18 research outputs found
Minimum Supersymmetric Standard Model on the Noncommutative Geometry
We have obtained the supersymmetric extension of spectral triple which
specify a noncommutative geometry(NCG). We assume that the functional space H
constitutes of wave functions of matter fields and their superpartners included
in the minimum supersymmetric standard model(MSSM). We introduce the internal
fluctuations to the Dirac operator on the manifold as well as on the finite
space by elements of the algebra A in the triple. So, we obtain not only the
vector supermultiplets which meditate SU(3)xSU(2)xU(1)_Y gauge degrees of
freedom but also Higgs supermultiplets which appear in MSSM on the same
standpoint. Accoding to the supersymmetric version of the spectral action
principle, we calculate the square of the fluctuated total Dirac operator and
verify that the Seeley-DeWitt coeffients give the correct action of MSSM. We
also verify that the relation between coupling constants of , and
is same as that of SU(5) unification theory
Supersymmetric Yang-Mills Theory on the Noncommutative Geometry
Recently, we found the supersymmetric counterpart of the spectral triple.
When we restrict the representation space to the fermionic functions of matter
fields, the counterpart which we name "the triple" reduces to the original
spectral triple which defines noncommutative geometry. We see that the
fluctuation to the supersymmetric Dirac operator induced by algebra in the
triple generates vector supermultiplet which mediates gauge interaction.
Following the supersymmetric version of spectral action principle, we calculate
the heat kernel expansion of the square of fluctuated Dirac operator and obtain
the correct supersymmetric Yang-Mills action with U(N) gauge symmetry.Comment: arXiv admin note: text overlap with arXiv:1201.344
Invasive Respiratory or Vasopressor Support and/or Death as a Proposed Composite Outcome Measure for Perioperative Care Research
BACKGROUND: There is a need for a clinically relevant and feasible outcome measure to facilitate clinical studies in perioperative care medicine. This large-scale retrospective cohort study proposed a novel composite outcome measure comprising invasive respiratory or vasopressor support (IRVS) and death. We described the prevalence of IRVS in patients undergoing major abdominal surgery and assessed the validity of combining IRVS and death to form a composite outcome measure. METHODS: We retrospectively collected perioperative data for 2776 patients undergoing major abdominal surgery (liver, colorectal, gastric, pancreatic, or esophageal resection) at Kyoto University Hospital. We defined IRVS as requirement for mechanical ventilation for ≥24 hours postoperatively, postoperative reintubation, or postoperative vasopressor administration. We evaluated the prevalence of IRVS within 30 postoperative days and examined the association between IRVS and subsequent clinical outcomes. The primary outcome of interest was long-term survival. Multivariable Cox proportional regression analysis was performed to adjust for the baseline patient and operative characteristics. The secondary outcomes were length of hospital stay and hospital mortality. RESULTS: In total, 85 patients (3.1%) received IRVS within 30 postoperative days, 15 of whom died by day 30. Patients with IRVS had a lower long-term survival rate (1- and 3-year survival probabilities, 66.1% and 48.5% vs 95.2% and 84.0%, respectively; P < .001, log-rank test) compared to those without IRVS. IRVS was significantly associated with lower long-term survival after adjustment for the baseline patient and operative characteristics (adjusted hazard ratio, 2.72; 95% confidence interval, 1.97–3.77; P < .001). IRVS was associated with a longer hospital stay (median [interquartile range], 65 [39–326] vs 15 [12–24] days; adjusted P < .001) and a higher hospital mortality (24.7% vs 0.5%; adjusted P < .001). Moreover, IRVS was adversely associated with subsequent clinical outcomes including lower long-term survival (adjusted hazard ratio, 1.78; 95% confidence interval, 1.21–2.63; P = .004) when the analyses were restricted to 30-day survivors. CONCLUSIONS: Patients with IRVS can experience ongoing risk of serious morbidity and less long-term survival even if alive at postoperative day 30. Our findings support the validity of using IRVS and/or death as a composite outcome measure for clinical studies in perioperative care medicine
Transient acute kidney injury after major abdominal surgery increases chronic kidney disease risk and 1-year mortality
[Purpose] We conducted a retrospective cohort study to determine incidences of transient and persistent acute kidney injury (AKI) after major abdominal surgery and their impacts on long-term outcome. [Materials and methods] We enrolled 3751 patients undergoing major abdominal surgery. Postoperative AKI was classified as transient or persistent based on the return of serum creatinine to the non-AKI range within 7 days post-surgery. Primary outcome was mortality within 1 year. We used multivariable Cox proportional hazard regression analysis to assess independent associations between AKI type and mortality. [Results] Most patients with AKI were classified as transient (84%). Compared to patients without AKI, both patients with transient and persistent AKI demonstrated elevated 1-year mortality rates [adjusted hazard ratio (95% confidence interval): 2.01 (1.34–2.93); P = 0.001, and 6.20 (3.00–11.43); P < 0.001, respectively] and greater risk of chronic kidney disease progression at 1 year [adjusted odds ratio (95% confidence interval): 3.87 (2.12–7.08) and 23.70 (9.64–58.22), respectively; both P < 0.001]. [Conclusions] Although most AKI cases after major abdominal surgery recover completely within 7 days, even these patients with transient AKI are at higher risk for 1-year mortality and chronic kidney disease progression compared to patients without AKI