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3.
Nat Commun ; 15(1): 6782, 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39117648

RESUMO

Intermetallic alloys have traditionally been characterized by their inherent brittleness due to their lack of sufficient slip systems and absence of strain hardening. However, here we developed a single-phase B2 high-entropy intermetallic alloy that is both strong and plastic. Unlike conventional intermetallics, this high-entropy alloy features a highly distorted crystalline lattice with complex chemical order, leading to multiple slip systems and high flow stress. In addition, the alloy exhibits a dynamic hardening mechanism triggered by dislocation gliding that preserves its strength across a wide range of temperatures. As a result, this high-entropy intermetallic circumvents precipitous thermal softening, with extensive plastic flows even at high homologous temperatures, outperforming a variety of both body-centered cubic and B2 alloys. These findings reveal a promising direction for the development of intermetallic alloys with broad engineering applications.

4.
bioRxiv ; 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39091808

RESUMO

Traumatic brain injury (TBI) remains a pervasive clinical problem associated with significant morbidity and mortality. However, TBI remains clinically and biophysically ill-defined, and prognosis remains difficult even with the standardization of clinical guidelines and advent of multimodality monitoring. Here we leverage a unique data set from TBI patients implanted with either intracranial strip electrodes during craniotomy or quad-lumen intracranial bolts with depth electrodes as part of routine clinical practice. By extracting spectral profiles of this data, we found that the presence of narrow-band oscillatory activity in the beta band (12-30 Hz) closely corresponds with the neurological exam as quantified with the standard Glasgow Coma Scale (GCS). Further, beta oscillations were distributed over the cortical surface as traveling waves, and the evolution of these waves corresponded to recovery from coma, consistent with the putative role of waves in perception and cognitive activity. We consequently propose that beta oscillations and traveling waves are potential biomarkers of recovery from TBI. In a broader sense, our findings suggest that emergence from coma results from recovery of thalamo-cortical interactions that coordinate cortical beta rhythms.

5.
Zhonghua Yi Xue Za Zhi ; 104(25): 2323-2329, 2024 Jul 02.
Artigo em Chinês | MEDLINE | ID: mdl-38951104

RESUMO

Objective: To investigate the effectiveness and safety of multimodal analgesia in patients with end-stage head and neck cancer in open gastrostomy surgery. Methods: This was a randomized controlled trial. From June to December 2023, 50 patients with end-stage head and neck cancer who underwent elective open gastrostomy surgery in Beijing Tongren Hospital Affiliated to Capital Medical University were prospectively selected. The patients were divided into multimodal analgesia group and local anesthesia group using the random number table method according to different anesthesia methods, with 25 cases in each group. In multimodal analgesia group, a multimodal analgesia regimen was adopted: ultrasound-guided abdominal wall nerve block (rectus sheath block and transverse abdominis plane block)+intravenous injection of oxycodone+intravenous injection of flurbiprofen axetil and dexamethasone. In local anesthesia group, local infiltration anesthesia with ropivacaine was adopted. The main outcome measure was the incidence of intraoperative pain numeric rating scale (NRS) score>3 points in the two groups. The secondary observation indicators included NRS score and hemodynamic indexes [mean arterial pressure (MAP) and heart rate (HR)] at various time points during surgery [before anesthesia (T0), at the time of incision (T1), 10 minutes after surgery (T2), during gastric body traction (T3), and at the end of surgery (T4)], incidence of adverse reactions, postoperative patient satisfaction score, as well as the NRS scores at rest and activity (coughing) within 24 hours after surgery. Results: The multimodal analgesia group included 21 males and 4 females, aged (61.4±9.9) years. There were 19 males and 6 females in the local anesthesia group, aged (58.6±10.8) years. The incidence of intraoperative NRS score>3 points and the incidence of salvage analgesia in the multimodal analgesia group were both 12.0% (3/25), which were lower than 60.0% (15/25) in the local anesthesia group, and the differences were statistically significant (all P<0.001); The NRS score [M (Q1, Q3)] at T3 in the multimodal analgesia group was 2 (2, 3) points, which were lower than 5 (3, 6) points in the local anesthesia group (P<0.05). There were smaller variabilities in MAP and HR in the multimodal analgesia group than those in the local anesthesia group (all P<0.05). The incidence of intraoperative tachycardia, surgical traction reaction, and nausea in the multimodal analgesia group was lower than that in the local anesthesia group (all P<0.05). The postoperative satisfaction score of patients in the multimodal analgesia group was (9.25±0.71) points, which were higher than (7.33±0.87) points in the local anesthesia group (P<0.001). NRS score during postoperative activity within 24 hours in the multimodal analgesia group were (2.36±0.75) points, which were lower than (3.03±0.81) points of the local anesthesia group (P=0.005). No adverse reactions such as urinary retention, nausea, vomiting and dizziness occurred in both groups. Conclusion: Compared with local anesthesia, the multimodal analgesic strategy could provide better analgesic effect and longer duration, better hemodynamic stability, and fewer intraoperative adverse reactions in patients with end-stage head and neck cancer undergoing open gastrostomy.


Assuntos
Analgesia , Gastrostomia , Neoplasias de Cabeça e Pescoço , Bloqueio Nervoso , Humanos , Neoplasias de Cabeça e Pescoço/cirurgia , Analgesia/métodos , Bloqueio Nervoso/métodos , Gastrostomia/métodos , Masculino , Anestesia Local , Dor Pós-Operatória , Feminino , Manejo da Dor/métodos , Estudos Prospectivos , Anestésicos Locais/administração & dosagem , Pessoa de Meia-Idade , Medição da Dor
6.
Benef Microbes ; 15(4): 357-371, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38955353

RESUMO

Constipation during pregnancy can induce serious complications, including miscarriage and preterm labour, while the evidence of probiotics in improving constipation during pregnancy was little. In this study, 29 healthy pregnant women and 65 constipated pregnant women were enrolled to assess the effectiveness of probiotics on constipation during pregnancy. Our results showed that the probiotics were effective in improving the Constipation Severity Scale (CSS) and Bristol Stool Scale (BSS) scores, including increasing defecation frequency, decreasing defecation time, and improving fecal characteristics. 16S rRNA sequencing revealed that the probiotics effectively restored the diversity of intestinal microbiota. At the phylum level, Firmicutes (13.27% vs 57.20%) and Actinobacteria (3.77% vs 12.80%) were increased, while Bacteroidetes (77.82% vs 20.24%) was decreased. At the level of the genus, Faecalibacterium (2.03% vs 10.33%), Bifidobacterium (1.21% vs 8.56%), and Phascolarctobacterium (0.05% vs 2.88%), the beneficial bacteria were increased, while the Bacteroides (29.23% vs 12.28%) and Prevotella (24.32% vs 4.92%) were decreased. In conclusion, these results indicated that probiotics can effectively relieve the constipation symptoms by improving the diversity of intestinal microbiota, regulating the disturbance of microflorae, and restoring the balance of microflorae to exert a stronger moderating effect than diet and lifestyle modification. Our results provided clinical data and a theoretical basis for the exploitation of probiotics in treating constipation during pregnancy. Chinese Clinical Trial Registry: ChiCTR2100052069.


Assuntos
Constipação Intestinal , Fezes , Microbioma Gastrointestinal , Probióticos , RNA Ribossômico 16S , Constipação Intestinal/terapia , Constipação Intestinal/microbiologia , Constipação Intestinal/tratamento farmacológico , Humanos , Feminino , Probióticos/administração & dosagem , Probióticos/uso terapêutico , Gravidez , Microbioma Gastrointestinal/efeitos dos fármacos , Adulto , Fezes/microbiologia , RNA Ribossômico 16S/genética , Bactérias/classificação , Bactérias/genética , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Complicações na Gravidez/microbiologia , Complicações na Gravidez/terapia , Complicações na Gravidez/tratamento farmacológico , Adulto Jovem , Defecação/efeitos dos fármacos
7.
Phys Rev Lett ; 132(26): 261001, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38996294

RESUMO

Precision measurements by the Alpha Magnetic Spectrometer (AMS) on the International Space Station of the deuteron (D) flux are presented. The measurements are based on 21×10^{6} D nuclei in the rigidity range from 1.9 to 21 GV collected from May 2011 to April 2021. We observe that over the entire rigidity range the D flux exhibits nearly identical time variations with the p, ^{3}He, and ^{4}He fluxes. Above 4.5 GV, the D/^{4}He flux ratio is time independent and its rigidity dependence is well described by a single power law ∝R^{Δ} with Δ_{D/^{4}He}=-0.108±0.005. This is in contrast with the ^{3}He/^{4}He flux ratio for which we find Δ_{^{3}He/^{4}He}=-0.289±0.003. Above ∼13 GV we find a nearly identical rigidity dependence of the D and p fluxes with a D/p flux ratio of 0.027±0.001. These unexpected observations indicate that cosmic deuterons have a sizable primarylike component. With a method independent of cosmic ray propagation, we obtain the primary component of the D flux equal to 9.4±0.5% of the ^{4}He flux and the secondary component of the D flux equal to 58±5% of the ^{3}He flux.

8.
Public Health ; 235: 63-70, 2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-39059089

RESUMO

OBJECTIVES: Research on parent-child interaction (PCI) and its impact on children's weight status is a thriving study area. However, their potential pathways have not been established. This study investigated the association between PCI and children's body-mass index z score (BMIz) examining the role of appetite self-regulation (ASR) as a mediator. STUDY DESIGN: Mediation analysis. METHODS: We included children from 33 kindergartens in Wuhan with parents' consent, measuring children's height and weight, and calculating BMIz. To assess the PCI quality, we utilized the Brigance Parent-Child Interactions Scale. Additionally, children's ASR was tested by satiety responsiveness (SR) and food responsiveness (FR) using the Children's Eating Behavior Questionnaire. Quantile regression was employed to examine the PCI-BMIz association, while mediation analysis was conducted to explore ASR's mediating effect on the relationship between PCI and BMIz. RESULTS: Of 3973 children (53.88% boys) included in the analysis, the mean BMIz was 0.24 ± 1.13. The results revealed that children with poorer PCI quality have higher BMIz across all selected BMIz percentiles, except for the 5th percentile. Furthermore, these associations were significant across most percentiles, whether for boys or girls. Mediation analysis suggested that these associations were partially mediated by children's ASR (indFR = -0.026, PFR < 0.001; indSR = -0.058, PSR < 0.001), with stronger effects observed among boys. CONCLUSION: The variation in how strongly BMIz was linked to PCI across different percentiles suggests that children with poorer PCI have higher BMIz. The link is partially mediated through children's ASR. It's important to pay attention to the PCI quality in children with higher BMIz levels, especially in boys.

9.
Eur J Paediatr Dent ; : 1, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38957934

RESUMO

AIM: During adolescence, there is a significant surge in height and total body mass of males. Consequently, they simultaneously experience enhancements in their circulatory and respiratory systems, which adapt to these physiological transformations. The purpose of present study was to investigate the developmental changes in male pharyngeal airway from adolescence to adulthood. METHODS: Lateral cephalograms of 192 males were obtained and divided into 5 groups: early adolescence (age 10-13 years), middle adolescence (age 14-17 years), late adolescence (age 18-21 years), early adulthood (age 22-30 years), and middle adulthood (ages 31-50 years). The dimensions of pharyngeal airway spaces and the related anatomical structures were investigated. The one-way analysis of variance and Pearson correlation analysis were employed for statistical analysis. CONCLUSION: During middle adolescence, the pharyngeal airway seems to be nearly completed in males. A significant negative correlation was found between the ANB angle and SPS, TPS, and EPS values.

10.
Zhonghua Fu Chan Ke Za Zhi ; 59(7): 522-529, 2024 Jul 25.
Artigo em Chinês | MEDLINE | ID: mdl-39056129

RESUMO

Objective: To explore the relationship between amniotic fluid and peripheral blood inflammatory factors and the pregnancy outcomes after emergency cervical cerclage, and to identify effective indicators for predicting adverse pregnancy outcomes after the procedure. Methods: A case-control study was conducted, including pregnant women who were hospitalized at Sun Yat-sen Memorial Hospital, from January 1, 2013, to July 31, 2019, and underwent emergency cervical cerclage due to cervical dilatation at gestational age between 16 and 28 weeks. A total of 85 pregnant women who underwent amniocentesis for the detection of amniotic fluid inflammatory factors during the perioperative period were included. Based on whether their baby was perinatal death, the participants were divided into the case group (28 cases with perinatal death) and the control group (57 cases with live births). Univariate logistic regression analysis was performed to identify risk factors associated with adverse pregnancy outcomes, followed by multivariate logistic regression analysis to establish a regression model and nomogram. Results: (1) The levels of tumor necrosis factor α (TNF-α), interleukin (IL)-1ß, IL-6, IL-8, IL-10 in the amniotic fluid during the perioperative period and postoperative serum C-reactive protein (CRP) were significantly higher in the case group compared to the control group (all P<0.05). The case group underwent emergency cervical cerclage at an earlier gestational age compared to the control group, and their cervical dilation was greater than that of the control group (all P<0.05). However, there were no significant differences in the white blood cell counts, neutrophil percentage, and the level of preoperative CRP in the peripheral blood of pregnant women during the perioperative period (all P>0.05). (2) Univariate logistic regression analysis showed that the levels of amniotic fluid WBC, TNF-α, IL-1ß, IL-2 receptor (IL-2R), IL-6, IL-8, IL-10, postoperative CRP in the peripheral blood, gestational age at cerclage and cervical dilation were associated with adverse pregnancy outcomes (all P<0.05). Multivariate regression analysis indicated that only the levels of amniotic fluid WBC and TNF-α were independent risk factors for perinatal death. (3) Based on clinical practice, a multivariate logistic regression model was constructed including the levels of amniotic fluid TNF-α, WBC, gestational age at cervical cerclage, and cervical dilation. A nomogram and calibration curve were plotted, which suggested its good predictive value for adverse pregnancy outcomes. Conclusions: During the perioperative period of emergency cervical cerclage, the levels of amniotic fluid WBC, TNF-α, IL-1ß, IL-2R, IL-6, IL-8, IL-10 are associated with adverse pregnancy outcomes, with amniotic fluid WBC and TNF-α showing the closest relationship. However, there is no significant correlation between maternal peripheral hemogram during the perioperative period and adverse pregnancy outcomes. A model constructed by amniotic fluid TNF-α, WBC, cervical cerclage gestational age, and cervical dilation has a good predictive effect on adverse pregnancy outcomes.


Assuntos
Líquido Amniótico , Cerclagem Cervical , Incompetência do Colo do Útero , Humanos , Amniocentese , Líquido Amniótico/metabolismo , Estudos de Casos e Controles , Feminino , Gravidez , Incompetência do Colo do Útero/cirurgia , Resultado da Gravidez , Nascimento Prematuro , Fatores de Risco , Fator de Necrose Tumoral alfa/metabolismo , Inflamação , Interleucina-8 , Interleucina-6/metabolismo
11.
bioRxiv ; 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39071342

RESUMO

Drug discovery pipelines rely on the availability of isolated primary hepatocytes for investigating potential hepatotoxicity prior to clinical application. These hepatocytes are typically isolated from livers rejected for transplantation and subsequently cryopreserved for later usage. The gold-standard cryopreservation technique, slow-freezing, is a labor-intensive process, with significant post-storage viability loss. In this work, we introduce parallelized droplet vitrification, a technique for high-volumetric, rapid vitrification of suspended cells. We show the utility of this technique through the single-run vitrification of the whole-rate liver hepatocyte yield, resulting in a 1600% increase in single-batch vitrification and a 500% increase in droplet generation rate compared to previous droplet vitrification approaches. Additionally, we showed that these implementations maintained improved post-preservation outcomes in primary rat hepatocytes.

12.
Zhonghua Yi Xue Za Zhi ; 104(29): 2728-2733, 2024 Jul 30.
Artigo em Chinês | MEDLINE | ID: mdl-39075991

RESUMO

Objective: To compare the effects of general anesthesia between remimazolam and propofol in pediatric patients undergoing binocular strabismus day surgery. Methods: Prospectively, 60 pediatric patients, American Society of Anesthesiologists (ASA) grade Ⅰ-Ⅱ, scheduled to undergo binocular strabismus daytime surgery in Beijing Tongren Hospital under general anesthesia with laryngeal mask airway from December 2021 to May 2022 were selected. They were randomly divided into Remimazolam group and Propofol group with 30 cases in each group, according to the ratio of 1∶1 by SPSS program. Patients in Remimazolam group were induced by remimazolam, remifentanil and micuronium chloride, and maintained by remimazolam and remifentanil. Patients in Propofol group were induced by propofol, remifentanil and micuronium chloride, and maintained by propofol and remifentanil. Patients in Remimazolam group were given 0.1 mg of flumazenil for antagonism 3 minutes after operation, while children in Propofol group waited for natural awakening. The primary outcome was the time from drug withdrawal to laryngeal mask removal after operation. The secondary outcomes included the time for consciousness loss during induction, intraoperative hemodynamic data [mean arterial pressure (MAP) and heart rate], the success rate of sedation, the awareness rate during operation, and the incidence of adverse events after admission to postanesthesia care unit(PACU). Results: The Remimazolam group included 12 males and 18 females, aged (5.0±1.4) years. There were 14 males and 16 females in the Propofol group, aged (5.3±1.3) years. The time from drug withdrawal to laryngeal mask removal in Remimazolam group was (6.5±1.2) min, which was shorter than that in Propofol group of (10.7±1.9) min (P<0.001). The time for consciousness loss during induction was (38.1±4.8) s in Remimazolam group, which was longer than that in Propofol group of (31.6±4.9) s (P<0.001). The variability of MAP and heart rate of patients during operation in Remimazolam group was lower than that in Propofol group (all P<0.05). There was no significant difference in sedation success rate, intraoperative awareness and adverse reactions in PACU between the two groups (all P>0.05). Conclusion: In pediatric patients with binocular strabismus during daytime surgery, general anesthesia with remimazolam can shorten the time from drug withdrawal to laryngeal mask removal after operation without increasing the incidence of postoperative adverse reactions and can provide more stable hemodynamics.


Assuntos
Anestesia Geral , Propofol , Estrabismo , Humanos , Propofol/administração & dosagem , Estrabismo/cirurgia , Criança , Estudos Prospectivos , Masculino , Feminino , Pré-Escolar , Benzodiazepinas/uso terapêutico , Período de Recuperação da Anestesia , Anestésicos Intravenosos/administração & dosagem
13.
Phys Rev Lett ; 133(2): 021901, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-39073971

RESUMO

Using data samples collected with the BESIII detector operating at the BEPCII storage ring, the cross section of the inclusive process e^{+}e^{-}→η+X, normalized by the total cross section of e^{+}e^{-}→hadrons, is measured at eight center-of-mass energy points from 2.0000 to 3.6710 GeV. These are the first measurements with momentum dependence in this energy region. Our measurement shows a significant discrepancy compared to the existing fragmentation functions. To address this discrepancy, a new QCD analysis is performed at the next-to-next-to-leading order with hadron mass corrections and higher twist effects, which can explain both the established high-energy data and our measurements reasonably well.

14.
Zhonghua Liu Xing Bing Xue Za Zhi ; 45(6): 824-832, 2024 Jun 10.
Artigo em Chinês | MEDLINE | ID: mdl-38889982

RESUMO

Objective: The epidemiological characteristics of tuberculosis deaths among Chinese residents from 2006 to 2021 were analyzed, and the tuberculosis mortality rate from 2022 to 2027 was predicted to provide a reference for tuberculosis prevention and control in China. Methods: The data set of tuberculosis deaths from 2006 to 2021 was published regularly by the China CDC, and the crude mortality rate (CMR) and age-standardized mortality rates (ASMR) were calculated according to the population structure of China in 2000. The distribution characteristics of age, sex, region, and time of tuberculosis deaths were analyzed, the Joinpoint regression analysis model was used to analyze the changing trend, and the grey model was applied to predict CMR and ASMR from 2022 to 2027. Results: From 2006 to 2021, the CMR and ASMR of tuberculosis showed a downward trend among males and females, urban and rural areas, and all age groups, in a word, all the Chinese residents. Except for the age group ≥85 years old, the mortality trend was insignificant. In the eastern, central, or western regions. CMR and ASMR were significantly higher in males than in females.CMR and ASMR were significantly lower in urban areas than in rural areas. In general, active tuberculosis patients present a higher mortality rate. The CMR and ASMR in the western region were higher than those in the eastern and central regions and lower in the eastern region than in the central region, but the differences were less obvious. The ASMR of the eastern cities was lower than that of the central and western regions, and the ASMR of the central cities was higher than that of the western region from 2006 to 2009 and 2012 and lower than that of the western region in other years. The ASMR in the western countryside was higher than that in the eastern and central regions and lower in the eastern part than in the central region, but the difference was not obvious. The grey model prediction results show that the CMR (/100 000) of Chinese residents from 2022 to 2027 is 1.585, 1.471, 1.360, 1.250, 1.143, and 1.038, and the ASMR (/100 000) is 0.779, 0.653, 0.531, 0.411, 0.295 and 0.181, respectively. Conclusions: The CMR and ASMR of tuberculosis will continue to decline, and extraordinary achievements have been made in tuberculosis prevention and control in Chinese residents from 2006 to 2021 and, presumably, from 2022 to 2027. However, tuberculosis screening and treatment programs in the western region, men, the elderly population, and rural areas should be further strengthened, and targeted prevention and control measures should be formulated to reduce mortality.


Assuntos
População Rural , Tuberculose , Humanos , China/epidemiologia , Tuberculose/mortalidade , Tuberculose/epidemiologia , Masculino , Feminino , População Rural/estatística & dados numéricos , Idoso , População Urbana/estatística & dados numéricos , Adulto , Pessoa de Meia-Idade , Idoso de 80 Anos ou mais , Adolescente , Adulto Jovem , População do Leste Asiático
15.
Opt Express ; 32(11): 20401-20411, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38859152

RESUMO

A FMCW LiDAR system of both the distributed feedback laser and external cavity laser is established in baseband beat notes, rather than up-conversion to an intermediate frequency to exclude flicker noise. Meanwhile, utilizing fast-scanning MEMS mirrors, high-quality real-time (1 fps) 4-D images of the slow-moving object (10 mm/s) can be directly constructed at the baseband with a central frequency as low as 100 kHz and a small Doppler shift. The proposed LiDAR architecture based on such a low-frequency baseband significantly improves the optical power budget on the transmitter side and eliminates the costly high-speed sampling circuits on the receiver side.

17.
Phys Rev Lett ; 132(23): 231902, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38905649

RESUMO

Using (10.087±0.044)×10^{9} J/ψ events collected with the BESIII detector at the BEPCII storage ring, the processes Λp→Λp and Λ[over ¯]p→Λ[over ¯]p are studied, where the Λ/Λ[over ¯] baryons are produced in the process J/ψ→ΛΛ[over ¯] and the protons are the hydrogen nuclei in the cooling oil of the beam pipe. Clear signals are observed for the two reactions. The cross sections in -0.9≤cosθ_{Λ/Λ[over ¯]}≤0.9 are measured to be σ(Λp→Λp)=(12.2±1.6_{stat}±1.1_{syst}) and σ(Λ[over ¯]p→Λ[over ¯]p)=(17.5±2.1_{stat}±1.6_{syst}) mb at the Λ/Λ[over ¯] momentum of 1.074 GeV/c within a range of ±0.017 GeV/c, where the θ_{Λ/Λ[over ¯]} are the scattering angles of the Λ/Λ[over ¯] in the Λp/Λ[over ¯]p rest frames. Furthermore, the differential cross sections of the two reactions are also measured, where there is a slight tendency of forward scattering for Λp→Λp, and a strong forward peak for Λ[over ¯]p→Λ[over ¯]p. We present an approach to extract the total elastic cross sections by extrapolation. The study of Λ[over ¯]p→Λ[over ¯]p represents the first study of antihyperon-nucleon scattering, and these new measurements will serve as important inputs for the theoretical understanding of the (anti)hyperon-nucleon interaction.

18.
Nat Commun ; 15(1): 5029, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38866733

RESUMO

Relativistic electron-positron plasmas are ubiquitous in extreme astrophysical environments such as black-hole and neutron-star magnetospheres, where accretion-powered jets and pulsar winds are expected to be enriched with electron-positron pairs. Their role in the dynamics of such environments is in many cases believed to be fundamental, but their behavior differs significantly from typical electron-ion plasmas due to the matter-antimatter symmetry of the charged components. So far, our experimental inability to produce large yields of positrons in quasi-neutral beams has restricted the understanding of electron-positron pair plasmas to simple numerical and analytical studies, which are rather limited. We present the first experimental results confirming the generation of high-density, quasi-neutral, relativistic electron-positron pair beams using the 440 GeV/c beam at CERN's Super Proton Synchrotron (SPS) accelerator. Monte Carlo simulations agree well with the experimental data and show that the characteristic scales necessary for collective plasma behavior, such as the Debye length and the collisionless skin depth, are exceeded by the measured size of the produced pair beams. Our work opens up the possibility of directly probing the microphysics of pair plasmas beyond quasi-linear evolution into regimes that are challenging to simulate or measure via astronomical observations.

19.
Phys Rev Lett ; 132(19): 191902, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38804946

RESUMO

We report the measurement of the inclusive cross sections for e^{+}e^{-}→nOCH (where nOCH denotes non-open charm hadrons) with improved precision at center-of-mass (c.m.) energies from 3.645 to 3.871 GeV. We observe three resonances: R(3760), R(3780), and R(3810) with significances of 8.1σ, 13.7σ, and 8.8σ, respectively. The R(3810) state is observed for the first time, while the R(3760) and R(3780) states are observed for the first time in the nOCH cross sections. Two sets of resonance parameters describe the energy-dependent line shape of the cross sections well. In set I [set II], the R(3810) state has mass (3805.7±1.1±2.7) [(3805.7±1.1±2.7)] MeV/c^{2}, total width (11.6±2.9±1.9) [(11.5±2.8±1.9)] MeV, and an electronic width multiplied by the nOCH decay branching fraction of (10.9±3.8±2.5) [(11.0±3.4±2.5)] eV. In addition, we measure the branching fractions B[R(3760)→nOCH]=(25.2±16.1±30.4)%[(6.4±4.8±7.7)%] and B[R(3780)→nOCH]=(12.3±6.6±8.3)%[(10.4±4.8±7.0)%] for the first time. The R(3760) state can be interpreted as an open-charm (OC) molecular state, but containing a simple four-quark state component. The R(3810) state can be interpreted as a hadrocharmonium state.

20.
J Prev Alzheimers Dis ; 11(3): 769-779, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38706293

RESUMO

BACKGROUND: As the global population ages, cognitive impairment (CI) becomes more prevalent. Tea has been one of the most popular drinks in the world. Several studies have demonstrated that tea consumption has an impact on cognitive function. OBJECTIVE: This study aims to examine the association between tea consumption and cognitive function and explore the potential effect of genetics on the relationship between tea consumption and CI risk in older adults. DESIGN: This is a prospective longitudinal study using data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). SETTING: Six waves of data from CLHLS containing 76,270 subjects were analyzed. Generalized estimation equations (GEE) with a logit link function were adopted to estimate the effect of tea consumption on CI risk from a cross-sectional and longitudinal perspective. PARTICIPANTS: A population-based cohort of adults aged 65-105 years. MEASUREMENTS: The frequency and type of tea consumption were obtained by questionnaires. CI was measured based on MMSE. Polygenic risk was measured using the polygenic score approach described by the International Schizophrenia. RESULTS: The results showed that drinking green tea had a better protective effect on cognitive function than other types of tea, the incidence of CI gradually decreased with the increase of tea consumption frequency, and men were more likely to benefit from tea consumption. Additionally, we also found a significant interaction between tea consumption and genetic risk, measured by polygenic risk score (PRS). CONCLUSIONS: Based on current research evidence, tea consumption, may be a simple and important measure for CI prevention.


Assuntos
Cognição , Disfunção Cognitiva , Chá , Humanos , Masculino , Idoso , Feminino , Estudos Longitudinais , Cognição/fisiologia , Disfunção Cognitiva/genética , Disfunção Cognitiva/epidemiologia , Idoso de 80 Anos ou mais , Estudos Prospectivos , Estudos Transversais , China/epidemiologia
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