Probing CP symmetry and weak phases with entangled double-strange baryons

Though immensely successful, the standard model of particle physics does not offer any explanation as to why our Universe contains so much more matter than antimatter. A key to a dynamically generated matter-antimatter asymmetry is the existence of processes that violate the combined charge conjugation and parity (CP) symmetry1. As such, precision tests of CP symmetry may be used to search for physics beyond the standard model. However, hadrons decay through an interplay of strong and weak processes, quantified in terms of relative phases between the amplitudes. Although previous experiments constructed CP observables that depend on both strong and weak phases, we present an approach where sequential two-body decays of entangled multi-strange baryon-antibaryon pairs provide a separation between these phases. Our method, exploiting spin entanglement between the double-strange Ξ- baryon and its antiparticle2 [Formula: see text], has enabled a direct determination of the weak-phase difference, (ξP - ξS) = (1.2 ± 3.4 ± 0.8) × 10-2 rad. Furthermore, three independent CP observables can be constructed from our measured parameters. The precision in the estimated parameters for a given data sample size is several orders of magnitude greater than achieved with previous methods3. Finally, we provide an independent measurement of the recently debated Λ decay parameter αΛ (refs. 4,5). The [Formula: see text] asymmetry is in agreement with and compatible in precision to the most precise previous measurement4.

Observation of the Singly Cabibbo Suppressed Decay Λ_{c}^{+}→nπ^{+}

The singly Cabibbo-suppressed decay Λ_{c}^{+}→nπ^{+} is observed for the first time with a statistical significance of 7.3σ by using 3.9  fb^{-1} of e^{+}e^{-} collision data collected at center-of-mass energies between 4.612 and 4.699 GeV with the BESIII detector at BEPCII. The branching fraction of Λ_{c}^{+}→nπ^{+} is measured to be (6.6±1.2_{stat}±0.4_{syst})×10^{-4}. By taking the upper limit of branching fractions of Λ_{c}^{+}→pπ^{0} from the Belle experiment, the ratio of branching fractions between Λ_{c}^{+}→nπ^{+} and Λ_{c}^{+}→pπ^{0} is calculated to be larger than 7.2 at the 90% confidence level, which disagrees with most predictions of the available phenomenological models. In addition, the branching fractions of the Cabibbo-favored decays Λ_{c}^{+}→Λπ^{+} and Λ_{c}^{+}→Σ^{0}π^{+} are measured to be (1.31±0.08_{stat}±0.05_{syst})×10^{-2} and (1.22±0.08_{stat}±0.07_{syst})×10^{-2}, respectively, which are consistent with previous results.

Treatment-related adverse events as predictive biomarkers of efficacy in patients with advanced neuroendocrine tumors treated with surufatinib: results from two phase III studies

Background

No validated biomarkers currently exist for predicting the efficacy outcomes in patients with neuroendocrine tumors (NETs) treated with antiangiogenic therapy. We aimed to evaluate the association between treatment-related adverse events (TRAEs) and efficacy outcomes of surufatinib in patients with advanced NET.

Patients and methods

We included patients with NET treated with surufatinib in two multicenter, randomized, double-blind, placebo-controlled, phase III trials (SANET-p and SANET-ep) in this study. The main exposure was the presence of any of the TRAEs including hypertension, proteinuria, and hemorrhage in the first 4 weeks of surufatinib treatment. The primary outcome of the study was investigator-assessed progression-free survival (PFS). PFS outcomes were estimated using the Kaplan–Meier method with the log-rank test. Hazard ratios (HRs) were calculated by using univariable and multivariable Cox proportional hazard regression models. Blinded independent image review committee (BIIRC) assessments and 4-week landmark analysis were also performed as supportive evaluations.

Results

During the study period, a total of 242 patients treated with surufatinib were included in the analysis, and 164 (68%) patients had at least one of hypertension, proteinuria, and hemorrhage in the first 4 weeks of treatment. The presence of TRAEs in the first 4 weeks was associated with prolonged median PFS [11.1 versus 9.2 months; HR 0.67, 95% confidence interval (CI) 0.47-0.97; P = 0.036]. In multivariable Cox regression analysis, the presence of TRAEs was also significantly associated with longer PFS (HR 0.65, 95% CI 0.44-0.97; P = 0.035). Similar results were obtained in the BIIRC assessments and 4-week landmark analysis.

Conclusions

Treatment-related hypertension, proteinuria, and hemorrhage could be potential biomarkers to predict antitumor efficacy of surufatinib in patients with advanced NET. Future prospective studies are needed to validate the findings.

Trial registration

ClinicalTrials.govNCT02589821; https://clinicaltrials.gov/ct2/show/NCT02589821 and ClinicalTrials.gov NCT02588170; https://clinicaltrials.gov/ct2/show/NCT02588170

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Treatment-related hypertension, proteinuria, or hemorrhage is associated with longer survival in NETs.

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The association is confirmed by the BIIRC assessments and 4-week landmark analysis.

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TRAEs can be biomarkers to predict antitumor efficacy in patients with NET.

Dexmedetomidine combined with endotracheal intubation laryngeal mask in anesthesia of patients with a cervical spine injury

OBJECTIVE

Tracheal intubation under general anesthesia is more likely to aggravate the injury of the cervical spine and spinal cord. We aim to explore the effect of dexmedetomidine combined with intubating laryngeal mask airway (ILMA) on anesthesia and stress response in patients with a cervical spine injury.

PATIENTS AND METHODS

One hundred twenty patients were retrospectively allocated into the control group (midazolam + ILMA) and intervention group (dexmedetomidine + ILMA). Their hemodynamics at T1 (before anesthesia induction), T2 (1 minute after anesthesia induction), T3 (immediately after intubation), and T4 (1 min after successful intubation) were also compared.

RESULTS

The heart rate (HR) and mean arterial pressure (MAP) of patients in the observation group were lower than those in the control group from T3 to T4 (both p = 0.000). Ramsay's score in the observation group was higher than the control group from T3 to T4 (both p= 0.000). No difference was observed in PaO2, PaCO2, and pH between the 2 groups. The level of serum cortisol (COR), plasma epinephrine (E), and norepinephrine (NE) in the observation group were lower than in the control group (p < 0.05) after induction.

CONCLUSIONS

Dexmedetomidine combined with ILMA could improve the first intubation success rate and tolerance in patients with cervical spine injury by maintaining stable hemodynamics and reducing the stress response of patients.

Measurement of the Cross Section for e^{+}e^{-}→Hadrons at Energies from 2.2324 to 3.6710 GeV

Based on electron-positron collision data collected with the BESIII detector operating at the Beijing Electron-Positron Collider II storage rings, the value of R≡σ(e^{+}e^{-}→hadrons)/σ(e^{+}e^{-}→μ^{+}μ^{-}) is measured at 14 center-of-mass energies from 2.2324 to 3.6710 GeV. The resulting uncertainties are less than 3.0% and are dominated by systematic uncertainties.

[Identification of traditional Chinese drugs containing active ingredients for treating myocardial infarction and analysis of their therapeutic mechanisms by network pharmacology and molecular docking]

OBJECTIVE

To identify traditional Chinese drugs that contain active ingredients for treatment of myocardial infarction (MI) and explore their therapeutic mechanisms using network pharmacology and molecular docking technology.

METHODS

The TCMSP database was used for screening the traditional Chinese drugs containing active ingredients for treating MI, and the related targets of MI and the candidate drugs were obtained from Genecards, OMIM, PharmGkb and PharmMapper databases. The common target network of the drug targets and disease targets was established using Venny2.1.0 software. GO and KEGG signal pathway enrichment analysis of the common targets was performed, and the protein-protein interaction (PPI) network was constructed for the targets. The targets in the PPI network were analyzed to identify the key targets, for which GO and KEGG pathway enrichment analyses were performed. Molecular docking was performed for the candidate ingredients and the key targets, and a total score ≥6 was used as the criteria for screening the therapeutic ingredients and their docking binding with key targets was verified. A human umbilical vein endothelial cell (HUVEC) model of oxygen-glucose deprivation (OGD) was used to validate the candidate ingredients and the key therapeutic targets for MI by Western blotting.

RESULTS

Our analysis identified Salvia miltiorrhiza and Dalbergiae odoriferae as the candidate drugs rich in active ingredients for treatment of MI. These ingredients involved 16 key therapeutic targets for MI, which participated in such biological processes as inflammatory response, angiogenesis, energy metabolism and oxidative stress and the pathways including HIF-1, VEGF, and TNF pathways. Sclareol and PTGS2 in Salvia miltiorrhiza and formononetin and KDR in Dalbergiae odoriferae all had high docking total scores. Western blotting showed that at medium and high doses, sclareol significantly inhibited PTGS2 expression and formononetin promoted KDR expressions in the cell models in a dose-dependent manner (P < 0.05).

CONCLUSION

Both Salvia miltiorrhiza and Dalbergiae odoriferae have good therapeutic effects on MI. Sclareol in Salvia miltiorrhiza and formononetin in Dalbergiae odoriferae regulate the expressions of KDR and PTGS2, respectively, to modulate the inflammatory response, angiogenesis, oxidative stress and energy metabolism and thus produce myocardial protective effects.

First Measurement of Polarizations in the Decay D^{0}→ωφ

Using a data sample corresponding to an integrated luminosity of 2.93  fb^{-1} collected at a center-of-mass energy sqrt[s]=3.773  GeV by the BESIII detector, the decay D^{0}→ωϕ is observed for the first time. The branching fraction is measured to be (6.48±0.96±0.40)×10^{-4} with a significance of 6.3σ, where the first and second uncertainties are statistical and systematic, respectively. An angular analysis reveals that the ϕ and ω mesons from the D^{0}→ωϕ decay are transversely polarized. The 95% confidence level upper limit on longitudinal polarization fraction is set to be less than 0.24, which is inconsistent with current theoretical expectations and challenges our understanding of the underlying dynamics in charm meson decays.

Pembrolizumab versus chemotherapy for patients with esophageal squamous cell carcinoma enrolled in the randomized KEYNOTE-181 trial in Asia

BACKGROUND

In the randomized phase III KEYNOTE-181 study, pembrolizumab prolonged overall survival (OS) compared with chemotherapy as second-line therapy in patients with advanced esophageal cancer and programmed death-ligand 1 (PD-L1) combined positive score (CPS) ≥10. We report a post hoc subgroup analysis of patients with esophageal squamous cell carcinoma (ESCC) enrolled in KEYNOTE-181 in Asia, including patients from the KEYNOTE-181 China extension study.

PATIENTS AND METHODS

Three hundred and forty Asian patients with advanced/metastatic ESCC were enrolled in KEYNOTE-181, including the China cohort. Patients were randomly assigned 1 : 1 to receive pembrolizumab 200 mg every 3 weeks for ≤2 years or investigator's choice of paclitaxel, docetaxel, or irinotecan. OS, progression-free survival, response, and safety were analyzed without formal comparisons. OS was evaluated based on PD-L1 CPS expression level.

RESULTS

In Asian patients with ESCC, median OS was 10.0 months with pembrolizumab and 6.5 months with chemotherapy [hazard ratio (HR), 0.63; 95% CI 0.50-0.80; nominal P < 0.0001]. Median progression-free survival was 2.3 months with pembrolizumab and 3.1 months with chemotherapy (HR, 0.79; 95% CI 0.63-0.99; nominal P = 0.020). Objective response rate was 17.1% with pembrolizumab and 7.1% with chemotherapy; median duration of response was 10.5 months and 7.7 months, respectively. In patients with PD-L1 CPS <1 tumors (pembrolizumab versus chemotherapy), the HR was 0.99 (95% CI 0.56-1.72); the HR (95% CI) for death was better for patients with PD-L1 CPS cut-offs >1 [CPS ≥1, 0.57 (0.44-0.75); CPS ≥5, 0.56 (0.41-0.76); CPS ≥10, 0.53 (0.37-0.75)]. Treatment-related adverse events were reported in 71.8% of patients in the pembrolizumab group and 89.8% in the chemotherapy group; grade 3-5 events were reported in 20.0% and 44.6%, respectively.

CONCLUSIONS

Pembrolizumab monotherapy demonstrated promising efficacy in Asian patients with ESCC, with fewer treatment-related adverse events than chemotherapy. PD-L1 CPS ≥1 is an appropriate cut-off and a predictive marker of pembrolizumab efficacy in Asian patients with ESCC.

Growth curve, blood parameters and carcass traits of grass-fed Angus steers

The increasing demand for natural products is currently transforming the meat industry, making grass-fed and finished beef a valuable option for improving profits. However, the transformation of conventional operations to grass-fed systems comprises many modifications, such as logistical, technological, and financial that could be very complex and expensive, involving economic risk. Therefore, in this study, we analyzed the growth curve, critical economic traits, and carcass quality and finished characteristics over several consecutive years in closely related grass-fed and finished Angus steers, to reduce the genetic effect on the results. We found that grass-fed steers require around 188 additional days to reach the market weight (approx. 470 kg) and had approximately 70% less average daily gain compared to the grain-fed and finished steers. Regression analysis demonstrated an interaction between feed and age (P < 0.01); thus, individual regressions were fitted for each regimen style, obtaining almost perfect linear curves for both treatments, which could be straightforwardly used in practical situations due to its simplicity. Six of eight carcass traits were different between grain-fed and grass-fed and finished steers. Hot-carcass weight, dressing, back fat, and quality grade were superior in grain-fed individuals, contrarily to yield grade and ribeye area/carcass ratio, which were better in grass-fed and finished steers (P < 0.05). Interestingly, the meat tenderness was certainly low and similar in both treatments (P = 0.25), indicating the feasibility of producing tender meat with animals under a grass-fed diet. Nevertheless, according to the quality grade analysis, grain-fed carcasses were greater ranked compared to grass-fed bodies (P < 0.01), regardless of their same tenderness. The results will provide valuable information for better understanding beef cattle in grass-feeding finishing systems, especially from weaning to harvest. Additionally, the study will expand the knowledge about the quality of meat obtained from animals that received grass exclusively, becoming relevant information for economic evaluation and management decisions for grass-based cattle operations.

Measurement of the Absolute Branching Fraction of D_{s}^{+}→τ^{+}ν_{τ} via τ^{+}→e^{+}ν_{e}ν[over ¯]_{τ}

Using a dataset of 6.32  fb^{-1} of e^{+}e^{-} annihilation data collected with the BESIII detector at center-of-mass energies between 4178 and 4226 MeV, we have measured the absolute branching fraction of the leptonic decay D_{s}^{+}→τ^{+}ν_{τ} via τ^{+}→e^{+}ν_{e}ν[over ¯]_{τ}, and find B_{D_{s}^{+}→τ^{+}ν_{τ}}=(5.27±0.10±0.12)×10^{-2}, where the first uncertainty is statistical and the second is systematic. The precision is improved by a factor of 2 compared to the previous best measurement. Combining with f_{D_{s}^{+}} from lattice quantum chromodynamics calculations or the |V_{cs}| from the CKMfitter group, we extract |V_{cs}|=0.978±0.009±0.012 and f_{D_{s}^{+}}=(251.1±2.4±3.0)  MeV, respectively. Combining our result with the world averages of B_{D_{s}^{+}→τ^{+}ν_{τ}} and B_{D_{s}^{+}→μ^{+}ν_{μ}}, we obtain the ratio of the branching fractions B_{D_{s}^{+}→τ^{+}ν_{τ}}/B_{D_{s}^{+}→μ^{+}ν_{μ}}=9.72±0.37, which is consistent with the standard model prediction of lepton flavor universality.

A Brief History of the Discovery of Amelogenin Nanoribbons In Vitro and In Vivo

Without evidence for an organic framework, biological and biochemical processes observed during amelogenesis provided limited information on how extracellular matrix proteins control the development of the complex fibrous architecture of human enamel. Over a decade ago, amelogenin nanoribbons were first observed from recombinant proteins during in vitro mineralization experiments in our laboratory. In enamel from mice lacking the enzyme kallikrein 4 (KLK4), we later uncovered ribbon-like protein structures that matched the morphology, width, and thickness of the nanoribbons assembled by recombinant proteins. Interestingly, similar structures had already been described since the 1960s, when enamel sections from various mammals were demineralized and stained for transmission electron microscopy analysis. However, at that time, researchers were not aware of the ability of amelogenin to form nanoribbons and instead associated the filamentous nanostructures with possible imprints of mineral ribbons in the gel-like matrix of developing enamel. Further evidence for the significance of amelogenin nanoribbons for enamel development was stipulated when recent mineralization experiments succeeded in templating and orienting the growth of apatite ribbons along the protein nanoribbon framework. This article provides a brief historical review of the discovery of amelogenin nanoribbons in our laboratory in the context of reports by others on similar structures in the developing enamel matrix.

Observation of D^{0}→K_{1}(1270)^{-}e^{+}ν_{e}

Using 2.93  fb^{-1} of e^{+}e^{-} collision data taken with the BESIII detector at a center-of-mass energy of 3.773 GeV, the observation of the D^{0}→K_{1}(1270)^{-}e^{+}ν_{e} semileptonic decay is presented. The statistical significance of the decay D^{0}→K_{1}(1270)^{-}e^{+}ν_{e} is greater than 10σ. The branching fraction of D^{0}→K_{1}(1270)^{-}e^{+}ν_{e} is measured to be (1.09±0.13_{-0.16}^{+0.09}±0.12)×10^{-3}. Here, the first uncertainty is statistical, the second is systematic, and the third originates from the assumed branching fraction of K_{1}(1270)^{-}→K^{-}π^{+}π^{-}. The fraction of longitudinal polarization in D^{0}→K_{1}(1270)^{-}e^{+}ν_{e} is determined for the first time to be 0.50±0.19_{stat}±0.08_{syst}.

First Measurement of the Absolute Branching Fraction of Λ→pμ^{-}ν[over ¯]_{μ}

The absolute branching fraction of Λ→pμ^{-}ν[over ¯]_{μ} is reported for the first time based on an e^{+}e^{-} annihilation sample of 10×10^{9}  J/ψ events collected with the BESIII detector at sqrt[s]=3.097  GeV. The branching fraction is determined to be B(Λ→pμ^{-}ν[over ¯]_{μ})=[1.48±0.21(stat)±0.08(syst)]×10^{-4}, which is improved by about 30% in precision over the previous indirect measurements. Combining this result with the world average of B(Λ→pe^{-}ν[over ¯]_{e}), we obtain the ratio {[Γ(Λ→pμ^{-}ν[over ¯]_{μ})]/[Γ(Λ→pe^{-}ν[over ¯]_{e})]} to be 0.178±0.028, which agrees with the standard model prediction assuming lepton flavor universality. The asymmetry of the branching fractions of Λ→pμ^{-}ν[over ¯]_{μ} and Λ[over ¯]→p[over ¯]μ^{+}ν_{μ} is also determined, and no evidence for CP violation is found.

The integrated stress response contributes to tRNA synthetase-associated peripheral neuropathy

Dominant mutations in ubiquitously expressed transfer RNA (tRNA) synthetase genes cause axonal peripheral neuropathy, accounting for at least six forms of Charcot-Marie-Tooth (CMT) disease. Genetic evidence in mouse and Drosophila models suggests a gain-of-function mechanism. In this study, we used in vivo, cell type–specific transcriptional and translational profiling to show that mutant tRNA synthetases activate the integrated stress response (ISR) through the sensor kinase GCN2 (general control nonderepressible 2). The chronic activation of the ISR contributed to the pathophysiology, and genetic deletion or pharmacological inhibition of Gcn2 alleviated the peripheral neuropathy. The activation of GCN2 suggests that the aberrant activity of the mutant tRNA synthetases is still related to translation and that inhibiting GCN2 or the ISR may represent a therapeutic strategy in CMT.

Molecular cloning and characterization of a novel aspartyl aminopeptidase from Trichinella spiralis

Trichinellosis is an important zoonotic parasitic disease worldwide and is principally caused by ingesting animal meat containing Trichinella infective larvae. Aspartyl aminopeptidase is an intracytoplasmic metalloproteinase that specifically hydrolyzes the N-terminus of polypeptides free of acidic amino acids (aspartic acid and glutamate), and plays an important role in the metabolism, growth and development of organisms. In this study, a novel T. spiralis aspartyl aminopeptidase (TsAAP) was cloned and expressed, and its biological properties and roles in worm growth and development were investigated. The results revealed that TsAAP transcription and expression in diverse T. spiralis stages were detected by RT-PCR and Western blotting, and primarily localized at cuticle, stichosome and intrauterine embryos of this nematode by immunofluorescence test. rTsAAP has the enzymatic activity of native AAP to hydrolyze the substrate H-Glu-pNA. There was a specific binding between rTsAAP and murine erythrocyte, and the binding site was localized in erythrocyte membrane proteins. Silencing of TsAAP gene by specific dsRNA significantly reduced the TsAAP expression, enzymatic activity, intestinal worm burdens and female fecundity. The results demonstrated that TsAAP participates in the growth, development and fecundity of T. spiralis and it might be a potential target molecule for anti-Trichinella vaccines.