to view the antigenic distance among various points. We analyzed and generated various EV-A71 VP1 sequences from Taiwan and Southeast Asian (SEA) countries, which were then used to produce recombinant rg-viruses and the viral proteins were purified for immunization of mice and rabbits. Antisera against various EV-A71 genotypes were used in neutralization assays against various Taiwan and SEA EV-A71 genotypes. Based on neutralization data from mice and rabbit antisera, we found that antisera produced from several genotypes were able to effectively neutralize the various Taiwan and SEA EV-A71 genotypes. Additionally, comparing the antigenic maps produced from mouse, rabbit and human antisera against different EV-A71 genotypes, a difference in clustering was seen and the spacing between points also differed. Based on antigenic mapping and neutralizing activities, B4 7008-HF and C4 M79 may be good potential vaccine candidates against EV-A71. • Synthetic biotechnology and reverse genetics virus production can produce genetically stable viruses. • Antisera from the immunization of proteins of EV-A71 genotypes can effectively neutralize Taiwan and Southeast Asia EV-A71. • Antigenic mapping of Taiwan and Southeast Asia antigens provides insight on potential EV-A71 vaccine candidates. [ABSTRACT FROM AUTHOR]

Wild poliovirus (WPV) persists in diverse locales worldwide, spreading outward from endemic areas. In response to the international threat of WPV transmission and changes in the national vaccination policy, we established an environmental surveillance system to monitor the circulation of wild and vaccine-related poliovirus in Taiwan. From July 2012 to December 2013, we collected sewage specimens every month from 10 sewage treatment plants located throughout Taiwan. The specimens were concentrated by the two-phase separation method and then inoculated into L20B, RD, and A549 cells for virus isolation. Viral isolates were identified and serotyped by immunofluorescence assay or molecular analysis. A total of 300 sewage samples were collected, and the results showed 163 samples (54.3%) were positive for virus, and 268 isolates were identified. Among these, 75 samples (25%) were positive for enterovirus (EV), but no poliovirus was found. In addition, 92 isolates were identified as enteroviruses and the most common serotypes were coxsackievirus B4, coxsackievirus B3, and coxsackievirus B2. Interestingly, 102 (34%) and 82 (27.3%) specimens were positive for mammalian orthoreovirus (MRV) and adenovirus, respectively. This study confirmed that sewage surveillance can be a useful additional modality for monitoring the possible presence of wild-type or vaccine-derived poliovirus in wastewater, and can indicate the current types of viruses circulating in the population. Furthermore, since MRV was found in children with acute necrotizing encephalopathy and meningitis, the high incidence of MRV detected by environmental surveillance warrants further investigation. [ABSTRACT FROM AUTHOR]

α-Thalassemia (α-thal) is one of the most prevalent genetic diseases in the world and is especially frequent in tropical and subtropical regions, including South China. The aim of this study was to investigate the prevalence and spectrum of α-thal in Guizhou Province as this information was unknown. A total of 40 α-thal carriers were determined in 1219 newborn umbilical cord blood samples by hemoglobin (Hb) electrophoresis combined with DNA analysis, which revealed that the carrier rate of α-thal in Guizhou Province was 3.28%. One thousand and forty-five individuals referred to our hospital were tested for α-thal mutations. Two hundred and twenty-four cases were determined as α-thal carriers or patients. A total of 11 genotypes and five different α-thal mutations were identified in these 224 cases. Of these mutations, more than 96.0% were deletions, including – –SEA(65.89%), –α3.7(rightward) (22.87%) and –α4.2(leftward) (7.74%). The other two nondeletional mutations, Hb Constant Spring (Hb CS, αCSα,HBA2: c.427T > C) and Hb Quong Sze [Hb QS, αQSα,HBA2: c.377T > C (orHBA1)] account for 2.71% and 0.78%, respectively. The results of this study will be useful in genetic counseling and prenatal diagnosis (PND) of α-thal in Guizhou Province. [ABSTRACT FROM PUBLISHER]

Abstract: Objectives: Although the population prevalence and mutation spectrum of β-thalassemia in most areas of south China have been characterized, the mutations have not been elucidated in Guizhou Province. The aim of this study was to investigate the spectrum of β-thalassemia in this province. Design and methods: We detected and analyzed β-globin gene mutations in 407 β-thalassemia patients and carriers by PCR-based reverse dot blot (RBD) and direct sequencing methods. Results: Twelve types of β-globin gene mutations were detected. Among the 12 different mutations, six mutations are common, accounting for 97% of mutated alleles. The most prevalent mutation is codon 17 (A→T) with an allele frequency of 40.7%. In addition, codon 121 (GAA>TAA), a rare dominant mutation, was detected in a patient with β-thalassemia intermedia for the first time in China. Conclusions: The results of this study will be useful in genetic counseling and prenatal diagnostic service of β-thalassemia in Guizhou Province. [Copyright &y& Elsevier]