Observation of an a_{0}-like State with Mass of 1.817 GeV in the Study of D_{s}^{+}→K_{S}^{0}K^{+}π^{0} Decays

Using e^{+}e^{-} annihilation data corresponding to an integrated luminosity of 6.32  fb^{-1} collected at center-of-mass energies between 4.178 and 4.226 GeV with the BESIII detector, we perform the first amplitude analysis of the decay D_{s}^{+}→K_{S}^{0}K^{+}π^{0} and determine the relative branching fractions and phases for intermediate processes. We observe an a_{0}-like state with mass of 1.817 GeV in its decay to K_{S}^{0}K^{+} for the first time. In addition, we measure the ratio {B[D_{s}^{+}→K[over ¯]^{*}(892)^{0}K^{+}]/B[D_{s}^{+}→K[over ¯]^{0}K^{*}(892)^{+}]} to be 2.35_{-0.23stat}^{+0.42}±0.10_{syst}. Finally, we provide a precision measurement of the absolute branching fraction B(D_{s}^{+}→K_{S}^{0}K^{+}π^{0})=(1.46±0.06_{stat}±0.05_{syst})%.

Precise Measurements of Decay Parameters and CP Asymmetry with Entangled Λ-Λ[over ¯] Pairs

Based on 10 billion J/ψ events collected at the BESIII experiment, a search for CP violation in Λ decay is performed in the difference between CP-odd decay parameters α_{-} for Λ→pπ^{-} and α_{+} for Λ[over ¯]→p[over ¯]π^{+} by using the process e^{+}e^{-}→J/ψ→ΛΛ[over ¯]. With a five-dimensional fit to the full angular distributions of the daughter baryon, the most precise values for the decay parameters are determined to be α_{-}=0.7519±0.0036±0.0024 and α_{+}=-0.7559±0.0036±0.0030, respectively. The Λ and Λ[over ¯] averaged value of the decay parameter is extracted to be α_{avg}=0.7542±0.0010±0.0024 with unprecedented accuracy. The CP asymmetry A_{CP}=(α_{-}+α_{+})/(α_{-}-α_{+}) is determined to be -0.0025±0.0046±0.0012, which is one of the most precise measurements in the baryon sector. The reported results for the decay parameter will play an important role in the studies of the polarizations and CP violations for the strange, charmed and beauty baryons.

First Observation of the Direct Production of the χ_{c1} in e^{+}e^{-} Annihilation

We study the direct production of the J^{PC}=1^{++} charmonium state χ_{c1}(1P) in electron-positron annihilation by carrying out an energy scan around the mass of the χ_{c1}(1P). The data were collected with the BESIII detector at the BEPCII collider. An interference pattern between the signal process e^{+}e^{-}→χ_{c1}(1P)→γJ/ψ→γμ^{+}μ^{-} and the background processes e^{+}e^{-}→γ_{ISR}J/ψ→γ_{ISR}μ^{+}μ^{-} and e^{+}e^{-}→γ_{ISR}μ^{+}μ^{-} is observed by combining all the data samples. The χ_{c1}(1P) signal is observed with a significance of 5.1σ. This is the first observation of a C-even state directly produced in e^{+}e^{-} annihilation. The electronic width of the χ_{c1}(1P) resonance is determined to be Γ_{ee}=(0.12_{-0.08}^{+0.13})  eV, which is of the same order of magnitude as theoretical calculations.

Evidence for a Neutral Near-Threshold Structure in the K_{S}^{0} Recoil-Mass Spectra in e^{+}e^{-}→K_{S}^{0}D_{s}^{+}D^{*-} and e^{+}e^{-}→K_{S}^{0}D_{s}^{*+}D^{-}

We study the processes e^{+}e^{-}→K_{S}^{0}D_{s}^{+}D^{*-} and e^{+}e^{-}→K_{S}^{0}D_{s}^{*+}D^{-}, as well as their charge conjugated processes, at five center-of-mass energies between 4.628 and 4.699 GeV, using data samples corresponding to an integrated luminosity of 3.8  fb^{-1} collected by the BESIII detector at the BEPCII storage ring. Based on a partial reconstruction technique, we find evidence of a structure near the thresholds for D_{s}^{+}D^{*-} and D_{s}^{*+}D^{-} production in the K_{S}^{0} recoil-mass spectrum, which we refer to as the Z_{cs}(3985)^{0}. Fitting with a Breit-Wigner line shape, we find the mass of the structure to be (3992.2±1.7±1.6)  MeV/c^{2} and the width to be (7.7_{-3.8}^{+4.1}±4.3)  MeV, where the first uncertainties are statistical and the second are systematic. The significance of the Z_{cs}(3985)^{0} signal is found to be 4.6σ including both the statistical and systematic uncertainty. We report the Born cross section multiplied by the branching fraction at different energy points. The mass of the Z_{cs}(3985)^{0} is close to that of the Z_{cs}(3985)^{+}. Assuming SU(3) symmetry, the cross section of the neutral channel is consistent with that of the charged one. Hence, we conclude that the Z_{cs}(3985)^{0} is the isospin partner of the Z_{cs}(3985)^{+}.

Observation of Resonance Structures in e^{+}e^{-}→π^{+}π^{-}ψ_{2}(3823) and Mass Measurement of ψ_{2}(3823)

Using a data sample corresponding to an integrated luminosity of 11.3  fb^{-1} collected at center-of-mass energies from 4.23 to 4.70 GeV with the BESIII detector, we measure the product of the e^{+}e^{-}→π^{+}π^{-}ψ_{2}(3823) cross section and the branching fraction B[ψ_{2}(3823)→γχ_{c1}]. For the first time, resonance structure is observed in the cross section line shape of e^{+}e^{-}→π^{+}π^{-}ψ_{2}(3823) with significances exceeding 5σ. A fit to data with two coherent Breit-Wigner resonances modeling the sqrt[s]-dependent cross section yields M(R_{1})=4406.9±17.2±4.5  MeV/c^{2}, Γ(R_{1})=128.1±37.2±2.3  MeV, and M(R_{2})=4647.9±8.6±0.8  MeV/c^{2}, Γ(R_{2})=33.1±18.6±4.1  MeV. Though weakly disfavored by the data, a single resonance with M(R)=4417.5±26.2±3.5  MeV/c^{2}, Γ(R)=245±48±13  MeV is also possible to interpret data. This observation deepens our understanding of the nature of the vector charmoniumlike states. The mass of the ψ_{2}(3823) state is measured as (3823.12±0.43±0.13)  MeV/c^{2}, which is the most precise measurement to date.

Physical activity patterns, genetic susceptibility, and risk of hip/knee osteoarthritis: a prospective cohort study based on the UK Biobank

OBJECTIVES

The effect of physical activity on hip/knee osteoarthritis (OA) and how it varies by genetic susceptibility to OA remains inconclusive.

METHODS

In a cohort study of UK Biobank, 436,166 OA-free participants were recruited in 2006-2010 and followed for knee/hip OA until the end of 2020. 28 physical activity-related items were collected at baseline. Cox regression was used to estimate associations between physical activity behaviors, as well as major activity patterns (i.e., significant principal components[PCs] identified by principal component analysis), and risk of OA, adjusting for multiple confounders. We further stratified the analyses by polygenic risk score (PRS) for OA to examine the impact of genetic susceptibility to OA on the studied association.

RESULTS

During a mean follow-up of 11.15 years, 13,227 hip and 21,119 knee OA cases were identified. 19, out of 28, studied items showed associations with increased OA risk. Compared with low adherence group(<1^st tertile of PC score for each pattern), individuals with high adherence to five identified patterns were associated with increased risk of OA. The moderate adherence to "strenuous sports"(HR = 0.93, 95%CI: 0.89-0.97) and "walking for pleasure"(HR = 0.93, 95%CI: 0.89-0.98) patterns was associated with reduced OA. Similar risk patterns were obtained in the stratified analysis by PRS levels for OA.

CONCLUSION

High intensity of most activity patterns were associated with increased OA. However, a protective effect was suggested for moderate adherence to patterns of "strenuous sports" and "walking for pleasure" that consistent across different genetic susceptibilities, underscoring the potential benefits of moderate-intensity physical activity on OA.

Regularized Spectral Spike Response Model: A Neuron Model for Robust Parameter Reduction

The modeling procedure of current biological neuron models is hindered by either hyperparameter optimization or overparameterization, which limits their application to a variety of biologically realistic tasks. This article proposes a novel neuron model called the Regularized Spectral Spike Response Model (RSSRM) to address these issues. The selection of hyperparameters is avoided by the model structure and fitting strategy, while the number of parameters is constrained by regularization techniques. Twenty firing simulation experiments indicate the superiority of RSSRM. In particular, after pruning more than 99% of its parameters, RSSRM with 100 parameters achieves an RMSE of 5.632 in membrane potential prediction, a VRD of 47.219, and an F1-score of 0.95 in spike train forecasting with correct timing (±1.4 ms), which are 25%, 99%, 55%, and 24% better than the average of other neuron models with the same number of parameters in RMSE, VRD, F1-score, and correct timing, respectively. Moreover, RSSRM with 100 parameters achieves a memory use of 10 KB and a runtime of 1 ms during inference, which is more efficient than the Izhikevich model.

[Exploring Japanese Kampo medicine in fighting epidemics: discovering and popularising croton and satou as 'specific drugs' to treat cholera]

Japanese Kampo medicine (medicine with Han Fang) was found effective to treat some epidemic diseases.Historical records show that Namikawa Saimin, a Kampo medicine (Han Fang Medicine) practitioner during the cholera pandemic in the period of Ansei in Japan (1858-1860), discovered that the treatment effect of croton fruit against cholera was remarkable. Another physician in Naniwa also found that satou (Zhǎ Dá, visceral stones of animals and livestock) had the same effect in treating cholera. Subsequently, Wani Tadatane, an official physician in Komatsu Han of Iyo Province, learned about Namikawa Saimin and the use of croton fruit, and a medical officer in Kohofu, Masugi Fuminori, also heard of the story of the physician from Naniwa. Wani Tadatane and Masugi Fuminori verified the effect of croton fruit and satou on cholera treatment respectively. They regarded these two medical materials as the 'specific drugs' for cholera treatment by drawing on the interpretation and understanding of traditional Chinese medicine in terms of the efficacy of these two drugs. In this sense, croton fruit as a 'specific drug' for cholera treatment was widely accepted in the Kampo medical field (Han medicine area in Japan). The development of the use of satou by Masugi Fuminori could not be traced back because of the lack of historical records.

First Measurement of High-Energy Reactor Antineutrinos at Daya Bay

This Letter reports the first measurement of high-energy reactor antineutrinos at Daya Bay, with nearly 9000 inverse beta decay candidates in the prompt energy region of 8-12 MeV observed over 1958 days of data collection. A multivariate analysis is used to separate 2500 signal events from background statistically. The hypothesis of no reactor antineutrinos with neutrino energy above 10 MeV is rejected with a significance of 6.2 standard deviations. A 29% antineutrino flux deficit in the prompt energy region of 8-11 MeV is observed compared to a recent model prediction. We provide the unfolded antineutrino spectrum above 7 MeV as a data-based reference for other experiments. This result provides the first direct observation of the production of antineutrinos from several high-Q_{β} isotopes in commercial reactors.

Observation of a State X(2600) in the π^{+}π^{-}η' System in the Process J/ψ→γπ^{+}π^{-}η'

Based on (10087±44)×10^{6}  J/ψ events collected with the BESIII detector, the process J/ψ→γπ^{+}π^{-}η^{'} is studied using two largest decay channels of the η^{'} meson, η^{'}→γπ^{+}π^{-} and η^{'}→ηπ^{+}π^{-}, η→γγ. A new resonance, which we denote as the X(2600), is observed with a statistical significance larger than 20σ in the π^{+}π^{-}η^{'} invariant mass spectrum, and it has a connection to a structure around 1.5  GeV/c^{2} in the π^{+}π^{-} invariant mass spectrum. A simultaneous fit on the π^{+}π^{-}η^{'} and π^{+}π^{-} invariant mass spectra with the two η^{'} decay modes indicates that the mass and width of the X(2600) state are 2618.3±2.0_{-1.4}^{+16.3}  MeV/c^{2} and 195±5_{-17}^{+26}  MeV, where the first uncertainties are statistical, and the second systematic.

[Evaluation of severity and prognosis of acute pancreatitis by CT severity index and modified CT severity index]

Objectives: To explore the role of computed tomography (CT) severity index (CTSI) and modified CT severity index (MCTSI) in assessing the severity of acute pancreatitis (AP) under the revised Atlanta classification (RAC) and predicting the clinical prognosis. Methods: Based on the prospectively entered AP database, the clinical data of consecutive adult AP inpatients admitted to the Department of Gastroenterology of the First Affiliated Hospital of Nanchang University from January 2012 to December 2020 were retrospectively screened. The imaging data were independently evaluated by two radiologists and entered to the database to calculate the CTSI and MCTSI scores. Their relationship with the difference of RAC severity grade and clinical prognosis was analyzed. Compared with Acute Physiology and Chronic Health Assessment Ⅱ (APACHE Ⅱ) score, the receiver operating characteristic curve was used to evaluate the predictive value of CTSI and MCTSI scores for persistent organ failure and infectious pancreatic necrosis (IPN). Results: A total of 2 612 patients with AP, aged (50±15) years, were included in the study, including 1 547 males (59.2%) and 1 065 females (40.8%). According to RAC standard, AP was divided into 699 cases (26.8%) of mild pancreatitis (MAP), 1 098 cases (42.0%) of moderately severe pancreatitis (MSAP), and 815 cases (31.2%) of severe pancreatitis (SAP). MCTSI judged AP severity similarly to RAC, with 668 cases of MAP (25.6%), 1 207 cases of MSAP (46.2%) and 737 cases of SAP (28.2%), while CTSI judged SAP patients less(400 cases, 15.3%). The severity of AP determined by CTSI and MCTSI scores was significantly correlated with clinical prognosis (r=0.06-0.43, all P<0.05). Compared with APACHE Ⅱ score, CTSI had the highest area under the curve (AUC) for predicting IPN (AUC=0.85, 95%CI: 0.83-0.87), followed by MCTSI (AUC=0.82, 95%CI: 0.80-0.85). APACHE Ⅱ was more accurate in predicting persistent organ failure than CTSI and MCTSI scores,with AUC of 0.73 (95%CI: 0.71-0.75), 0.72 (95%CI: 0.70-0.74) and 0.72 (95%CI: 0.70-0.74), respectively. Conclusions: AP severity judged by MCTSI is consistent with RAC, and SAP patients judged by CTSI are less than RAC. CTSI and MCTSI are significantly correlated with clinical prognosis. CTSI and MCTSI have higher accuracy in predicting IPN, but lower accuracy in predicting persistent organ failure than APACHE Ⅱ.

Observation of J/ψ Electromagnetic Dalitz Decays to X(1835), X(2120), and X(2370)

Using a sample of about 10^{10}  J/ψ events collected at a center-of-mass energy sqrt[s]=3.097  GeV with the BESIII detector, the electromagnetic Dalitz decays J/ψ→e^{+}e^{-}π^{+}π^{-}η^{'}, with η^{'}→γπ^{+}π^{-} and η^{'}→π^{+}π^{-}η, have been studied. The decay J/ψ→e^{+}e^{-}X(1835) is observed with a significance of 15σ, and also an e^{+}e^{-} invariant-mass dependent transition form factor of J/ψ→e^{+}e^{-}X(1835) is presented for the first time. The intermediate states X(2120) and X(2370) are also observed in the π^{+}π^{-}η^{'} invariant-mass spectrum with significances of 5.3σ and 7.3σ. The corresponding product branching fractions for J/ψ→e^{+}e^{-}X, X→π^{+}π^{-}η^{'} [X=X(1835), X(2120), and X(2370)] are reported.

P-378 Effect of luteinized unruptured follicle on the pregnancy outcomes of single high-quality frozen-thawed blastocyst transfer cycles

Study question

Does luteinized unruptured follicle affect the clinical outcome of natural cycles for single high-quality frozen-thawed blastocyst transfer (FBT) cycles?

Summary answer

Luteinized unruptured follicle negatively affects the pregnancy outcomes of single high-quality FBT.

What is known already

Recent evidence revealed that natural ovulation cycle with a corpus luteum for frozen-thawed embryo transfer is superior to hormone replacing therapy cycle in preventing early miscarriage and preeclampsia. However, it remains controversial whether a luteinized unruptured follicle of the natural cycle affect the pregnancy outcomes of FBT.

Study design, size, duration

This was a retrospective cohort study comparing the pregnancy outcomes of singe high-quality FBT among 283 cases of LUF cycles and 1083 cases of ovulation cycles between January 2015 to December 2020 in a private fertility center. The study was approved by the hospital's Ethics Committee.

Participants/materials, setting, methods

A natural cycle for FBT was performed for all included patients, and was categorized into LUF or ovulation group based on the continuously monitoring of transvaginal ultrasound. Pregnancy outcomes were compared between the two groups. Logistic regression analysis was performed to adjust for important confounders. P &lt; 0.05 was considered statistically significant.

Main results and the role of chance

Compared to ovulation group, the LUF group was associated with higher proportion of female indication of IVF treatment. There were no statistically significant differences regarding the parental age at oocyte retrieval, body mass index (BMI), cycle rank, infertility duration, proportion of nulliparity and fertilization method, endometrial thickness, and estrogen levels. P levers were higher in the ovulation group than those of LUF (P =0.028). Logistic regression indicated that after controlling for potential confounders, ovulation group was associated with higher incidence of ongoing pregnancy (aOR 1.460, 95% CI: 1.107-1.924) and live birth (aOR 1.455, 95% CI: 1.102-1.919). Ovulation group also had higher clinical pregnancy rate (aOR 1.255, 95% CI: 0.952-1.656) and lower early miscarriage rate (aOR 0.654, 95% CI: 0.394-1.087), but not reach statistical significance. Our results suggested that LUF negatively affected pregnancy outcomes of single high-quality FBT.

Limitations, reasons for caution

The primary limitation of this study was its retrospective nature, and it was difficult to distinguish some confounding factors.

Wider implications of the findings

Clinicians should counsel couples about the negative effect of LUF on the pregnancy outcome of FBT, particularly for those with few high-quality embryos.

Trial registration number

2018YFC1003900/2018YFC1003904, SZSM201502035

O-191 Endometriosis is associated with a lowered cumulative live birth rate by alters the macrophage polarization and the cytokine concentrations in follicular fluid

Study question

The impact of endometriosis on the outcomes of ART is still ambiguous and the mechanism by which endometriosis impacts fertility has not been fully elucidated

Summary answer

Endometriosis was associated with low CLBR in IVF, which might be due to the change of follicular microenvironment and compromising the quality of embryos.

What is known already

Despite the great advantages of IVF treatment in endometriosis-linked infertility, the impact of endometriosis on outcomes of infertility management with ART is controversial and few studies focused on the association between endometriosis and CLBR. Numerous mechanisms have been proposed in an effort to delineate the multifaceted pathophysiology that induces impairment of reproductive dynamics in patients with endometriosis. Reactive oxygen species, dysregulation of the immune system and cellular architectural disruption constitute the crucial mechanisms that detrimentally affect oocyte and embryo developmental potential. 

Study design, size, duration

This study retrospectively included 433 patients with endometriosis and 1299 patients with tuber factor infertility to evaluate the impact of endometriosis on IVF pregnancy outcome between January 2016 and December 2018.The basic study prospectively recruited 30 patients with ovarian endometriosis and 35 controls with tubal factor infertility to analyze polarization stage of macrophages in their follicular fluid, and another 20 females with ovarian endometriosis and 30 controls to detect cytokines in their FF. 

Participants/materials, setting, methods

Data on all women undergoing fresh or frozen IVF treatment cycles were analysed to compare the CLBR between endometriosis and tuber factor infertility patients. A cytometry panel of 4 antibodies (CD45, CD3, CD80, CD163) was designed to enumerate the numbers of MI and MII macrophages from the cell sediment from FF samples. Quantibody® array was utilized to determine the concentration of 10 cytokines in FF, including IFN-γ, IL-1α, IL-1β, IL-10,IL-13,IL-4, IL-6, IL-8, MCP-1 and TNF-α. 

Main results and the role of chance

The results showed that patients with endometriosis were associated with noticeably fewer retrievable oocytes, a lower oocyte maturity rate, decreased numbers of available and high-quality embryos (all p &lt; 0.001) in comparison with the control group. The clinical pregnancy and live birth rate of the endometriosis group were lower in the frozen-thawed embryo transfer cycles (p = 0.028 and p = 0.008, respectively), which leading to a declined cumulative live birth rate (CLBR) (p = 0.001). Logistic regression analysis indicated a close association between endometriosis and low CLBR (p = 0.002). Furthermore, the numbers of type I and type II macrophages in follicular fluid (FF) of patients with ovarian endometriosis were significantly increased compared with the control group (p &lt; 0.001). The expressions of IL-1α, IL-1β, TNF-α, IL-6, IL-13, and IL-10 in FF were higher in endometrioma group(p &lt; 0.05). The increased expression of cytokines was negatively correlated with embryo outcomes, including the numbers of total oocytes retrieved, mature oocytes, and fertilized oocytes, and the numbers of high-quality blastocysts and embryos. Additionally, IL-6 and IL-8 were positively correlated with AMH, rate of available blastocysts, number of blastocysts formed and available blastocysts, but were negatively associated with rate of MII oocytes. 

Limitations, reasons for caution

The present study being of a retrospective and monocentric study, may not come to a very convincing conclusion, and some unknown biases might still exist due to possible underestimation of some confounders.

Wider implications of the findings

Collectively, our results indicate that endometriosis does adversely affect pregnancy outcomes of ART, as women with endometriosis produce a lower quantity of oocytes and embryos. Moreover, endometriosis might play a role in oocyte or embryo outcomes via regulating the production of cytokines or the number of immune cells in FF. 

Trial registration number

no

P-620 Hormone replacement therapy with GnRH agonist pretreatment improves pregnancy outcomes in patients with previous intrauterine adhesions

Study question

Is there an optimal endometrial preparation protocol of frozen-thawed embryo transfer (FET) for patients with history of intrauterine adhesions (IUAs)?

Summary answer

Hormone replacement therapy with GnRH agonist pretreatment (HRT+GnRHa) is superior to conventional HRT protocol to improve pregnancy outcomes in patients with IUAs.

What is known already

FET follow hysteroscopic adhesiolysis or therapeutic treatment is being widely adopted in patients with IUAs. Proper endometrial preparation plays a key role to maximize IVF success rate and improve pregnancy results. However, it remains unclear whether there is an optimal endometrial preparation protocol for patients with history of IUAs.

Study design, size, duration

This was a retrospective cohort study of 1002 FET cycles with history IUAs in our fertility center between January 2015 to December 2020. The study was approved by the hospital's Ethics Committee.

Participants/materials, setting, methods

Eight hundred and forty-two conventional HRT cycles and 160 HRT+GnRHa cycles met the inclusion criteria were enrolled. Pregnancy outcomes were compared between the two groups. Logistic regression analysis was performed to adjust for important confounders. P &lt; 0.05 was considered statistically significant.

Main results and the role of chance

The HRT+GnRHa group was associated with higher cycle rank (1.79 vs 2.17, P =0.026) and longer infertility duration (3.04 vs 3.69, P =0.000) compared with conventional HRT group. While the latter had a higher proportion of blastocyst embryo transferred (P =0.024). There were no statistically significant differences regarding the parental age at oocyte retrieval, body mass index (BMI), number of total embryos transferred and top embryo transferred, proportion of nulliparity, indication of IVF treatment and fertilization method, and endometrial thickness. Logistic regression indicated that after controlling for potential confounders, the HRT+GnRHa group achieved higher incidence of clinical pregnancy (aOR 1.474, 95% CI: 1.002-2.170, P =0.049), ongoing pregnancy (aOR 1.823, 95% CI: 1.207-2.753, P =0.004), and live birth (aOR 1.975, 95% CI: 1.306-2.988, P =0.000) than the conventional HRT group. The miscarriage rate was comparable between the two groups (aOR 0.613, 95% CI: 0.293-1.283, P =0.194). Our results suggested that HRT+GnRHa is over conventional HRT protocol to improve pregnancy outcomes of patients with previous IUAs.

Limitations, reasons for caution

The primary limitation of this study was its retrospective nature, and it was difficult to distinguish some confounding factors. Besides, there was no grading of IUA severity as most adhesion separation surgeries were not performed in our hospital, and the detailed medical history was not available.

Wider implications of the findings

Our study offers evidence for the superiority of HRT with GnRH-a pretreatment to conventional HRT protocol in improving the pregnancy prognosis of patients with previous IUAs. Our finding deserves further confirmation in clinical practice.

Trial registration number

2018YFC1003900/2018YFC1003904, SZSM201502035

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.

Quantitative Assessment of Electroencephalogram Reactivity in Comatose Patients on Extracorporeal Membrane Oxygenation

Objective assessment of the brain's responsiveness in comatose patients on Extracorporeal Membrane Oxygenation (ECMO) support is essential to clinical care, but current approaches are limited by subjective methodology and inter-rater disagreement. Quantitative electroencephalogram (EEG) algorithms could potentially assist clinicians, improving diagnostic accuracy. We developed a quantitative, stimulus-based algorithm to assess EEG reactivity features in comatose patients on ECMO support. Patients underwent a stimulation protocol of increasing intensity (auditory, peripheral, and nostril stimulation). A total of 129 20-s EEG epochs were collected from 24 patients (age [Formula: see text], 10 females, 14 males) on ECMO support with a Glasgow Coma Scale[Formula: see text]8. EEG reactivity scores ([Formula: see text]-scores) were calculated using aggregated spectral power and permutation entropy for each of five frequency bands ([Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text]. Parameter estimation techniques were applied to [Formula: see text]-scores to identify properties that replicate the decision process of experienced clinicians performing visual analysis. Spectral power changes from audio stimulation were concentrated in the [Formula: see text] band, whereas peripheral stimulation elicited an increase in spectral power across multiple bands, and nostril stimulation changed the entropy of the [Formula: see text] band. The findings of this pilot study on [Formula: see text]-score lay a foundation for a future prediction tool with clinical applications.

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.

High-precision measurement of the W boson mass with the CDF II detector

The mass of the W boson, a mediator of the weak force between elementary particles, is tightly constrained by the symmetries of the standard model of particle physics. The Higgs boson was the last missing component of the model. After observation of the Higgs boson, a measurement of the W boson mass provides a stringent test of the model. We measure the W boson mass, M_W, using data corresponding to 8.8 inverse femtobarns of integrated luminosity collected in proton-antiproton collisions at a 1.96 tera-electron volt center-of-mass energy with the CDF II detector at the Fermilab Tevatron collider. A sample of approximately 4 million W boson candidates is used to obtain [Formula: see text], the precision of which exceeds that of all previous measurements combined (stat, statistical uncertainty; syst, systematic uncertainty; MeV, mega-electron volts; c, speed of light in a vacuum). This measurement is in significant tension with the standard model expectation.

Radiographic indexes in AP hip radiographs prior to total hip arthroplasty reveal candidates with low BMD

Using anteroposterior (AP) hip radiograph, we measured several indexes to investigate the association with bone mineral density (BMD) before THA and found a highly effective index to predict femoral BMD. This technique is helpful for both patients and clinicians to identify potential candidates with low BMD to whom DXA examination is particularly recommended.

INTRODUCTION

The purpose of the study is to identify patients with low bone mineral density (BMD) prior to total hip arthroplasty with the help of AP hip radiographs.

METHODS

Indexes on AP hip radiographs and T-scores from DXA examination of the lumbar spine and the affected hip were acquired from patients before THA. Indexes measured on AP hip radiographs including the canal calcar ratio (CCR), canal flare index (CFI), morphological cortical index (MCI), canal bone ratio (CBR), and canal bone area ratio (CBAR). The relevance between indexes and the T-score of femora was evaluated by correlation analysis, and the diagnostic value of indexes for osteopenia was examined by receiver operating characteristic (ROC) curves.

RESULTS

A total of 81 patients were included. The average value of CBR-7, CBR-10, and CBAR (7-10) were highly related to the T-score of femora (r =  - 0.592, r =  - 0.634, and r =  - 0.631, respectively, p < 0.0001). Results of the intra- and interobserver variation assessment was excellent. CBR-7, CBR-10, and CBAR (7-10) were significantly different between the non-osteopenia and osteopenia groups (p < 0.0001). CBR-10 had the biggest area under curve (AUC), means the great diagnostic value for osteopenia in the proximal femora (AUC = 0.821, cutoff value = 0.3805).

CONCLUSION

The canal bone ratio at 10 × 10^-2 m under the level of the lesser trochanter proved to be a great indicator of femoral osteopenia. Trial registration Chinese Clinical Trail Registry, ChiCTR2000041016. Registered 16 December 2020-Retrospectively registered, http://www.chictr.org.cn/listbycreater.aspx .