Engineering the next-generation synthetic cell factory driven by protein engineering

Synthetic cell factory offers substantial advantages in economically efficient production of biofuels, chemicals, and pharmaceutical compounds. However, to create a high-performance synthetic cell factory, precise regulation of cellular material and energy flux is essential. In this context, protein components including enzymes, transcription factor-based biosensors and transporters play pivotal roles. Protein engineering aims to create novel protein variants with desired properties by modifying or designing protein sequences. This review focuses on summarizing the latest advancements of protein engineering in optimizing various aspects of synthetic cell factory, including: enhancing enzyme activity to eliminate production bottlenecks, altering enzyme selectivity to steer metabolic pathways towards desired products, modifying enzyme promiscuity to explore innovative routes, and improving the efficiency of transporters. Furthermore, the utilization of protein engineering to modify protein-based biosensors accelerates evolutionary process and optimizes the regulation of metabolic pathways. The remaining challenges and future opportunities in this field are also discussed.

Improvement of the viability of Tetragenococcus halophilus under acidic stress by forming the biofilm cell structure based on RNA-Seq and iTRAQ analyses

BACKGROUND

Tetragenococcus halophilus is a halophilic lactic acid bacterium (LAB) isolated from soya sauce moromi. During the production of these fermented foods, acid stress is an inevitable environmental stress. In our previous study, T. halophilus could form biofilms and the cells in the biofilms exhibited higher cell viability under multiple environmental stresses, including acid stress.

RESULTS

In this study, the effect of preformed T. halophilus biofilms on cell survival, cellular structure, intracellular environment, and the expression of genes and proteins under acid stress was investigated. The result showed that acid stress with pH 4.30 for 1.5 h reduced the live T. halophilus cell count and caused cellular structure damage. However, T. halophilus biofilm cells exhibited greater cell survival under acid stress than the planktonic cells, and biofilm formation reduced the damage of acid stress to the cell membrane and cell wall. The biofilm cells maintained a higher level of H+ -ATPase activity and intracellular ammonia concentration after acid stress. The RNA-Seq and iTRAQ technologies revealed that the genes and proteins associated with ATP production, the uptake of trehalose and N-acetylmuramic acid, the assembly of H+ -ATPase, amino acid biosynthesis and metabolism, ammonia production, fatty acid biosynthesis, CoA biosynthesis, thiamine production, and acetoin biosynthesis might be responsible for the stronger acid tolerance of T. halophilus biofilm cells together.

CONCLUSION

These findings further explained the mechanisms that allowed LAB biofilm cells to resist environmental stress. © 2023 Society of Chemical Industry.

Intelligently Quantifying the Entire Irregular Dental Structure

Quantitative analysis of irregular anatomical structures is crucial in oral medicine, but clinicians often typically measure only several representative indicators within the structure as references. Deep learning semantic segmentation offers the potential for entire quantitative analysis. However, challenges persist, including segmentation difficulties due to unclear boundaries and acquiring measurement landmarks for clinical needs in entire quantitative analysis. Taking the palatal alveolar bone as an example, we proposed an artificial intelligence measurement tool for the entire quantitative analysis of irregular dental structures. To expand the applicability, we have included lightweight networks with fewer parameters and lower computational demands. Our approach finally used the lightweight model LU-Net, addressing segmentation challenges caused by unclear boundaries through a compensation module. Additional enamel segmentation was conducted to establish a measurement coordinate system. Ultimately, we presented the entire quantitative information within the structure in a manner that meets clinical needs. The tool achieved excellent segmentation results, manifested by high Dice coefficients (0.934 and 0.949), intersection over union (0.888 and 0.907), and area under the curve (0.943 and 0.949) for palatal alveolar bone and enamel in the test set. In subsequent measurements, the tool visualizes the quantitative information within the target structure by scatter plots. When comparing the measurements against representative indicators, the tool's measurement results show no statistically significant difference from the ground truth, with small mean absolute error, root mean squared error, and errors interval. Bland-Altman plots and intraclass correlation coefficients indicate the satisfactory agreement compared with manual measurements. We proposed a novel intelligent approach to address the entire quantitative analysis of irregular image structures in the clinical setting. This contributes to enabling clinicians to swiftly and comprehensively grasp structural features, facilitating the design of more personalized treatment plans for different patients, enhancing clinical efficiency and treatment success rates in turn.

Heralded Three-Photon Entanglement from a Single-Photon Source on a Photonic Chip

In the quest to build general-purpose photonic quantum computers, fusion-based quantum computation has risen to prominence as a promising strategy. This model allows a ballistic construction of large cluster states which are universal for quantum computation, in a scalable and loss-tolerant way without feed forward, by fusing many small n-photon entangled resource states. However, a key obstacle to this architecture lies in efficiently generating the required essential resource states on photonic chips. One such critical seed state that has not yet been achieved is the heralded three-photon Greenberger-Horne-Zeilinger (3-GHZ) state. Here, we address this elementary resource gap, by reporting the first experimental realization of a heralded 3-GHZ state. Our implementation employs a low-loss and fully programmable photonic chip that manipulates six indistinguishable single photons of wavelengths in the telecommunication regime. Conditional on the heralding detection, we obtain the desired 3-GHZ state with a fidelity 0.573±0.024. Our Letter marks an important step for the future fault-tolerant photonic quantum computing, leading to the acceleration of building a large-scale optical quantum computer.

Blood cell count-derived inflammation indices as predictors of the osteoporotic risk of postmenopausal women

OBJECTIVE

We investigated the associations between osteoporosis (OP) and systemic immune inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and platelet-to-lymphocyte ratio (PLR) in postmenopausal women.

PATIENTS AND METHODS

This retrospective study included 966 postmenopausal women. Logistic regression and receiver operating characteristic curve (ROC) analyses were applied to explore the relationships between SII, NLR, MLR, and PLR with the bone mineral density (BMD) and risk of OP.

RESULTS

Logistic regression analyses showed that SII, PLR, NLR, and MLR had independent negative associations with the OP risk. The ROC curve analysis showed that SII, NLR, and MLR predicted a low BMD, with NLR having the highest predictive value (area under the curve = 0.624). SII > 504.09, PLR > 131.87, NLR > 2.02, and MLR > 0.12 correlated with a particularly high OP risk.

CONCLUSIONS

High levels of SII, PLR, NLR, and MLR were associated with a high OP risk. In particular, NLR > 2.02 strongly predicted the risk of OP, thereby representing a valuable and convenient inflammatory marker of the OP risk.

Enzyme engineering for functional lipids synthesis: recent advance and perspective

Functional lipids, primarily derived through the modification of natural lipids by various processes, are widely acknowledged for their potential to impart health benefits. In contrast to chemical methods for lipid modification, enzymatic catalysis offers distinct advantages, including high selectivity, mild operating conditions, and reduced byproduct formation. Nevertheless, enzymes face challenges in industrial applications, such as low activity, stability, and undesired selectivity. To address these challenges, protein engineering techniques have been implemented to enhance enzyme performance in functional lipid synthesis. This article aims to review recent advances in protein engineering, encompassing approaches from directed evolution to rational design, with the goal of improving the properties of lipid-modifying enzymes. Furthermore, the article explores the future prospects and challenges associated with enzyme-catalyzed functional lipid synthesis.

Testosterone promotes the migration, invasion and EMT process of papillary thyroid carcinoma by up-regulating Tnnt1

PURPOSE

To explore the key genes and molecular pathways in the progression of thyroid papillary carcinoma (PTC) promoted by testosterone using RNA-sequencing technology, and to provide new drug targets for improving the therapeutic effect of PTC.

METHODS

Orchiectomy (ORX) was carried out to construct ORX mouse models. TPC-1 cells were subcutaneously injected for PTC formation in mice, and the tumor tissues were collected for RNA-seq. The key genes were screened by bioinformatics technology. Tnnt1 expression in PTC cells was knocked down or overexpressed by transfection. Cell counting kit-8 (CCK-8), colony formation assay, scratch assay and transwell assay were adopted, respectively, for the detection of cell proliferation, colony formation, migration and invasion. Besides, quantification real-time polymerase chain reaction (qRT-PCR) and western blot were utilized to determine the mRNA and protein expression levels of genes in tissues or cells.

RESULTS

Both estradiol and testosterone promoted the growth of PTC xenografts. The key gene Tnnt1 was screened and obtained by bioinformatics technology. Functional analysis revealed that overexpression of Tnnt1 could markedly promote the proliferation, colony formation, migration, invasion, and epithelial-to-mesenchymal transition (EMT) process of PTC cells, as well as could activate p38/JNK pathway. In addition, si-Tnt1 was able to inhibit the cancer-promoting effect of testosterone.

CONCLUSION

Based on the outcomes of bioinformatics and basic experiments, it is found that testosterone can promote malignant behaviors such as growth, migration, invasion and EMT process of PTC by up-regulating Tnnt1 expression. In addition, the function of testosterone may be achieved by activating p38/JNK signaling pathway.

Molecular docking and network pharmacological analysis of Scutellaria baicalensis against renal cell carcinoma

OBJECTIVE

This paper employs network pharmacology and molecular docking to analyze the active components, targets, and molecular mechanisms of Scutellaria baicalensis in treating renal cell carcinoma (RCC).

MATERIALS AND METHODS

The potential active target genes and components of Scutellaria baicalensis are obtained by searching the TCMSP database, and RCC targets are obtained using OMIM, Genecards, and Drugbank databases. The interaction of target proteins is analyzed thanks to STRING, and the component target disease network diagram is constructed through Cytoscape 3.8.2 software. Besides, KEGG, and GO enrichment analysis is performed using the Bioconductor bioinformatics R software package. AutoDock Vina 1.1.2, PyMol 2.5 and Maestro 12.9 software are used for molecular docking.

RESULTS

According to the results, Scutellaria baicalensis, which has 36 active ingredients, 500 drug targets, and 85 drug-disease common targets in the treatment of RCC, relies mainly on active ingredients, including wogonin, baicalein, acacetin, oroxylin A, moslosooflavone, salvigenin, and neobaicalein. In addition, the core components within Scutellaria baicalensis that contribute to the treatment of renal cancer are TP53, CCND1, STAT3, CASP3, JUN, VEGFA, AKT1, and EGFR; while the main molecular mechanisms that helps relieve RCC include PI3K-Akt, Ras, MAPK, p53, VEGF, and JAK-STAT signaling pathway. Molecular docking suggested that wogonin had a good binding affinity with core proteins CASP3, CCND1, JUN, STAT3, TP53, and VEGFA.

CONCLUSIONS

This study confirms that Scutellaria baicalensis can treat RCC in a multi-component, multi-target, and multi-way manner.

Association of Computed Tomography Radiomics Signature with Progression-free Survival in Neuroblastoma Patients

AIMS

To investigate the association of computed tomography radiomics signature with progression-free survival (PFS) in neuroblastoma patients.

MATERIALS AND METHODS

We retrospectively included 167 neuroblastoma patients who were divided into a training set and a test set through stratified sampling at a ratio of 7:3. Regions of interest of the primary tumours were delineated on pretreatment contrast-enhanced computed tomography images and radiomics features were extracted from them. The intraclass correlation coefficient, Pearson correlation coefficient, and least absolute shrinkage and selection operator Cox regression algorithm were applied to select radiomics features and construct the radiomics signature. The effectiveness of the signature in predicting PFS was evaluated using the concordance index (C-index) and 95% confidence interval in both the training and the test sets. The time-dependent receiver operator characteristic curve of the radiomics signature was plotted and the area under the curve (AUC) was calculated. A calibration curve was used to assess the difference between the predicted probability of the radiomics signature and the observed probability at different time points.

RESULTS

The radiomics signature was composed of six features, which achieved a C-index of 0.733 (95% confidence interval 0.664-0.803) in the training set and 0.734 (95% confidence interval 0.608-0.861) in the test set. In the training set, the radiomics signature yielded an AUC of 0.707, 0.737, 0.788, 0.859 and 0.829 for 1-, 2-, 3-, 4- and 5-year PFS, respectively. Similarly, the radiomics signature exhibited an AUC of 0.738, 0.807, 0.761, 0.787 and 0.818 for 1-, 2-, 3-, 4- and 5-year PFS, respectively, in the test set. The calibration curves showed no significant difference between the predicted probability of the radiomics signature and the observed probability for up to 5 years.

CONCLUSIONS

Computed tomography radiomics features exhibit a significant correlation with the PFS of neuroblastoma patients, particularly in terms of long-term outcomes.

Serum CTRP3 concentrations are positively correlated with disease severity in women with postmenopausal osteoporosis: a population-based cross-sectional study

OBJECTIVE

Osteoporosis is a leading public health problem that contributes to increasingly high rates of osteoporotic vertebral compression fractures among older adults. This study was developed with the goal of assessing serum C1q/TNF-related protein-3 (CTRP3) levels in postmenopausal osteoporosis (PMOP) patients and exploring the correlations between these levels and PMOP severity.

PATIENTS AND METHODS

A population-based cross-sectional study of old women with osteoporosis was conducted. All women underwent both clinical and dual-energy X-ray absorptiometry examinations. Serum CTRP3, procollagen type I N propeptide (P1NP), and C-terminal telopeptide of type I collagen (CTX-1) concentrations in these patients were measured via ELISA. Bone tumor markers were additionally assessed. Receiver operating characteristic (ROC) analyses were utilized to assess the diagnostic performance of CTRP3 when identifying PMOP.

RESULTS

This study included 54 PMOP patients, 62 patients with osteopenia, and 60 age-matched patients without PMOP. Serum CTRP3 concentrations in PMOP patients were significantly lower than in the other two groups. Bone mineral density (BMD) was positively correlated with serum CTRP3 levels in all study participants, whereas it was negatively correlated with levels of P1NP and CTX-1. ROC analyses also suggested that reductions in serum CTRP3 levels may offer value as a diagnostic indicator of PMOP.

CONCLUSIONS

Present data highlight a close relationship between CTRP3 and PMOP, with lower serum CTRP3 levels being closely associated with BMD, such that they may represent a protective marker for PMOP.

A Machine Learning Method to Predict Pathological Complete Response of Esophageal Cancer after Neoadjuvant Chemoradiotherapy with Clinicohematological Markers and MR Radiomics: A Multi-Center Study

PURPOSE/OBJECTIVE(S)

Nearly 30% of patients with local advanced esophageal cancer achieved pathological complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT), who may benefit from organ-preservation strategy under accurate prediction of pCR. We aimed to develop and validate machine learning models based on clinicohematological markers and MR radiomics to accurately predict pCR of esophageal cancer after nCRT.

MATERIALS/METHODS

In this multi-center study, eligible patients with esophageal cancer who received baseline MR scan (T2-weighted image) and nCRT plus surgery were enrolled between September 2014 and September 2022 at institution 1 (training set) and between December 2017 and August 2021 at institution 2 (testing set). Pre-nCRT and post-nCRT blood test results were collected to calculate hematological markers. Models were constructed by machine learning based on clinicohematological markers and MR radiomics to predict pCR. Area under the curve (AUC) and cut-off analysis were used to evaluate model performances.

RESULTS

Totally 154 patients (81 in the training set and 73 in the testing set) were enrolled. The combined model integrating pre-nCRT monocyte-to-lymphocyte ratio and 6 radiomics features achieved AUC of 0.800 (95% CI 0.671-0.918) in the testing set, with sensitivity of 79.2% (95% CI 62.5%-95.8%), specificity of 83.7% (95% CI 73.5%-93.9%), positive predictive value of 76.0% (95% CI 62.5%-90.0%), and negative predictive value of 89.6% (95% CI 82.0%-95.8%).

CONCLUSION

A machine learning model based on clinicohematological markers and MR radiomics to predict pCR after nCRT for patients with esophageal cancer was developed and validated, providing a novel tool for personalized treatment. It is necessary to further validate in more large datasets.

Chemoradiotherapy Combined with Nab-Paclitaxel plus Cisplatin in Patients with Locally Advanced Borderline Resectable or Unresectable Esophageal Squamous Cell Carcinoma: A Phase I/II Study

PURPOSE/OBJECTIVE(S)

To evaluate the efficacy and safety of nanoparticle albumin-bound paclitaxel (nab-PTX) plus cisplatin as the regimen of conversional chemoradiotherapy (cCRT) in locally advanced borderline resectable or unresectable esophageal squamous cell carcinoma (ESCC).

MATERIALS/METHODS

Patients with locally advanced ESCC (cT3-4, Nany, M0-1, M1 was limited to lymph node metastasis in the supraclavicular area) were enrolled. All the patients received the cCRT of nab-PTX plus cisplatin. After the cCRT, those resectable patients received esophagectomy; those unresectable patients continued to receive the definitive chemoradiotherapy (dCRT). The locoregional control (LRC), overall survival (OS), progression-free survival (PFS), distant metastasis free survival (DMFS), pathological complete response (pCR), R0 resection rate and adverse events (AEs) were calculated.

RESULTS

A total of 45 patients with ESCC treated from October 2019 to May 2021 were finally included. The median follow-up time was 30.3 months. The LRC, OS, EFS, DMFS at 1and 2 years were 81.5%, 86.6%, 64.3%, 73.2% and 72.4%, 68.8%, 44.8%, 52.7% respectively. 21 patients (46.7%) received conversional chemoradiotherapy plus surgery (cCRT+S). The pCR rate and R0 resection rate were 47.6% and 84.0%. The LRC rate at 1 and 2 years were 95.0%, 87.1% in cCRT+S patients and 69.3%, 58.7% in dCRT patients respectively (HR, 5.14; 95% CI, 1.10-23.94; P = 0.021). The OS rate at 1 and 2 years were 95.2% and 84.2% in resectable patients compared to 78.8% and 54.4% in unresectable patients (HR, 3.41; 95% CI, 1.10-10.61; P = 0.024). The toxicities during chemoradiotherapy were tolerated, the most common grade 3-4 toxicities were radiation esophagitis (15.6%).

CONCLUSION

Nab-PTX plus cisplatin were effective and safe as the regimen of conversional chemoradiotherapy of ESCC. The patients receiving conversional chemoradiotherapy plus surgery (cCRT+S) were prone to have a better survival.

Non-parametric estimation of the age-at-onset distribution from a cross-sectional sample

We propose and study a simple and innovative non-parametric approach to estimate the age-of-onset distribution for a disease from a cross-sectional sample of the population that includes individuals with prevalent disease. First, we estimate the joint distribution of two event times, the age of disease onset and the survival time after disease onset. We accommodate that individuals had to be alive at the time of the study by conditioning on their survival until the age at sampling. We propose a computationally efficient expectation-maximization (EM) algorithm and derive the asymptotic properties of the resulting estimates. From these joint probabilities we then obtain non-parametric estimates of the age-at-onset distribution by marginalizing over the survival time after disease onset to death. The method accommodates categorical covariates and can be used to obtain unbiased estimates of the covariate distribution in the source population. We show in simulations that our method performs well in finite samples even under large amounts of truncation for prevalent cases. We apply the proposed method to data from female participants in the Washington Ashkenazi Study to estimate the age-at-onset distribution of breast cancer associated with carrying BRCA1 or BRCA2 mutations.

First Dark Matter Search with Nuclear Recoils from the XENONnT Experiment

We report on the first search for nuclear recoils from dark matter in the form of weakly interacting massive particles (WIMPs) with the XENONnT experiment, which is based on a two-phase time projection chamber with a sensitive liquid xenon mass of 5.9 ton. During the (1.09±0.03)  ton yr exposure used for this search, the intrinsic ^{85}Kr and ^{222}Rn concentrations in the liquid target are reduced to unprecedentedly low levels, giving an electronic recoil background rate of (15.8±1.3)  events/ton yr keV in the region of interest. A blind analysis of nuclear recoil events with energies between 3.3 and 60.5 keV finds no significant excess. This leads to a minimum upper limit on the spin-independent WIMP-nucleon cross section of 2.58×10^{-47}  cm^{2} for a WIMP mass of 28  GeV/c^{2} at 90% confidence level. Limits for spin-dependent interactions are also provided. Both the limit and the sensitivity for the full range of WIMP masses analyzed here improve on previous results obtained with the XENON1T experiment for the same exposure.

Searching for Heavy Dark Matter near the Planck Mass with XENON1T

Multiple viable theoretical models predict heavy dark matter particles with a mass close to the Planck mass, a range relatively unexplored by current experimental measurements. We use 219.4 days of data collected with the XENON1T experiment to conduct a blind search for signals from multiply interacting massive particles (MIMPs). Their unique track signature allows a targeted analysis with only 0.05 expected background events from muons. Following unblinding, we observe no signal candidate events. This Letter places strong constraints on spin-independent interactions of dark matter particles with a mass between 1×10^{12} and 2×10^{17}  GeV/c^{2}. In addition, we present the first exclusion limits on spin-dependent MIMP-neutron and MIMP-proton cross sections for dark matter particles with masses close to the Planck scale.

B-Cell-Activating Factor Contributes to Elevation of the Content of Regulatory B Cells in Neonatal Sepsis

We studied the role of B cell-activating factor (BAFF) in PI3K/AKT/mTOR signaling pathway in promoting proliferation and maintaining survival of regulatory B lymphocytes (Breg) in newborns with sepsis. The peripheral blood samples were collected from preterm neonates (n=40) diagnosed with sepsis on the day of diagnosis and on days 7, 14, and 21 after diagnosis, as well as from the matched preterm neonates without sepsis (n=40; control group). The peripheral blood mononuclear cells and B cells were isolated, cultured, and stimulated with LPS and immunostimulant CpG-oligodeoxynucleotide (CpG-ODN). Proliferation and differentiation of B-cells into CD19⁺CD24^hiCD38^hi Breg cells and the role of the PI3K/AKT/mTOR signaling pathway in these processes were studied by flow cytometry, real-time quantitative reverse transcription PCR (qRT-PCR), and Western blotting. BAFF levels in the peripheral blood of neonates with sepsis were significantly increased at one week after diagnosis in parallel with increasing trend of expression of BAFF receptor. When applied with LPS and CpG-ODN, BAFF promoted differentiation of B cells into CD19⁺CD24^hiCD38^hi Breg cells. Phosphorylation of 4E-BP1 factor and 70S6K kinase located downstream in PI3K/AKT/mTOR signaling pathway was significantly up-regulated when stimulated with BAFF in combination with LPS and CpG-ODN. Thus, increased level of BAFF activates PI3K/AKT/mTOR signaling pathway and induces in vitro differentiation of peripheral blood B cells into CD19⁺CD24^hiCD38^hi Breg cells.

Higher Incidence of Unruptured Intracranial Aneurysms among Black and Hispanic Women on Screening MRA in Large Urban Populations

BACKGROUND AND PURPOSE

Intracranial aneurysms have a reported prevalence of 1%-2% in the general population. Currently, only patients with a strong family history or autosomal dominant polycystic kidney disease are screened for intracranial aneurysms using MRA. The purpose of this study was to determine whether there are other specific patient populations at risk that should be offered screening for intracranial aneurysms.

MATERIALS AND METHODS

This is a retrospective case-control study of adult patients who underwent a screening MRA of their brain at our comprehensive stroke center from 2011 to 2020. Patients with a history of a known brain aneurysm were excluded. Data were extracted on patient demographics and medical comorbidities. Bivariate analyses were performed, followed by multivariable logistic regression, to identify factors associated with a positive MRA screen for incidental aneurysms.

RESULTS

Of 24,397 patients eligible for this study, 2084 screened positive for a possible intracranial aneurysm. On bivariate analysis, significant differences were present in the following categories: age, sex, race and ethnicity, chronic constipation, and hyperlipidemia. On logistic regression analysis, older age (+10 years: OR = 10.01; 95% CI, 10.01-10.02; P = .001), female sex (OR = 1.37; 95% CI, 1.24-1.51; P = .001), non-Hispanic Black (OR = 1.19; 95% CI, 1.02-1.40; P = .031), and Hispanic ethnicity (OR = 1.35; 95% CI, 1.16-1.58; P = .001) versus non-Hispanic White remained significant when adjusted for other factors.

CONCLUSIONS

Targeted screening for high-risk elderly women of Black or Hispanic descent will yield higher positive findings for brain aneurysms, which may mitigate the risk of rupture. Whether this is a cost-effective approach has yet to be determined.

Calorie restriction ameliorates hyperglycemia, modulates the disordered gut microbiota, and mitigates metabolic endotoxemia and inflammation in type 2 diabetic rats

PURPOSE

The effects of calorie restriction (CR) on gut microbiota and the mechanism of CR ameliorating hyperglycemia in streptozotocin (STZ)-induced T2DM model rats were explored.

METHODS

High-fat diet and STZ injection were applied to induce T2DM model rats. Rats were divided into the following three groups: the control-diet ad libitum group, the T2DM model group fed with ad libitum diet, and the T2DM group fed with 30% restriction diet. 16S rRNA sequencing was used to determine the bacterial communities. Lipopolysaccharide (LPS)-binding protein (LBP), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were measured.

RESULTS

Glucose tolerance and insulin sensitivity were improved by CR, as well as the levels of fasting and random plasma glucose. Besides, CR not only modulated the overall structure of gut microbiota but also had selective enrichment in anti-inflammatory bacteria such as Lachnospiraceae_NK4A136_group, Ruminococcaceae_9, Allobaculum, Alistipes, and Oscillibacter, and decreased pro-inflammatory pathogenic bacteria such as Bacteroides, Lachnoclostridium, and Bifidobacterium. Tax4Fun indicated that CR could regulate related functional pathways such as lipopolysaccharide biosynthesis, and the plasma levels of LBP, IL-6, and TNF-α were markedly reduced by CR, suggesting the mechanism of CR ameliorating hyperglycemia may associate with the modulation of disordered gut microbiota and the reduction of metabolic endotoxemia and inflammation.

CONCLUSION

CR could ameliorate hyperglycemia, the mechanism of which may associate with the alteration of the overall structure of gut microbiota, restoration of disordered microbiota function, and the downregulation of metabolic endotoxemia and inflammation in diabetic rats.

Association between Frailty Assessed Using Two Electronic Medical Record-Based Frailty Assessment Tools and Long-Term Adverse Prognosis in Older Critically Ill Survivors

OBJECTIVES

Frailty has become an independent risk factor for adverse outcomes in critically ill patients. This study aimed to explore the predictive ability of two electronic medical record-based frailty assessment tools, the Hospital Frailty Risk Score (HFRS) and Frailty Index based on physiological and laboratory tests (FI-lab), for long-term adverse prognosis in older critically ill survivors.

DESIGN

Retrospective observational study.

SETTING AND PARTICIPANTS

9,082 critically ill survivors aged ≥ 65 years.

MEASUREMENTS

The HFRS and the 33-item FI-lab were constructed based on the published literature. Cox and logistic regression models assessed the association between frailty and 1-year mortality and post-discharge care needs.

RESULTS

2,586 patients died within 1 year of follow-up. In fully adjusted models, frailty assessed using both the HFRS (per point, hazard ratio [HR] 1.06, 95% confidential interval [CI] 1.05-1.06; intermediate frailty risk, HR 2.00, 95% CI 1.78-2.25; high frailty risk, HR 3.06, 95% CI 2.68-3.50) and FI-lab (per 0.01 points, HR 1.03, 95% CI 1.03-1.03; intermediate frailty risk, HR 1.59, 95% CI 1.44-1.76; high frailty risk, HR 2.30, 95% CI 2.06-2.57) was associated with mortality. Addition of frailty indicators improved the predictive validity of the Sequential Organ Failure Assessment score for mortality (HFRS alone ∆ C-index 0.034; FI-lab alone ∆ C-index 0.016; HFRS and FI-lab combined ∆ C-index 0.042). The HFRS but not the FI-lab was associated with higher probability of post-discharge care needs.

CONCLUSION

Both the HFRS and FI-lab could independently predict 1-year mortality in older critically ill survivors. Adding the HFRS to the SOFA score model improved it more than adding the FI-lab. The greatest improvement was achieved when both frailty indicators were used together. These findings suggest that electronic medical record-based frailty assessment methods can be useful tools for predicting long-term outcomes in older critically ill patients.

Search for New Physics in Electronic Recoil Data from XENONnT

We report on a blinded analysis of low-energy electronic recoil data from the first science run of the XENONnT dark matter experiment. Novel subsystems and the increased 5.9 ton liquid xenon target reduced the background in the (1, 30) keV search region to (15.8±1.3)  events/(ton×year×keV), the lowest ever achieved in a dark matter detector and ∼5 times lower than in XENON1T. With an exposure of 1.16 ton-years, we observe no excess above background and set stringent new limits on solar axions, an enhanced neutrino magnetic moment, and bosonic dark matter.

Effects of weight loss on bone turnover, inflammatory cytokines, and adipokines in Chinese overweight and obese adults

PURPOSE

Plenty of studies have examined the long term effect of weight loss on bone mineral density. This study aimed to explore the effects of 10% weight loss on early changes in bone metabolism as well as the possible influencing factors.

METHODS

Overweight and obese outpatients (BMI > 24.0 kg/m²) were recruited from the nutrition clinic and followed a calorie-restricted, high-protein, low-carbohydrate diet program. Dietary intake, body composition, serum procollagen type I N-propeptide (PINP), β-Crosslaps, PTH, 25(OH) VitD, a series of inflammatory cytokines and adipokines were measured for the participants before starting to lose weight and after 10% weight loss (NCT04207879).

RESULTS

A total of 75 participants were enrolled and 37 participants achieved a weight loss of at least 10%. It was found that PINP decreased (p = 0.000) and the β-Crosslaps increased (p = 0.035) in female participants. Decreases in PTH (p = 0.001), serum IL-2 (p = 0.013), leptin (p = 0.001) and increases in 25(OH) VitD (p = 0.001), serum ghrelin (p = 0.033) were found in 37 participants after 10% of their weight had been lost. Change in PINP was detected to be significantly associated with change in lean body mass (r = 0.418, p = 0.012) and change in serum ghrelin(r = - 0.374, p = 0.023).

CONCLUSIONS

Bone formation was suppressed and bone absorption was increased in female subjects after a 10% weight loss. Bone turnover was found to be associated with lean body mass and affected by the circulating ghrelin level.

Material radiopurity control in the XENONnT experiment

The selection of low-radioactive construction materials is of the utmost importance for rare-event searches and thus critical to the XENONnT experiment. Results of an extensive radioassay program are reported, in which material samples have been screened with gamma-ray spectroscopy, mass spectrometry, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{222}$$\end{document}222Rn emanation measurements. Furthermore, the cleanliness procedures applied to remove or mitigate surface contamination of detector materials are described. Screening results, used as inputs for a XENONnT Monte Carlo simulation, predict a reduction of materials background (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim $$\end{document}∼17%) with respect to its predecessor XENON1T. Through radon emanation measurements, the expected \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{222}$$\end{document}222Rn activity concentration in XENONnT is determined to be 4.2 (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{+0.5}_{-0.7}$$\end{document}-0.7+0.5) \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upmu $$\end{document}μBq/kg, a factor three lower with respect to XENON1T. This radon concentration will be further suppressed by means of the novel radon distillation system.

Performance of a generative adversarial network using ultrasound images to stage liver fibrosis and predict cirrhosis based on a deep-learning radiomics nomogram

AIM

To investigate the performance of a generative adversarial network (GAN) model for staging liver fibrosis and its radiomics-based nomogram for predicting cirrhosis.

MATERIALS AND METHODS

This two-centre retrospective study included 434 patients for whom input data of ultrasound images and histopathological data (obtained within 1 month of ultrasound examinations) were assigned to the training cohort (249 patients), the internal cohort (92 patients), and the external (93 patients) cohort. A data augmentation method based on a GAN model was used. The discriminative performance was evaluated for classifying fibrosis of S4 and ≥S3. Deep-learning radiomics features were extracted for the prediction of cirrhosis (S4). To perform feature reduction and selection, the least absolute shrinkage and selection operator (LASSO) algorithm was applied. Radiomics scores, along with clinical factors, were incorporated into a nomogram using multivariable logistic regression analysis. The performance of the models was estimated with respect to discrimination power, calibration, and clinical benefits.

RESULTS

The areas under the receiver operating characteristic curve (AUCs) values of the GAN were 0.832/0.762 (≥S3), and 0.867/0.835 (S4) for internal/external test sets, respectively. The radiomics nomogram that intergrated radiomics scores and clinical factors showed good calibration and discrimination ability of 0.922 (AUC) in the training dataset, 0.896 in the internal dataset, and 0.861 in the external dataset. Decision curve analysis (DCA) demonstrated that the nomogram outperformed radiologist and haematological indices in terms of the most clinical benefits.

CONCLUSIONS

The GAN model could be applied to discriminate fibrosis stages, and a favourable predictive accuracy for diagnosing cirrhosis was achieved using a deep-learning radiomics nomogram.

Study of the doubly charmed tetraquark [Formula: see text]

Quantum chromodynamics, the theory of the strong force, describes interactions of coloured quarks and gluons and the formation of hadronic matter. Conventional hadronic matter consists of baryons and mesons made of three quarks and quark-antiquark pairs, respectively. Particles with an alternative quark content are known as exotic states. Here a study is reported of an exotic narrow state in the D0D0π+ mass spectrum just below the D*+D0 mass threshold produced in proton-proton collisions collected with the LHCb detector at the Large Hadron Collider. The state is consistent with the ground isoscalar [Formula: see text] tetraquark with a quark content of [Formula: see text] and spin-parity quantum numbers JP = 1+. Study of the DD mass spectra disfavours interpretation of the resonance as the isovector state. The decay structure via intermediate off-shell D*+ mesons is consistent with the observed D0π+ mass distribution. To analyse the mass of the resonance and its coupling to the D*D system, a dedicated model is developed under the assumption of an isoscalar axial-vector [Formula: see text] state decaying to the D*D channel. Using this model, resonance parameters including the pole position, scattering length, effective range and compositeness are determined to reveal important information about the nature of the [Formula: see text] state. In addition, an unexpected dependence of the production rate on track multiplicity is observed.

Cardiac progenitor cell-derived extracellular vesicles promote endothelial cell activation through both associated- and co-isolated proteins

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): ERC Consolidator Grant: EVICARE

Background

Extracellular vesicle (EVs) are small, cell-derived lipid bilayer enclosed particles that play a role in intercellular communication through the delivery of their content which includes nucleic acids and proteins. Cardiac progenitor cell (CPC)-derived EVs have been shown to protect the myocardium against ischemia/reperfusion injury via proangiogenic effects. However, the underlying mechanisms for CPC-EV-mediated angiogenesis remain elusive. Here, we investigated protein-mediated effects of CPC-EVs on the endothelium, and explored EV-dependent and –independent recipient cell activation.

Methods

CPCs were stimulated with calcium ionophore (Ca ion-EVs), previously shown to influence EV release, or vehicle (veh-EVs) for 24 hours and crude EVs were isolated using size exclusion chromatography (SEC). EV concentration and size was assessed using nanoparticle tracking analysis and proteomic composition was profiled using mass spectrometry. Following SEC, iodixanol gradient ultracentrifugation was used to separate EVs from free proteins. CPC-EVs deficient in individual proteins were generated using CRISPR/Cas9 machinery. EV- and protein fractions were functionally characterized based on their potency to activate human microvascular endothelial cells (HMEC-1) and induce wound closure. HMEC-1 activation upon EV-delivery was determined by phosphoproteomics.

Results

HMEC-1 displayed increased wound closure and activation of AKT-mTOR and (Insulin/IGF-) MAPK signaling pathways upon stimulation with veh-EVs but not with Ca ion-EVs, confirmed by phosphoproteomic analysis. MS-proteomic analysis identified multiple proteins strongly enriched in veh-EVs compared with Ca ion-EVs. GO analysis of these candidate proteins revealed their involvement cell migration and –adhesion. This raised the question whether these identified proteins were truly associated to CPC-EVs, or merely co-isolated. Pure EVs isolated using iodixanol gradients lost part of their ability to activate HMEC-1 compared to crude EV preparations. This hints towards a co-stimulatory role of co-isolated proteins in recipient cell activation. When investigating the contribution of individual candidate proteins to CPC-EV functionality, knock-out of NID1 did not affect EV function, while knock-out of PAPP-A resulted in CPC-EVs with reduced functionality. The IGF-receptor inhibitor PPP abrogated CPC-EV-induced HMEC-1 activation, supporting the association of EV-associated PAPP-A with the activation of intracellular IGF-1-MAPK signaling.

Conclusions

A specific set of EV proteins including PAPP-A is identified that may be functionally responsible for the activation of endothelial cells upon exposure to CPC-EVs. It is important to identify if these proteins are EV-associated or represent co-isolated factors that contribute to endothelial cell activation. This may lead to a better mechanistic understanding of CPC-EV-mediated cell activation and translation of EV-mediated therapeutics.

Small molecule-mediated rapid maturation of human induced pluripotent stem cell derived cardiomyocytes

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): Gravitation Program “Materials Driven Regeneration” by the Netherlands Organization for Scientific Research (RegmedXB #024.003.013) and the Marie Skłodowska-Curie Actions (Grant agreement RESCUE #801540). The EU-funded project BRAV3 (H2020, ID:874827)

Background

Human-induced pluripotent stem cell (iPSC)-derived cardiomyocytes (iPSC-CMs) do not display all hallmarks of mature human primary cardiomyocytes: the ability to use fatty acids as an energy source, high mitochondrial mass, increased nuclei polyploidism, synchronized electrical conduction, and forceful contractions. Instead, their phenotype is similar to immature cardiomyocytes in the late fetal stage. This immaturity represents a bottleneck to their application in 1) disease modeling – as most cardiac (genetic) diseases have a middle-age onset – and 2) clinical use, where integration and functional coupling are key. So far, the mainly used methods to enhance iPSC-CM maturation include prolonged time-in-culture, 3D culture, cyclic mechanical stretch, and electrical stimulation with specialized media. However, these protocols are laborious, costly, and not easily scalable.

Methods

In this study, we developed a simple, low cost, and rapid protocol using two peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A/PGC-1α) activating small molecules: Asiatic Acid (AA) and GW501516 (GW) to promote cardiomyocyte maturity by inducing a metabolic switch to fatty acid utilization and increased mitochondrial biogenesis.

Results

Monolayers of iPSC-CMs were incubated with AA and GW every other day for 10 days resulting in increased expression of fatty acid-metabolism-related genes (5 and 10-fold increase in CPT1B gene expression, respectively), mitochondria biogenesis (protein expression of ATP5A) and fusion (50 and 100-fold increase in OPA1 gene expression, respectively). In addition, AA treated iPSC-CMs responded in the seahorse mitochondria stress test more rapidly to an artificial increase in mitochondrial activity and showed a higher flexibility in substrate utilization in the seahorse stress test. A more mature electrophysiological functionality was shown by increased ion channel gene expression (KCNA4, SCN5A, GJA1, CACNA1C, and SCN1B) and enhanced synchronous contraction in treated samples. Moreover, maturation was further shown by increased sarcomeric gene expression (5 and 7-fold increase in TNNI3 in AA and GW respectively) and nuclear polyploidism (>4N fold 2.16 and 1.48-fold increase in AA and GW respectively).

Conclusions

Collectively, these findings show that AA and GW trigger a metabolic switch and induce extensive maturation of iPSC-CMs, providing a rapid and cost-effective method to obtain iPSC-CMs that more closely resemble their adult counterparts.

Susceptibility-weighted imaging cannot distinguish radionecrosis from recurrence in brain metastases after radiotherapy: a comparison with high-grade gliomas

AIM

To explore the efficiency of susceptibility-weighted imaging (SWI) in the differential diagnosis of recurrence from radionecrosis in brain metastases (BM) and in high-grade gliomas (HGG).

MATERIALS AND METHODS

From September 2016 to November 2018, 56 patients with BM and 42 patients with HGG were included in this retrospective study. BM and HGG were assigned to the recurrence and radionecrosis groups according to their histopathology or follow-up results. The proportion of dark signal intensity (proDSI), which was defined as the area of dark signal on SWI or the enhancing area on contrast-enhanced T1-weighted imaging (T1WI), was calculated for each patient. Analysis of variance (ANOVA) with Tukey's honestly significant difference test was used for the repeat multiple comparisons. Receiver operating characteristic curve analysis was performed to validate the diagnostic performance.

RESULTS

For HGG, the proDSI in the recurrence group was significantly lower than that in the radionecrosis group (0.13 ± 0.05 versus 0.43 ± 0.11, p<0.001); however, for BM, no statistical difference was found between groups (0.49 ± 0.09 versus 0.46 ± 0.08, p=0.26). proDSI had the best diagnostic performance (AUC = 0.87, 95% CI: 0.76-0.98; sensitivity = 0.87; specificity = 0.88) for HGG, when a cut-off value of 0.21 was selected.

CONCLUSIONS

Semi-quantitative analysis using SWI is feasible for the differential diagnosis between recurrence and radionecrosis in HGG, but is not feasible in BM. Semi-quantitative assessment based on SWI should interpreted with caution in BM after radiotherapy in clinical practice.

Angular Analysis of D^{0}→π^{+}π^{-}μ^{+}μ^{-} and D^{0}→K^{+}K^{-}μ^{+}μ^{-} Decays and Search for CP Violation

The first full angular analysis and an updated measurement of the decay-rate CP asymmetry of the D^{0}→π^{+}π^{-}μ^{+}μ^{-} and D^{0}→K^{+}K^{-}μ^{+}μ^{-} decays are reported. The analysis uses proton-proton collision data collected with the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV. The dataset corresponds to an integrated luminosity of 9  fb^{-1}. The full set of CP -averaged angular observables and their CP asymmetries are measured as a function of the dimuon invariant mass. The results are consistent with expectations from the standard model and with CP symmetry.

Rhoifolin ameliorates osteoarthritis via the Nrf2/NF-κB axis: in vitro and in vivo experiments

OBJECTIVE

Osteoarthritis (OA) is an age-related degenerative disease accompanied by an increasing number of senescent cells and chronic low-grade inflammation. Rhoifolin (ROF) showed considerable inhibition to inflammation, but its role in chondrocyte senescence and OA progress has not been fully characterized. We aimed to evaluate the protective effects of ROF on OA through a series of in vitro and in vivo experiments.

METHODS

The role of ROF in the expression of senescence-associated secretory phenotype (SASP) factors was investigated using RT-qPCR, western blotting, and ELISA. Chondrocyte senescence was assessed by SA-β-gal staining. We applied molecular docking to screen candidate proteins regulated by ROF. Meanwhile, SASP factors and cellular senescence were further assessed after the transfection of Nrf2 siRNA. In the anterior cruciate ligament transection (ACLT) rat model, X-ray, hematoxylin-eosin (HE), and Masson's staining were performed to evaluate the therapeutic effects of ROF on OA.

RESULTS

We found that ROF inhibited SASP factors expression and senescence phenotype in IL-1β-treated chondrocytes. Furthermore, ROF suppressed IL-1β-induced activation of the NF-κB pathway cascades. Also, molecular docking and knock-down studies demonstrated that ROF might bind to Nrf2 to suppress the NF-κB pathway. In vivo, ROF ameliorated the OA process in the ACLT rat model.

CONCLUSIONS

ROF inhibits SASP factors expression and senescence phenotype in chondrocytes and ameliorates the progression of OA via the Nrf2/NF-κB axis, which supports ROF as a potential therapeutic agent for the treatment of OA.

Observation of Two New Excited Ξ_{b}^{0} States Decaying to Λ_{b}^{0}K^{-}π^{+}

Two narrow resonant states are observed in the Λ_{b}^{0}K^{-}π^{+} mass spectrum using a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the LHCb experiment and corresponding to an integrated luminosity of 6  fb^{-1}. The minimal quark content of the Λ_{b}^{0}K^{-}π^{+} system indicates that these are excited Ξ_{b}^{0} baryons. The masses of the Ξ_{b}(6327)^{0} and Ξ_{b}(6333)^{0} states are m[Ξ_{b}(6327)^{0}]=6327.28_{-0.21}^{+0.23}±0.12±0.24 and m[Ξ_{b}(6333)^{0}]=6332.69_{-0.18}^{+0.17}±0.03±0.22  MeV, respectively, with a mass splitting of Δm=5.41_{-0.27}^{+0.26}±0.12  MeV, where the uncertainties are statistical, systematic, and due to the Λ_{b}^{0} mass measurement. The measured natural widths of these states are consistent with zero, with upper limits of Γ[Ξ_{b}(6327)^{0}]<2.20(2.56) and Γ[Ξ_{b}(6333)^{0}]<1.60(1.92)  MeV at a 90% (95%) credibility level. The significance of the two-peak hypothesis is larger than nine (five) Gaussian standard deviations compared to the no-peak (one-peak) hypothesis. The masses, widths, and resonant structure of the new states are in good agreement with the expectations for a doublet of 1D Ξ_{b}^{0} resonances.

A combination of bioinformatics analysis and rational design strategies to enhance keratinase thermostability for efficient biodegradation of feathers

Keratinase has shown great significance and application potentials in the biodegradation and recycle of keratin waste due to its unique and efficient hydrolysis ability. However, the inherent instability of the enzyme limits its practical utilization. Herein, we obtained a thermostability-enhanced keratinase based on a combination of bioinformatics analysis and rational design strategies for the efficient biodegradation of feathers. A systematical in silico analysis combined with filtering of virtual libraries derived a smart library for experimental validation. Synergistic mutations around the highly flexible loop, the calcium binding site and the non-consensus amino acids generated a dominant mutant which increased the optimal temperature of keratinase from 40 °C to 60 °C, and the half-life at 60 °C was increased from 17.3 min to 66.1 min. The mutant could achieve more than 66% biodegradation of 50 g/L feathers to high-valued keratin product with a major molecular weight of 36 kDa. Collectively, this work provided a promising keratinase variant with enhanced thermostability for efficient conversion of keratin wastes to valuable products. It also generated a general strategy to facilitate enzyme thermostability design which is more targeted and predictable.

Measurement of the Nuclear Modification Factor and Prompt Charged Particle Production in p-Pb and pp Collisions at sqrt[s_{NN}]=5 TeV

The production of prompt charged particles in proton-lead collisions and in proton-proton collisions at the nucleon-nucleon center-of-mass energy sqrt[s_{NN}]=5  TeV is studied at LHCb as a function of pseudorapidity (η) and transverse momentum (p_{T}) with respect to the proton beam direction. The nuclear modification factor for charged particles is determined as a function of η between -4.8<η<-2.5 (backward region) and 2.0<η<4.8 (forward region), and p_{T} between 0.2<p_{T}<8.0  GeV/c. The results show a suppression of charged particle production in proton-lead collisions relative to proton-proton collisions in the forward region and an enhancement in the backward region for p_{T} larger than 1.5  GeV/c. This measurement constrains nuclear PDFs and saturation models at previously unexplored values of the parton momentum fraction down to 10^{-6}.

Directed evolution driving the generation of an efficient keratinase variant to facilitate the feather degradation

Keratinases can specifically degrade keratins, which widely exist in hair, horns, claws and human skin. There is a great interest in developing keratinase to manage keratin waste generated by the poultry industry and reusing keratin products in agriculture, medical treatment and feed industries. Degradation of keratin waste by keratinase is more environmentally friendly and more sustainable compared with chemical and physical methods. However, the wild-type keratinase-producing strains usually cannot meet the requirements of industrial production, and some are pathogenic, limiting their development and utilization. The main purpose of this study is to improve the catalytic performance of keratinase via directed evolution technology for the degradation of feathers. We first constructed a mutant library through error-prone PCR and screened variants with enhanced enzyme activity. The keratinase activity was further improved through fermentation conditions optimization and fed-batch strategies in a 7-L bioreactor. As a result, nine mutants with enhanced activity were identified and the highest enzyme activity was improved from 1150 to 8448 U/mL finally. The mutant achieved efficient biodegradation of feathers, increasing the degradation rate from 49 to 88%. Moreover, a large number of amino acids and soluble peptides were obtained as degradation products, which were excellent protein resources to feed. Therefore, the study provided a keratinase mutant with application potential in the management of feather waste and preparation of protein feed additive.

Pregnancy outcome after in-vitro fertilization/intracytoplasmic sperm injection in women with congenital uterus didelphys

OBJECTIVE

To investigate the pregnancy and obstetric outcomes of patients with congenital uterus didelphys who achieved clinical pregnancy after in-vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI).

METHODS

This was a retrospective matched-cohort study of 83 infertile patients with uterus didelphys who underwent IVF/ICSI and achieved clinical pregnancy from January 2005 to December 2018 at our center. For each patient in the study group, three control patients with normal uterine morphology who underwent IVF/ICSI in 2018 were selected randomly. Patients in the two groups were matched for number of gestational sacs, maternal age, infertility type, cause of infertility, fertilization method, endometrial thickness 1 day before embryo transfer and number of embryos transferred. The classification of congenital uterine anomalies was based on the American Fertility Society system (1988). The pregnancy and obstetric outcomes of the didelphic and control groups were compared separately for singleton and twin pregnancies, and for all pregnancies combined.

RESULTS

In singleton pregnancies, women with uterus didelphys had increased risk of preterm birth (odds ratio (OR), 4.68; rate difference (RD), 0.14; P < 0.001), Cesarean section (OR, 2.80; RD, 0.17; P = 0.016) and birth weight < 2500 g (OR, 4.06; RD, 0.10; P = 0.017) compared to women with normal uterine morphology. In twin pregnancies, the presence of uterus didelphys was associated with increased risk of preterm delivery (OR, 4.79; RD, 0.37; P = 0.006), perinatal mortality (OR, 3.16; RD, 0.19; P = 0.043) and birth weight < 2500 g (OR, 9.57; RD, 0.35; P = 0.001).

CONCLUSIONS

The presence of uterus didelphys was associated with significantly increased risk of some adverse pregnancy outcomes compared to pregnancies with normal uterine morphology in women who underwent IVF/ICSI. A twin pregnancy in women with uterus didelphys was associated with worse perinatal outcome. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Study of Z Bosons Produced in Association with Charm in the Forward Region

Events containing a Z boson and a charm jet are studied for the first time in the forward region of proton-proton collisions. The data sample used corresponds to an integrated luminosity of 6  fb^{-1} collected at a center-of-mass energy of 13 TeV with the LHCb detector. In events with a Z boson and a jet, the fraction of charm jets is determined in intervals of Z-boson rapidity in the range 2.0<y(Z)<4.5. A sizable enhancement is observed in the forwardmost y(Z) interval, which could be indicative of a valencelike intrinsic-charm component in the proton wave function.

Evidence for a New Structure in the J/ψp and J/ψp[over ¯] Systems in B_{s}^{0}→J/ψpp[over ¯] Decays

An amplitude analysis of flavor-untagged B_{s}^{0}→J/ψpp[over ¯] decays is performed using a sample of 797±31 decays reconstructed with the LHCb detector. The data, collected in proton-proton collisions between 2011 and 2018, correspond to an integrated luminosity of 9  fb^{-1}. Evidence for a new structure in the J/ψp and J/ψp[over ¯] systems with a mass of 4337_{-4}^{+7} _{-2}^{+2}  MeV and a width of 29_{-12}^{+26} _{-14}^{+14}  MeV is found, where the first uncertainty is statistical and the second systematic, with a significance in the range of 3.1 to 3.7σ, depending on the assigned J^{P} hypothesis.

Analysis of Neutral B-Meson Decays into Two Muons

Branching fraction and effective lifetime measurements of the rare decay B_{s}^{0}→μ^{+}μ^{-} and searches for the decays B^{0}→μ^{+}μ^{-} and B_{s}^{0}→μ^{+}μ^{-}γ are reported using proton-proton collision data collected with the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV, corresponding to a luminosity of 9  fb^{-1}. The branching fraction B(B_{s}^{0}→μ^{+}μ^{-})=(3.09_{-0.43-0.11}^{+0.46+0.15})×10^{-9} and the effective lifetime τ(B_{s}^{0}→μ^{+}μ^{-})=2.07±0.29±0.03  ps are measured, where the first uncertainty is statistical and the second systematic. No significant signal for B^{0}→μ^{+}μ^{-} and B_{s}^{0}→μ^{+}μ^{-}γ decays is found and upper limits B(B^{0}→μ^{+}μ^{-})<2.6×10^{-10} and B(B_{s}^{0}→μ^{+}μ^{-}γ)<2.0×10^{-9} at the 95% C.L. are determined, where the latter is limited to the range m_{μμ}>4.9  GeV/c^{2}. The results are in agreement with the standard model expectations.

Phospholipids (PLs) know-how: exploring and exploiting phospholipase D for its industrial dissemination

Owing to their numerous nutritional and bioactive functions, phospholipids (PLs), which are major components of biological membranes in all living organisms, have been widely applied as nutraceuticals, food supplements, and cosmetic ingredients. To date, PLs are extracted solely from soybean or egg yolk, despite the diverse market demands and high cost, owing to a tedious and inefficient manufacturing process. A microbial-based manufacturing process, specifically phospholipase D (PLD)-based biocatalysis and biotransformation process for PLs, has the potential to address several challenges associated with the soybean- or egg yolk-based supply chain. However, poor enzyme properties and inefficient microbial expression systems for PLD limit their wide industrial dissemination. Therefore, sourcing new enzyme variants with improved properties and developing advanced PLD expression systems are important. In the present review, we systematically summarize recent achievements and trends in the discovery, their structural properties, catalytic mechanisms, expression strategies for enhancing PLD production, and its multiple applications in the context of PLs. This review is expected to assist researchers to understand current advances in this field and provide insights for further molecular engineering efforts toward PLD-mediated bioprocessing.

Improving the Intensity of Integrated Expression for Microbial Production

Chromosomal integration of exogenous genes is preferred for industrially related fermentation, as plasmid-mediated fermentation leads to extra metabolic burden and genetic instability. Moreover, with the development and advancement of genome engineering and gene editing technologies, inserting genes into chromosomes has become more convenient; integration expression is extensively utilized in microorganisms for industrial bioproduction and expected to become the trend of recombinant protein expression. However, in actual research and application, it is important to enhance the expression of heterologous genes at the host genome level. Herein, we summarized the basic principles and characteristics of genomic integration; furthermore, we highlighted strategies to improve the expression of chromosomal integration of genes and pathways in host strains from three aspects, including chassis cell optimization, regulation of expression elements in gene expression cassettes, optimization of gene dose level and integration sites on chromosomes. Moreover, we reviewed and summarized the relevant studies on the application of integrated expression in the exploration of gene function and the various types of industrial microorganism production. Consequently, this review would serve as a reference for the better application of integrated expression.

Branching Fraction Measurements of the Rare B_{s}^{0}→ϕμ^{+}μ^{-} and B_{s}^{0}→f_{2}^{'}(1525)μ^{+}μ^{-} Decays

The branching fraction of the rare B_{s}^{0}→ϕμ^{+}μ^{-} decay is measured using data collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV, corresponding to integrated luminosities of 1, 2, and 6  fb^{-1}, respectively. The branching fraction is reported in intervals of q^{2}, the square of the dimuon invariant mass. In the q^{2} region between 1.1 and 6.0  GeV^{2}/c^{4}, the measurement is found to lie 3.6 standard deviations below a standard model prediction based on a combination of light cone sum rule and lattice QCD calculations. In addition, the first observation of the rare B_{s}^{0}→f_{2}^{'}(1525)μ^{+}μ^{-} decay is reported with a statistical significance of 9 standard deviations and its branching fraction is determined.

Review of arginase as a promising biocatalyst: characteristics, preparation, applications and future challenges

As a committed step in the urea cycle, arginase cleaves l-arginine to form l-ornithine and urea. l-Ornithine is essential to: cell proliferation, collagen formation and other physiological functions, while the urea cycle itself converts highly toxic ammonia to urea for excretion. Recently, arginase was exploited as an efficient catalyst for the environmentally friendly synthesis of l-ornithine, an abundant nonprotein amino acid that is widely employed as a food supplement and nutrition product. It was also proposed as an arginine-reducing agent in order to treat arginase deficiency and to be a means of depleting arginine to treat arginine auxotrophic tumors. Targeting arginase inhibitors of the arginase/ornithine pathway offers great promise as a therapy for: cardiovascular, central nervous system diseases and cancers with high arginase expression. In this review, recent advances in the characteristics, structure, catalytic mechanism and preparation of arginase were summarized, with a focus being placed on the biotechnical and medical applications of arginase. In particular, perspectives have been presented on the challenges and opportunities for the environmentally friendly utilization of arginase during l-ornithine production and in therapies.

Observation of the Mass Difference between Neutral Charm-Meson Eigenstates

A measurement of mixing and CP violation in neutral charm mesons is performed using data reconstructed in proton-proton collisions collected by the LHCb experiment from 2016 to 2018, corresponding to an integrated luminosity of 5.4  fb^{-1}. A total of 30.6 million D^{0}→K_{S}^{0}π^{+}π^{-} decays are analyzed using a method optimized for the measurement of the mass difference between neutral charm-meson eigenstates. Allowing for CP violation in mixing and in the interference between mixing and decay, the mass and decay-width differences are measured to be x_{CP}=[3.97±0.46(stat)±0.29(syst)]×10^{-3} and y_{CP}=[4.59±1.20(stat)±0.85(syst)]×10^{-3}, respectively. The CP-violating parameters are measured as Δx=[-0.27±0.18(stat)±0.01(syst)]×10^{-3} and Δy=[0.20±0.36(stat)±0.13(syst)]×10^{-3}. This is the first observation of a nonzero mass difference in the D^{0} meson system, with a significance exceeding seven standard deviations. The data are consistent with CP symmetry and improve existing constraints on the associated parameters.

Observation of New Resonances Decaying to J/ψK^{+} and J/ψϕ

The first observation of exotic states with a new quark content cc[over ¯]us[over ¯] decaying to the J/ψK^{+} final state is reported with high significance from an amplitude analysis of the B^{+}→J/ψϕK^{+} decay. The analysis is carried out using proton-proton collision data corresponding to a total integrated luminosity of 9  fb^{-1} collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV. The most significant state, Z_{cs}(4000)^{+}, has a mass of 4003±6_{-14}^{+4}  MeV, a width of 131±15±26  MeV, and spin parity J^{P}=1^{+}, where the quoted uncertainties are statistical and systematic, respectively. A new 1^{+}  X(4685) state decaying to the J/ψϕ final state is also observed with high significance. In addition, the four previously reported J/ψϕ states are confirmed and two more exotic states, Z_{cs}(4220)^{+} and X(4630), are observed with significance exceeding 5 standard deviations.