Search

Purely leptonic decays of the charged D meson have been studied using the reaction e+e- → D*+D- at a center of mass energy of 4.03 GeV. A search was performed for D → μνμ recoiling against a D0 or D+ which had been reconstructed from its hadronic decay products. A single event candidate was found in the reaction e+e- → D*+D-, where D*+ → π+D0 with the D0 → K-π+, and the recoiling D- decaying via D- → μ-ν̄μ. This yields a branching fraction value B(D → μνμ) = 0.08+0.16+0.05-0.05-0.02%, and a corresponding value of the pseudoscalar decay constant fD = 300+180+80-150-40 MeV. © 1998 Elsevier Science B.V. All rights reserved.

Purely leptonic decays of the charged D meson have been studied using the reaction e+e- → D*+D- at a center of mass energy of 4.03 GeV. A search was performed for D → μνμ recoiling against a D0 or D+ which had been reconstructed from its hadronic decay products. A single event candidate was found in the reaction e+e- → D*+D-, where D*+ → π+D0 with the D0 → K-π+, and the recoiling D- decaying via D- → μ-ν̄μ. This yields a branching fraction value B(D → μνμ) = 0.08+0.16+0.05-0.05-0.02%, and a corresponding value of the pseudoscalar decay constant fD = 300+180+80-150-40 MeV. © 1998 Elsevier Science B.V. All rights reserved.

The absolute inclusive branching fraction of (Formula presented) has been measured from data collected by the BES detector at a center-of-mass energy of 4.03 GeV, corresponding to an integrated luminosity of 22.3 pb(Formula presented). At this energy, direct pair production (Formula presented) has been observed. We have selected (Formula presented) candidate events by reconstructing five hadronic decay modes (Formula presented), (Formula presented), (Formula presented), (Formula presented) and (Formula presented) and have searched for inclusive (Formula presented)’s in the recoiling (Formula presented). We observed three recoiling (Formula presented)’s in the 166.4 (Formula presented) 31.8 (Formula presented) candidate events, which leads to the absolute branching fraction (Formula presented) and (Formula presented). © 1998 The American Physical Society.

The absolute inclusive branching fraction of (Formula presented) has been measured from data collected by the BES detector at a center-of-mass energy of 4.03 GeV, corresponding to an integrated luminosity of 22.3 pb(Formula presented). At this energy, direct pair production (Formula presented) has been observed. We have selected (Formula presented) candidate events by reconstructing five hadronic decay modes (Formula presented), (Formula presented), (Formula presented), (Formula presented) and (Formula presented) and have searched for inclusive (Formula presented)’s in the recoiling (Formula presented). We observed three recoiling (Formula presented)’s in the 166.4 (Formula presented) 31.8 (Formula presented) candidate events, which leads to the absolute branching fraction (Formula presented) and (Formula presented). © 1998 The American Physical Society.

The absolute inclusive semileptonic branching fraction of the [Formula presented] meson has been measured based on [Formula presented] of [Formula presented] collision data collected with the Beijing Spectrometer at [Formula presented] At this energy, the [Formula presented] are produced in pairs: [Formula presented] We reconstructed [Formula presented] [Formula presented] events in five hadronic decay modes. In the recoil system of these events, several [Formula presented] inclusive semileptonic decays were observed and the branching fraction is estimated to be [Formula presented] © 1997 The American Physical Society.

The absolute inclusive semileptonic branching fraction of the [Formula presented] meson has been measured based on [Formula presented] of [Formula presented] collision data collected with the Beijing Spectrometer at [Formula presented] At this energy, the [Formula presented] are produced in pairs: [Formula presented] We reconstructed [Formula presented] [Formula presented] events in five hadronic decay modes. In the recoil system of these events, several [Formula presented] inclusive semileptonic decays were observed and the branching fraction is estimated to be [Formula presented] © 1997 The American Physical Society.

The cross section for e+e-→ρπ has been measured by the BES detector at BEPC at center-of-mass energies covering a 40 MeV interval spanning the J/ψresonance. The data are used to search for the vector gluonium state hypothesized by Brodsky, Lepage, and Tuan as an explanation of the ρπ puzzle in charmonium physics. The shape of the ρπ cross section is compatible with that of the total hadronic cross section. No distortions indicating the presence of a vector glueball are seen. © 1996 The American Physical Society.

A data-driven energy scan in the immediate vicinity of the τ pair production threshold has been performed using the Beijing Spectrometer at the Beijing Electron-Positron Collider. Approximately 5pb-1 of data, distributed over 12 scan points, have been collected. A previous mass value for the τ lepton, obtained using only the eµ final state, has been published. In this paper, the final BES result on the mass measurement is presented. The analysis is based on the combined data from the ee, eµ, eh, µµ, µh, and hh final states, where h denotes a charged Π or K. A maximum likelihood fit to the τ pair production cross section data yields the value mT=1776.96-0.21 -0.17+0.18+0.25. © 1995 The American Physical Society.

The Beijing Spectrometer (BES) experiment has observed purely leptonic decays of the Ds meson in the reaction e+e-→Ds+Ds- at a c.m. energy of 4.03 GeV. Three events are observed in which one Ds decays hadronically to φπ, K̄*0K, or K̄0K, and the other decays leptonically to μνμ or τντ. With the assumption of μ-τ universality, values of the branching fraction, B(Ds→μνμ)=(1.5-0.6-0.2+1.3+0.3)%, and the Ds pseudoscalar decay constant, fDs=(4.3-1.3-0.4+1.5+0.4)×102 MeV, are obtained. © 1995 The American Physical Society.

Aim: To elucidate whether differences exist in the impact on retarding the elongation of axial length (AL) among children with myopia when utilizing orthokeratology (ortho-k) lenses employing the corneal refractive therapy (CRT) design versus those employing the vision shaping treatment (VST) design., Methods: This retrospective clinical trial aimed to collect and analyze AL data from individuals who wore ortho-k lenses for three years. A total of 654 subjects were enrolled and prescribed one of the three specific brands of ortho-k lenses: CRT, Euclid, and Mouldway. The study's primary focus was to compare the rates of AL elongation and myopic progression across these three brands of ortho-k lenses., Results: In the 3-year follow-up, the AL elongation exhibited variations of 0.73±0.36 mm in the CRT lens group, 0.59±0.37 mm in the Euclid lens group, and 0.63±0.38 mm in the Mouldway lens group. A noteworthy disparity emerged between the CRT and Mouldway groups ( P <0.01), as well as between the CRT and Euclid groups ( P <0.001). Additionally, it was observed that 32.1% of participants who wore CRT lenses experienced a decelerated progression of myopia, in contrast to 47.2% in the Euclid group and 44.4% in the Mouldway group. Statistical analyses revealed a statistically significant distinction between the CRT and Euclid groups ( P <0.01), and similarly, the CRT group demonstrated a statistically significant difference when compared to the Mouldway group ( P <0.05)., Conclusion: Ortho-k lenses represent a pragmatic strategy for mitigating the advancement of myopia. In contradistinction to ortho-k lenses utilizing the CRT design, those employing the VST design exhibited a more favorable impact regarding retarding AL elongation., Competing Interests: Conflicts of Interest: Ni HL, None; Chen X, None; Chen DY, None; Hu PK, None; Wu ZY, None., (International Journal of Ophthalmology Press.)

Circadian homeostasis in mammals is a key intrinsic mechanism for responding to the external environment. However, the interplay between circadian rhythms and the tumor microenvironment (TME) and its influence on metastasis are still unclear. Here, in patients with colorectal cancer (CRC), disturbances of circadian rhythm and the accumulation of monocytes and granulocytes were closely related to metastasis. Moreover, dysregulation of circadian rhythm promoted lung metastasis of CRC by inducing the accumulation of myeloid-derived suppressor cells (MDSCs) and dysfunctional CD8 + T cells in the lungs of mice. Also, gut microbiota and its derived metabolite taurocholic acid (TCA) contributed to lung metastasis of CRC by triggering the accumulation of MDSCs in mice. Mechanistically, TCA promoted glycolysis of MDSCs epigenetically by enhancing mono-methylation of H3K4 of target genes and inhibited CHIP-mediated ubiquitination of PDL1. Our study links the biological clock with MDSCs in the TME through gut microbiota/metabolites in controlling the metastatic spread of CRC, uncovering a systemic mechanism for cancer metastasis., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

A brand-new procedure for the synthesis of 3-alkynylated 3,3-disubstituted isoindolinones has been disclosed via a HOTf or Fe(OTf) 3 -catalyzed dehydrative alkynylation of 3-hydroxyisoindolinones with terminal alkynes. Aryl, alkenyl and alkyl terminal alkynes are suitable to couple with a broad range of 3-hydroxyisoindolinones to afford the desired products in moderate to good yields. This protocol features the use of an inexpensive catalyst, mild reaction conditions, broad substrate scope and easy elaboration of the products.

Intervertebral disc is a highly rhythmical tissue. As a key factor linking biorhythm and inflammatory response, the shielding effect of NR1D1 in the process of intervertebral disc degeneration remains unclear. Here, we first confirmed that NR1D1 in the nucleus pulposus tissue presents periodic rhythmic changes and decreases in expression with intervertebral disc degeneration. Second, when NR1D1 was activated by SR9009 in vitro , NLRP3 inflammasome assembly and IL-1β production were inhibited, while ECM synthesis was increased. Finally, the vivo experiments further confirmed that the activation of NR1D1 can delay the process of disc degeneration to a certain extent. Mechanistically, we demonstrate that NR1D1 can bind to IL-1β and NLRP3 promoters, and that the NR1D1/NLRP3/IL-1β pathway is involved in this process. Our results demonstrate that the activation of NR1D1 can effectively reduce IL-1β secretion, alleviate LPS-induced NPMSC pyroptosis, and protect ECM degeneration., Competing Interests: The authors declare no competing interests., (© 2024 The Authors.)

The semipinacol rearrangement is a powerful and versatile method for constructing all-carbon quaternary stereocenters. The development of catalytic asymmetric semipinacol rearrangements using multifunctionalizable electrophiles remains highly sought-after in organic synthesis. In this study, a catalytic enantioselective allylic cation-induced semipinacol rearrangement reaction was presented that enables the simultaneous construction of two skipped chiral carbon centers. Chiral Ir(I)-(P,olefin) and Sc(OTf) 3 catalysts cooperatively initiate the asymmetric allylic alkylation of alkenyl cyclobutanols with allylic alcohols, triggering ring expansion of the cyclobutanol moiety through a stereoselective 1,2-alkyl migration. The reaction afforded a range of cyclopentanones bearing an α-quaternary carbon that is adjacent to a chiral allyl scaffold. The products were applied to synthesize enantioenriched fused tricyclopentanoids bearing four stereogenic carbon centers.

A Hg(OTf) 2 -catalyzed tandem phospha -Michael addition/cyclization/dehydration of 2-hydroxychalcones with H -phosphine oxides is presented. This protocol provides a new and supplementary approach for the preparation of 4-phosphorylated 4 H -chromenes in good yields (up to 99%). In addition, this domino reaction allows the successful construction of two new C-P and C-O bonds in a one-pot operation.

A nickel-catalyzed reductive cross-coupling of aziridines and allylic chlorides was realized by using manganese metal as the reducing agent. This protocol afforded a convenient approach to obtain β-allyl-substituted arylethylamines bearing various functional groups. The utility of this reaction was also demonstrated by scale-up preparation and diverse transformations, including the synthesis of Baclofen and several bioactive molecular motifs.

Hydrogels as flexible sensor have attracted significant attention due to its conductivity, stretchability and flexibility. However, it is still a great challenge to prepare hydrogels that simultaneously possess high strength, anti-fatigue, self-adhesion, and anti-freezing. Herein, a multifunctional dual-network hydrogel was prepared by in situ polymerization of acrylic monomer in chitosan chains, and coordinated with aluminum chloride and glycerol. Based on chain entanglement, hydrogen bonding and coordination interactions, this dual-network hydrogel exhibited excellent mechanical properties, good fatigue resistance, and excellent adhesion performance. It can be used as a strain sensor for its stable conductivity and high sensitivity, which could monitor both large human motions and subtle motions. Due to the presence of glycerol, the hydrogel showed outstanding freezing resistance and still kept flexible and conductive even at low temperatures (-20 °C). This hydrogel can be applied as a flexible wearable sensor for monitoring human motion in extreme low-temperature condition., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2022. Published by Elsevier Ltd.)

The cascade of Ir-catalyzed enantioselective allylic amination and Cu-catalyzed alkyne-azide cycloaddition was designed for the asymmetric synthesis of homoallylic amidines. The nucleophilic addition of an in situ-generated enantioenriched tertiary allylamine to a ketenimine intermediate triggers a rapid and stereospecific zwitterionic aza-Claisen rearrangement in a 1,3-chiral transfer manner. The approach allows modular access to enantioenriched α-chiral homoallylic amidines in high yields with a high level of enantiomeric purity.

We herein report a Ni-catalyzed three-component cross-electrophile coupling of 1,3-dienes with aldehydes and aryl bromides using manganese metal as the reducing agent. This efficient protocol accomplishes dicarbofunctionalization of 1,3-dienes to synthesize diverse structural 1,4-disubstituted homoallylic alcohols by forming two new C-C bonds in one time. Mechanistic study suggests that an allyl-nickel(I) species is involved in the catalytic cycle.

The vinyl-substituted oxyallyl carbonates were exploited as a new C,O-dipole for enantioselective Pd-catalyzed (3+2) cycloaddition. The corresponding oxyallyl-Pd species was weakly nucleophilic to react with activated carbonyl compounds, affording multisubstituted and enantioenriched oxazolidinones and 1,3-dioxolanes with a high degree of chemo- and stereoselectivity. The synthetic transformations of oxazolidinone product were carried out to build enantioenriched α-chiral aminoketone and epoxy derivatives.

A regio- and stereoselective nickel-catalyzed three-component coupling reaction of aldehydes, 1,3-dienes, and alkenylzirconium reagents was realized. The ligand- and additive-free protocol afforded a convenient approach to the synthesis of skipped diene compounds bearing various functionals (e.g., hydroxyl, carbonyl, halide) and heterocyclic groups. The products were readily transformed into structurally diverse polyenes. The utility of this reaction was also demonstrated by the one-pot operation and scale-up preparation.

The iridium-catalyzed enantioselective coupling reaction of vinyl azides and allylic electrophiles is presented and provides access to β-chiral carbonyl derivatives. Vinyl azides are used as acetamide enolate or acetonitrile carbanion surrogates, leading to γ,δ-unsaturated β-substituted amides as well as nitriles with excellent enantiomeric excess. These products are readily transformed into chiral N-containing building blocks and pharmaceuticals. A mechanism is proposed to rationalize the chemoselectivity of this coupling reaction.

A copper-catalyzed three-component reaction of terminal alkynes, TsN 3 , and tertiary allylic amines is developed toward the one-pot synthesis of α-allylic amidines. The product was synthesized on gram scale under 1 mol % of catalyst loading. Transformations of products into alkenyl amine and other nitrogen-containing compounds are demonstrated without any loss of stereochemical information.

Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose.

Objective: To investigate the significance of monitoring the gradients between transcutaneous PCO(2) and end-tidal PCO(2) [P(c-et)CO(2)] in patients with septic shock. Method: Thirty-five mechanically ventilated patients with early septic shock were enrolled as the study group and 18 non-septic shock patients with stable hemodynamics as the control group between May 2014 and October 2016. The patients with septic shock were treated by early goal-directed therapy (EGDT) within 6 hours since hospitalization. The differences of baseline level of P(c-et)CO(2) and arterial lactate concentration (LAC) between the two groups and the variations of these indexes after EGDT in the study group were compared respectively. Results: The baseline levels of P(c-et)CO(2) and LAC in patients with septic shock were significantly higher than those of the control group [(26.0±16.2) mmHg vs (11.0±5.6) mmHg (1 mmHg=0.133 kPa) and (4.0±1.7) mmol/L vs (1.6±0.6)mmol/L, all P =0.000]. The area under receiver operator characteristic (ROC) curve (AUC) for baseline P(c-et)CO(2) and LAC was 0.924 (95% CI : 0.851-0.996) and 0.931 (95% CI : 0.872-1.000), respectively. P(c-et)CO(2) >12.6 mmHg and LAC >2.5 mmol/L could discriminate septic shock patients from those without shock with the same sensibility of 97% and the specificity of 83% and 78% respectively. With regard to the prognosis (Day 28) of the patients with septic shock, AUC for baseline P(c-et)CO(2) and LAC was 0.709 (95% CI : 0.533-0.886) and 0.714 (95% CI : 0.545-0.883), respectively. P(c-et)CO(2) >20.0 mmHg and LAC>3.6 mmol/L could discriminate survivors from non-survivors with the same sensibility of 92% and the same specificity of 76%. All the patients in the study group completed EGDT within 6 hours after admission, 20 (57.1%) passed EGDT and 17 (85.0%) survived, 15 (42.9%) failed EGDT and 4 (26.7%) survived, and the survival rates were significantly different ( F =9.844, P =0.001). After EGDT, P(c-et)CO(2) (21.0±9.5 mmHg) and LAC(3.3±2.5 mmol/L)reduced significantly compared with the baselines ( P =0.008 and P =0.046), and the associated AUC was 0.905(95% CI : 0.792-1.000) and 0.747 (95% CI : 0.576-0.917)respectively. P(c-et)CO(2) > 16.5 mmHg and LAC > 3.1 mmol/L could discriminate survivors from non-survivors with the sensibility of 97% and 91%, and the specificity of 78% and 69%, respectively. Conclusions: P(c-et)CO(2) >12.6 mmHg could play the same role as LAC in recognizing early septic shock. EGDT was an effective therapy for the septic shock and P(c-et)CO(2) reflected efficacy. P(c-et)CO(2)>20 mmHg before EGDT and >16.5 mmHg after EGDT both could predict the 28 d prognosis of patients with septic shock, and the effect of the former was equal to that of LAC, but the latter was better than LAC.

Despite increasing evidence highlighting the role of NPY in the modulation of inflammatory reaction, surprisingly little is known about the direct effects of NPY on the release of proinflammatory mediators. In the present work, we have evaluated the effects of NPY on the release of TNF-α, IL-1β, IL-6 and HMGB1 mediators in peritoneal macrophages. Our results demonstrate for the first time that NPY can directly induce active HMGB1 release and cytoplasmic translocation, while the production of TNF-α, IL-1β and IL-6 is not affected. PKC and ERK pathway inhibitors can abolish the promotive effect of NPY on HMGB1 secretion. Thus, our results indicate that NPY might impact on the innate immune system by directly potentiating the HMGB1 release from the macrophage., (Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.)

Objective: To investigate the safety and effects of early bronchoscopy on atelectasis of the ventilation patients, whom had experienced craniotomy for severe cranial trauma and hemorrhage., Methods: Fifty-five patients suffered from severe cranial trauma and hemorrhage with Glascow coma scores (GCS) less than 8 complicated by atelectasis after craniotomy were early given sputum suction by bronchoscope via extratracheal intubation and broncho-alveolar lavage (BAL) during tracheal intubation and mechanical ventilation. During the treatment, patients' consciousness, vital signs and arterial blood gas were closely monitored. The relevant data, before, during (5, 10, and 25 minutes), bronchoscopy treatment completed and 30 minutes after bronchoscopy, were recorded and analyzed., Results: Eighty-two time of bronchoscopies and 111 time of local BALs in 55 patients were completed and were effective for atelectasis. The patient's GCS (5.6±2.5 vs. 5.4±2.6, P>0.05), heart rate (HR), respiratory rate (RR), systolic blood pressure (SBP), blood oxygenous saturation (SaO(2)) were not deteriorated during bronchoscopy. Compared with pre-bronchoscopy, the HR and SBP decreased (HR: 88.2±14.2 bpm vs. 98.2±18.3 bpm, SBP: 110.6±18.2 mm Hg vs. 118.4±18.5 mm Hg, both P<0.05), and SaO(2) increased (0.982±0.022 vs. 0.945±0.035, P<0.05), pH, arterial partial pressure of oxygen (PaO(2)) and arterial partial pressure of carbon dioxide (PaCO(2)) had no significant changes during bronchoscopy. There was obviously increased in PaO(2) (84.5±14.4 mm Hg, 81.6±18.2 mm Hg vs. 76.2±15.4 mm Hg, both P<0.05), and decreased in PaCO(2) (27.0±12.8 mm Hg, 29.3±18.2 mm Hg vs. 36.5±11.6 mm Hg, both P<0.05) respectively, significantly decreased in alveolar arterial pressure of oxygen difference [P ((A-a))O(2)] at 10 minutes and 25 minutes, and at the time bronchoscopy treatment completed and the time 30 minutes after compared with before bronchoscopy (36.1±4.7 mm Hg, 32.4±6.2 mm Hg, 32.5±5.2 mm Hg, 31.2±7.2 mm Hg vs. 38.5±5.6 mm Hg, all P<0.05). All patients had not encounter side effects related with bronchoscopy and ventilation., Conclusion: The bronchoscope via extratracheal intubation for sputum suction and BAL were safe and effective treatment to the patients suffered from severe cranial trauma or hemorrhage complicated by atelectasis after craniotomy during mechanical ventilation, without obvious changes of the vital signs.

Objective: To investigate the effect of conductive keratoplasty (CK) for presbyopia and 2 years follow-up., Methods: This study is prospective clinical trial. CK was performed on 34 patients for presbyopia, in which 26 hyperopic patients underwent binocular operations and 8 emmetropic patients underwent monocular operation. The following-up time was 24 months., Results: At 24 months postoperatively, for the hyperopia group, binocular uncorrected near visual acuity (33 cm) (5-logMAR) (4.63 ± 0.12) was increased significantly (t = 9.237, P < 0.001) compared pre-operatively (4.06 ± 0.15); binocular uncorrected distance visual acuity (4.99 ± 0.02) was significantly increased (t = 6.718, P < 0.05) compared pre-operatively (4.82 ± 0.21); for the emmetropia group, binocular uncorrected near visual acuity (33 cm) (5-logMAR) (4.68 ± 0.16) was increased significantly (t = 10.413, P < 0.001) compared pre-operatively (4.13 ± 0.18); binocular uncorrected distance visual acuity was same as pre-operative one; compared pre-operatively (+0.97 ± 0.63D), manifest refractive spherical equivalent was decreased significantly (P < 0.001) to peak value (-1.21 ± 1.00) D at 1 week, and then regressed to a relative plateau (-0.40 ± 0.70) D at 24 months; the regressive rate was decreased from (+0.35 ± 0.44) D/month at 1 month postoperatively to (+0.01 ± 0.01) D/months at 24 months postoperatively. Contrast sensitivity and glare sensitivity, intraocular pressure, tear break-up time, endothelial cell count, central corneal thickness, stereopsis function and best corrected visual acuity were not significantly changed., Conclusions: For treatment of presbyopia, CK appeared to be safe, effective, refractive-predictable and controllable, and relatively stable at 24 months post-operatively. More long-time follow-up is necessary for further evaluation.

Presbyopia is age-related reduction in amplitude of accommodation and can not read comfortably. Current methods such as single-focus glasses, bifocal glasses and progressive additional lens are the most widely used for correction of presbyopia. All surgical solutions for presbyopia do not improve the physiological amplitude of accommodation. This article is an attempt to review the advances in surgical management of presbyopia.