Using the entire Belle data sample of 980 fb−1 of e+e− collisions, we present the results of a study of excited Ωc charmed baryons in the decay mode Ξc+K−. We show confirmation of four of the five ...narrow states reported by the LHCb Collaboration: the Ωc(3000), Ωc(3050), Ωc(3066), and Ωc(3090).
Lower gastrointestinal perforation is rare and challenging to diagnose in patients presenting with an acute abdomen. However, no study has examined the frequency and associated factors of diagnostic ...errors related to lower gastrointestinal perforation. This large-scale multicenter retrospective study investigated the frequency of diagnostic errors and identified the associated factors. Factors at the level of the patient, symptoms, situation, and physician were included in the analysis. Data were collected from nine institutions, between January 1, 2015 and December 31, 2019. Timely diagnosis was defined as diagnosis at the first visit in computed tomography (CT)-capable facilities or referral to an appropriate medical institution immediately following the first visit to a non-CT-capable facility. Cases not meeting this definition were defined as diagnostic errors that resulted in delayed diagnosis. Of the 439 cases of lower gastrointestinal perforation identified, delayed diagnosis occurred in 138 cases (31.4%). Multivariate logistic regression analysis revealed a significant association between examination by a non-generalist and delayed diagnosis. Other factors showing a tendency with delayed diagnosis included presence of fever, absence of abdominal tenderness, and unavailability of urgent radiology reports. Initial misdiagnoses were mainly gastroenteritis, constipation, and small bowel obstruction. In conclusion, diagnostic errors occurred in about one-third of patients with a lower gastrointestinal perforation.
Cold adaptation is one of the most important functions for the human. In this study we focused on its relationship to mitochondria. The mitochondrion itself exists in human cells and has a vital ...function in generating ATP and heat. Mitochondria have their own genome, which enables modern humans to classify the mitochondria haplogroup. Recent studies have suggested that these haplogroups were shaped by climatic change and the mitochondrial genome influence balance between ATP and heat generation. In this study we hypothesized that human cold adaptability is influenced by the mitochondrial haplogroup. Our purpose was to investigate the association between mitochondrial haplogroup and psychophysiological responses during cold exposure. We focus on haplogroup D, the biggest group in Japan and also a major group in northern Asia, including Siberia. Subjects were 18 young Japanese university students divided into two groups: the D group and the non-D group. There was no significant difference of height, weight, BMI, or BSA between them. Cold exposure was induced for 90 minutes in a climatic chamber; for the first 30 minutes, the air temperature was decreased from 27℃ to 10℃ and, for the last 60 minutes, the temperature was maintained at 10℃. Rectal and skin temperatures, oxygen consumption (VO2), blood pressure, and thermal comfortability were measured during the experiment. The result showed that the D group had significantly higher Tre during cold exposure (p<0.001), with no significant difference in VO2 and mean skin temperature. This suggests that mitochondrial haplogroup D is associated with cold resistance and haplogroup.
We report the result for a search for the leptonic decay of B+→μ+νμ using the full Belle dataset of 711 fb−1 of integrated luminosity at the ϒ(4S) resonance. In the Standard Model leptonic B-meson ...decays are helicity and Cabibbo-Kobayashi-Maskawa suppressed. To maximize sensitivity an inclusive tagging approach is used to reconstruct the second B meson produced in the collision. The directional information from this second B meson is used to boost the observed μ into the signal B-meson rest frame, in which the μ has a monochromatic momentum spectrum. Though its momentum is smeared by the experimental resolution, this technique improves the analysis sensitivity considerably. Analyzing the μ momentum spectrum in this frame we find B(B+→μ+νμ)=(5.3±2.0±0.9)×10−7 with a one-sided significance of 2.8 standard deviations over the background-only hypothesis. This translates to a frequentist upper limit of B(B+→μ+νμ)<8.6×10−7 at 90% confidence level. The experimental spectrum is then used to search for a massive sterile neutrino, B+→μ+N, but no evidence is observed for a sterile neutrino with a mass in a range of 0–1.5 GeV. The determined B+→μ+νμ branching fraction limit is further used to constrain the mass and coupling space of the type II and type III two-Higgs-doublet models.
We present the first measurements of the absolute branching fractions of Ξc+ decays into Ξ−π+π+ and pK−π+ final states. Our analysis is based on a data set of (772±11)×106 BB¯ pairs collected at the ...ϒ(4S) resonance with the Belle detector at the KEKB e+e− collider. We measure the absolute branching fraction of B¯0→Λ¯c−Ξc+ with the Ξc+ recoiling against Λ¯c− in B¯0 decays resulting in B(B¯0→Λ¯c−Ξc+)=1.16±0.42(stat.)±0.15(syst.)×10−3. We then measure the product branching fractions B(B¯0→Λ¯c−Ξc+)B(Ξc+→Ξ−π+π+) and B(B¯0→Λ¯c−Ξc+)B(Ξc+→pK−π+). Dividing these product branching fractions by B¯0→Λ¯c−Ξc+ yields B(Ξc+→Ξ−π+π+)=2.86±1.21(stat.)±0.38(syst.)% and B(Ξc+→pK−π+)=0.45±0.21(stat.)±0.07(syst.)%. Our result for B(Ξc+→Ξ−π+π+) can be combined with Ξc+ branching fractions measured relative to Ξc+→Ξ−π+π+ to set the absolute scale for many Ξc+ branching fractions.
We report measurements of the branching fractions of singly Cabibbo-suppressed decays Λc+ → pη and Λc+ → pπ0 using the full Belle data sample corresponding to an integrated luminosity of 980.6 ...fb−1. The data were collected by the Belle detector at the KEKB e+ e− asymmetric energy collider. A clear Λ + c signal is seen in the invariant mass distribution of p η . The fitted number of signal events of the Λc+ → pη process is 7734 ± 263 ; from this, we measure the ratio of branching fractions B ( Λc+→ pη ) / B ( Λc+ → pK− π+ ) = 2.258 ± 0. 077 ( stat ) ± 0.122 ( syst ) × 10 − 2 , from which we infer the branching fraction B ( Λc+ → pη ) = 1.42 ± 0.05 ( stat ) ± 0.11 ( syst ) × 10−3. In addition, no significant signal for Λc+ → pπ0 is found, so an upper limit on the branching fraction of B ( Λc+ → pπ0) < 8.0 × 10−5 at a 90% credibility level is set, more than 3 times better than the best current upper limit.
Positron emission tomography (PET) is widely used in the fields of clinical and basic medicine. The PET device utilizes coincidence logic to detect annihilation photons emitted from positrons and ...estimates physiological functions of human organs in vivo. Radiopharmaceutical 18F- fluorodeoxyglucose (FDG), an analogue of glucose, is trapped metabolically in cells after being administered into the body, and can be substantially used for evaluating physiological and biochemical functions in vivo. Here, we attempted to describe the basics of PET as well as to apply the technique together with 18F-FDG as a tracer for evaluating organ glucose metabolism induced by exercise. Three-dimensional (3D) FDG-PET was applied to normal volunteers who performed exercise to evaluate whole-body glucose metabolism. Regions of interest analysis were drawn on visually defined regions (i.e., lower limbs, thigh, liver, intestine, brain, heart, etc.) to determine radioactivity distribution. FDG-PET clearly showed the recruitment of energy resources from abdominal organs to lower limb skeletal muscles to balance energy expenditures. The results suggested that 3D FDG-PET can be applied as an imaging tool to physical medicine.
We report the first observation of the double strange baryon Ξ(1620)0 in its decay to Ξ−π+ via Ξ+c → Ξ−π+π+ decays based on a 980 fb−1 data sample collected with the Belle detector at the KEKB ...asymmetric-energy e+e− collider. The mass and width are measured to be 1610.4 ± 6.0(stat)+6.1−4.2(syst) MeV /c2 and 59.9 ± 4.8(stat)+2.8−7.1(syst) MeV, respectively. We obtain 4.0σ evidence of the Ξ(1690)0 with the same data sample. These results shed light on the structure of hyperon resonances with strangeness S = −2