Publications by authors named "Chunyu Liu"

338 Publications

Development of a novel reporter gene assay to evaluate antibody-dependent cellular phagocytosis for anti-CD20 therapeutic antibodies.

Int Immunopharmacol 2021 Sep 11;100:108112. Epub 2021 Sep 11.

Division of Monoclonal Antibody Products, National Institu-tes for Food and Drug Control, Key Laboratory of the Ministry of Health for Research on Quality and Standardization of Biotech Products, Beijing 102629, China.

More than 100 monoclonal antibodies (mAbs) have been approved by FDA. The mechanism of action (MoA) involves in neutralization of a specific target via the Fab region and Fc effector functions through Fc region, while the latter include complement-dependent cytotoxicity (CDC), antibody-dependent cell-mediated cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP). ADCP has been recognized one of the most important MoAs, especially for anti-cancer mAbs in recent years. However, traditional bioassays measuring ADCP always introduced primary macrophages and flow cytometry, which are difficult to handle and highly variable. In this study, we engineered a monoclonal Jurkat/NFAT/CD32a-FcεRIγ effector cell line that stably expresses CD32a-FcεRIγ chimeric receptor and NFAT-controlled luciferase. The corresponding mAb could bind with the membrane antigens on the target cells with its Fab fragment and CD32a-FcεRIγ on the effector cells with its Fc fragment, leading to the crosslinking of CD32a-FcεRIγ and the resultant expression of subsequent NFAT-controlled luciferase, which represents the bioactivity of ADCP based on the MoA of the mAb. With rituximab as the model mAb, Raji cells as the target cells, and Jurkat/NFAT/CD32a-FcεRIγ cells as the effector cells, we adopted the strategy of Design of Experiment (DoE) to optimize the bioassay. Then we fully validated the established bioassay according to ICH-Q2(R1), which proved the good assay performance characteristics of the bioassay, including specificity, accuracy, precision, linearity, stability and robustness. This RGA can be applied to evaluate the -ADCP bioactivity for anti-CD20 mAbs in lot release, stability testing as well as biosimilar comparability. The engineered cells may also potentially be used to evaluate the ADCP bioactivity of mAbs with other targets.
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http://dx.doi.org/10.1016/j.intimp.2021.108112DOI Listing
September 2021

miR‑486‑5p suppresses gastric cancer cell growth and migration through downregulation of fibroblast growth factor 9.

Mol Med Rep 2021 11 7;24(5). Epub 2021 Sep 7.

Department of General Surgery, First Affiliated Hospital of Jiamusi University, Jiamusi, Heilongjiang 154002, P.R. China.

Non‑coding RNAs serve essential roles in regulating mRNA and protein expression and dysregulation of non‑coding RNAs participates in a variety of types of cancer. microRNAs (miRNAs/miRs), which are 21‑24 nucleotides non‑coding RNAs, have been shown to be important for the development of gastric cancer (GC). However, the role of miR‑486‑5p in GC remains to be elucidated. The present study found that miR‑486‑5p was downregulated in GC tissues. Comparing with gastric normal cells GES‑1, GC cells, including MKN‑45, AGS, HGC27 and MKN74, had reduced abundance of miR‑486‑5p transcript. CCK8 and colony formation assays demonstrated that GC cell growth and proliferation were enhanced by miR‑486‑5p inhibitors and were suppressed by miR‑486‑5p mimics. miR‑486‑5p also suppressed cell cycle process and migration and promoted apoptosis in GC cells, as verified by propidium iodide (PI) staining, Transwell assay and PI/Annexin V staining. miR‑486‑5p downregulated fibroblast growth factor 9 (FGF9) through combining to its 3'untranslated region. Overexpression of FGF9 accelerated the growth and proliferation of GC cells. The expression of miR‑486‑5p was negatively associated with FGF9 mRNA expression in GC samples. These results revealed that miR‑486‑5p was a tumor suppressor in GC. Downregulation of FGF9 contributed to the role of miR‑486‑5p in GC.
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http://dx.doi.org/10.3892/mmr.2021.12411DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8436225PMC
November 2021

Epigenome-wide association study of mitochondrial genome copy number.

Hum Mol Genet 2021 Aug 20. Epub 2021 Aug 20.

Population Sciences Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.

We conducted cohort- and race-specific epigenome-wide association analyses of mtDNA copy number (mtDNA CN) measured in whole blood from participants of African and European origins in five cohorts (n = 6182, mean age 57-67 years, 65% women). In the meta-analysis of all the participants, we discovered 21 mtDNA CN-associated CpG sites (p < 1 x 10-7), with a 0.7 to 3.0 standard deviation increase (3 CpGs) or decrease (18 CpGs) in mtDNA CN corresponding to a 1% increase in DNA methylation. Several significant CpGs have been reported to be associated with at least two risk factors (e.g. chronological age or smoking) for cardiovascular disease (CVD). Five genes (PRDM16, NR1H3, XRCC3, POLK, and PDSS2), which harbor nine significant CpGs, are known to be involved in mitochondrial biosynthesis and functions. For example, NR1H3 encodes a transcription factor that is differentially expressed during an adipose tissue transition. The methylation level of cg09548275 in NR1H3 was negatively associated with mtDNA CN (effect size = -1.71, p = 4 x 10-8) and positively associated with the NR1H3 expression level (effect size = 0.43, p = 0.0003), which indicates that the methylation level in NR1H3 may underlie the relationship between mtDNA CN, the NR1H3 transcription factor, and energy expenditure. In summary, the study results suggest that mtDNA CN variation in whole blood is associated with DNA methylation levels in genes that are involved in a wide range of mitochondrial activities. These findings will help reveal molecular mechanisms between mtDNA CN and CVD.
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http://dx.doi.org/10.1093/hmg/ddab240DOI Listing
August 2021

Comparison of laparoscopic and open living donor hepatectomy: A meta-analysis.

Medicine (Baltimore) 2021 Aug;100(32):e26708

Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.

Abstract: Laparoscopic donor hepatectomy (LDH), accepted as a minimally invasive approach, has become increasingly popular for living donor liver transplant. However, the outcomes of LDH remain to be fully clarified when compared with open living donor hepatectomy. Thus, our meta-analysis was designed to assess the efficacy of laparoscopic in comparison with conventional open donor hepatectomy.The PubMed, Cochrane, and Embase electronic databases were searched to identify the articles concerning the comparison of the efficacy of laparoscopic versus open surgery in treatment of living donor liver transplantation updated to March, 2020. The main search terms and medical Subject Heading terms were: "living donor," "liver donor," "minimally invasive," "laparoscopic surgery," and "open surgery." After rigorous evaluation on quality, the data was extracted from eligible publications. The outcomes of interest included intraoperative and postoperative results.The inclusion criteria were met by a total of 20 studies. In all, 2001 subjects involving 633 patients who received laparoscopic surgery and 1368 patients who received open surgery were included. According to the pooled result of surgery duration, the laparoscopic surgery was associated with shorter duration of hospital stay (MD = -1.07, 95% CI -1.85 to -0.29; P = .007), less blood loss (MD = -57.57, 95% CI -65.07 to -50.07; P < .00001), and less postoperative complications (OR = 0.61, 95% CI 0.44-0.85; P = .003). And the open donor hepatectomy achieved a trend of shorter operation time (MD = 30.31, 95% CI 13.93-46.69; P = .0003) than laparoscopic group. Similar results were found in terms of ALT (P = .52) as well as the AST (P = .47) peak level between the 2 groups.LDH showed the better perioperative outcomes as compared with open donor hepatectomy. The findings revealed that LDH may be a feasible and safe procedure for the living donor liver transplantation.
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http://dx.doi.org/10.1097/MD.0000000000026708DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8360485PMC
August 2021

Absence of coding somatic single nucleotide variants within well-known candidate genes in late-onset sporadic Alzheimer's Disease based on the analysis of multi-omics data.

Neurobiol Aging 2021 Jul 21. Epub 2021 Jul 21.

Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences; Department of Psychiatry, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China; Department of Psychiatry, SUNY Upstate Medical University, Syracuse, NY, USA; School of Psychology, Shaanxi Normal University, Xi'an, Shaanxi, China. Electronic address:

Somatic mutations arise randomly or are induced by environmental factors, which may increase the risk of Alzheimer's disease (AD). Identifying somatic mutations in sporadic AD (SAD) may provide new insight of the disease. To evaluate the potential contribution of somatic single nucleotide variations (SNVs), particularly that of well-known AD-candidate genes, we investigated sequencing data sets from four platforms: whole-genome sequencing (WGS), deep whole-exome sequencing (WES) on paired brain and liver samples, RNA sequencing (RNA-seq), and single-cell whole-genome sequencing (scWGS) of brain samples from 16 AD patients and 16 non-AD individuals. We found that the average number, mean variant allele fractions (VAFs) and mutational signatures of somatic SNVs have similar distributions between AD brains and non-AD brains. We did not identify any somatic SNVs within coding regions of the APP, PSEN1, PSEN2, nor in APOE. This study shows that somatic SNVs within the coding region of AD-candidate genes are unlikely to be a common causal factor for SAD.
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http://dx.doi.org/10.1016/j.neurobiolaging.2021.07.010DOI Listing
July 2021

Comparative safety and tolerability of approved PARP inhibitors in cancer: A systematic review and network meta-analysis.

Pharmacol Res 2021 Aug 11;172:105808. Epub 2021 Aug 11.

Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China; Research Laboratory of Tumor Epigenetics and Genomics for General Surgery, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu 610041, China. Electronic address:

Background: We aimed to evaluate comparative safety and tolerability of the approved PARP inhibitors in people with cancer.

Methods: Eligible studies included randomized controlled trials comparing an approved PARP inhibitor (fluzoparib, olaparib, rucaparib, niraparib, or talazoparib) with placebo or chemotherapy in cancer patients. Outcomes of interest included: serious adverse event (SAE), discontinuation due to adverse event (AE), interruption of treatment due to AE, dose reduction due to AE, and specific grade 1-5 AEs.

Results: Ten trials including 3763 participants and six treatments (olaparib, rucaparib, niraparib, talazoparib, placebo, and protocol-specified single agent chemotherapy) were identified. SAE and discontinuation of treatment did not differ significantly among the four approved PARP inhibitors. Regarding interruption of treatment and dose reduction due to AE, statistically significant differences and statistically non-significant trend were observed. Talazoparib is associated with a higher risk of interruption of treatment and dose reduction (excluding rucaparib) due to AE as compared with the other drugs. Niraparib showed a trend of lower risk of AE related dose reduction as compared with the other drugs. Furthermore, there were significant differences in specific grade 1-5 AE among the four drugs.

Conclusion: The safety profile of the four approved PARP inhibitors is comparable in terms of SAE and AE-related discontinuation of treatment. Statistically significant differences in the AEs spectrum and AEs related dose interruption and dose reduction demonstrated the prompt identification of AE and dose personalization seem mandatory to obtain maximal benefit from PARP inhibitors.
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http://dx.doi.org/10.1016/j.phrs.2021.105808DOI Listing
August 2021

Homozygous mutations in cause male infertility with oligoasthenoteratozoospermia in humans and mice.

J Med Genet 2021 Aug 4. Epub 2021 Aug 4.

Obstetrics and Gynecology Hospital, NHC Key Laboratory of Reproduction Regulation (Shanghai Institute for Biomedical and Pharmaceutical Technologies), State Key Laboratory of Genetic Engineering at School of Life Sciences, Fudan University, Shanghai, China

Background: Oligoasthenoteratozoospermia is a typical feature of sperm malformations leading to male infertility. Only a few genes have been clearly identified as pathogenic genes of oligoasthenoteratozoospermia.

Methods And Results: Here, we identified a homozygous frameshift variant (c.731dup, p.Asn244Lysfs*3) in , which is preferentially expressed in the human testis, using whole-exome sequencing in a cohort of 100 Chinese men with multiple morphological abnormalities of the sperm flagella (MMAF). In an additional cohort of 167 MMAF-affected men from North Africa, Iran and France, we identified a second subject harbouring a homozygous frameshift variant (c.799_817del, p.Glu267Lysfs*72). Both affected men presented a typical MMAF phenotype with an abnormally low sperm concentration (ie, oligoasthenoteratozoospermia). Transmission electron microscopy analysis of the sperm flagella affected by deficiency further revealed dramatic disorganisation of the axoneme. Immunofluorescence assays of the spermatozoa showed that deficiency resulted in almost absent staining of CCDC34 and intraflagellar transport-B complex-associated proteins (such as IFT20 and IFT52). Furthermore, we generated a mouse frameshift mutant using CRISPR-Cas9 technology. -mutated ( ) male mice were sterile and presented oligoasthenoteratozoospermia with typical MMAF anomalies. Intracytoplasmic sperm injection has good pregnancy outcomes in both humans and mice.

Conclusions: Our findings support that is crucial to the formation of sperm flagella and that biallelic deleterious mutations in / cause male infertility with oligoasthenoteratozoospermia in humans and mice.
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http://dx.doi.org/10.1136/jmedgenet-2021-107919DOI Listing
August 2021

Presence and transmission of mitochondrial heteroplasmic mutations in human populations of European and African ancestry.

Mitochondrion 2021 Jul 21;60:33-42. Epub 2021 Jul 21.

Framingham Heart Study, Framingham, MA 01702, USA; Population Sciences Branch, NHLBI/NIH, Bethesda, MD 20892, USA.

We investigated the concordance of mitochondrial DNA heteroplasmic mutations (heteroplasmies) in 6745 maternal pairs of European (EA, n = 4718 pairs) and African (AA, n = 2027 pairs) Americans in whole blood. Mother-offspring pairs displayed the highest concordance rate, followed by sibling-sibling and more distantly-related maternal pairs. The allele fractions of concordant heteroplasmies exhibited high correlation (R = 0.8) between paired individuals. Discordant heteroplasmies were more likely to be in coding regions, be nonsynonymous or nonsynonymous-deleterious (p < 0.001). The number of deleterious heteroplasmies was significantly correlated with advancing age (20-44, 45-64, and ≥65 years, p-trend = 0.01). One standard deviation increase in heteroplasmic burden (i.e., the number of heteroplasmies carried by an individual) was associated with 0.17 to 0.26 (p < 1e - 23) standard deviation decrease in mtDNA copy number, independent of age. White blood cell count and differential count jointly explained 0.5% to 1.3% (p ≤ 0.001) variance in heteroplasmic burden. A genome-wide association and meta-analysis identified a region at 11p11.12 (top signal rs779031139, p = 2.0e - 18, minor allele frequency = 0.38) associated with the heteroplasmic burden. However, the 11p11.12 region is adjacent to a nuclear mitochondrial DNA (NUMT) corresponding to a 542 bp area of the D-loop. This region was no longer significant after excluding heteroplasmies within the 542 bp from the heteroplasmic burden. The discovery that blood mtDNA heteroplasmies were both inherited and somatic origins and that an increase in heteroplasmic burden was strongly associated with a decrease in average number of mtDNA copy number in blood are important findings to be considered in association studies of mtDNA with disease traits.
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http://dx.doi.org/10.1016/j.mito.2021.07.004DOI Listing
July 2021

Bi-allelic truncating variants in CFAP206 cause male infertility in human and mouse.

Hum Genet 2021 Sep 13;140(9):1367-1377. Epub 2021 Jul 13.

Université Grenoble Alpes, INSERM U1209, CNRS UMR 5309, Institute for Advanced Biosciences, Team Genetics Epigenetics and Therapies of Infertility, 38000, Grenoble, France.

Spermatozoa are polarized cells with a head and a flagellum joined together by the connecting piece. Flagellum integrity is critical for normal sperm function, and flagellum defects consistently lead to male infertility. Multiple morphological abnormalities of the flagella (MMAF) is a distinct sperm phenotype consistently leading to male infertility due to a reduced or absent sperm motility associated with severe morphological and ultrastructural flagellum defects. Despite numerous genes recently described to be recurrently associated with MMAF, more than half of the cases analyzed remain unresolved, suggesting that many yet uncharacterized gene defects account for this phenotype. By performing a retrospective exome analysis of the unsolved cases from our initial cohort of 167 infertile men with a MMAF phenotype, we identified one individual carrying a homozygous frameshift variant in CFAP206, a gene encoding a microtubule-docking adapter for radial spoke and inner dynein arm. Immunostaining experiments in the patient's sperm cells demonstrated the absence of WDR66 and RSPH1 proteins suggesting severe radial spokes and calmodulin and spoke-associated complex defects. Using the CRISPR-Cas9 technique, we generated homozygous Cfap206 knockout (KO) mice which presented with male infertility due to functional, structural and ultrastructural sperm flagellum defects associated with a very low rate of embryo development using ICSI. Overall, we showed that CFAP206 is essential for normal sperm flagellum structure and function in human and mouse and that bi-allelic mutations in CFAP206 cause male infertility in man and mouse by inducing morphological and functional defects of the sperm flagellum that may also cause ICSI failures.
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http://dx.doi.org/10.1007/s00439-021-02313-zDOI Listing
September 2021

Bi-allelic mutations of DNAH10 cause primary male infertility with asthenoteratozoospermia in humans and mice.

Am J Hum Genet 2021 08 7;108(8):1466-1477. Epub 2021 Jul 7.

Institute of Reproductive and Stem Cell Engineering, School of Basic Medical Science, Central South University, Changsha 410000, China; Clinical Research Center for Reproduction and Genetics in Hunan Province, Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha 410000, China. Electronic address:

Multiple morphological abnormalities of the sperm flagella (MMAF)-induced asthenoteratozoospermia is a common cause of male infertility. Previous studies have identified several MMAF-associated genes, highlighting the condition's genetic heterogeneity. To further define the genetic causes underlying MMAF, we performed whole-exome sequencing in a cohort of 643 Chinese MMAF-affected men. Bi-allelic DNAH10 variants were identified in five individuals with MMAF from four unrelated families. These variants were either rare or absent in public population genome databases and were predicted to be deleterious by multiple bioinformatics tools. Morphological and ultrastructural analyses of the spermatozoa obtained from men harboring bi-allelic DNAH10 variants revealed striking flagellar defects with the absence of inner dynein arms (IDAs). DNAH10 encodes an axonemal IDA heavy chain component that is predominantly expressed in the testes. Immunostaining analysis indicated that DNAH10 localized to the entire sperm flagellum of control spermatozoa. In contrast, spermatozoa from the men harboring bi-allelic DNAH10 variants exhibited an absence or markedly reduced staining intensity of DNAH10 and other IDA components, including DNAH2 and DNAH6. Furthermore, the phenotypes were recapitulated in mouse models lacking Dnah10 or expressing a disease-associated variant, confirming the involvement of DNAH10 in human MMAF. Altogether, our findings in humans and mice demonstrate that DNAH10 is essential for sperm flagellar assembly and that deleterious bi-allelic DNAH10 variants can cause male infertility with MMAF. These findings will provide guidance for genetic counseling and insights into the diagnosis of MMAF-associated asthenoteratozoospermia.
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http://dx.doi.org/10.1016/j.ajhg.2021.06.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8387467PMC
August 2021

CFAP65 is required in the acrosome biogenesis and mitochondrial sheath assembly during spermiogenesis.

Hum Mol Genet 2021 Jul 7. Epub 2021 Jul 7.

Institute of Reproductive and Stem Cell Engineering, School of Basic Medicine, Central South University, Changsha 410078, China.

Asthenoteratospermia is a common cause of male infertility. Recent studies have revealed that CFAP65 mutations lead to severe asthenoteratospermia due to acrosome hypoplasia and flagellum malformations. However, the molecular mechanism underlying CFAP65-associated sperm malformation is largely unclear. Here, we initially examined the role of CFAP65 during spermiogenesis using Cfap65 knockout (Cfap65-/-) mice. The results showed that Cfap65-/- male mice exhibited severe asthenoteratospermia characterized by morphologically defective sperm heads and flagella. In Cfap65-/- mouse testes, hyper-constricted sperm heads were apparent in step 9 spermatids accompanied by abnormal manchette development, and acrosome biogenesis was abnormal in the maturation phase. Moreover, subsequent flagellar elongation was also severely affected and characterized by disrupted assembly of the mitochondrial sheath (MS) in Cfap65-/- male mice. Furthermore, the proteomic analysis revealed that the proteostatic system during acrosome formation, manchette organization, and MS assembly was disrupted when CFAP65 was lost. Importantly, endogenous immunoprecipitation and immunostaining experiments revealed that CFAP65 may form a cytoplasmic protein network comprising MNS1, RSPH1, TPPP2, ZPBP1, and SPACA1. Overall, these findings provide insights into the complex molecular mechanisms of spermiogenesis by uncovering the essential roles of CFAP65 during sperm head shaping, acrosome biogenesis, and MS assembly.
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http://dx.doi.org/10.1093/hmg/ddab185DOI Listing
July 2021

Early-life famine exposure and rheumatoid arthritis in Chinese adult populations: a retrospective cohort study.

BMJ Open 2021 07 5;11(7):e043416. Epub 2021 Jul 5.

Vanke School of Public Health, Tsinghua University, Beijing, China

Objective: This study aimed to explore the association between famine exposure in early life and the odds of rheumatoid arthritis (RA) in adulthood.

Design: A population-based retrospective cohort study.

Setting: China.

Participants: A total of 111 706 participants (1775 with RA) born from 1956 to 1964 were selected from the baseline survey of a large cohort in China.

Primary And Secondary Outcome Measures: Four famine exposure groups were generated based on dates of birth, namely prenatal-exposed, infant-exposed, preschool-exposed and non-exposed groups. Logistic regressions were used to explore the association between famine exposure and self-reported RA in adulthood, adjusting for sex, region, monthly income, highest education, alcohol consumption, tobacco use, body mass index (BMI) and metabolic equivalent tasks. Analyses were also performed with stratification for sex (female or male), residing region (urban or rural), famine severity (severe or non-severe) and BMI (≥24 or <24).

Results: The study included 1775 (1.59%) RA cases and 109 931 (98.41%) non-RA controls. Among them, 22 413 (20.06%) were prenatal-exposed, 14 899 (13.34%) were infant-exposed and 34 356 (30.76%) were preschool-exposed. Prenatal exposure to famine was not associated with onset of RA in adulthood. Infant-exposed group and preschool-exposed group had significantly elevated odds of getting RA compared with non-exposed group (infant-exposed: OR=1.44, 95% CI 1.24 to 1.67; preschool-exposed: OR=1.38, 95% CI 1.22 to 1.57, p<0.001), and the relationship was stronger among women, urban residents and participants with BMI ≥24. Similar results were additionally observed when an age-balanced control group was used.

Conclusions: Exposure to the Great Chinese Famine in early life after birth especially in infancy may be associated with a higher risk of RA in adulthood. Strengthening early-life nutrition could be an implication to prevent future RA.
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http://dx.doi.org/10.1136/bmjopen-2020-043416DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8258564PMC
July 2021

Optical Design of Imaging Spectrometer Based on Linear Variable Filter for Nighttime Light Remote Sensing.

Sensors (Basel) 2021 Jun 24;21(13). Epub 2021 Jun 24.

Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.

Nighttime light remote sensing has unique advantages on reflecting human activities, and thus has been used in many fields including estimating population and GDP, analyzing light pollution and monitoring disasters and conflict. However, the existing nighttime light remote sensors have many limitations because they are subject to one or more shortcomings such as coarse spatial resolution, restricted swath width and lack of multi-spectral data. Therefore, we propose an optical system of imaging spectrometer based on linear variable filter. The imaging principle, optical specifications, optical design, imaging performance analysis and tolerance analysis are illustrated. The optical system with a focal length of 100 mm, F-number 4 and 43° field of view in the spectrum range of 400-1000 nm is presented, and excellent image quality is achieved. The system can obtain the multi-spectral images of eight bands with a spatial resolution of 21.5 m and a swath width of 320 km at the altitude of 500 km. Compared with the existing nighttime light remote sensors, our system possesses the advantages of high spatial and high spectral resolution, wide spectrum band and wide swath width simultaneously, greatly making up for the shortage of the present systems. The result of tolerance analysis shows our system satisfy the requirements of fabrication and alignment.
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http://dx.doi.org/10.3390/s21134313DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8271715PMC
June 2021

Novel Mutations in X-Linked, -Induced Asthenoteratozoospermia and Male Infertility.

Cells 2021 Jun 25;10(7). Epub 2021 Jun 25.

Reproductive Medicine Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei 230022, China.

Male infertility is a multifactorial disease with a strong genetic background. Abnormal sperm morphologies have been found to be closely related to male infertility. Here, we conducted whole-exome sequencing in a cohort of 150 Han Chinese men with asthenoteratozoospermia. Two novel hemizygous mutations were identified in , an X-linked gene preferentially expressed in the testis and encoding a deubiquitinating enzyme. These variants are extremely rare in human population genome databases and have been predicted to be deleterious by multiple bioinformatics tools. Hematoxylin-eosin staining and electron microscopy analyses of the spermatozoa from men harboring hemizygous variants showed a highly aberrant morphology and ultrastructure of the sperm heads and flagella. Real-time quantitative PCR and immunoblotting assays revealed obviously reduced levels of mRNA and protein in the spermatozoa from men harboring hemizygous deleterious variants of . Furthermore, intracytoplasmic sperm injections performed on infertile men harboring hemizygous variants achieved satisfactory outcomes. Overall, our study demonstrates that is essential for normal sperm morphogenesis, and hemizygous mutations can induce X-linked asthenoteratozoospermia. These findings will provide effective guidance for the genetic and reproductive counseling of infertile men with asthenoteratozoospermia.
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http://dx.doi.org/10.3390/cells10071594DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8307012PMC
June 2021

Association of Habitual Physical Activity With Home Blood Pressure in the Electronic Framingham Heart Study (eFHS): Cross-sectional Study.

J Med Internet Res 2021 Jun 24;23(6):e25591. Epub 2021 Jun 24.

Department of Medicine, UMass Medical School, Worcester, MA, United States.

Background: When studied in community-based samples, the association of physical activity with blood pressure (BP) remains controversial and is perhaps dependent on the intensity of physical activity. Prior studies have not explored the association of smartwatch-measured physical activity with home BP.

Objective: We aimed to study the association of habitual physical activity with home BP.

Methods: Consenting electronic Framingham Heart Study (eFHS) participants were provided with a study smartwatch (Apple Watch Series 0) and Bluetooth-enabled home BP cuff. Participants were instructed to wear the watch daily and transmit BP values weekly. We measured habitual physical activity as the average daily step count determined by the smartwatch. We estimated the cross-sectional association between physical activity and average home BP using linear mixed effects models adjusting for age, sex, wear time, antihypertensive drug use, and familial structure.

Results: We studied 660 eFHS participants (mean age 53 years, SD 9 years; 387 [58.6%] women; 602 [91.2%] White) who wore the smartwatch 5 or more hours per day for 30 or more days and transmitted three or more BP readings. The mean daily step count was 7595 (SD 2718). The mean home systolic and diastolic BP (mmHg) were 122 (SD 12) and 76 (SD 8). Every 1000 increase in the step count was associated with a 0.49 mmHg lower home systolic BP (P=.004) and 0.36 mmHg lower home diastolic BP (P=.003). The association, however, was attenuated and became statistically nonsignificant with further adjustment for BMI.

Conclusions: In this community-based sample of adults, higher daily habitual physical activity measured by a smartwatch was associated with a moderate, but statistically significant, reduction in home BP. Differences in BMI among study participants accounted for the majority of the observed association.
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http://dx.doi.org/10.2196/25591DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8277303PMC
June 2021

Identification of Novel Biallelic Variants in Female Infertility With Preimplantation Embryonic Lethality.

Front Genet 2021 11;12:666136. Epub 2021 Jun 11.

Reproductive Medicine Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China.

Preimplantation embryonic lethality is a rare cause of primary female infertility. It has been reported that variants in the transducin-like enhancer of split 6 () gene can lead to preimplantation embryonic lethality. However, the incidence of variants in patients with preimplantation embryonic lethality is not fully understood. In this study, we identified four patients carrying novel biallelic variants in a cohort of 28 patients with preimplantation embryonic lethality by whole-exome sequencing and bioinformatics analysis, accounting for 14.29% (4/28) of the cohort. Immunofluorescence showed that the TLE6 levels in oocytes from patients were much lower than in normal control oocytes, suggesting that the variants result in the lower expression of the TLE6 protein in oocytes. In addition, a retrospective analysis showed that the four patients underwent a total of nine failures of fertilization and intracytoplasmic sperm injection attempts, and one of them became pregnant on the first attempt using donated oocytes. Our study extends the genetic spectrum of female infertility caused by variants in and further confirms previously reported findings that TLE6 plays an essential role in early embryonic development. In such case, oocyte donation may be the preferred treatment.
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http://dx.doi.org/10.3389/fgene.2021.666136DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8226231PMC
June 2021

Loss of DRC1 function leads to multiple morphological abnormalities of the sperm flagella and male infertility in human and mouse.

Hum Mol Genet 2021 Jun 24. Epub 2021 Jun 24.

State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, 211166, China.

Motile cilia and flagellar defects can result in primary ciliary dyskinesia (PCD), which is a multisystemic genetic disorder that affects roughly 1:10000 individuals. The nexin-dynein regulatory complex (N-DRC) links neighboring doublet microtubules within flagella, serving as a central regulatory hub for motility in Chlamydomonas. Herein, we identified two homozygous DRC1 variants in human patients that were associated with multiple morphological abnormalities of the sperm flagella (MMAF) and male infertility. Drc1-/-, Drc1R554X/R554X, and Drc1W244X/W244X mice on the C57BL/6 background suffered from prepubertal mortality. However, when the ICR background was introduced, some of these mice were able to survive and recapitulate the MMAF phenotypes detected in human patients. By analyzing these animals, we determined that DRC1 is an essential regulator of N-DRC assembly in cilia and flagella. When DRC1 is absent, this results in the shortening of cilia and consequent impairment of their motility. Damage associated with DRC1 deficiency in sperm flagella was more pronounced than in cilia, as manifested by complete axoneme structural disorder in addition to the loss of the DRC structure. Together, these findings suggest that DRC1 is required for the structural stability of flagella but not cilia, emphasizing the key role of this protein in mammalian species.
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http://dx.doi.org/10.1093/hmg/ddab171DOI Listing
June 2021

Associations of Alcohol Consumption with Cardiovascular Disease-Related Proteomic Biomarkers: The Framingham Heart Study.

J Nutr 2021 Sep;151(9):2574-2582

Department of Biostatistics, School of Public Health, Boston University, Boston, MA, USA.

Background: Alcohol consumption and cardiovascular disease (CVD) have a complex relation.

Objectives: We examined the associations between alcohol consumption, fasting plasma proteins, and CVD risk.

Methods: We performed cross-sectional association analyses of alcohol consumption with 71 CVD-related plasma proteins, and also performed prospective association analyses of alcohol consumption and protein concentrations with 3 CVD risk factors (obesity, hypertension, and diabetes) in 6745 Framingham Heart Study (FHS) participants (mean age 49 y; 53% women).

Results: A unit increase in log10 transformed alcohol consumption (g/d) was associated with an increased risk of hypertension (HR = 1.14; 95% CI: 1.04, 1.26; P = 0.007), and decreased risks of obesity (HR = 0.80; 95% CI: 0.71, 0.91; P = 4.6 × 10-4) and diabetes (HR: 0.68; 95% CI: 0.58, 0.80; P = 5.1 × 10-6) in a median of 13-y (interquartile = 7, 14) of follow-up. We identified 43 alcohol-associated proteins in a discovery sample (n = 4348, false discovery rate <0.05) and 20 of them were significant (P <0.05/43) in an independent validation sample (n = 2397). Eighteen of the 20 proteins were inversely associated with alcohol consumption. Four of the 20 proteins demonstrated 3-way associations, as expected, with alcohol consumption and CVD risk factors. For example, a greater concentration of APOA1 was associated with higher alcohol consumption (P = 1.2 × 10-65), and it was also associated with a lower risk of diabetes (P = 8.5 × 10-6). However, several others showed unexpected 3-way associations.

Conclusions: We identified 20 alcohol-associated proteins in 6745 FHS samples. These alcohol-associated proteins demonstrated complex relations with the 3 CVD risk factors. Future studies with integration of more proteomic markers and larger sample size are warranted to unravel the complex relation between alcohol consumption and CVD risk.
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http://dx.doi.org/10.1093/jn/nxab186DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8417922PMC
September 2021

Epidemiological and clinical characteristics of stone composition: a single-center retrospective study.

Urolithiasis 2021 May 31. Epub 2021 May 31.

Department of Urology, The Second Hospital of Tianjin Medical University, 23 Pingjiang Road, Hexi District, Tianjin, People's Republic of China.

The aim of the study was to investigate the epidemiological characteristics of stone components in patients with urolithiasis and analyze the associations between stone components with patients' clinical characteristics. A total of 7126 patients with urolithiasis between July 2005 and June 2020 were retrospectively analyzed. In this research, calcium oxalate stones (74.6%) accounted for the highest proportion, followed by infection stones (11.8%), uric acid (10.6%), brushite (2.0%), and others (1.1%). The change in trend in the composition of urinary stones revealed that the proportion of uric acid declined steadily, while the content of infection stones increased gradually over 15 years. The results also suggested that stone composition was significantly associated with PM2.5, gender, age, BMI, diabetes, hypertension, CCVD, alcohol consumption, albumin, creatinine, WBCHP, leukocyte, urine pH, nitrite and urine culture (P < 0.05). However, there was no significant correlation between stone composition with smoking, WBC and NEU% (P > 0.05). Our study concluded that calcium oxalate represented the highest proportion, followed by infection stones, uric acid, brushite, and others. The proportion of uric acid declined steadily, while the infection stones increased gradually. Furthermore, the factors influencing the formation of urinary calculi are PM2.5, gender, age, BMI, diabetes, hypertension, CCVD, alcohol consumption, albumin, creatinine, WBCHP, leukocyte, urine pH, nitrite and urine culture. Collectively, these results may provide clues to establish effective prevention and management strategies for urinary calculi.
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http://dx.doi.org/10.1007/s00240-021-01274-2DOI Listing
May 2021

Drug Response-Related DNA Methylation Changes in Schizophrenia, Bipolar Disorder, and Major Depressive Disorder.

Front Neurosci 2021 13;15:674273. Epub 2021 May 13.

Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Department of Psychiatry, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China.

Pharmacotherapy is the most common treatment for schizophrenia (SCZ), bipolar disorder (BD), and major depressive disorder (MDD). Pharmacogenetic studies have achieved results with limited clinical utility. DNA methylation (DNAm), an epigenetic modification, has been proposed to be involved in both the pathology and drug treatment of these disorders. Emerging data indicates that DNAm could be used as a predictor of drug response for psychiatric disorders. In this study, we performed a systematic review to evaluate the reproducibility of published changes of drug response-related DNAm in SCZ, BD and MDD. A total of 37 publications were included. Since the studies involved patients of different treatment stages, we partitioned them into three groups based on their primary focuses: (1) medication-induced DNAm changes ( = 8); (2) the relationship between DNAm and clinical improvement ( = 24); and (3) comparison of DNAm status across different medications ( = 14). We found that only BDNF was consistent with the DNAm changes detected in four independent studies for MDD. It was positively correlated with clinical improvement in MDD. To develop better predictive DNAm factors for drug response, we also discussed future research strategies, including experimental, analytical procedures and statistical criteria. Our review shows promising possibilities for using BDNF DNAm as a predictor of antidepressant treatment response for MDD, while more pharmacoepigenetic studies are needed for treatments of various diseases. Future research should take advantage of a system-wide analysis with a strict and standard analytical procedure.
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http://dx.doi.org/10.3389/fnins.2021.674273DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8155631PMC
May 2021

Identifying nootropic drug targets via large-scale cognitive GWAS and transcriptomics.

Neuropsychopharmacology 2021 09 25;46(10):1788-1801. Epub 2021 May 25.

Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.

Broad-based cognitive deficits are an enduring and disabling symptom for many patients with severe mental illness, and these impairments are inadequately addressed by current medications. While novel drug targets for schizophrenia and depression have emerged from recent large-scale genome-wide association studies (GWAS) of these psychiatric disorders, GWAS of general cognitive ability can suggest potential targets for nootropic drug repurposing. Here, we (1) meta-analyze results from two recent cognitive GWAS to further enhance power for locus discovery; (2) employ several complementary transcriptomic methods to identify genes in these loci that are credibly associated with cognition; and (3) further annotate the resulting genes using multiple chemoinformatic databases to identify "druggable" targets. Using our meta-analytic data set (N = 373,617), we identified 241 independent cognition-associated loci (29 novel), and 76 genes were identified by 2 or more methods of gene identification. Actin and chromatin binding gene sets were identified as novel pathways that could be targeted via drug repurposing. Leveraging our transcriptomic and chemoinformatic databases, we identified 16 putative genes targeted by existing drugs potentially available for cognitive repurposing.
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http://dx.doi.org/10.1038/s41386-021-01023-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8357785PMC
September 2021

Cross-Disorder Analysis of De Novo Mutations in Neuropsychiatric Disorders.

J Autism Dev Disord 2021 May 10. Epub 2021 May 10.

National Clinical Research Center for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Xiangya Road, Kaifu District, Changsha, 410013, Hunan, China.

The clinical similarity among different neuropsychiatric disorders (NPDs) suggested a shared genetic basis. We catalogued 23,109 coding de novo mutations (DNMs) from 6511 patients with autism spectrum disorder (ASD), 4,293 undiagnosed developmental disorder (UDD), 933 epileptic encephalopathy (EE), 1022 intellectual disability (ID), 1094 schizophrenia (SCZ), and 3391 controls. We evaluated that putative functional DNMs contribute to 38.11%, 34.40%, 33.31%, 10.98% and 6.91% of patients with ID, EE, UDD, ASD and SCZ, respectively. Consistent with phenotype similarity and heterogeneity in different NPDs, they show different degree of genetic association. Cross-disorder analysis of DNMs prioritized 321 candidate genes (FDR < 0.05) and showed that genes shared in more disorders were more likely to exhibited specific expression pattern, functional pathway, genetic convergence, and genetic intolerance.
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http://dx.doi.org/10.1007/s10803-021-05031-7DOI Listing
May 2021

Review of multi-omics data resources and integrative analysis for human brain disorders.

Brief Funct Genomics 2021 07;20(4):223-234

Department of Biostatistics, Virginia Commonwealth University.

In the last decade, massive omics datasets have been generated for human brain research. It is evolving so fast that a timely update is urgently needed. In this review, we summarize the main multi-omics data resources for the human brains of both healthy controls and neuropsychiatric disorders, including schizophrenia, autism, bipolar disorder, Alzheimer's disease, Parkinson's disease, progressive supranuclear palsy, etc. We also review the recent development of single-cell omics in brain research, such as single-nucleus RNA-seq, single-cell ATAC-seq and spatial transcriptomics. We further investigate the integrative multi-omics analysis methods for both tissue and single-cell data. Finally, we discuss the limitations and future directions of the multi-omics study of human brain disorders.
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http://dx.doi.org/10.1093/bfgp/elab024DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8287916PMC
July 2021

Hyaluronic acid facilitates bone repair effects of calcium phosphate cement by accelerating osteogenic expression.

Bioact Mater 2021 Nov 8;6(11):3801-3811. Epub 2021 Apr 8.

Center for Human Tissues and Organs Degeneration, Shenzhen Institutes of Advanced Technology, Chinese Academy of Science, Shenzhen, 518055, PR China.

Calcium phosphate cements (CPC) are widely anticipated to be an optimum bone repair substitute due to its satisfied biocompatibility and degradability, suitable to be used in minimally invasive treatment of bone defects. However the clinical application of CPC is still not satisfied by its poor cohesiveness and mechanical properties, in particular its osteoinductivity. Hyaluronic acid reinforced calcium phosphate cements (HA/CPC) showed extroadinary potential not only enhancing the compressive strength of the cements but also significantly increasing its osteoinductivity. In our study, the compressive strength of HA/CPC increased significantly when the cement was added 1% hyaluronic acid (denoted as 1-HA/CPC). In the meantime, hyaluronic acid obviously promoted ALP activity, osteogenic related protein and mRNA expression of hBMSCs (human bone marrow mesenchymal stem cells) , cement group of HA/CPC with 4% hyaluronic acid adding (denoted as 4-HA/CPC) showed optimal enhancement in hBMSCs differentiation. After being implanted in rat tibial defects, 4-HA/CPC group exhibited better bone repair ability and bone growth promoting factors, comparing to pure CPC and 1-HA/CPC groups. The underlying biological mechanism of this stimulation for HA/CPC may be on account of higher osteogenic promoting factors secretion and osteogenic genes expression with hyaluronic acid incorporation. These results indicate that hyaluronic acid is a highly anticipated additive to improve physicochemical properties and osteoinductivity performance of CPCs for minimally invasive healing of bone defects.
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http://dx.doi.org/10.1016/j.bioactmat.2021.03.028DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8058907PMC
November 2021

Biomimetic hydroxyapate/polydopamine composites with good biocompatibility and efficiency for uncontrolled bleeding.

J Biomed Mater Res B Appl Biomater 2021 Apr 13. Epub 2021 Apr 13.

State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian, P.R. China.

Uncontrolled bleeding is thought to be the most deadly cause of pre-hospital, traffic, and military accidents death. However, the popular commercial hemostats can only realize the hemostasis of mild bleeding. Therefore, we developed polydopamine (PDA) composite materials (PMs), which applied hydroxyapatite as the parent body. The PMs were produced via lyophilization and functionalized with amino, phenol hydroxyls groups, which endowed hydrophobicity to materials. This ensured a high aggregation ability of blood cells to the PMs and they were tested to be as high as 300% compared with the negative control group. The clotting time was shortened to 79.7% compared with the usually used commercial hemostat (Celox) in the test of in vitro hemostasis. Through the results of PT and APTT tests, blood coagulation index test, and the analysis of intracellular Ca activation, we further understood the mechanism of the hemostasis of the materials, which explained the low blood loss and quick coagulation time of the PM hemostats in detail. Besides, the low hemolysis and cytotoxicity of the PMs suggested the good biocompatibility of the hemostats, which was further proved by the regular morphology maintained by erythrocytes in the hemolysis tests. The study of nanoscale composites led the research for the methods of hemostasis.
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http://dx.doi.org/10.1002/jbm.b.34849DOI Listing
April 2021

Agonal Factors Distort Gene-Expression Patterns in Human Postmortem Brains.

Front Neurosci 2021 25;15:614142. Epub 2021 Mar 25.

Center for Medical Genetics, Department of Psychiatry, School of Life Sciences, National Clinical Research Center on Mental Disorders, The Second Xiangya Hospital, Central South University, Changsha, China.

Agonal factors, the conditions that occur just prior to death, can impact the molecular quality of postmortem brains, influencing gene expression results. Our study used gene expression data of 262 samples from ROSMAP with the detailed terminal state recorded for each donor, such as fever, infection, and unconsciousness. Fever and infection were the primary contributors to brain gene expression changes, brain cell-type-specific gene expression, and cell proportion changes. Furthermore, we also found that previous studies of gene expression in postmortem brains were confounded by agonal factors. Therefore, correction for agonal factors is important in the step of data preprocessing. Our analyses revealed fever and infection contributing to gene expression changes in postmortem brains and emphasized the necessity of study designs that document and account for agonal factors.
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http://dx.doi.org/10.3389/fnins.2021.614142DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8027124PMC
March 2021

Mid- to Late- Life Body Mass Index and Dementia Risk: 38 Years of Follow-up of the Framingham Study.

Am J Epidemiol 2021 Apr 8. Epub 2021 Apr 8.

Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA, USA.

Growing evidence relates Body Mass index (BMI) to poorer health outcomes; however, results across studies associating BMI and dementia are conflicting. A total of 3632 Framingham Offspring participants aged 20 to 60 years at their second health exam (1979-1982) were included in this study with 190 cases of incident dementia identified by 2017. Cox proportional hazards regression models were performed to investigate the association of BMI at each of their 8 exams as a baseline for dementia risk, and the associations between obesity and dementia across age groups. Spline models were fitted to investigate non-linear associations between BMI and dementia. Each 1 kg/m2 increase in BMI at 40-49 years was associated with higher risk of dementia, but lower risk after 70 years. Obesity at 40-49 years was associated with higher risk of dementia. Overall, the relationship between BMI and dementia risk was heterogeneous across the adult age range. Monitoring BMI at different age may mediate risk for dementia across an individual's lifetime.
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http://dx.doi.org/10.1093/aje/kwab096DOI Listing
April 2021

Au et al. Response to Body mass index and risk of dementia- potential explanations for lifecourse differences in risk estimates and future research directions.

Am J Epidemiol 2021 Apr 8. Epub 2021 Apr 8.

Framingham Heart Study, Boston University School of Medicine, Boston, MA, USA.

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http://dx.doi.org/10.1093/aje/kwab097DOI Listing
April 2021

Snapshot Imaging Spectrometer Based on Pixel-Level Filter Array (PFA).

Sensors (Basel) 2021 Mar 25;21(7). Epub 2021 Mar 25.

Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.

Snapshot spectral imaging technology plays an important role in many fields. However, most existing snapshot imaging spectrometers have the shortcomings of a large volume or heavy computational burden. In this paper, we present a novel snapshot imaging spectrometer based on the pixel-level filter array (PFA), which can simultaneously obtain both spectral and spatial information. The system is composed of a fore-optics, a PFA, a relay lens, and a monochromatic sensor. The incoming light first forms an intermediate image on the PFA through the fore-optics. Then, the relay lens reimages the spectral images on the PFA onto the monochromatic sensor. Through the use of the PFA, we can capture a three-dimensional (spatial coordinates and wavelength) datacube in a single exposure. Compared with existing technologies, our system possesses the advantages of a simple implementation, low cost, compact structure, and high energy efficiency by removing stacked dispersive or interferometric elements. Moreover, the characteristic of the direct imaging mode ensures the low computational burden of the system, thus shortening the imaging time. The principle and design of the system are described in detail. An experimental prototype is built and field experiments are carried out to verify the feasibility of the proposed scheme.
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http://dx.doi.org/10.3390/s21072289DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8037454PMC
March 2021

The Instrument Design of Lightweight and Large Field of View High-Resolution Hyperspectral Camera.

Sensors (Basel) 2021 Mar 24;21(7). Epub 2021 Mar 24.

Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.

The design of compact hyperspectral cameras with high ground resolution and large field of view (FOV) is a challenging problem in the field of remote sensing. In this paper, the time-delayed integration (TDI) of the digital domain is applied to solve the issue of insufficient light energy brought by high spatial resolution, and a hyperspectral camera with linear variable filters suitable for digital domain TDI technology is further designed. The camera has a wavelength range of 450-950 nm, with an average spectral resolution of 10.2 nm. The paper also analyzed the effects of digital domain TDI on the signal-noise ratio (SNR) and the spectral resolution. During its working in orbits, we have obtained high-SNR images with a swath width of 150 km, and a ground sample distance (GSD) of 10 m @ 500 km. The design of the hyperspectral camera has an improved spatial resolution while reducing the cost.
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http://dx.doi.org/10.3390/s21072276DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8037560PMC
March 2021
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