Publications by authors named "Siqi Zhu"

54 Publications

High-Pressure O Annealing Enhances the Crystallinity of Ultrawide-Band-Gap Sesquioxides Combined with Graphene for Vacuum-Ultraviolet Photovoltaic Detection.

ACS Appl Mater Interfaces 2021 Apr 31;13(14):16660-16668. Epub 2021 Mar 31.

School of Materials, Sun Yat-sen University, Guangzhou, Guangdong 510275, China.

(AlGa)O is emerging as a promising wide-band-gap sesquioxide for vacuum-ultraviolet (VUV, 10-200 nm) photodetectors and high-power field-effect transistors. However, how the key parameters such as the band gap and crystalline phase of the (AlGa)O-based device vary with stoichiometry has not been explicitly defined, which is due to the unclear underlying mechanism of the Al local coordination environment. In this work, a high-pressure O (20 atm) annealing (HPOA) strategy that can significantly improve the crystallinity of β-(AlGa)O and achieve a tunable optical band gap was proposed, facilitating the revelation of the local structure of Al varying with Al content and the kinetic mechanism of Al diffusion. By combining the as-HPOA-treated single-crystalline β-(AlGa)O films with p-type graphene (p-Gr), which serves as a transparent conductor, a VUV photovoltaic detector is fabricated, showing an improved photovoltage (0.80 V) and fast temporal response (2.1 μs). All of these findings provide a rewarding and important strategy for enhancing the band-gap tunability of sesquioxides, as well as the flexibility of zero-power-consumption photodetectors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsami.1c00429DOI Listing
April 2021

Shape effect on the electronic state and nonlinear optical properties in the regulable Y-shaped quantum dots under applied electric field.

Opt Express 2021 Feb;29(4):5848-5855

The electronic state and nonlinear optical properties in the Y-shaped quantum dots has been theoretically investigated by adjusting the shape with the applied electric field. Within the effective-mass approximation, the energy levels and the wave functions of the system are obtained by means of the finite difference method. The results show that both the strength or the in-plane orientation of external electric field and the shape of regulable Y-shaped quantum dots have a significant influence on the electronic state, optical absorption coefficients and the refractive index changes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OE.414828DOI Listing
February 2021

Vector vortex state preservation in Fresnel cylindrical diffraction.

Opt Lett 2021 Mar;46(6):1313-1316

The vector vortex light beam, which exhibits a space-variant polarization state and is coupled with orbital angular momentum of light, has been drawing much attention due to its fundamental interest and potential applications in a wide range. Here we reveal both theoretically and experimentally that a diffractive structure having cylindrical symmetry is shown to be transparent for the vector vortex state of light with arbitrary topology. We demonstrate such an intriguing phenomenon in the Fresnel diffraction condition, where the vector Helmholtz wave equation can be utilized in the paraxial regime. Our demonstration has implications in control and manipulation of vector vortex light beams in diffractive optics, and hence, it may find potential applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OL.416414DOI Listing
March 2021

Hyperspectral microscopy combined with DAPI staining for the identification of hepatic carcinoma cells.

Biomed Opt Express 2021 Jan 8;12(1):173-180. Epub 2020 Dec 8.

Guangdong Provincial Engineering Research Center of Crystal and Laser Technology, Guangzhou 510632, China.

In this study, the DAPI staining is firstly reported for use in the identification of hepatic carcinoma cells based on hyperspectral microscopy. Nuclei in cancer cells usually contain more aneuploidies than that in normal cells, leading to the change of DNA content. Here, we stain hepatic carcinoma tissues and normal hepatic tissues with 4',6-diamidino-2-phenylindole (DAPI) which is sensitive to the DNA content as a fluorochrome binds to DNA. Consequently, the difference in DNA content between hepatic carcinoma cells and normal hepatic cells can be identified by the fluorescent spectral characteristics. Harnessing the hyperspectral microscopy, we find that the fluorescent properties of these two kinds of cells are different not only in the intensity but also in the spectral shape. These properties are exploited to train a support vector machine (SVM) model for classifying cells. The results show that the sensitivity and specificity for the identification of 1000 hepatic carcinoma samples are 99.3% and 99.1%, respectively.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/BOE.412158DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7899502PMC
January 2021

2D van der Waals Molecular Crystal β-HgI : Economical, Rapid, and Substrate-Free Liquid-Phase Synthesis and Strong In-Plane Optical Anisotropy.

Small 2021 Jan 15;17(2):e2005368. Epub 2020 Dec 15.

State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials, Sun Yat-Sen University, Guangzhou, Guangdong, 510275, China.

2D materials have a great potential for wide-range applications due to their adjustable bandgap characteristics and special crystal structures. β-HgI is a new 2D van der Waals inorganic molecular crystal material with a wide bandgap of 4.03 eV, on whose preparation and properties there are few relevant reports due to the feature of instability of molecular crystals. Here, an economical method to control the synthesis of large-size 2D β-HgI single crystal by using a mineralizer-assisted solution is reported. According to angle-resolved polarization Raman spectroscopy and first-principles optical absorption calculation, 2D β-HgI flake has a strong in-plane anisotropic light scattering characteristic and high optical absorption dichroism (a /a  = 3.4), which is due to a low in-plane symmetry of the orthorhombic structure of β-HgI . More importantly, due to the molecular crystal structure of β-HgI , its sensitivity to temperature is less than that of 2D materials such as MoS , which has been confirmed by temperature-dependent Raman spectroscopy. In the work, more 2D inorganic molecular crystals are studied in the aspect of growth, which provides a theoretical basis for 2D molecular crystal optoelectronic devices' potential applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/smll.202005368DOI Listing
January 2021

MELD Score Reflects the Mood, Sleep, and Daily Living Ability in Liver Transplantation Candidates: A Descriptive Study.

Ann Transplant 2020 Dec 1;25:e926857. Epub 2020 Dec 1.

Department of Psychological Medicine, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China (mainland).

BACKGROUND This study aimed to assess the psychosocial status (mood, sleep quality, and activities of daily living) of candidates on an orthotopic liver transplantation (OLT) waiting list and to identify the association between psychosocial factors and MELD score in end-stage liver disease (ESLD). MATERIAL AND METHODS Fifty-three OLT waiting list candidates completed 4 scales (Hamilton Rating Scale for Depression [HAMD-17], Hamilton Anxiety Rating Scale [HAM-A], Pittsburgh Sleep Quality Index [PSQI], Activities of Daily Living Scale [ADL]) to assess their affective status, sleep quality, and daily living ability. Candidates were divided into 2 groups, the high MELD score group (MELD score ≥15) and the low MELD score group (MELD score.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.12659/AOT.926857DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7720912PMC
December 2020

Breast Cancer Mortality among Women with a or Mutation in a Magnetic Resonance Imaging Plus Mammography Screening Program.

Cancers (Basel) 2020 Nov 23;12(11). Epub 2020 Nov 23.

Women's College Research Institute, University of Toronto, Toronto, ON M5G 1N8, Canada.

Annual breast magnetic resonance imaging (MRI) plus mammography is the standard of care for screening women with inherited mutations. However, long-term breast cancer-related mortality with screening is unknown. Between 1997 and June 2011, 489 previously unaffected mutation carriers aged 25 to 65 years were screened with annual MRI plus mammography on our study. Thereafter, participants were eligible to continue MRI screening through the high-risk Ontario Breast Screening Program. In 2019, our data were linked to the Ontario Cancer Registry of Cancer Care Ontario to identify all incident cancers, vital status and causes of death. Observed breast cancer mortality was compared to expected mortality for age-matched women in the general population. There were 91 women diagnosed with breast cancer (72 invasive and 19 ductal carcinoma in situ (DCIS)) with median follow-up 7.4 (range: 0.1 to 19.2) years. Four deaths from breast cancer were observed, compared to 2.0 deaths expected (standardized mortality ratio (SMR) 2.0, = 0.14). For the 489 women in the study, the probability of not dying of breast cancer at 20 years from the date of the first MRI was 98.2%. Annual screening with MRI plus mammography is a reasonable option for women who decline or defer risk-reducing mastectomy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/cancers12113479DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7700272PMC
November 2020

Evaluation of a Novel Missense Mutation in Gene Causing Progressive Familial Intrahepatic Cholestasis Type 3.

Dis Markers 2020 15;2020:6292818. Epub 2020 Jun 15.

Laboratory of Medical Genetics, Harbin Medical University, Harbin 150081, China.

Progressive familial intrahepatic cholestasis type 3 (PFIC3) is a hepatic disorder occurring predominantly in childhood and is difficult to diagnose. PFIC3, being a rare autosomal recessive disease, is caused by genetic mutations in both alleles of , resulting in the disruption of the bile secretory pathway. The identification of pathogenic effects resulting from different mutations in ABCB4 is the key to revealing the internal cause of disease. These mutations cause truncation, instability, misfolding, and impaired trafficking of the MDR3 protein. Here, we reported a girl, with a history of intrahepatic cholestasis and progressive liver cirrhosis, with an elevated gamma-glutamyltransferase level. Genetic screening whole exome sequencing found a novel homozygous missense mutation :c.1195G>C:p.V399L, and the patient was diagnosed with PFIC3. Various computational tools predicted the variant to be deleterious and evolutionary conserved. For functional characterization studies, plasmids, encoding wild-type and selected established mutant constructs, were expressed in human embryonic kidney (HEK-293T) and hepatocellular carcinoma (HepG2) cells. expression analysis observed a reduced expression of mutant protein compared to wild-type protein. We found that wild type was localized at the apical canalicular membrane, while mutant p.V399L showed intracellular retention. Intracellular mistrafficking proteins usually undergo proteasomal or lysosomal degradation. We found that after treatment with proteasomal inhibitor MG132 and lysosomal inhibitor bafilomycin A1, MDR3 expression of V399L was significantly increased. A decrease in MDR3 expression of mutant V399L protein may be a result of proteasomal or lysosomal degradation. Pharmacological modulator cyclosporin A and intracellular low temperature (30°C) treatment significantly rescued both the folding defect and the active maturation of the mutant protein. Our study identified a novel pathogenic mutation which expanded the mutational spectrum of the gene and may contribute to understanding the molecular basis of PFIC3. Therefore, genetic screening plays a conclusive role in the diagnosis of rare heterogenic disorders like PFIC3.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2020/6292818DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7315263PMC
June 2020

Quantitative Assessment of Tip Effects in Single-Molecule High-Speed Atomic Force Microscopy Using DNA Origami Substrates.

Angew Chem Int Ed Engl 2020 08 7;59(34):14336-14341. Epub 2020 Jul 7.

Technical and Macromolecular Chemistry, Paderborn University, Warburger Str. 100, 33098, Paderborn, Germany.

High-speed atomic force microscopy (HS-AFM) is widely employed in the investigation of dynamic biomolecular processes at a single-molecule level. However, it remains an open and somewhat controversial question, how these processes are affected by the rapidly scanned AFM tip. While tip effects are commonly believed to be of minor importance in strongly binding systems, weaker interactions may significantly be disturbed. Herein, we quantitatively assess the role of tip effects in a strongly binding system using a DNA origami-based single-molecule assay. Despite its femtomolar dissociation constant, we find that HS-AFM imaging can disrupt monodentate binding of streptavidin (SAv) to biotin (Bt) even under gentle scanning conditions. To a lesser extent, this is also observed for the much stronger bidentate SAv-Bt complex. The presented DNA origami-based assay can be universally employed to quantify tip effects in strongly and weakly binding systems and to optimize the experimental settings for their reliable HS-AFM imaging.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/anie.202005884DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7496922PMC
August 2020

Bacterial Flagella Loss under Starvation.

Authors:
Siqi Zhu Beile Gao

Trends Microbiol 2020 10 23;28(10):785-788. Epub 2020 May 23.

CAS Key Laboratory of Tropical Marine Bio Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, 511458, China. Electronic address:

The bacterial flagellum is beneficial in most cases but it can become a burden when the energy source is low because it is very costly to assemble and energize for motility. Recent electron cryo-tomography and real-time fluorescence microscopy studies suggest that bacteria can remove their flagella under starvation in a programmed way.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.tim.2020.05.002DOI Listing
October 2020

Combinatorial approach of in silico and in vitro evaluation of MLH1 variant associated with Lynch syndrome like metastatic colorectal cancer.

Biosci Rep 2020 06;40(6)

Laboratory of Medical Genetics, Harbin Medical University, Harbin 150081, China.

Colorectal cancer (CRC) is the third most developing cancer worldwide and Lynch syndrome (LS) accounts for 3-4% of CRC. Genetic alteration in any of DNA mismatch repair (MMR) gene is the major cause of LS that disrupt the normal upstream and downstream MMR events. Germline mutation of MLH1 in heterozygous state have an increased risk for CRC. Defective MMR pathway mostly results in microsatellite instability (MSI) that occurs in high percentage of CRC associated tumors. Here, we reported a patient with LS like metastatic CRC (mCRC) associated with other related cancers. Whole exome sequencing (WES) of the proband was performed to identify potential causative gene. Genetic screening validated by Sanger sequencing identified a heterozygous missense mutation in exon 12 of MLH1 (c.1151T>A, p.V384D). The clinical significance of identified variant was elucidated on the basis of clinicopathological data, computational predictions and various in vitro functional analysis. In silico predictions classified the variant to be deleterious and evolutionary conserved. In vitro functional studies revealed a significant decrease in protein expression because of stability defect leading to loss of MMR activity. Mutant residue found in MutL transducer domain of MLH1 that localized in the nucleus but translocation was not found to be significantly disturbed. In conclusion, our study give insight into reliability of combinatorial prediction approach of in silico and in vitro expression analysis. Hence, we highlighted the pathogenic correlation of MLH1 variant with LS associated CRC as well as help in earlier diagnosis and surveillance for improved management and genetic counselling.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1042/BSR20200225DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7269917PMC
June 2020

Ancient Genomes Reveal the Evolutionary History and Origin of Cashmere-Producing Goats in China.

Mol Biol Evol 2020 07;37(7):2099-2109

Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China.

Goats are one of the most widespread farmed animals across the world; however, their migration route to East Asia and local evolutionary history remain poorly understood. Here, we sequenced 27 ancient Chinese goat genomes dating from the Late Neolithic period to the Iron Age. We found close genetic affinities between ancient and modern Chinese goats, demonstrating their genetic continuity. We found that Chinese goats originated from the eastern regions around the Fertile Crescent, and we estimated that the ancestors of Chinese goats diverged from this population in the Chalcolithic period. Modern Chinese goats were divided into a northern and a southern group, coinciding with the most prominent climatic division in China, and two genes related to hair follicle development, FGF5 and EDA2R, were highly divergent between these populations. We identified a likely causal de novo deletion near FGF5 in northern Chinese goats that increased to high frequency over time, whereas EDA2R harbored standing variation dating to the Neolithic. Our findings add to our understanding of the genetic composition and local evolutionary process of Chinese goats.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/molbev/msaa103DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7306693PMC
July 2020

Trypophobia as an urbanized emotion: comparative research in ethnic minority regions of China.

PeerJ 2020 18;8:e8837. Epub 2020 Mar 18.

Faculty of Arts and Science, Kyushu University, Fukuoka, Japan.

Trypophobia is a strong emotion of disgust evoked by clusters of holes or round objects (e.g., lotus seed pod). It has become increasingly popular and been studied since 2010s, mainly in the West and Japan. Considering this, trypophobia might be a modern emotion, and hence urbanization possibly plays key roles in trypophobia. To address this issue, we compared the degree of trypophobia between urban and less urban people in China. In an experiment, we asked participants about their degree of discomfort from trypophobic images. The results showed that trypophobia occurred in both groups, although the effect size was larger in urban than less urban people. Moreover, post-experimental interviews and post-hoc analyses revealed that older people in less urban area did not experience as much trypophobia. Our findings suggest that trypophobia links to urbanization and age-related properties.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7717/peerj.8837DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7085289PMC
March 2020

Cryopreservation of DNA Origami Nanostructures.

Small 2020 04 4;16(13):e1905959. Epub 2020 Mar 4.

Technical and Macromolecular Chemistry, Paderborn University, Warburger Str. 100, 33098, Paderborn, Germany.

Although DNA origami nanostructures have found their way into numerous fields of fundamental and applied research, they often suffer from rather limited stability when subjected to environments that differ from the employed assembly conditions, that is, suspended in Mg -containing buffer at moderate temperatures. Here, means for efficient cryopreservation of 2D and 3D DNA origami nanostructures and, in particular, the effect of repeated freezing and thawing cycles are investigated. It is found that, while the 2D DNA origami nanostructures maintain their structural integrity over at least 32 freeze-thaw cycles, ice crystal formation makes the DNA origami gradually more sensitive toward harsh sample treatment conditions. Whereas no freeze damage could be detected in 3D DNA origami nanostructures subjected to 32 freeze-thaw cycles, 1000 freeze-thaw cycles result in significant fragmentation. The cryoprotectants glycerol and trehalose are found to efficiently protect the DNA origami nanostructures against freeze damage at concentrations between 0.2 × 10 and 200 × 10 m and without any negative effects on DNA origami shape. This work thus provides a basis for the long-term storage of DNA origami nanostructures, which is an important prerequisite for various technological and medical applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/smll.201905959DOI Listing
April 2020

Functional Characterization of a Missense Variant of Identified in Lynch Syndrome Pedigree.

Dis Markers 2020 29;2020:8360841. Epub 2020 Jan 29.

Laboratory of Medical Genetics, Harbin Medical University, Harbin 150081, China.

Lynch syndrome (LS) is the most common hereditary colorectal cancer (CRCs) inherited in an autosomal-dominant manner. Here, we reported a multigeneration Chinese family clinically diagnosed with LS according to the Amsterdam II criteria. To identify the underlying causative gene for LS in this family, whole-exome sequencing (WES) was performed. A germline missense variant (c.2054C>T:p.S685F) in exon 18 of was successfully identified by WES. Sanger sequencing verified the results of WES and also confirmed the cosegregation of the missense variant in all affected members of the family including two unaffected family members. Bioinformatic tools predicted the identified variant as deleterious. Immunohistochemistry (IHC) staining showed loss of MLH1 and PMS2 protein expression. expression analysis also revealed that the identified missense variant (c.2054C>T:p.S685F) results in reduced expression of both MLH1 and PMS2 proteins. Based on the American College of Medical Genetics and Genomics (ACMG) guidelines, the missense mutation c.2054C>T in was classified as a "pathogenic" variant. Two unaffected family members were later recommended for colonoscopy and other important cancer diagnostic inspections every 1-2 years as both were at higher risk of LS. In conclusion, our findings widen the genotypic spectrum of mutations responsible for LS. This study increases the phenotypic spectrum of LS which will certainly help the clinicians in diagnosing LS in multigeneration families. This study also puts emphasis on the importance of genetic counselling for the benefit of asymptomatic carriers of MMR gene variants who are at higher risk of LS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2020/8360841DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7008259PMC
October 2020

Efficient high-power orthogonally-polarized dual-wavelength Nd:YLF laser at 1314 and 1321 nm.

Opt Express 2019 Nov;27(23):32949-32957

We demonstrate an 806 nm laser diode end-pumped continuous-wave (CW) and actively Q-switched (AQS) orthogonally-polarized dual-wavelength Nd:YLF laser operating at 1314 and 1321 nm. Benefitting from the small difference of the stimulated emission cross sections at 1314 and 1321 nm in Nd:YLF crystal, the power equalized emissions at both wavelengths were achieved by simply titling the output coupler. A maximum CW output power of 9.2 W was obtained with the incident pump power of 32.5 W, giving an optical-to-optical conversion efficiency of approximately 28% and a slope efficiency of approximately 33%. Furthermore, active Q-switching was realized by inserting a Brewster-cut acousto optic modulator. For an incident pump power of 30 W, this oscillator delivered an average power of 6.5 W at a pulse repetition frequency (PRF) of 20 kHz, and a pulse energy of 2.6 mJ with a peak power of approximately 72 kW at a PRF of 1 kHz.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OE.27.032949DOI Listing
November 2019

Early diagnosis of gastric cancer based on deep learning combined with the spectral-spatial classification method.

Biomed Opt Express 2019 Oct 9;10(10):4999-5014. Epub 2019 Sep 9.

Department of Gastroenterology and Endocrinology, The 74th Group Army Hospital of People's Liberation Army, Guangdong, Guangzhou, 510318, China.

The development of an objective and rapid method that can be used for the early diagnosis of gastric cancer has important clinical application value. In this study, the fluorescence hyperspectral imaging technique was used to acquire fluorescence spectral images. Deep learning combined with spectral-spatial classification methods based on 120 fresh tissues samples that had a confirmed diagnosis by histopathological examinations was used to automatically identify and extract the "spectral + spatial" features to construct an early diagnosis model of gastric cancer. The model results showed that the overall accuracy for the nonprecancerous lesion, precancerous lesion, and gastric cancer groups was 96.5% with specificities of 96.0%, 97.3%, and 96.7% and sensitivities of 97.0%, 96.3%, and 96.6%, respectively. Therefore, the proposed method can increase the diagnostic accuracy and is expected to be a new method for the early diagnosis of gastric cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/BOE.10.004999DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6788605PMC
October 2019

Effect of Staple Age on DNA Origami Nanostructure Assembly and Stability.

Molecules 2019 Jul 16;24(14). Epub 2019 Jul 16.

Technical and Macromolecular Chemistry, Paderborn University, Warburger Str. 100, 33098 Paderborn, Germany.

DNA origami nanostructures are widely employed in various areas of fundamental and applied research. Due to the tremendous success of the DNA origami technique in the academic field, considerable efforts currently aim at the translation of this technology from a laboratory setting to real-world applications, such as nanoelectronics, drug delivery, and biosensing. While many of these real-world applications rely on an intact DNA origami shape, they often also subject the DNA origami nanostructures to rather harsh and potentially damaging environmental and processing conditions. Furthermore, in the context of DNA origami mass production, the long-term storage of DNA origami nanostructures or their pre-assembled components also becomes an issue of high relevance, especially regarding the possible negative effects on DNA origami structural integrity. Thus, we investigated the effect of staple age on the self-assembly and stability of DNA origami nanostructures using atomic force microscopy. Different harsh processing conditions were simulated by applying different sample preparation protocols. Our results show that staple solutions may be stored at -20 °C for several years without impeding DNA origami self-assembly. Depending on DNA origami shape and superstructure, however, staple age may have negative effects on DNA origami stability under harsh treatment conditions. Mass spectrometry analysis of the aged staple mixtures revealed no signs of staple fragmentation. We, therefore, attribute the increased DNA origami sensitivity toward environmental conditions to an accumulation of damaged nucleobases, which undergo weaker base-pairing interactions and thus lead to reduced duplex stability.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/molecules24142577DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6680526PMC
July 2019

Upregulation of MGP by HOXC8 promotes the proliferation, migration, and EMT processes of triple-negative breast cancer.

Mol Carcinog 2019 10 1;58(10):1863-1875. Epub 2019 Jul 1.

Center for Stem Cell and Translational Medicine, School of Life Sciences, Anhui University, Hefei, Anhui.

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype which accounts for 15%-20% of all breast cancer cases. The management of TNBC has remained a challenge due to its lack of targeted therapy. Previously, we reported that homeobox C8 (HOXC8) was involved in metastasis and migration of breast cancer cells. By chromatin immunoprecipitation and luciferase assays, we found that HOXC8 functioned as a transcription factor to activate the transcription of matrix Gla protein (MGP) gene, leading to an increase in the proliferation, anchorage-independent growth, and migration of TNBC cells. We further demonstrated that MGP expression promoted the epithelial-mesenchymal transition (EMT) process of TNBC cells, but not the other subtypes of breast cancer, suggesting that MGP induced EMT to promote proliferation and migration of TNBC cells. Moreover, we found that MGP was upregulated in clinical breast specimens compared to normal breast tissues and high MGP expression was statistically associated with poor, relapse-free survival for TNBC patients, indicating that MGP is probably a novel biomarker or therapeutic target for TNBC patients. Together, our results showed that the HOXC8-MGP axis played an important role in the tumorigenesis of TNBC and might be a promising therapeutic target for TNBC treatment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/mc.23079DOI Listing
October 2019

Homeobox C8 is a transcriptional repressor of E-cadherin gene expression in non-small cell lung cancer.

Int J Biochem Cell Biol 2019 09 13;114:105557. Epub 2019 Jun 13.

School of Life Sciences, Anhui University, Hefei, Anhui Province, PR China. Electronic address:

Loss of E-cadherin expression is a hallmark of epithelial-mesenchymal transition (EMT) in tumor progression. Because previous findings suggested that homeobox C8 (HOXC8) promotes EMT in non-small-cell lung cancer (NSCLC), we investigated whether E-cadherin is a target of HOXC8 protein. In this study, we report that HOXC8 binds to the E-cadherin promoter and acts as a transcriptional repressor to regulate E-cadherin transcription in NSCLC. We further show that loss of E-cadherin leads to an increase in anchorage-independent growth and migration of NSCLC cells, and the inhibitory effects mediated by HOXC8 knockdown can be largely rescued by reduction of E-cadherin expression, suggesting that the HOXC8-E-cadherin pathway is involved in lung cancer progression. Moreover, analysis of E-cadherin and HOXC8 expression indicates that expression of HOXC8 is strongly correlated with loss of E-cadherin expression, and high HOXC8 / low E-cadherin expression is significantly correlated with poor survival for lung cancer patients. Taken together, these data indicate that E-cadherin is a target gene of HOXC8 and that the loss of E-cadherin promotes the growth and migration of NSCLC.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.biocel.2019.06.005DOI Listing
September 2019

Identification of a pathogenic mutation in a Chinese pedigree with polycystic kidney disease.

Mol Med Rep 2019 Apr 31;19(4):2671-2679. Epub 2019 Jan 31.

Laboratory of Medical Genetics, Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China.

Polycystic kidney disease (PKD) is a life‑threatening inherited disease with a morbidity of 1:500‑1,000 worldwide. Numerous progressively enlarging cysts are observed in the bilateral kidneys of patients with PKD, inducing structural damage and loss of kidney function. The present study analyzed one family with PKD. Whole exome sequencing of the proband was performed to detect the pathogenic gene present in the family. Candidate gene segments for lineal consanguinity in the family were amplified by nest polymerase chain reaction, followed by Sanger sequencing. One novel duplication variant (NM_001009944.2:c.9359dupA:p.Y3120_E3121delinsX) and one missense mutation (c.G9022A:p.V3008M) were detected in PKD1. Additionally, the pathogenic substitutions in PKD1 published from the dataset were analyzed. Following analysis and confirmation, the duplication variant NM_001009944.2:c.9359dupA:p.Y3120_E3121delinsX in PKD1, within the polycystin‑1, lipoxygenase, α‑toxin domain, was considered to be the pathogenic factor in the examined family with autosomal dominant PKD. Additionally, based on the analysis of 4,805 pathogenic substitutions in PKD1 within various regions, the presence of the missense mutation in the N‑terminal domain of polycystin‑1 may present high pathogenicity in ADPKD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3892/mmr.2019.9921DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6423614PMC
April 2019

Dual-type hyperspectral microscopic imaging for the identification and analysis of intestinal fungi.

Biomed Opt Express 2018 Sep 27;9(9):4496-4508. Epub 2018 Aug 27.

Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Guangzhou 510632, China.

A method based on a dual-type (transmission and fluorescence) hyperspectral microscopic image system was developed to identify species of intestinal fungi. Living fungi are difficult to identify via transmission spectra or fluorescence spectra alone. We propose an identification method based on both fluorescence and transmission spectra that employs a series of image processing methods. Three species of intestinal fungi were used to evaluate the method. The results demonstrate that the specificity of the model trained with dual-type spectra was 98.36%, whereas the specificities achieved by training with fluorescence spectra and transmission spectra alone were 94.04% and 92.88%, respectively.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/BOE.9.004496DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6157763PMC
September 2018

Diagnosis of early gastric cancer based on fluorescence hyperspectral imaging technology combined with partial-least-square discriminant analysis and support vector machine.

J Biophotonics 2019 05 28;12(5):e201800324. Epub 2019 Jan 28.

Department of Gastroenterology and Endocrinology, The 74th Group Army Hospital of the PLA, Guangzhou, China.

This study investigated the feasibility of using fluorescence hyperspectral imaging technology to diagnose of early-stage gastric cancer. Fluorescence spectral images of 76 patients who were pathologically diagnosed as non-atrophic gastritis, premalignant lesions and gastric cancer were collected. Fluorescence spectra at 100-pixel points were randomly extracted after binarization. Diagnostic models of non-atrophic gastritis, premalignant lesions and gastric cancer were constructed through partial-least-square discriminant analysis (PLS-DA) and support vector machine (SVM) algorithms. The prediction effects of PLS-DA and SVM models were compared. Results showed that the average spectra of normal, precancerous and gastric cancer tissues significantly differed at 496, 546, 640 and 670 nm, and regular changes in fluorescence intensity at 546 nm were in the following order: normal > precancerous lesions > gastric cancer. Additionally, the effect of the diagnostic model established by SVM is significantly better than PLS-DA which accuracy, specificity and sensitivity are above 94%. Experimental results revealed that the fast diagnostic model of early gastric cancer by combining fluorescence hyperspectral imaging technology and improved SVM was effective and feasible, thereby providing an accurate and rapid method for diagnosing early-stage gastric cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jbio.201800324DOI Listing
May 2019

Diagnosis of dermatophytosis using single fungus endogenous fluorescence spectrometry.

Biomed Opt Express 2018 Jun 21;9(6):2733-2742. Epub 2018 May 21.

Department of Optoelectronic Engineering, Jinan University, Guangzhou 510632, China.

We propose to use a single fungus endogenous fluorescence spectrometry base on a hyperspectral fluorescence microscope for the diagnosis of dermatophytosis. Dermatophyte samples, including were imaged, and the endogenous fluorescence spectrum of a single fungus was calculated. High contrast fluorescence images and endogenous fluorescence spectrum of the single fungus were used to identify the type of dermatophyte. Morphologically similar and can be distinguished using an endogenous fluorescence spectrum of the single fungus. Meanwhile, our result showed that the sensitivity and specificity of identifying were 95% and 93%, and the sensitivity and specificity of identifying were 94% and 93%.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/BOE.9.002733DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6154188PMC
June 2018

Efficient enhancement of bismuth near infrared luminescence by the co-doping of tantalum in GYAP crystal.

Opt Express 2018 Sep;26(18):23207-23214

Bi/Ta double doped GdYAlO (Bi/Ta:GYAP) near-infrared (NIR) laser crystal was successfully grown. The codoping of Ta was demonstrated to effectively enhance the NIR fluorescence emission in Bi/Ta:GYAP crystal for the first time. The introduced Ta ion can induce the change of valence states from Bi to Bi based on the charge compensation mechanism, bringing about the enhanced NIR fluorescence emission. The three NIR fluorescence emission peaks centering at 1005, 1195, and 1280 nm were ascribed to three different Bi active centers in Bi/Ta:GYAP crystal. These results suggest that the Bi/Ta:GYAP crystal may have potential applications in NIR broadband lasers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OE.26.023207DOI Listing
September 2018

Tandem Hydration of Diisonitriles Triggered by Isonitrile Hydratase in Streptomyces thioluteus.

Org Lett 2018 06 4;20(12):3562-3565. Epub 2018 Jun 4.

State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology , Huazhong Agricultural University , Wuhan 430070 , China.

The biosynthetic pathway of diisonitrile chalkophore SF2768 was identified in Streptomyces thioluteus through heterologous expression recently. Isolation and structure elucidation of the N-substituted formamides that coexisted with the diisonitriles implied that a hydration event was involved. In vitro enzymatic assays of an endogenous isonitrile hydratase suggested a rare sequential-hydration of the diisonitriles. Additionally, the results of Cu-CAS assays indicate that both partial and complete hydration led to the loss of the copper-chelating ability of SF2768.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.orglett.8b01341DOI Listing
June 2018

Charge compensation effects of Yb on the Bi: near-infrared emission in PbF crystal.

Opt Lett 2018 May;43(10):2372-2375

The use of Yb codoping for enhancing the near-infrared (NIR) emission in Bi, Yb codoped PbF crystal was investigated for the first time, to the best of our knowledge. The NIR and visible fluorescence emission properties of the as-grown crystals were investigated in detail. It was found that the Yb ion can act as an effective charge compensated ion to bring about the conversion from Bi to Bi, enhancing the NIR fluorescence emission in Bi:PbF crystal. Moreover, the NIR fluorescence emission peaking at around 1090 and 1485 nm was demonstrated to be two different Bi related centers, Bi(I) and Bi(II), respectively. These results suggest that Bi, Yb codoped PbF crystal may become an attractive gain material for developing NIR broadband lasers under pumps of different wavelengths.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OL.43.002372DOI Listing
May 2018

Sensitization and deactivation effects of Ndon the Ho : 3.9  μm emission in a PbF crystal.

Opt Lett 2017 Jul;42(13):2559-2562

The use of Nd codoping for sensitizing the Ho ion and enhancing the ∼3.9  μm emission from Ho:I5→I5 was investigated in the PbF crystal for the first time, to the best of our knowledge. The ∼3.9  μm fluorescence emission properties and energy transfer mechanism of the as-grown crystals were investigated. The results show that the Nd ion can act as a sensitizer to the Ho ion, providing an efficient excitation channel, making the Ho/Nd:PbF crystal propitious to be pumped by commercialized InGaAs laser diodes (LDs). Moreover, an enhanced ∼3.9  μm emission was obtained in the Ho/Nd:PbF crystal due to the codoping of Nd ions, leading to an efficient energy transfer from a lower laser level of Ho:I5 to Nd:I4, while having little influence on the higher laser level of Ho:I5. These advantageous spectroscopic characteristics indicate that the Ho/Nd:PbF crystal might have potential application in ∼3.9  μm mid-infrared lasers under a conventional 808 nm LD pump.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OL.42.002559DOI Listing
July 2017

Time-dependent effect of electrical stimulation on osteogenic differentiation of bone mesenchymal stromal cells cultured on conductive nanofibers.

J Biomed Mater Res A 2017 Dec 20;105(12):3369-3383. Epub 2017 Sep 20.

State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, P. R. China.

Bone tissue engineering using bone mesenchymal stromal cells (BMSCs) is a multidisciplinary strategy that requires biodegradable scaffold, cell, various promoting cues to work simultaneously. Electrical stimulation (ES) is known able to promote osteogenic differentiation of BMSCs, but it is interesting to know how can it play the strongest promotion effect. To strengthen local ES on BMSCs, parallel-aligned conductive nanofibers were electrospun from the mixtures of poly(L-lactide) (PLLA) and multi-walled carbon nanotubes (MWCNTs), and used for cell culture. Osteogenic differentiation of BMSCs was conducted by applying ES (direct current, 1.5 V, 1.5 h/day) perpendicular to the fiber direction during the day 1-7, day 8-14, or day 15-21 period of the osteoinductive culture. In comparison with ES-free groups, bone-related markers and genes were found significantly up-regulated when ES was applied on BMSCs growing on nanofibers having higher conductivity. When the ES was applied at the earlier stage of osteoinductive culture, the promotion effect on osteogenic differentiation would be stronger. In the presence of a BMP blocker, the down-regulated expressions of bone-related genes were able to be slightly recovered by ES, especially when the ES was applied at the beginning of osteoinductive culture (i.e. day 1-7). The promotion effect generated by ES in the early stage was found sustainable to later stages of differentiation, while those ES applied at later stages of differentiation should have missed the optimal point. In other words, later ES was not so necessary in inducing the osteogenic differentiation of BMSCs. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3369-3383, 2017.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jbm.a.36181DOI Listing
December 2017

Directional release of the stored ultrashort light pulses from a tunable Bragg-grating microcavity.

Opt Express 2017 Jul;25(15):17589-17599

We demonstrate numerically the ability for directionally releasing the stored ultrashort light pulse from a microcavity by means of two-pulse nonlinear interaction in a cascading Bragg grating structure. The setting is built by a chirped grating segment which is linked through a uniform segment, including a tunable microcavity located at the junction between the two components. Our simulations show that stable trapping of an ultrashort light pulse can be achieved in the setting. The stored light pulse in a microcavity can be possibly released, by nonlinearly interacting with the lateral incident control pulse. Importantly, by breaking the symmetry of potential cavity, the stably trapped light pulse can be successfully released from the microcavity to the expected direction. Owing to the induced optical nonlinearity, the released ultrashort light pulses could preserve their shapes, propagating in a form of Bragg grating solitons through the uniform component, which is in contrast to the extensively studied light pulse trappings in photonic crystal cavities which operate at the linear regime.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OE.25.017589DOI Listing
July 2017