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1.
Histol Histopathol ; : 18752, 2024 Apr 22.
Article in English | MEDLINE | ID: mdl-38716745

ABSTRACT

BACKGROUND: This study investigates the association between NAT10 expression and clinical parameters while assessing prognostic outcomes in esophageal squamous cell carcinoma (ESCC) patients. Furthermore, the study seeks to elucidate the functional role of NAT10 in neoplastic cell proliferation and apoptosis. MATERIALS AND METHODS: NAT10 expression was assessed in ESCC tissue microarrays through immunohistochemistry (IHC) tests. We employed SPSS software to analyze the correlation between NAT10 staining data, clinical indicators, and their implications for patient prognosis. Small interference RNA (siRNA) was utilized to inhibit NAT10 expression in two esophageal cancer cell lines, TE-1 and KYSE150. Subsequently, we meticulously quantified and compared cellular proliferation and apoptotic ratios among experimental groups. NAT10, Ki67, and Caspase3 expression levels in different groups were evaluated using quantitative polymerase chain reaction (qPCR) and Western blot (WB) assays. Statistical analyses were conducted using GraphPad Prism software, with significance at p<0.05. RESULTS: Our findings indicate that NAT10 is overexpressed in ESCC tissues and exhibits a significant correlation with tumor diameter and overall patient survival. Decreasing NAT10 expression led to the inhibition of tumor cell proliferation and the promotion of apoptosis. Furthermore, siRNA-mediated NAT10 inhibition resulted in the downregulation of Ki67 expression and the concomitant upregulation of Caspase3. CONCLUSION: The observed overexpression of NAT10 in ESCC tissues is associated with larger tumor diameters and reduced patient survival. NAT10 appears to play a pivotal role in the progression of esophageal cancer by influencing cell proliferation and apoptosis. These findings suggest potential clinical implications, with Ki67 and Caspase3 potentially participating in this intricate molecular biological process.

2.
Sci Transl Med ; 16(747): eadl1722, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38748773

ABSTRACT

The evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) requires ongoing monitoring to judge the ability of newly arising variants to escape the immune response. A surveillance system necessitates an understanding of differences in neutralization titers measured in different assays and using human and animal serum samples. We compared 18 datasets generated using human, hamster, and mouse serum and six different neutralization assays. Datasets using animal model serum samples showed higher titer magnitudes than datasets using human serum samples in this comparison. Fold change in neutralization of variants compared to ancestral SARS-CoV-2, immunodominance patterns, and antigenic maps were similar among serum samples and assays. Most assays yielded consistent results, except for differences in fold change in cytopathic effect assays. Hamster serum samples were a consistent surrogate for human first-infection serum samples. These results inform the transition of surveillance of SARS-CoV-2 antigenic variation from dependence on human first-infection serum samples to the utilization of serum samples from animal models.


Subject(s)
Antibodies, Neutralizing , Antibodies, Viral , COVID-19 , Neutralization Tests , SARS-CoV-2 , Animals , Humans , SARS-CoV-2/immunology , COVID-19/immunology , COVID-19/blood , COVID-19/virology , Mice , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Cricetinae , Antibodies, Viral/blood , Antibodies, Viral/immunology , Disease Models, Animal
3.
Res Sq ; 2024 Apr 08.
Article in English | MEDLINE | ID: mdl-38659814

ABSTRACT

Diverse and rapidly mutating viruses pose challenges to immunogen and vaccine design. In this study, we evaluated the ability of memory B-cells obtained from two independent NHP trials to cross-react with individual HIV-1 vaccine components of two different multivalent immunization strategies. We demonstrated that while an HIV-1 Env multiclade, multivalent immunization regimen resulted in a dominant memory B-cell response that converged toward shared epitopes, in a sequential immunization with clonally-related non-stabilized gp140 HIV-1 Envs followed by SOSIP-stabilized gp140 trimers, the change in immunogen format resulted in repriming of the B-cell response.

4.
Open Forum Infect Dis ; 11(2): ofad673, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38379566

ABSTRACT

We evaluated the immunologic response to a novel vaccine regimen that included 2 doses of NVX-CoV2373 (Novavax) followed by 1 dose of BNT162b2 (Pfizer-BioNTech) monovalent booster vaccine. A durable neutralizing antibody response to Omicron BA.4/BA.5 and BA.1 variants was observed at month 6 after the booster, while immune escape was noted for the XBB.1.5 variant.

5.
Elife ; 122024 Feb 22.
Article in English | MEDLINE | ID: mdl-38385642

ABSTRACT

CD4 T follicular helper cells (Tfh) are essential for establishing serological memory and have distinct helper attributes that impact both the quantity and quality of the antibody response. Insights into Tfh subsets that promote antibody persistence and functional capacity can critically inform vaccine design. Based on the Tfh profiles evoked by the live attenuated measles virus vaccine, renowned for its ability to establish durable humoral immunity, we investigated the potential of a Tfh1/17 recall response during the boost phase to enhance persistence of HIV-1 Envelope (Env) antibodies in rhesus macaques. Using a DNA-prime encoding gp160 antigen and Tfh polarizing cytokines (interferon protein-10 (IP-10) and interleukin-6 (IL-6)), followed by a gp140 protein boost formulated in a cationic liposome-based adjuvant (CAF01), we successfully generated germinal center (GC) Tfh1/17 cells. In contrast, a similar DNA-prime (including IP-10) followed by gp140 formulated with monophosphoryl lipid A (MPLA) +QS-21 adjuvant predominantly induced GC Tfh1 cells. While the generation of GC Tfh1/17 cells with CAF01 and GC Tfh1 cells with MPLA +QS-21 induced comparable peak Env antibodies, the latter group demonstrated significantly greater antibody concentrations at week 8 after final immunization which persisted up to 30 weeks (gp140 IgG ng/ml- MPLA; 5500; CAF01, 2155; p<0.05). Notably, interferon γ+Env-specific Tfh responses were consistently higher with gp140 in MPLA +QS-21 and positively correlated with Env antibody persistence. These findings suggest that vaccine platforms maximizing GC Tfh1 induction promote persistent Env antibodies, important for protective immunity against HIV.


Subject(s)
AIDS Vaccines , HIV-1 , Animals , Macaca mulatta , Chemokine CXCL10 , HIV Antibodies , DNA
6.
J Virol ; 98(1): e0147823, 2024 Jan 23.
Article in English | MEDLINE | ID: mdl-38085509

ABSTRACT

Consistent elicitation of serum antibody responses that neutralize diverse clades of HIV-1 remains a primary goal of HIV-1 vaccine research. Prior work has defined key features of soluble HIV-1 Envelope (Env) immunogen cocktails that influence the neutralization breadth and potency of multivalent vaccine-elicited antibody responses including the number of Env strains in the regimen. We designed immunization groups that consisted of different numbers of SOSIP Env strains to be used in a cocktail immunization strategy: the smallest cocktail (group 2) consisted of a set of two Env strains, which were a subset of the three Env strains that made up group 3, which, in turn, were a subset of the six Env strains that made up group 4. Serum neutralizing titers were modestly broader in guinea pigs that were immunized with a cocktail of three Envs compared to cocktails of two and six, suggesting that multivalent Env immunization could provide a benefit but may be detrimental when the cocktail size is too large. We then adapted the LIBRA-seq platform for antibody discovery to be compatible with guinea pigs, and isolated several tier 2 neutralizing monoclonal antibodies. Three antibodies isolated from two separate guinea pigs were similar in their gene usage and CDR3s, establishing evidence for a guinea pig public clonotype elicited through vaccination. Taken together, this work investigated multivalent HIV-1 Env immunization strategies and provides a novel methodology for screening guinea pig B cell receptor antigen specificity at a high-throughput level using LIBRA-seq.IMPORTANCEMultivalent vaccination with soluble Env immunogens is at the forefront of HIV-1 vaccination strategies but little is known about the influence of the number of Env strains included in vaccine cocktails. Our results suggest that adding more strains is sometimes beneficial but may be detrimental when the number of strains is too high. In addition, we adapted the LIBRA-seq platform to be compatible with guinea pig samples and isolated several tier 2 neutralizing monoclonal antibodies, some of which share V and J gene usage and >70% CDR3 identity, thus establishing the existence of public clonotypes in guinea pigs elicited through vaccination.


Subject(s)
AIDS Vaccines , Antibody Formation , HIV-1 , Animals , Guinea Pigs , AIDS Vaccines/immunology , Antibodies, Monoclonal , Antibodies, Neutralizing , env Gene Products, Human Immunodeficiency Virus/genetics , HIV Antibodies , HIV Infections/immunology , HIV-1/genetics
7.
Arch Gerontol Geriatr ; 117: 105248, 2024 02.
Article in English | MEDLINE | ID: mdl-37897854

ABSTRACT

BACKGROUND: The Asian Working Group for Sarcopenia (AWGS) introduced the concept of "possible sarcopenia" in 2019. However, the association between possible sarcopenia and hip fracture is not well characterized. Hence, we conducted a study to explore this association in older Chinese adults. METHODS: This was a population-based cohort study based on nationally representative data from the China Health and Retirement Longitudinal Study. Individuals aged ≥60 years with no history of hip fracture at baseline (2011-2012) were included and followed up until September 2018. Possible sarcopenia was defined based on the AWGS 2019 criteria during the study period, and the occurrence of hip fractures was monitored. The association between possible sarcopenia and hip fractures was assessed using Cox proportional hazards regression models. RESULTS: A total of 4,011 participants were included, of whom 44.8 % had possible sarcopenia. During the 7-year follow-up, 197 individuals experienced hip fractures. Individuals with possible sarcopenia had a significantly higher risk of hip fractures than those without possible sarcopenia (hazard ratio: 2.00, 95 % confidence interval: 1.46-2.75; P < 0.001). The association was consistently observed across various subgroups based on age, sex, and overweight status. CONCLUSIONS: This study identified possible sarcopenia as a significant risk factor for hip fractures in older Chinese adults. These findings underscore the importance of addressing possible sarcopenia as a preventive measure to reduce the incidence of hip fractures.


Subject(s)
Hip Fractures , Sarcopenia , Humans , Middle Aged , Aged , Sarcopenia/complications , Sarcopenia/epidemiology , Longitudinal Studies , Cohort Studies , Hip Fractures/epidemiology , Risk Factors , China/epidemiology
8.
Nat Commun ; 14(1): 7107, 2023 11 04.
Article in English | MEDLINE | ID: mdl-37925510

ABSTRACT

Adjuvants and antigen delivery kinetics can profoundly influence B cell responses and should be critically considered in rational vaccine design, particularly for difficult neutralizing antibody targets such as human immunodeficiency virus (HIV). Antigen kinetics can change depending on the delivery method. To promote extended immunogen bioavailability and to present antigen in a multivalent form, native-HIV Env trimers are modified with short phosphoserine peptide linkers that promote tight binding to aluminum hydroxide (pSer:alum). Here we explore the use of a combined adjuvant approach that incorporates pSer:alum-mediated antigen delivery with potent adjuvants (SMNP, 3M-052) in an extensive head-to-head comparison study with conventional alum to assess germinal center (GC) and humoral immune responses. Priming with pSer:alum plus SMNP induces additive effects that enhance the magnitude and persistence of GCs, which correlate with better GC-TFH cell help. Autologous HIV-neutralizing antibody titers are improved in SMNP-immunized animals after two immunizations. Over 9 months after priming immunization of pSer:alum with either SMNP or 3M-052, robust Env-specific bone marrow plasma cells (BM BPC) are observed. Furthermore, pSer-modification of Env trimer reduce targeting towards immunodominant non-neutralizing epitopes. The study shows that a combined adjuvant approach can augment humoral immunity by modulating immunodominance and shows promise for clinical translation.


Subject(s)
HIV Infections , Immunity, Humoral , Animals , Germinal Center , Adjuvants, Immunologic/pharmacology , Antigens , Primates , Antibodies, Neutralizing , HIV Antibodies , env Gene Products, Human Immunodeficiency Virus
10.
Vaccines (Basel) ; 11(11)2023 Oct 30.
Article in English | MEDLINE | ID: mdl-38005994

ABSTRACT

At the heart of the DNA/ALVAC/gp120/alum vaccine's efficacy in the absence of neutralizing antibodies is a delicate balance of pro- and anti-inflammatory immune responses that effectively decreases the risk of SIVmac251 acquisition in macaques. Vaccine efficacy is linked to antibodies recognizing the V2 helical conformation, DC-10 tolerogenic dendritic cells eliciting the clearance of apoptotic cells via efferocytosis, and CCR5 downregulation on vaccine-induced gut homing CD4+ cells. RAS activation is also linked to vaccine efficacy, which prompted the testing of IGF-1, a potent inducer of RAS activation with vaccination. We found that IGF-1 changed the hierarchy of V1/V2 epitope recognition and decreased both ADCC specific for helical V2 and efferocytosis. Remarkably, IGF-1 also reduced the expression of CCR5 on vaccine-induced CD4+ gut-homing T-cells, compensating for its negative effect on ADCC and efferocytosis and resulting in equivalent vaccine efficacy (71% with IGF-1 and 69% without).

11.
bioRxiv ; 2023 Nov 11.
Article in English | MEDLINE | ID: mdl-37986885

ABSTRACT

A vaccine that can achieve protective immunity prior to sexual debut is critical to prevent the estimated 410,000 new HIV infections that occur yearly in adolescents. As children living with HIV can make broadly neutralizing antibody (bnAb) responses in plasma at a faster rate than adults, early childhood is an opportune window for implementation of a multi-dose HIV immunization strategy to elicit protective immunity prior to adolescence. Therefore, the goal of our study was to assess the ability of a B cell lineage-designed HIV envelope SOSIP to induce bnAbs in early life. Infant rhesus macaques (RMs) received either BG505 SOSIP or the germline-targeting BG505 GT1.1 SOSIP (n=5/group) with the 3M-052-SE adjuvant at 0, 6, and 12 weeks of age. All infant RMs were then boosted with the BG505 SOSIP at weeks 26, 52 and 78, mimicking a pediatric immunization schedule of multiple vaccine boosts within the first two years of life. Both immunization strategies induced durable, high magnitude binding antibodies and plasma autologous virus neutralization that primarily targeted the CD4-binding site (CD4bs) or C3/465 epitope. Notably, three BG505 GT1.1-immunized infants exhibited a plasma HIV neutralization signature reflective of VRC01-like CD4bs bnAb precursor development and heterologous virus neutralization. Finally, infant RMs developed precursor bnAb responses at a similar frequency to that of adult RMs receiving a similar immunization strategy. Thus, a multi-dose immunization regimen with bnAb lineage designed SOSIPs is a promising strategy for inducing protective HIV bnAb responses in childhood prior to adolescence when sexual HIV exposure risk begins.

12.
bioRxiv ; 2023 Sep 27.
Article in English | MEDLINE | ID: mdl-37808679

ABSTRACT

The antigenic evolution of SARS-CoV-2 requires ongoing monitoring to judge the immune escape of newly arising variants. A surveillance system necessitates an understanding of differences in neutralization titers measured in different assays and using human and animal sera. We compared 18 datasets generated using human, hamster, and mouse sera, and six different neutralization assays. Titer magnitude was lowest in human, intermediate in hamster, and highest in mouse sera. Fold change, immunodominance patterns and antigenic maps were similar among sera. Most assays yielded similar results, except for differences in fold change in cytopathic effect assays. Not enough data was available for conclusively judging mouse sera, but hamster sera were a consistent surrogate for human first-infection sera.

13.
Front Immunol ; 14: 1271686, 2023.
Article in English | MEDLINE | ID: mdl-37854587

ABSTRACT

Introduction: Neutralizing antibodies (Abs) are one of the immune components required to protect against viral infections. However, developing vaccines capable of eliciting neutralizing Abs effective against a broad array of HIV-1 isolates has been an arduous challenge. Objective: This study sought to test vaccines aimed to induce Abs against neutralizing epitopes at the V1V2 apex of HIV-1 envelope (Env). Methods: Four groups of rabbits received a DNA vaccine expressing the V1V2 domain of the CRF01_AE A244 strain on a trimeric 2J9C scaffold (V1V2-2J9C) along with a protein vaccine consisting of an uncleaved prefusion-optimized A244 Env trimer with V3 truncation (UFO-BG.ΔV3) or a V1V2-2J9C protein and their respective immune complexes (ICs). These IC vaccines were made using 2158, a V1V2-specific monoclonal Ab (mAb), which binds the V2i epitope in the underbelly region of V1V2 while allosterically promoting the binding of broadly neutralizing mAb PG9 to its V2 apex epitope in vitro. Results: Rabbit groups immunized with the DNA vaccine and uncomplexed or complexed UFO-BG.ΔV3 proteins (DNA/UFO-UC or IC) displayed similar profiles of Env- and V1V2-binding Abs but differed from the rabbits receiving the DNA vaccine and uncomplexed or complexed V1V2-2J9C proteins (DNA/V1V2-UC or IC), which generated more cross-reactive V1V2 Abs without detectable binding to gp120 or gp140 Env. Notably, the DNA/UFO-UC vaccine elicited neutralizing Abs against some heterologous tier 1 and tier 2 viruses from different clades, albeit at low titers and only in a fraction of animals, whereas the DNA/V1V2-UC or IC vaccines did not. In comparison with the DNA/UFO-UC group, the DNA/UFO-IC group showed a trend of higher neutralization against TH023.6 and a greater potency of V1V2-specific Ab-dependent cellular phagocytosis (ADCP) but failed to neutralize heterologous viruses. Conclusion: These data demonstrate the capacity of V1V2-2J9C-encoding DNA vaccine in combination with UFO-BG.ΔV3, but not V1V2-2J9C, protein vaccines, to elicit homologous and heterologous neutralizing activities in rabbits. The elicitation of neutralizing and ADCP activities was modulated by delivery of UFO-BG.ΔV3 complexed with V2i mAb 2158.


Subject(s)
HIV Infections , HIV Seropositivity , HIV-1 , Vaccines, DNA , Animals , Rabbits , HIV Antibodies , Antigen-Antibody Complex , Vaccination , Antibodies, Neutralizing , Epitopes , DNA
14.
J Virol ; 97(11): e0109423, 2023 Nov 30.
Article in English | MEDLINE | ID: mdl-37874153

ABSTRACT

IMPORTANCE: Despite the advent of highly active anti-retroviral therapy, people are still dying from HIV-related causes, many of whom are children, and a protective vaccine or cure is needed to end the HIV pandemic. Understanding the nature and activation states of immune cell subsets during infection will provide insights into the immunologic milieu associated with viremia suppression that can be harnessed via therapeutic strategies to achieve a functional cure, but these are understudied in pediatric subjects. We evaluated humoral and adaptive host immunity associated with suppression of viremia in rhesus macaques infected soon after birth with a pathogenic SHIV. The results from our study provide insights into the immune cell subsets and functions associated with viremia control in young macaques that may translate to pediatric subjects for the design of future anti-viral strategies in HIV-1-infected infants and children and contribute to an understudied area of HIV-1 pathogenesis in pediatric subjects.


Subject(s)
Animals, Newborn , Disease Models, Animal , HIV Infections , Macaca mulatta , Simian Acquired Immunodeficiency Syndrome , Viremia , Animals , Child , Humans , Animals, Newborn/immunology , HIV Infections/immunology , HIV Infections/virology , Macaca mulatta/immunology , Macaca mulatta/virology , Simian Acquired Immunodeficiency Syndrome/immunology , Simian Acquired Immunodeficiency Syndrome/virology , Simian Immunodeficiency Virus/immunology , Simian Immunodeficiency Virus/physiology , Viremia/immunology , Viremia/virology , HIV/immunology , HIV/physiology
15.
Science ; 382(6666): eadj0070, 2023 10 06.
Article in English | MEDLINE | ID: mdl-37797027

ABSTRACT

During the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, multiple variants escaping preexisting immunity emerged, causing reinfections of previously exposed individuals. Here, we used antigenic cartography to analyze patterns of cross-reactivity among 21 variants and 15 groups of human sera obtained after primary infection with 10 different variants or after messenger RNA (mRNA)-1273 or mRNA-1273.351 vaccination. We found antigenic differences among pre-Omicron variants caused by substitutions at spike-protein positions 417, 452, 484, and 501. Quantifying changes in response breadth over time and with additional vaccine doses, our results show the largest increase between 4 weeks and >3 months after a second dose. We found changes in immunodominance of different spike regions, depending on the variant an individual was first exposed to, with implications for variant risk assessment and vaccine-strain selection.


Subject(s)
Antigens, Viral , COVID-19 , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , mRNA Vaccines , Humans , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , Cross Reactions , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Antigens, Viral/genetics , Antigens, Viral/immunology , mRNA Vaccines/immunology , Vaccination , Amino Acid Substitution
16.
Biomater Sci ; 11(23): 7616-7622, 2023 Nov 21.
Article in English | MEDLINE | ID: mdl-37828832

ABSTRACT

Nanoprobes for efficient tumor-targeted imaging and therapy are urgently needed for clinical tumor theranostics. Herein, inspired by the heterogeneity of the tumor microenvironment, we report a covalent organic framework (COF)-derived biomimetic nanozyme for precise tumor-targeted imaging and NIR-II photothermal-catalysis-enhanced chemotherapy (PTCEC). Using a crystalline nanoscale COF as the precursor, a peroxidase-like porous N-doped carbonous nanozyme (PNC) was obtained, which was cloaked with an M1 macrophage cell membrane (M1m) to create a multifunctional biomimetic nanoprobe for tumor-targeted imaging and therapy. The M1m coating enabled the nanoprobe to target cancer cells and tumor tissues for highly efficient tumor imaging and drug delivery. The peroxidase-like activity of the PNC allowed for the conversion of intratumoral H2O2 into toxic ˙OH that synergized with its NIR-II photothermal effect to strengthen the chemotherapy. Therefore, highly efficient tumor-targeted imaging and NIR-II PTCEC were realized with an M1 macrophage mimic nanoprobe. This work provides a feasible tactic for a biomimetic theranostic nanoprobe and will inspire the development of new bioactive nanomaterials for clinical tumor theranostic applications.


Subject(s)
Metal-Organic Frameworks , Nanoparticles , Neoplasms , Humans , Hydrogen Peroxide , Theranostic Nanomedicine/methods , Neoplasms/diagnostic imaging , Neoplasms/drug therapy , Peroxidases/therapeutic use , Cell Line, Tumor , Nanoparticles/chemistry , Tumor Microenvironment
17.
Int J Infect Dis ; 137: 28-39, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37820782

ABSTRACT

BACKGROUND: Stochastic interventional vaccine efficacy (SVE) analysis is a new approach to correlate of protection (CoP) analysis of a phase III trial that estimates how vaccine efficacy (VE) would change under hypothetical shifts of an immune marker. METHODS: We applied nonparametric SVE methodology to the COVE trial of messenger RNA-1273 vs placebo to evaluate post-dose 2 pseudovirus neutralizing antibody (nAb) titer against the D614G strain as a CoP against COVID-19. Secondly, we evaluated the ability of these results to predict VE against variants based on shifts of geometric mean titers to variants vs D614G. Prediction accuracy was evaluated by 13 validation studies, including 12 test-negative designs. RESULTS: SVE analysis of COVE supported post-dose 2 D614G titer as a CoP: estimated VE ranged from 66.9% (95% confidence interval: 36.2, 82.8%) to 99.3% (99.1, 99.4%) at 10-fold decreased or increased titer shifts, respectively. The SVE estimates only weakly predicted variant-specific VE estimates (concordance correlation coefficient 0.062 for post 2-dose VE). CONCLUSION: SVE analysis of COVE supports nAb titer as a CoP for messenger RNA vaccines. Predicting variant-specific VE proved difficult due to many limitations. Greater anti-Omicron titers may be needed for high-level protection against Omicron vs anti-D614G titers needed for high-level protection against pre-Omicron COVID-19.


Subject(s)
COVID-19 , Vaccines , Humans , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/prevention & control , RNA, Messenger/genetics
18.
Bioresour Technol ; 388: 129728, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37683710

ABSTRACT

Both in-situ and ex-situ electrolytic H2 supply have been used for biomethane production from CO2. However, the pros and cons of them have not been systematically compared. The present study makes this comparison using a 20 L continuous stirred-tank reactor equipped with external and internal electrolyzers. Compared to the ex-situ H2 supply, the in-situ electrolytic H2 bubbles were one order of magnitude smaller, which resulted in improved H2 mass transfer and biomass growth. Consequently, the methane production rate and the coulombic efficiency of the in-situ H2 supply (0.51 L·L-1·d-1, 96%) were higher than those of the ex-situ H2 supply (0.30 L·L-1·d-1, 56%). However, due to high internal resistance, the energy consumption for the in-situ electrolysis was 2.54 times higher than the ex-situ electrolysis. Therefore, the in-situ electrolytic H2 supply appears to be more promising, but reducing energy consumption is the key to the success of this technology.


Subject(s)
Carbon Dioxide , Methane , Electrolysis , Bioreactors , Biomass , Hydrogen , Biofuels
19.
Entropy (Basel) ; 25(8)2023 Jul 27.
Article in English | MEDLINE | ID: mdl-37628155

ABSTRACT

Federated learning is a distributed machine learning framework, which allows users to save data locally for training without sharing data. Users send the trained local model to the server for aggregation. However, untrusted servers may infer users' private information from the provided data and mistakenly execute aggregation protocols to forge aggregation results. In order to ensure the reliability of the federated learning scheme, we must protect the privacy of users' information and ensure the integrity of the aggregation results. This paper proposes an effective secure aggregation verifiable federated learning scheme, which has both high communication efficiency and privacy protection function. The scheme encrypts the gradients with a single mask technology to securely aggregate gradients, thus ensuring that malicious servers cannot deduce users' private information from the provided data. Then the masked gradients are hashed to verify the aggregation results. The experimental results show that our protocol is more suited for bandwidth-constraint and offline-users scenarios.

20.
bioRxiv ; 2023 Aug 14.
Article in English | MEDLINE | ID: mdl-37645950

ABSTRACT

A series of SARS-CoV-2 variants emerged during the pandemic under selection for neutralization resistance. Convalescent and vaccinated sera show consistently different cross-neutralization profiles depending on infecting or vaccine variants. To understand the basis of this heterogeneity, we modeled serum cross-neutralization titers for 165 sera after infection or vaccination with historically prominent lineages tested against 18 variant pseudoviruses. Cross-neutralization profiles were well captured by models incorporating autologous neutralizing titers and combinations of specific shared and differing mutations between the infecting/vaccine variants and pseudoviruses. Infecting/vaccine variant-specific models identified mutations that significantly impacted cross-neutralization and quantified their relative contributions. Unified models that explained cross-neutralization profiles across all infecting and vaccine variants provided accurate predictions of holdout neutralization data comprising untested variants as infecting or vaccine variants, and as test pseudoviruses. Finally, comparative modeling of 2-dose versus 3-dose mRNA-1273 vaccine data revealed that the third dose overcame key resistance mutations to improve neutralization breadth. HIGHLIGHTS: Modeled SARS-CoV-2 cross-neutralization using mutations at key sitesIdentified resistance mutations and quantified relative impactAccurately predicted holdout variant and convalescent/vaccine sera neutralizationShowed that the third dose of mRNA-1273 vaccination overcomes resistance mutations.

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