Publications by authors named "Di Tian"

136 Publications

Manipulating Berry curvature of SrRuO thin films via epitaxial strain.

Proc Natl Acad Sci U S A 2021 May;118(18)

State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, 100084 Beijing, China;

Berry curvature plays a crucial role in exotic electronic states of quantum materials, such as the intrinsic anomalous Hall effect. As Berry curvature is highly sensitive to subtle changes of electronic band structures, it can be finely tuned via external stimulus. Here, we demonstrate in SrRuO thin films that both the magnitude and sign of anomalous Hall resistivity can be effectively controlled with epitaxial strain. Our first-principles calculations reveal that epitaxial strain induces an additional crystal field splitting and changes the order of Ru orbital energies, which alters the Berry curvature and leads to the sign and magnitude change of anomalous Hall conductivity. Furthermore, we show that the rotation of the Ru magnetic moment in real space of a tensile-strained sample can result in an exotic nonmonotonic change of anomalous Hall resistivity with the sweeping of magnetic field, resembling the topological Hall effect observed in noncoplanar spin systems. These findings not only deepen our understanding of anomalous Hall effect in SrRuO systems but also provide an effective tuning knob to manipulate Berry curvature and related physical properties in a wide range of quantum materials.
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http://dx.doi.org/10.1073/pnas.2101946118DOI Listing
May 2021

Rapid SARS-CoV-2 antigen detection potentiates early diagnosis of COVID-19 disease.

Biosci Trends 2021 Mar 26. Epub 2021 Mar 26.

Department of Infectious Disease, Shanghai Public Health Clinical Center, Shanghai, China.

As the COVID-19 epidemic is still ongoing, a more rapid detection of SARS-CoV-2 infection such as viral antigen-detection needs to be evaluated for early diagnosis of COVID-19 disease. Here, we report the dynamic changes of SARS-CoV-2 viral antigens in nasopharyngeal swabs of COVID-19 patients and its association with the viral nucleic acid clearance and clinical outcomes. Eighty-five COVID-19 patients were enrolled for detection of SARS-CoV-2 viral antigens, including 57 anti-SARS-CoV-2 antibody negative cases and 28 antibody positive cases. The viral antigen could be detected in 52.63% (30/57) patients with SARS-CoV-2 antibody negative at the early stage of SARS-CoV-2 infection, especially in the first 5 days after disease onset (p = 0.0018) and disappeared in about 8 days after disease onset. Viral antigens were highly detectable in patients with low Ct value (less than 30) of SARS-CoV-2 nucleic acid RT-PCT assay, suggesting the expression of viral antigen was associated with high viral load. Furthermore, positive antigen detection indicated disease progression, nine cases with positive antigen (9/30, 30.0%), in contrast to two cases (2/27, 7.40%) (p = 0.0444) with negative antigen, which progressed into severe disease. Thus, the viral antigens were persistent in early stages of infection when virus was in highly replicating status, and viral antigen detection promises to rapidly screen positive patients in the early stage of SARS-CoV-2 infection.
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http://dx.doi.org/10.5582/bst.2021.01090DOI Listing
March 2021

Luminescence lifetime imaging of ultra-long room temperature phosphorescence on a smartphone.

Anal Bioanal Chem 2021 May 26;413(12):3291-3297. Epub 2021 Mar 26.

Wuhan National Lab for Optoelectronics and Key Lab of Materials Chemistry for Energy Conversion and Storage of Ministry of Education, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, Hubei, China.

Luminescence lifetime imaging plays an important role in distinguishing the luminescence decay rates in time-resolved luminescence imaging. However, traditional imaging instruments used for detecting lifetimes within milliseconds would be time-consuming when imaging ultra-long luminescence lifetimes over subseconds. Herein, we present an accessible and simple optical system for detecting lifetimes of persistent luminescence. A smartphone integrated with a UV LED, a dichroic mirror, and a lens was used for recording the persistent luminescence. With only a few seconds of data acquisition, a luminescence lifetime image could be processed from the video by exponential fitting of the gray level of each pixel to the delay time. Since this approach only requires single excitation, no synchronous control is needed, greatly simplifying the apparatus and saving the cost. The apparatus was successfully used for ultra-long luminescence lifetime imaging of mouse tissue dyed with a persistent luminescence molecule. This miniaturized apparatus exhibits huge potentiality in time-resolved luminescence imaging for luminescence study and biological detection.
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http://dx.doi.org/10.1007/s00216-021-03266-yDOI Listing
May 2021

The predictive effect of the platelet-to-lymphocyte ratio (PLR) and the neutrophil-to-lymphocyte ratio (NLR) on the risk of death in patients with severe fever with thrombocytopenia syndrome (SFTS): a multi-center study in China.

Ann Transl Med 2021 Feb;9(3):208

Center of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University. Beijing, China.

Background: Severe fever with thrombocytopenia syndrome is caused by infection with the severe fever with thrombocytopenia syndrome virus.

Methods: Between April 2011 and December 2019, data on consecutive patients who were diagnosed with severe fever with thrombocytopenia syndrome were prospectively collected from five medical centers in China. The score of the death risk model was correlated with the platelet-to-lymphocyte ratio and the neutrophil-to-lymphocyte ratio. Multivariable Cox analyses were used to identify the independent factors associated with mortality.

Results: During the study period, 763 patients were diagnosed with severe fever with thrombocytopenia syndrome; 415 of these patients were enrolled in our study. We found that the neutrophil-to-lymphocyte ratio of the group that died was significantly higher on admission (P=0.007) than that of the group that survived, and the neutrophil-to-lymphocyte ratio showed a positive correlation with the score of the death risk model. Multivariate Cox regression suggested that a neutrophil-to-lymphocyte ratio greater than 5.4 was an independent risk factor for survival time (HR=6.767, P=0.011). Platelet-to-lymphocyte ratio did not show a special role in this study.

Conclusions: A neutrophil-to-lymphocyte ratio greater than 5.4 can increase the risk of death and decrease the survival time of patients. In summary, the neutrophil-to-lymphocyte ratio provides a supplementary means for effectively managing severe fever with thrombocytopenia syndrome (SFTS).
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http://dx.doi.org/10.21037/atm-20-4736DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7940944PMC
February 2021

Rhomboid protein 2 of Eimeria maxima provided partial protection against infection by homologous species.

Vet Res 2021 Feb 18;52(1):29. Epub 2021 Feb 18.

MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.

Rhomboid-like proteases (ROMs) are considered as new candidate antigens for developing new-generation vaccines due to their important role involved in the invasion of apicomplexan protozoa. In prior works, we obtained a ROM2 sequence of Eimeria maxima (EmROM2). This study was conducted to evaluate the immunogenicity and protective efficacy of EmROM2 recombinant protein (rEmROM2) and EmROM2 DNA (pVAX1-EmROM2) against infection by Eimeria maxima (E. maxima). Firstly, Western blot assay was conducted to analyze the immunogenicity of rEmROM2. The result showed that rEmROM2 was recognized by chicken anti-E. maxima serum. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot assay revealed apparent transcription and expression of EmROM2 at the injection site. qRT-PCR (quantitative real-time PCR), flow cytometry and indirect ELISA indicated that vaccination with rEmROM2 or EmROM2 DNA significantly upregulated the transcription level of cytokines (IFN-γ, IL-2, IL-4, IL-10, IL-17, TGF-β and TNF SF15), the proportion of CD8 and CD4 T lymphocytes and serum IgG antibody response. Ultimately, a vaccination-challenge trial was performed to evaluate the protective efficacy of rEmROM2 and pVAX1-EmROM2 against E. maxima. The result revealed that vaccination with rEmROM2 or pVAX1-EmROM2 significantly alleviated enteric lesions, weight loss, and reduced oocyst output caused by challenge infection of E. maxima, and provided anticoccidial index (ACI) of more than 160, indicating partial protection against E. maxima. In summary, vaccination with rEmROM2 or pVAX1-EmROM2 activated notable humoral and cell-mediated immunity and provided partial protection against E. maxima. These results demonstrated that EmROM2 protein and DNA are promising vaccine candidates against E. maxima infection.
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http://dx.doi.org/10.1186/s13567-020-00886-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7893758PMC
February 2021

Single-cell analysis of nonhuman primate preimplantation development in comparison to humans and mice.

Dev Dyn 2021 Jan 15. Epub 2021 Jan 15.

Department of Human Genetics, David Geffen School of Medicine, UCLA, Los Angeles, California, USA.

Background: Genetic programs underlying preimplantation development and early lineage segregation are highly conserved across mammals. It has been suggested that nonhuman primates would be better model organisms for human embryogenesis, but a limited number of studies have investigated the monkey preimplantation development. In this study, we collect single cells from cynomolgus monkey preimplantation embryos for transcriptome profiling and compare with single-cell RNA-seq data derived from human and mouse embryos.

Results: By weighted gene-coexpression network analysis, we found that cynomolgus gene networks have greater conservation with human embryos including a greater number of conserved hub genes than that of mouse embryos. Consistently, we found that early ICM/TE lineage-segregating genes in monkeys exhibit greater similarity with human when compared to mouse, so are the genes in signaling pathways such as LRP1 and TCF7 involving in WNT pathway. Last, we tested the role of one conserved pre-EGA hub gene, SIN3A, using a morpholino knockdown of maternal RNA transcripts in monkey embryos followed by single-cell RNA-seq. We found that SIN3A knockdown disrupts the gene-silencing program during the embryonic genome activation transition and results in developmental delay of cynomolgus embryos.

Conclusion: Taken together, our study provided new insight into evolutionarily conserved and divergent transcriptome dynamics during mammalian preimplantation development.
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http://dx.doi.org/10.1002/dvdy.295DOI Listing
January 2021

A mitogen-activated protein kinase PoxMK1 mediates regulation of the production of plant-biomass-degrading enzymes, vegetative growth, and pigment biosynthesis in Penicillium oxalicum.

Appl Microbiol Biotechnol 2021 Jan 6;105(2):661-678. Epub 2021 Jan 6.

State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, Guangxi, People's Republic of China.

Mitogen-activated protein kinase (MAPK) cascades are broadly conserved and play essential roles in multiple cellular processes, including fungal development, pathogenicity, and secondary metabolism. Their function, however, also exhibits species and strain specificity. Penicillium oxalicum secretes plant-biomass-degrading enzymes (PBDEs) that contribute to the carbon cycle in the natural environment and to utilization of lignocellulose in industrial processes. However, knowledge of the MAPK pathway in P. oxalicum has been relatively limited. In this study, comparative transcriptomic analysis of P. oxalicum, cultured on different carbon sources, found ten putative kinase genes with significantly modified transcriptional levels. Six of these putative kinase genes were knocked out in the parental strain ∆PoxKu70, and deletion of the gene, Fus3/Kss1-like PoxMK1 (POX00158), resulted in the largest reduction (91.1%) in filter paper cellulase production. Further tests revealed that the mutant ∆PoxMK1 lost 37.1 to 92.2% of PBDE production, under both submerged- and solid-state fermentation conditions, compared with ∆PoxKu70. In addition, the mutant ∆PoxMK1 had reduced vegetative growth and increased pigment biosynthesis. Comparative transcriptomic analysis showed that PoxMK1 deletion from P. oxalicum downregulated the expression of major PBDE genes and known regulatory genes such as PoxClrB and PoxCxrB, whereas the transcription of pigment biosynthesis-related genes was upregulated. Comparative phosphoproteomic analysis revealed that PoxMK1 deletion considerably modified phosphorylation of key transcription- and signal transduction-associated proteins, including transcription factors Mcm1 and Atf1, RNA polymerase II subunits Rpb1 and Rpb9, MAPK-associated Hog1 and Ste7, and cyclin-dependent kinase Kin28. These findings provide novel insights into understanding signal transduction and regulation of PBDE gene expression in fungi.Key points• PoxMK1 is involved in expression of PBDE- and pigment synthesis-related genes.• PoxMK1 is required for vegetative growth of P. oxalicum.• PoxMK1 is involved in phosphorylation of key TFs, kinases, and RNA polymerase II.
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http://dx.doi.org/10.1007/s00253-020-11020-0DOI Listing
January 2021

A smartphone-read ultrasensitive and quantitative saliva test for COVID-19.

Sci Adv 2021 01 8;7(2). Epub 2021 Jan 8.

Center for Cellular and Molecular Diagnostics, Tulane University School of Medicine, 1430 Tulane Ave., New Orleans, LA 70112, USA.

Point-of-care COVID-19 assays that are more sensitive than the current RT-PCR (reverse transcription polymerase chain reaction) gold standard assay are needed to improve disease control efforts. We describe the development of a portable, ultrasensitive saliva-based COVID-19 assay with a 15-min sample-to-answer time that does not require RNA isolation or laboratory equipment. This assay uses CRISPR-Cas12a activity to enhance viral amplicon signal, which is stimulated by the laser diode of a smartphone-based fluorescence microscope device. This device robustly quantified viral load over a broad linear range (1 to 10 copies/μl) and exhibited a limit of detection (0.38 copies/μl) below that of the RT-PCR reference assay. CRISPR-read SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) RNA levels were similar in patient saliva and nasal swabs, and viral loads measured by RT-PCR and the smartphone-read CRISPR assay demonstrated good correlation, supporting the potential use of this portable assay for saliva-based point-of-care COVID-19 diagnosis.
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http://dx.doi.org/10.1126/sciadv.abe3703DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7793573PMC
January 2021

Dynamic anti-spike protein antibody profiles in COVID-19 patients.

Int J Infect Dis 2021 Feb 10;103:540-548. Epub 2020 Dec 10.

Shanghai Institute of Immunology, Department of Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China. Electronic address:

Objectives: This study intended to investigate the dynamics of anti-spike (S) IgG and IgM antibodies in COVID-19 patients.

Methods: Anti-S IgG/IgM was determined by a semi-quantitative fluorescence immunoassay in the plasma of COVID-19 patients at the manifestation and rehabilitation stages. The immunoreactivity to full-length S proteins, C-terminal domain (CTD), and N-terminal domain (NTD) of S1 fragments were determined by an ELISA assay. Clinical properties at admission and discharge were collected simultaneously.

Results: The positive rates of anti-S IgG/IgM in COVID-19 patients were elevated after rehabilitation compared to the in-patients. Anti-S IgG and IgM were not apparent until day 14 and day ten, respectively, according to Simple Moving Average analysis with five days' slide window deduction. More than 90% of the rehabilitation patients exhibited IgG and IgM responses targeting CTD-S1 fragments. Decreased total peripheral lymphocytes, CD4 and CD8 T cell counts were seen in COVID-19 patients at admission and recovered after the rehabilitation.

Conclusions: Anti-S IgG and IgM do not appear at the onset with the decrease in T cells, making early serological screening less significant. However, the presence of high IgG and IgM to S1-CTD in the recovered patients highlights humoral responses after SARS-CoV-2 infection, which might be associated with efficient immune protection in COVID-19 patients.
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http://dx.doi.org/10.1016/j.ijid.2020.12.014DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7836795PMC
February 2021

Could the ambient higher temperature decrease the transmissibility of COVID-19 in China?

Environ Res 2021 02 3;193:110576. Epub 2020 Dec 3.

School of Public Health and Management, Ningxia Medical University, Yinchuan, 750001, Ningxia, China; The Key Laboratory of Environmental Factors and Chronic Disease Control of Ningxia, Yinchuan, 750001, Ningxia, China. Electronic address:

Background: Existing literatures demonstrated that meteorological factors could be of importance in affecting the spread patterns of the respiratory infectious diseases. However, how ambient temperature may influence the transmissibility of COVID-19 remains unclear.

Objectives: We explore the association between ambient temperature and transmissibility of COVID-19 in different regions across China.

Methods: The surveillance data on COVID-19 and meteorological factors were collected from 28 provincial level regions in China, and estimated the instantaneous reproductive number (R). The generalized additive model was used to assess the relationship between mean temperature and R.

Results: There were 12,745 COVID-19 cases collected in the study areas. We report the associated effect of temperature on R is likely to be negative but not of statistical significance, which holds for most Chinese regions.

Conclusions: We found little statistical evidence for that the higher temperature may reduce the transmissibility of COVID-19. Since intensive control measures against the COVID-19 epidemics were implemented in China, we acknowledge this may impact the underlying effect size estimation, and thus cautiousness should be taken when interpreting our findings.
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http://dx.doi.org/10.1016/j.envres.2020.110576DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7713592PMC
February 2021

Immune suppression in the early stage of COVID-19 disease.

Nat Commun 2020 11 17;11(1):5859. Epub 2020 Nov 17.

Center for Precision Medicine Multi-Omics Research, Peking University Health Science Center, Peking University, 100191, Beijing, China.

The outbreak of COVID-19 has become a worldwide pandemic. The pathogenesis of this infectious disease and how it differs from other drivers of pneumonia is unclear. Here we analyze urine samples from COVID-19 infection cases, healthy donors and non-COVID-19 pneumonia cases using quantitative proteomics. The molecular changes suggest that immunosuppression and tight junction impairment occur in the early stage of COVID-19 infection. Further subgrouping of COVID-19 patients into moderate and severe types shows that an activated immune response emerges in severely affected patients. We propose a two-stage mechanism of pathogenesis for this unusual viral infection. Our data advance our understanding of the clinical features of COVID-19 infections and provide a resource for future mechanistic and therapeutics studies.
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http://dx.doi.org/10.1038/s41467-020-19706-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7673112PMC
November 2020

Responsive Photonic Crystal Microcapsules of Block Copolymers with Enhanced Monochromaticity.

ACS Nano 2020 Nov 16;14(11):16057-16064. Epub 2020 Nov 16.

State Key Lab of Materials Processing and Die and Mould Technology and Key Lab of Materials Chemistry for Energy Conversion and Storage (HUST) of Ministry of Education, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China.

Self-assembly of block copolymers (BCPs) has been developed as a promising approach for constructing photonic crystal (PC) microspheres for dynamic optical modulation. However, high curvature in the center of microspheres usually distorts the periodic core structure, leading to an inconsistency of photonic bandgap and poor monochromaticity of structural color. Herein, we report a simple yet robust strategy for fabricating responsive PC microcapsules of polystyrene--poly(2-vinylpyridine) through self-emulsification strategy. Interestingly, the microcapsules exhibit bright structural color with significantly enhanced monochromaticity, compared to their solid counterpart, since the microcapsules have no irregular cores. The structural colors of the PC microcapsules not only exhibit a variability through binary mixing of BCPs but also show a responsiveness to pH value. As a colored microcarrier, the PC microcapsules show a potential for visualizing the pH-dependent release behavior of encapsulated hydrophilic cargos on account of pH-responsive structural color.
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http://dx.doi.org/10.1021/acsnano.0c07898DOI Listing
November 2020

Effects of nitrogen addition on microbial residues and their contribution to soil organic carbon in China's forests from tropical to boreal zone.

Environ Pollut 2021 Jan 28;268(Pt B):115941. Epub 2020 Oct 28.

Institute of Ecology, College of Urban and Environmental Sciences, And Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, 100871, China. Electronic address:

Atmospheric nitrogen (N) deposition has a significant influence on soil organic carbon (SOC) accumulation in forest ecosystems. Microbial residues, as by-products of microbial anabolism, account for a significant fraction of soil C pools. However, how N deposition affects the accumulation of soil microbial residues in different forest biomes remains unclear. Here, we investigated the effects of six/seven-year N additions on microbial residues (amino sugar biomarkers) in eight forests from tropical to boreal zone in eastern China. Our results showed a minor change in the soil microbial residue concentrations but a significant change in the contribution of microbial residue-C to SOC after N addition. The contribution of fungal residue-C to SOC decreased under low N addition (50 kg N ha yr) in the tropical secondary forest (-19%), but increased under high N addition (100 kg N ha yr) in the temperate Korean pine mixed forest (+21%). The contribution of bacterial residue-C to SOC increased under the high N addition in the subtropical Castanopsis carlesii forest (+26%) and under the low N addition in the temperate birch forest (+38%), respectively. The responses of microbial residue-C in SOC to N addition depended on the changes in soil total N concentration and fungi to bacteria ratio under N addition and climate. Taken together, these findings provide the experimental evidence that N addition diversely regulates the formation and composition of microbial-derived C in SOC in forest ecosystems.
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http://dx.doi.org/10.1016/j.envpol.2020.115941DOI Listing
January 2021

Dandelion extract relaxes mouse airway smooth muscle by blocking VDLCC and NSCC channels.

Cell Biosci 2020 28;10:125. Epub 2020 Oct 28.

School of Pharmaceutical Sciences, South-Central University for Nationalities, 182 Min-Zu Road, Wuhan, 430074 China.

Background: Asthma is one of the main intractable diseases recognized by the international medical community. The current widely used bronchodilators for asthma-β2-adrenal receptor agonists-have limited therapeutic effects, necessitating the development of novel antiasthma drugs with increased efficacy and fewer adverse effects. In this study, we investigated the relaxant effects and underlying mechanism of an ethyl acetate extract from dandelion (EAED) on mouse airway smooth muscle.

Methods: The effects of EAED on agonist-induced precontraction in mouse airway smooth muscle were evaluated with force measurement. Mouse lung slices were used to study the effects of EAED on bronchial smooth muscle. The intracellular Ca concentration was measured using a calcium imaging system. L-type voltage-dependent calcium channel (VDLCC) and non-selective cationic channel (NSCC) currents were measured by patch-clamp. The lung functions of healthy and asthmatic mouse groups were assessed via the forced oscillation technique.

Results: EAED inhibits acetylcholine-induced sustained contractions of whole airway smooth muscle by inhibiting VDLCCs, NSCCs, and some unknown channels, reduces the agonist-induced increase in the cytosolic free Ca concentration in airway smooth muscle cells, blocks VDLCC and NSCC currents, and relieves the respiratory resistance of healthy and asthmatic mice.

Conclusions: EAED may have potential beneficial effects on mitigating asthma attacks.
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http://dx.doi.org/10.1186/s13578-020-00470-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7592536PMC
October 2020

Comparative analysis of the main haematological indexes and RNA detection for the diagnosis of SARS-CoV-2 infection.

BMC Infect Dis 2020 Oct 20;20(1):779. Epub 2020 Oct 20.

School of Public Health, Zunyi Medcial University, Zunyi, Guizhou, 563000, P.R. China.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has become a public health emergency of international concern. SARS-CoV-2 RNA detection is the diagnostic criterion for coronavirus disease 2019 (COVID-19). Nevertheless, RNA detection has many limitations, such as being time-consuming and cost-prohibitive, and it must be performed in specialized laboratories. Virus antibody detection is a routine method for screening for multiple viruses, but data about SARS-CoV-2 antibody detection are limited.

Method: Throat swabs and blood were collected from 67 suspected SARS-CoV-2 infection patients at the Affiliated Hospital of Zunyi Medical University and Zunyi Fourth People's Hospital isolated observation departments. Throat swab samples were subjected to SARS-CoV-2 RNA detection by real-time PCR. Blood was used subjected to SARS-CoV-2 IgG/IgM detection by an enzyme-linked immunosorbent assay (ELISA) and gold immunochromatography assay (GICA). Blood underwent C-reactive protein detection by immunoturbidimetry, and white blood cells, neutrophil percentages and lymphocyte percentages were counted and calculated, respectively. Clinical symptoms, age and lifestyle habits (smoking and drinking) in all patients were recorded. Data were analysed using SPSS version 19. The results were confirmed by T and χ tests; correlations with detection results were analysed by kappa coefficients. Odds ratio (OR) and corrected OR values were analysed by logistic regression. P < 0.05 was considered statistically significant.

Results: Of the 67 patients included in this study, 26 were SARS-CoV-2 RNA-positive. GICA IgM sensitivity was 50.9% (13/26), and specificity was 90.2% (37/41). ELISA IgM sensitivity was 76.9% (20/26), and specificity was 90.2% (37/41). ELISA IgG sensitivity was 76.9% (20/26), and specificity was 95.1% (39/41). The kappa coefficients between RNA detection and ELISA IgG, ELISA IgM, and GICA IgM results were 0.741 (P < 0.01), 0.681 (P < 0.01) and 0.430 (P < 0.01), respectively.

Conclusion: Among the candidate blood indicators, serum IgG and IgM detected by ELISA had the best consistency and validity when compared with standard RNA detection; these indicators can be used as potential preliminary screening tools to identify those who should undergo nucleic acid detection in laboratories without RNA detection abilities or as a supplement to RNA detection.
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http://dx.doi.org/10.1186/s12879-020-05489-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7573872PMC
October 2020

De novo mutation of cancer-related genes associates with particular neurodevelopmental disorders.

J Mol Med (Berl) 2020 12 12;98(12):1701-1712. Epub 2020 Oct 12.

National Clinical Research Center for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, 87 #, Xiangya Road, Changsha, 410008, Hunan, China.

Epidemiological studies have shown an increased prevalence of cancer in some patients with neurodevelopmental disorder (NDD); however, the genetic mechanisms regarding how cancer-related genes (CRGs) contribute to NDD remain unclear. We performed bioinformatic analyses on 219 CRGs from OMIM and de novo mutations (DNMs) from 16,498 patients with different NDDs and 3391 controls. Our results showed that autism spectrum disorder, undiagnosed neurodevelopmental disorder, congenital heart disease and intellectual disability, but not epileptic encephalopathy and schizophrenia, harboured significantly more putative functional DNMs in CRGs, compared with controls, providing genetic evidence supporting previous epidemiological surveys. We further detected 26 CRGs with recurrent putative functional DNMs that showed high expression in the human brain during the prenatal stage and in non-brain organs in adults. The proteins coded by the 26 CRGs and known NDD candidate genes formed a functional network that is involved in brain development and tumorigenesis. Overall, we proposed 39 cancer-targeting drugs that could be investigated for treating patients with NDD, which would be potentially cost-effective. In conclusion, DNMs contribute to specific NDDs and there may be a shared genetic basis between NDDs and cancer, highlighting the importance of considering cancer-targeting drugs with potential curative effects in patients with NDDs. KEY MESSAGES: • The contribution of DNMs in NDD is consistent with epidemiological surveys. • We highlighted 26 CRGs, including nine genes with more than five functional DNMs. • Specific expression patterns underlie the genetic mechanism of CRGs in NDD. • Specific functional networks underlie the genetic mechanism of CRGs in NDD. • The shared genetic aetiology suggests potential mutual treatment strategies.
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http://dx.doi.org/10.1007/s00109-020-01991-yDOI Listing
December 2020

An Epidemiologic Study of COVID-19 Patients in a State Psychiatric Hospital: High Penetrance With Early CDC Guidelines.

Psychiatr Serv 2020 12 6;71(12):1285-1287. Epub 2020 Oct 6.

Department of Psychiatry and Behavioral Sciences (Thompson, Mikolajewski), Department of Microbiology and Immunology (Smither), and Department of Pathology and Laboratory Medicine (Lin, Tian), Tulane University School of Medicine, New Orleans; Tulane University of School of Public Health and Tropical Medicine, New Orleans (Kissinger, McCrossen); LaCATS-Clinical Translational Unit, New Orleans (Chamarthi).

Objective: This study aimed to explore the transmission of COVID-19 in a U.S. state psychiatric hospital setting.

Methods: Symptomatic and asymptomatic patients were tested throughout a large psychiatric hospital to determine penetrance. The hospital followed initial Centers for Disease Control and Prevention (CDC) guidelines.

Results: Seventy-eight percent (N=51 of 65) of tested patients in the building where the first positive patient was housed (building zero) tested positive for COVID-19. Eighty-eight percent (N=14 of 16) of tested asymptomatic patients in building zero were positive, compared with 12% (N=6 of 51) of randomly selected asymptomatic patients in a sample from the rest of the hospital.

Conclusions: A high percentage of patients can become positive for COVID-19 despite following initial CDC guidelines. As such, use of masks by all patients in close-quarter settings prior to the first positive case appears warranted. Recent CDC guidelines align with this strategy.
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http://dx.doi.org/10.1176/appi.ps.202000270DOI Listing
December 2020

Clinical manifestations of death with severe fever and thrombocytopenia syndrome: A meta-analysis and systematic review.

J Med Virol 2021 06 30;93(6):3960-3968. Epub 2020 Sep 30.

Center of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, China.

Severe hemorrhagic fever disease is caused by severe fever with thrombocytopenia syndrome virus (SFTSV) infection, which belongs to the Phlebovirus genus in the Bunyaviridae family. A comprehensive literature search of PubMed, Web of Science, Embase, Cochrane Library, Chinese National Knowledge Infrastructure databases, Wan Fang Data, Sinomed Database, and VIP database was conducted for articles which have described the clinical manifestation of deceased patients. Data from selected studies were pooled by using STATA VERSION 15.0 software. Finally, 29 articles comprising 4717 laboratory-confirmed SFTSV cases were included in this analysis. We found there were significant differences between the two groups for fatigue, headache, underlying disease, vomiting, diarrhea, skin bleeding, neurological symptoms, arrhythmia, diffuse intravascular coagulation, and multiple organ failure. There were some significant differences between the fatal and nonfatal groups, and we need to pay more attention to the above symptoms to distinguish between fatal and nonfatal patients.
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http://dx.doi.org/10.1002/jmv.26518DOI Listing
June 2021

A portable and field optical emission spectrometry coupled with microplasma trap for high sensitivity analysis of arsenic and antimony simultaneously.

Talanta 2020 Oct 22;218:121161. Epub 2020 May 22.

Institute of Quality Standard and Testing Technology for Agro-products, Chinese Academy of Agricultural Sciences, And Key Laboratory of Agro-food Safety and Quality, Ministry of Agriculture and Rural Affairs, Beijing, 100081, China.

In this work, a portable and reliable optical emission spectrometric (OES) instrument based on solid acid hydride generation (HG) and subsequent in situ dielectric barrier discharge (DBD) preconcentration was first developed for simultaneous and field analysis of ultratrace As and Sb in environmental water. In situ DBD fulfilled both gas phase enrichment (GPE) and excitation; effective enrichment made it possible to use a low-cost charge coupled device (CCD) as detector. To simplify field protocol, solid tablet made from sulfamic acid was first used to replace hydrochloric acid for co-generation of As and Sb hydrides. Moisture interference was eliminated by carrier gas sweeping without any desiccant. After calculating peak volume for emission data handling, detection limits (LODs) were 0.5 μg L for As and 0.2 μg L for Sb, respectively, with <3% relative standard deviations (RSDs) at 10 μg L; linear dynamic ranges (R>0.995) were 2-200 μg L for As and 1-200 μg L for Sb, respectively. The results agreed with certified values of CRMs and recoveries were 87-97% vs. inductively coupled plasma mass spectrometry. The running costs can be controlled within one dollar per use. This HG-in situ DBD trap-OES scheme, with demonstrated advantages in sensitivity, low-cost, power (<60 W), size (0.6 m × 0.5 m × 0.3 m), weight (15 kg), gas consumption (300 measurements per 4 L tank), and multi-element capability, was implemented in a miniature spectrometer for field analysis.
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http://dx.doi.org/10.1016/j.talanta.2020.121161DOI Listing
October 2020

Interleukin 22 in Liver Injury, Inflammation and Cancer.

Int J Biol Sci 2020 29;16(13):2405-2413. Epub 2020 Jun 29.

The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, 230022, China.

Interleukin 22(IL-22), a member of the IL-10 cytokine family and is an emerging CD4+Th cytokine that plays an important role in anti-microbial defense, homeostasis and tissue repair. We are interested in IL-22 as it has the double function of suppressing or encouraging inflammation in various disease models including hepatic inflammation. As a survival factor for hepatocytes, IL-22 plays a protective role in many kinds of liver diseases, such as hepatitis, liver fibrosis, or hepatocellular carcinoma (HCC) by binding to the receptors IL-22R1 and IL-10R2. Overexpression of IL-22 reduces liver fibrosis by attenuating the activation of hepatic stellate cell (the main cell types involved in hepatic fibrosis), and down-regulating the levels of inflammatory cytokines. Administration of exogenous IL-22 increases the replication of hepatocytes by inhibiting cell apoptosis and promoting mitosis, ultimately plays a contributing role in liver regeneration. Furthermore, treatment with IL-22 activates hepatic signal transducer and activator of transcription 3 (STAT3), ameliorates hepatic oxidative stress and alcoholic fatty liver, effectively alleviate the liver damage caused by alcohol and toxicant. In conclusion, the hepatoprotective functions and liver regeneration promoting effect of IL-22 suggests the therapeutic potential of IL-22 in the treatment of human hepatic diseases.
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http://dx.doi.org/10.7150/ijbs.38925DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7378634PMC
June 2020

Ultra-sensitive and high-throughput CRISPR-p owered COVID-19 diagnosis.

Biosens Bioelectron 2020 Sep 23;164:112316. Epub 2020 May 23.

Center for Cellular and Molecular Diagnostics, Tulane University School of Medicine, 1430 Tulane Ave., New Orleans, LA, 70112, USA; Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, 1430 Tulane Ave., New Orleans, LA, 70112, USA. Electronic address:

Recent research suggests that SARS-CoV-2-infected individuals can be highly infectious while asymptomatic or pre-symptomatic, and that an infected person may infect 5.6 other individuals on average. This situation highlights the need for rapid, sensitive SARS-CoV-2 diagnostic assays capable of high-throughput operation that can preferably utilize existing equipment to facilitate broad, large-scale screening efforts. We have developed a CRISPR-based assay that can meet all these criteria. This assay utilizes a custom CRISPR Cas12a/gRNA complex and a fluorescent probe to detect target amplicons produced by standard RT-PCR or isothermal recombinase polymerase amplification (RPA), to allow sensitive detection at sites not equipped with real-time PCR systems required for qPCR diagnostics. We found this approach allowed sensitive and robust detection of SARS-CoV-2 positive samples, with a sample-to-answer time of ~50 min, and a limit of detection of 2 copies per sample. CRISPR assay diagnostic results obtained nasal swab samples of individuals with suspected COVID-19 cases were comparable to paired results from a CDC-approved quantitative RT-PCR (RT-qPCR) assay performed in a state testing lab, and superior to those produced by same assay in a clinical lab, where the RT-qPCR assay exhibited multiple invalid or inconclusive results. Our assay also demonstrated greater analytical sensitivity and more robust diagnostic performance than other recently reported CRISPR-based assays. Based on these findings, we believe that a CRISPR-based fluorescent application has potential to improve current COVID-19 screening efforts.
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http://dx.doi.org/10.1016/j.bios.2020.112316DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7245202PMC
September 2020

Numerical Simulations and the Design of Magnetic Field-Enhanced Electron Impact Ion Source with Hollow Cylinder Structure.

J Anal Methods Chem 2020 25;2020:2809485. Epub 2020 Jan 25.

Beijing SHRIMP Center, Institute of Geology Chinese Academy of Geological Sciences, Beijing 100037, China.

An electron impact ion source-adopted magnetic field-enhanced technology has been designed for enhancing the electron intensity and the ionization efficiency. Based on the ion optic focus mechanism, an electron impact ionization source was designed, and the electron entrance into the ionization chamber was designed with a hollow cylinder structure to improve the ion extraction efficiency. Numerical simulation and optimal geometry were optimized by SIMION 8.0 to provide higher electron intensity and ion transmission efficiency. To improve the electron intensity, the influence of the filament potential and magnetic intensity was investigated, and the values of 70 eV and 150 Gs were chosen in our apparatus. Based on the optimal parameters, the air in the lab and oxygen gas was detected by the homemade apparatus, and the ion intensity was detected in the positive and negative ion modes, respectively. The homemade electron impact ion source apparatus has the potential to enhance ionization efficiency applied in the mass spectrometer ionization source.
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http://dx.doi.org/10.1155/2020/2809485DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7204179PMC
January 2020

Clinical and epidemiological features of COVID-19 family clusters in Beijing, China.

J Infect 2020 08 23;81(2):e26-e30. Epub 2020 Apr 23.

The Infectious Disease Diagnostic, Therapeutic and Research Centers, Beijing Ditan Hospital, Capital Medical University, Beijing, China; Beijing Key Laboratory of Emerging and Re-emerging Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, China. Electronic address:

Background: Since its discovery, SARS-CoV-2 has been spread throughout China before becoming a global pandemic. In Beijing, family clusters are the main mode of human-human transmission accounting for 57.6% of the total confirmed cases.

Method: We present the epidemiological and clinical features of the clusters of three large and one small families.

Result: Our results revealed that SARS-CoV-2 is transmitted quickly through contact with index case, and a total of 22/24 infections were observed. Among those infected, 20/22 had mild symptoms and only two had moderate to severe clinical manifestations. Children in the families generally showed milder symptoms. The incubation period varied from 2 to 13 days, and the shedding of virus from the upper respiratory tract lasted from 5 to over 30 days. A prolonged period of virus shedding (>30 days) in upper respiratory tract was observed in 6/24 cases.

Conclusion: SARS-CoV-2 is transmitted quickly in the form of family clusters. While the infection rate is high within the cluster, the disease manifestations, latent period, and virus shedding period varied greatly. We therefore recommend rigorously testing contacts even during the no-symptom phase and consider whether viral shedding has ceased before stopping isolation measures for an individual.
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http://dx.doi.org/10.1016/j.jinf.2020.04.018DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7177072PMC
August 2020

Contamination of neonicotinoid insecticides in soil-water-sediment systems of the urban and rural areas in a rapidly developing region: Guangzhou, South China.

Environ Int 2020 06 10;139:105719. Epub 2020 Apr 10.

SCNU Environmental Research Institute, School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, PR China. Electronic address:

Residues and distribution of neonicotinoid insecticides (NEOs) in soil-water-sediment systems of the urban and rural areas of Guangzhou, South China were investigated. A total of 104 soil samples from 7 different functional zones and 29 water/sediment samples from creeks were collected. The results showed that at least one neonicotinoid insecticide was detected in all samples. The summed levels of five target neonicotinoids (∑neonics) were in the range of 0.003-229 ng/g dw for soil samples, 7.94-636 ng/L for water samples, and 0.017-31.3 ng/g dw for sediment samples, with a geometric mean of 0.59 ng/g dw, 153 ng/L and 1.11 ng/g dw, respectively. Soils from agricultural areas contained the highest residual NEOs, followed by commercial, traffic, residential, industrial, educational zones and parks. Among the seven different functional zones studied, imidacloprid was the most dominant NEO in the agricultural areas and commercial zones, whereas acetamiprid was dominant in the other five functional zones with different land-use types. Thiamethoxam and acetamiprid were the main NEOs in water and sediment samples collected from 29 creeks. The pollution of NEOs in soils, water and sediments from rural areas was higher than that in the counterparts from urban areas. Residual concentration of NEOs detected in soils, water and sediments showed significant correlations with each other. The distribution of NEOs in soil-water-sediment systems indicated that NEOs tended to concentrate in water, followed by sediments and soils, especially in urban areas. An evaluation of the exposure to the current level of the ∑NEOs in Guangzhou suggests a significant risk for aquatic and soil organisms, particularly under chronic exposures. The results of the present study offer valuable data to better understand the contamination and ecological risks of neonicotinoid insecticides in the rapidly developing urbanized region of South China.
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http://dx.doi.org/10.1016/j.envint.2020.105719DOI Listing
June 2020

Laser-induced breakdown spectroscopy of ammonia gas with resonant vibrational excitation.

Opt Express 2020 Jan;28(2):1197-1205

In this work, laser-induced breakdown spectroscopy (LIBS) of gaseous ammonia (NH) molecules on- and off-resonant vibrational excitation was studied in open air. A wavelength-tunable, continuous wave (CW), carbon dioxide (CO) laser tuned at a resonant absorption peak (9.219 µm) within the infrared radiation (IR) range was used to resonantly excite the vibration of the N-H wagging mode of ammonia molecules. A pulsed Nd:YAG laser (1064 nm, 15 ns) was used to break down the ammonia gas for plasma imaging and spectral measurements. In this study, plasmas generated with the ammonia molecules without additional CO laser beam irradiation and with additional CO laser beam irradiation with the wavelengths on- and off-resonant vibrational excitation of ammonia molecules were investigated and referred as LIBS, LIBS-RE-ON and LIBS-RE-OFF, respectively. The experimental results showed that the temporal and spatial evolution as well as electron temperature and density of plasmas induced with LIBS and LIBS-RE-OFF were consistent but differed from LIBS-RE-ON. Compared with LIBS and LIBS-RE-OFF, plasmas in LIBS-RE-ON showed larger spatial expansion and enhanced emission after a delay time of 1 µs in this study, as well as significantly enhanced electron temperature by ∼ 64%. Time-resolved electron temperatures and densities showed that the emission signal enhancement in LIBS-RE-ON can be primarily attributed to the electron temperature enhancement. Signal enhancement in LIBS indicated improved detection sensitivity. This study could inspire future works on LIBS for gas detection with improved sensitivity and selectivity probably by using ultrafast/intense laser-induced molecular breakdown/ionization with resonant vibrational excitation of molecules.
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http://dx.doi.org/10.1364/OE.382663DOI Listing
January 2020

Persistence and clearance of viral RNA in 2019 novel coronavirus disease rehabilitation patients.

Chin Med J (Engl) 2020 May;133(9):1039-1043

Department of Infectious Disease, Shanghai Public Health Clinical Center, Shanghai 201508, China.

Background: A patient's infectivity is determined by the presence of the virus in different body fluids, secretions, and excreta. The persistence and clearance of viral RNA from different specimens of patients with 2019 novel coronavirus disease (COVID-19) remain unclear. This study analyzed the clearance time and factors influencing 2019 novel coronavirus (2019-nCoV) RNA in different samples from patients with COVID-19, providing further evidence to improve the management of patients during convalescence.

Methods: The clinical data and laboratory test results of convalescent patients with COVID-19 who were admitted to from January 20, 2020 to February 10, 2020 were collected retrospectively. The reverse transcription polymerase chain reaction (RT-PCR) results for patients' oropharyngeal swab, stool, urine, and serum samples were collected and analyzed. Convalescent patients refer to recovered non-febrile patients without respiratory symptoms who had two successive (minimum 24 h sampling interval) negative RT-PCR results for viral RNA from oropharyngeal swabs. The effects of cluster of differentiation 4 (CD4)+ T lymphocytes, inflammatory indicators, and glucocorticoid treatment on viral nucleic acid clearance were analyzed.

Results: In the 292 confirmed cases, 66 patients recovered after treatment and were included in our study. In total, 28 (42.4%) women and 38 men (57.6%) with a median age of 44.0 (34.0-62.0) years were analyzed. After in-hospital treatment, patients' inflammatory indicators decreased with improved clinical condition. The median time from the onset of symptoms to first negative RT-PCR results for oropharyngeal swabs in convalescent patients was 9.5 (6.0-11.0) days. By February 10, 2020, 11 convalescent patients (16.7%) still tested positive for viral RNA from stool specimens and the other 55 patients' stool specimens were negative for 2019-nCoV following a median duration of 11.0 (9.0-16.0) days after symptom onset. Among these 55 patients, 43 had a longer duration until stool specimens were negative for viral RNA than for throat swabs, with a median delay of 2.0 (1.0-4.0) days. Results for only four (6.9%) urine samples were positive for viral nucleic acid out of 58 cases; viral RNA was still present in three patients' urine specimens after throat swabs were negative. Using a multiple linear regression model (F = 2.669, P = 0.044, and adjusted R = 0.122), the analysis showed that the CD4+ T lymphocyte count may help predict the duration of viral RNA detection in patients' stools (t = -2.699, P = 0.010). The duration of viral RNA detection from oropharyngeal swabs and fecal samples in the glucocorticoid treatment group was longer than that in the non-glucocorticoid treatment group (15 days vs. 8.0 days, respectively; t = 2.550, P = 0.013) and the duration of viral RNA detection in fecal samples in the glucocorticoid treatment group was longer than that in the non-glucocorticoid treatment group (20 days vs. 11 days, respectively; t = 4.631, P < 0.001). There was no statistically significant difference in inflammatory indicators between patients with positive fecal viral RNA test results and those with negative results (P > 0.05).

Conclusions: In brief, as the clearance of viral RNA in patients' stools was delayed compared to that in oropharyngeal swabs, it is important to identify viral RNA in feces during convalescence. Because of the delayed clearance of viral RNA in the glucocorticoid treatment group, glucocorticoids are not recommended in the treatment of COVID-19, especially for mild disease. The duration of RNA detection may relate to host cell immunity.
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http://dx.doi.org/10.1097/CM9.0000000000000774DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7147278PMC
May 2020

[Hereditary gingival fibromatosis: a three-generation case report].

Hua Xi Kou Qiang Yi Xue Za Zhi 2020 Feb;38(1):104-107

Center of Stomatology, Xiangya Hospital, Central South University, Changsha 410008, China.

Hereditary gingival fibromatosis (HGF) is a familial hereditary disease; while it is rare and usually benign, it is also characterized by the slow and progressive development of gingival tissue. This paper reports on the clinical examina-tion and history of HGF in a family of patients.
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http://dx.doi.org/10.7518/hxkq.2020.01.019DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7184293PMC
February 2020

Effect of N fertilizer types on NO and NO emissions under drip fertigation from an agricultural field in the North China Plain.

Sci Total Environ 2020 May 23;715:136903. Epub 2020 Jan 23.

State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.

NO and NO emissions from a winter wheat-summer maize rotation field in the North China Plain were comparably investigated under three different treatments: 1) flood irrigation (A-Flood treatment) plus fertilization of NHCl, 2) drip fertigation (A-Drip treatment) plus fertilization of NHCl and 3) drip fertigation (AN-Drip treatment) plus fertilization of a mixture of Ca(NO) and NHCl. The annual NO cumulative emissions from the A-Drip treatment and the A-Flood treatment were almost identical, whereas it from the AN-Drip treatment was significantly lower (33%) than that from the A-Flood treatment. Compared with the A-Flood treatment, the annual NO cumulative emission from the A-Drip treatment was significantly increased by 140% but it from the AN-Drip treatment was only slightly increased by 14%. Compared with drip fertigation with NHCl, drip fertigation with the mixture of Ca(NO) and NHCl significantly reduced the cumulative emissions of NO (31%) and NO (52%) from the nitrification dominated fields by decreasing the supplement of NH substrate. Among the three fertilization treatments, the yields of the maize from the A-Drip and AN-Drip treatments were significantly increased, while the yields of the wheat were almost the same. Considering the benefit of increasing yields and reducing N fertilizer and water input, the application of nitrate-based fertilizer instead of partial ammonium-based fertilizer through drip fertigation could be a promising method for keeping agronomic productivity and environmental sustainability.
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http://dx.doi.org/10.1016/j.scitotenv.2020.136903DOI Listing
May 2020

A Nitrogen-Doped Manganese Oxide Nanoparticles/Porous Carbon Nanosheets Hybrid Material: A High-Performance Anode for Lithium Ion Batteries.

Chempluschem 2019 Dec;84(12):1805-1815

College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, P.R. China.

A nitrogen-doped MnO nanoparticles/ porous carbon nanosheets (N-MnO/PCS) composite was synthesized by the room-temperature redox reaction between KMnO and PCS followed by a facile carbothermal reduction, and a subsequent coating process of urea onto MnO/PCS and heat treatment. N-MnO nanoparticles with a grain size of about 30 nm are homogenously embedded on the surface of the N-PCS, corresponding to a high loading of 50.09 wt.% in the resulting composite. Benefiting from the enhanced reaction kinetics as well as electrical conductivity and continuous transport pathways of Li /electron resulting from the N-doping and hybridization of the cross-linked porous carbon substrate, the as-synthesized N-MnO/PCS-1 electrode delivers a large reversible specific capacity (1497.2 mA h g at 100 mA g after 160 cycles), outstanding rate capacities (710.6 mA h g at 1 A g and 640.1 mA h g at 2 A g ) and long-term cycling stability with specific capacity (976 mA h g at 0.5 A g after cycling 300 cycles). The simple and green synthesis and electronic properties of this composite mean that it has great potential as a high-capacity anode material for practical application in large-scale energy storage devices.
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http://dx.doi.org/10.1002/cplu.201900586DOI Listing
December 2019

Bimetallic MOF Nanosheets Decorated on Electrospun Nanofibers for High-Performance Asymmetric Supercapacitors.

ACS Appl Mater Interfaces 2020 Jan 27;12(1):1280-1291. Epub 2019 Dec 27.

Alan G. MacDiarmid Institute, College of Chemistry , Jilin University , 2699 Qianjin Street , Changchun 130012 , P. R. China.

The rational design of metal-organic framework (MOF)-based materials with a huge specific surface area, high redox activity, and favorable conductivity is currently a hot subject for their potential usage in supercapacitor electrodes. Herein, novel bimetallic MOFs with a flowerlike nanosheet structure grown on the electrospun nanofibers (PPNF@M-Ni MOF, M = Co, Zn, Cu, Fe) have been prepared by controlling the incorporation of various types of metal ions, which display superior electrochemical performance. For example, PPNF@Co-Ni MOF possesses a large specific capacitance of 1096.2 F g (specific capacity of 548.1 C g) at 1 A g and excellent rate performance. In addition, an asymmetric solid-state device composed of PPNF@Co-Ni MOF (positive materials) and KOH-activated carbon nanofibers embedded with reduced graphene oxide (negative materials) reaches a maximum energy density of 93.6 Wh kg at the power density of 1600.0 W kg and long cycling life. This work may greatly advance the research toward the design of supported MOF-based electrode materials for a promising prospect in energy conversion and storage.
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http://dx.doi.org/10.1021/acsami.9b16420DOI Listing
January 2020