Natural organisms such as photosynthetic bacteria, algae, and plants employ complex molecular machinery to convert solar energy into biochemical fuel. An important common feature shared by most of ...these photosynthetic organisms is that they capture photons in the form of excitons typically delocalized over a few to tens of pigment molecules embedded in protein environments of light-harvesting complexes (LHCs). Delocalized excitons created in such LHCs remain well protected despite being swayed by environmental fluctuations and are delivered successfully to their destinations over 100 nanometer distances in about 100 ps times. Decades of experimental and theoretical investigation have produced a large body of information offering insight into major structural, energetic, and dynamical features contributing to LHCs’ extraordinary capability to harness photons using delocalized excitons. The objective of this review is (i) to provide a comprehensive account of major theoretical, computational, and spectroscopic advances that have contributed to this body of knowledge, and (ii) to clarify the issues concerning the role of delocalized excitons in achieving efficient energy transport mechanisms. The focus of this review is on three representative systems: the Fenna-Matthews-Olson complex of green sulfur bacteria, the light-harvesting 2 complex of purple bacteria, and phycobiliproteins of cryptophyte algae. Although we offer a more in-depth and detailed description of theoretical and computational aspects, major experimental results and their implications are also assessed in the context of achieving excellent light-harvesting functionality. Future theoretical and experimental challenges to be addressed in gaining a better understanding and utilization of delocalized excitons are also discussed.
Background
Classifications of intraductal papillary mucinous neoplasm (IPMN) remain ambiguous, especially for the mixed type. Factors predicting malignancy remain unclear. The aim of this study was ...to evaluate the usefulness of factors predicting malignancy in the new international consensus guidelines for resection of branch duct‐type (BD)‐IPMN and to compare them with those in the previous version.
Methods
A prospectively collected database of patients with biopsy‐proven BD‐IPMN was analysed to compare factors between the first and second consensus guidelines, particularly as predictors of malignancy.
Results
Of 350 patients with BD‐IPMN, sensitivity (0·724) and balanced accuracy (0·751) of the second guidelines were superior to those (0·639 and 0·730) in the first version at the expense of slightly reduced specificity (0·779 versus 0·822 for the first version) by random forest models. Multiple logistic regression analysis showed that main pancreatic duct dilatation greater than 5 mm (hazard ratio (HR) 4·54, 95 per cent confidence interval 2·45 to 8·41; P < 0·001), mural nodules (HR 6·27, 3·27 to 12·01; P < 0·001) and carbohydrate antigen 19–9 level above 37 units/ml (HR 4·03, 1·83 to 8·90; P = 0·001) were independent predictors of BD‐IPMN malignancy.
Conclusion
The new consensus guidelines provide better sensitivity, performance of factors predicting malignancy, and balanced accuracy in the diagnosis of BD‐IPMN malignancy. Size alone was limited in predicting malignancy. Variability in clinical significance of the individual factors associated with a risk of malignancy indicates the need for a tailored approach in the management of patients with BD‐IPMN.
Cyst size alone is not useful
Human lung adenocarcinoma, the most prevalent form of lung cancer, is characterized by many molecular abnormalities. K-ras mutations are associated with the initiation of lung adenocarcinomas, but ...K-ras-independent mechanisms may also initiate lung tumors. Here, we find that the runt-related transcription factor Runx3 is essential for normal murine lung development and is a tumor suppressor that prevents lung adenocarcinoma. Runx3-/- mice, which die soon after birth, exhibit alveolar hyperplasia. Importantly, Runx3-/- bronchioli exhibit impaired differentiation, as evidenced by the accumulation of epithelial cells containing specific markers for both alveolar (that is SP-B) and bronchiolar (that is CC10) lineages. Runx3-/- epithelial cells also express Bmi1, which supports self-renewal of stem cells. Lung adenomas spontaneously develop in aging Runx3+/- mice ( approximately 18 months after birth) and invariably exhibit reduced levels of Runx3. As K-ras mutations are very rare in these adenomas, Runx3+/- mice provide an animal model for lung tumorigenesis that recapitulates the preneoplastic stage of human lung adenocarcinoma development, which is independent of K-Ras mutation. We conclude that Runx3 is essential for lung epithelial cell differentiation, and that downregulation of Runx3 is causally linked to the preneoplastic stage of lung adenocarcinoma.
The RENO experiment reports more precisely measured values of θ_{13} and |Δm_{ee}^{2}| using ∼2200 live days of data. The amplitude and frequency of reactor electron antineutrino (νover ¯_{e}) ...oscillation are measured by comparing the prompt signal spectra obtained from two identical near and far detectors. In the period between August 2011 and February 2018, the far (near) detector observed 103 212 (850 666) νover ¯_{e} candidate events with a background fraction of 4.8% (2.0%). A clear energy and baseline dependent disappearance of reactor νover ¯_{e} is observed in the deficit of the measured number of νover ¯_{e}. Based on the measured far-to-near ratio of prompt spectra, we obtain sin^{2}2θ_{13}=0.0896±0.0048(stat)±0.0047(syst) and |Δm_{ee}^{2}|=2.68±0.12(stat)±0.07(syst)×10^{-3} eV^{2}.
Previous linkage analysis of an Asian population proposed possible candidate genes for mandibular prognathism, such as Matrilin-1 (cartilage matrix protein). To investigate the association between ...the single-nucleotide polymorphisms (SNPs) in Matrilin-1 and mandibular prognathism, we investigated three sequence variants (-158 T>C, 7987 G>A, 8572 C>T) in 164 mandibular prognathism patients and 132 control individuals with a normal occlusion. The results showed that the 8572 TT genotypes in Matrilin-1 showed increased risk of mandibular prognathism (OR = 9.28, 95% Cl = 1.19~197.57, P < 0.05), whereas the 7987 AA genotype showed a protective effect for mandibular prognathism (OR = 0.16, 95% Cl = 0.05~0.47, P < 0.05). Genotyping results showed that the Matrilin-1 polymorphism haplotype TGC (ht4; 158T, 7987G, and 8572C alleles) had a pronounced risk effect for mandibular prognathism compared with controls (OR = 5.16, 95% Cl = 2.03~13.93, P < 0.01). The results suggest that polymorphisms in Matrilin-1 could be used as a marker for genetic susceptibility to mandibular prognathism.
We report a fuel-dependent reactor electron antineutrino (νover ¯_{e}) yield using six 2.8 GW_{th} reactors in the Hanbit nuclear power plant complex, Yonggwang, Korea. The analysis uses 850 666 ...νover ¯_{e} candidate events with a background fraction of 2.0% acquired through inverse beta decay (IBD) interactions in the near detector for 1807.9 live days from August 2011 to February 2018. Based on multiple fuel cycles, we observe a fuel ^{235}U dependent variation of measured IBD yields with a slope of (1.51±0.23)×10^{-43} cm^{2}/fission and measure a total average IBD yield of (5.84±0.13)×10^{-43} cm^{2}/fission. The hypothesis of no fuel-dependent IBD yield is ruled out at 6.6σ. The observed IBD yield variation over ^{235}U isotope fraction does not show significant deviation from the Huber-Mueller (HM) prediction at 1.3 σ. The measured fuel-dependent variation determines IBD yields of (6.15±0.19)×10^{-43} and (4.18±0.26)×10^{-43} cm^{2}/fission for two dominant fuel isotopes ^{235}U and ^{239}Pu, respectively. The measured IBD yield per ^{235}U fission shows the largest deficit relative to the HM prediction. Reevaluation of the ^{235}U IBD yield per fission may mostly solve the reactor antineutrino anomaly (RAA) while ^{239}Pu is not completely ruled out as a possible contributor to the anomaly. We also report a 2.9 σ correlation between the fractional change of the 5 MeV excess and the reactor fuel isotope fraction of ^{235}U.
Background
The fate of the portal vein (PV) after pancreatoduodenectomy, especially its long‐term patency and associated complications, has received little attention. The aim of this study was to ...explore the long‐term patency rate of the PV after pancreatoduodenectomy, focusing on risk factors for PV stenosis/occlusion and associated complications.
Methods
Serial CT images of patients who underwent pancreatoduodenectomy for periampullary cancer between January 2000 and June 2012 in a single institution were evaluated for PV stenosis or occlusion.
Results
A total of 826 patients were enrolled. The PV stenosis/occlusion rate after pancreatoduodenectomy was 19·6 per cent and the 5‐year patency rate 69·9 per cent. The most frequent cause of PV stenosis/occlusion was local recurrence followed by postoperative change and PV thrombosis. Patients who underwent PV resection had a higher PV stenosis/occlusion rate than those who did not (51 versus 17·4 per cent; P < 0·001). The 3‐year patency rate was highest in patients with cancer of the ampulla of Vater and lowest in patients with pancreatic cancer (91·9 versus 55·5 per cent respectively; P < 0·001). Multivariable analysis showed that risk factors for PV stenosis/occlusion included primary tumour location, chemoradiotherapy and PV resection. PV stenosis or occlusion without disease recurrence was observed in 17·3 per cent of the patients. PV resection and grade B or C pancreatic fistula were independent risk factors for PV stenosis/occlusion. Among 162 patients with PV stenosis or occlusion, five (3·1 per cent) had fatal recurrent gastrointestinal bleeding.
Conclusion
PV stenosis or occlusion is common after pancreatoduodenectomy, particularly if the PV has been resected and/or chemoradiotherapy was given after surgery. Although recurrence is the most frequent cause of PV stenosis/occlusion, this complication is found in a significant proportion of patients without disease recurrence.
Occlusion common with or without recurrence
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