Triplet-Mediator Ligand-Protected Metal Nanocluster Sensitizers for Photon Upconversion.

Triplet-triplet annihilation photon upconversion (TTA-UC) is attracting a great deal of attention as a viable approach to exploit unutilized wavelengths of light in solar-driven devices. Recently, ligand-protected metal nanoclusters have emerged as a compelling platform for serving as triplet sensitizers for TTA-UC. In this study, we developed an atomically precise, triplet-mediator ligand (TL)-protected metal nanocluster, Au2Cu6(S-Adm)6[P(DPA)3]2 (Au2Cu6DPA; S-Adm = 1-adamanthanethiolate, DPA = 9,10-diphenylanthracene). In Au2Cu6DPA, the excitation of the Au2Cu6 core rapidly generates a metal-to-ligand charge transfer state, followed by the formation of the long-lived triplet state (approximately 150 µs) at a DPA site in the TL. By combining Au2Cu6DPA with a DPA annihilator, we achieved a red-to-blue upconversion quantum yield (ΦUCg) of 20.7 ± 0.4% (50% max.) with a low threshold excitation intensity of 36 mW cm-2 at 640 nm. This quantum yield almost reaches the maximum limit achievable using a DPA annihilator and establishes a record-setting value, outperforming previously reported nanocrystal and nanocluster sensitizers. Furthermore, strong upconversion emission based on a pseudo-first-order TTA process was observed under 1 sun illumination, indicating that the Au2Cu6DPA sensitizer holds promise for applications in solar-energy-based systems.

Neural mechanisms of information seeking.

We ubiquitously seek information to make better decisions. Particularly in the modern age, when more information is available at our fingertips than ever, the information we choose to collect determines the quality of our decisions. Decision neuroscience has long adopted empirical approaches where the information available to decision-makers is fully controlled by the researchers, leaving neural mechanisms of information seeking less understood. Although information seeking has long been studied in the context of the exploration-exploitation trade-off, recent studies have widened the scope to investigate more overt information seeking in a way distinct from other decision processes. Insights gained from these studies, accumulated over the last few years, raise the possibility that information seeking is driven by the reward system signaling the subjective value of information. In this piece, we review findings from the recent studies, highlighting the conceptual and empirical relationships between distinct literatures, and discuss future research directions necessary to establish a more comprehensive understanding of how individuals seek information as a part of value-based decision-making.

Microglia sense astrocyte dysfunction and prevent disease progression in an Alexander disease model.

Alexander disease (AxD) is an intractable neurodegenerative disorder caused by GFAP mutations. It is a primary astrocyte disease with a pathological hallmark of Rosenthal fibres within astrocytes. AxD astrocytes show several abnormal phenotypes. Our previous study showed that AxD astrocytes in model mice exhibit aberrant Ca2+ signals that induce AxD aetiology. Here, we show that microglia have unique phenotypes with morphological and functional alterations, which are related to the pathogenesis of AxD. Immunohistochemical studies of 60TM mice (AxD model) showed that AxD microglia exhibited highly ramified morphology. Functional changes in microglia were assessed by Ca2+ imaging using hippocampal brain slices from Iba1-GCaMP6-60TM mice and two-photon microscopy. We found that AxD microglia showed aberrant Ca2+ signals, with high frequency Ca2+ signals in both the processes and cell bodies. These microglial Ca2+ signals were inhibited by pharmacological blockade or genetic knockdown of P2Y12 receptors but not by tetrodotoxin, indicating that these signals are independent of neuronal activity but dependent on extracellular ATP from non-neuronal cells. Our single-cell RNA sequencing data showed that the expression level of Entpd2, an astrocyte-specific gene encoding the ATP-degrading enzyme NTPDase2, was lower in AxD astrocytes than in wild-type astrocytes. In situ ATP imaging using the adeno-associated virus vector GfaABC1D ATP1.0 showed that exogenously applied ATP was present longer in 60TM mice than in wild-type mice. Thus, the increased ATP level caused by the decrease in its metabolizing enzyme in astrocytes could be responsible for the enhancement of microglial Ca2+ signals. To determine whether these P2Y12 receptor-mediated Ca2+ signals in AxD microglia play a significant role in the pathological mechanism, a P2Y12 receptor antagonist, clopidogrel, was administered. Clopidogrel significantly exacerbated pathological markers in AxD model mice and attenuated the morphological features of microglia, suggesting that microglia play a protective role against AxD pathology via P2Y12 receptors. Taken together, we demonstrated that microglia sense AxD astrocyte dysfunction via P2Y12 receptors as an increase in extracellular ATP and alter their morphology and Ca2+ signalling, thereby protecting against AxD pathology. Although AxD is a primary astrocyte disease, our study may facilitate understanding of the role of microglia as a disease modifier, which may contribute to the clinical diversity of AxD.

The Sasaki-W anastomosis for recurrent Crohn's disease stenosis after the Kono-S anastomosis.

BACKGROUND: Postoperative recurrence is frequently encountered in the management of patients with Crohn's disease and is most often found at the anastomotic site. A novel technique, the Sasaki-W anastomosis, is an antimesenteric cutback end-to-end isoperistaltic anastomosis. We report a patient with Crohn's disease who underwent partial intestinal resection for postoperative anastomotic stenosis, reconstructed with the Sasaki-W anastomosis, after initial intestinal resection reconstructed with a Kono-S anastomosis. CASE PRESENTATION: A 30-year-old male was diagnosed with Crohn's disease and treated with mesalamine and adalimumab, and he underwent ileocecal resection using the Kono-S anastomosis at the time of diagnosis. He was treated with infliximab without any symptoms or recurrence for 7 years. He was admitted presenting with upper abdominal pain. Physical examination showed mild tenderness and distension in the upper abdomen. Laboratory data showed no remarkable findings. Computed tomography scan showed wall thickening in the ileum with proximal dilation and fluid retention. Non-operative management with antibiotics and fasting did not improve the symptoms within 7 days. Ten days after admission, ileocecal resection reconstructed with the Sasaki-W anastomosis was performed. At operation, there was a 15-cm intestinal stenosis at the site of the previous Kono-S anastomosis. The transverse colon and ileum were reconstructed with the Sasaki-W anastomosis. The postoperative course was uneventful, and the patient was discharged 17 days postoperatively. The patient had no obstructive symptoms and no findings consistent with bowel obstruction were observed on computed tomography scan one year postoperatively. CONCLUSIONS: The Sasaki-W anastomosis is a viable option for intestinal reconstruction in patients with postoperative recurrence after a Kono-S anastomosis.

Relationship between lumbar facet joint osteoarthritis and comorbidities: A cross-sectional study in the Japanese community.

BACKGROUND: Few epidemiological studies have evaluated associations between lumbar facet joint (LFJ) osteoarthritis (OA) and comorbidities. This study aimed to investigate the prevalence of LFJ OA in a Japanese community population and associations between LFJ OA and underlying diseases, including lower extremity OA. METHODS: This epidemiological cross-sectional study evaluated LFJ OA in 225 Japanese community residents (81 males, 144 females; median age, 66 years) using magnetic resonance imaging (MRI). LFJ OA from L1-L2 to L5-S1 was evaluated using a 4-grade classification. Associations between LFJ OA and comorbidities were examined using multiple logistic regression analyses adjusting for age, sex, and body mass index. RESULTS: Prevalences of LFJ OA were 28.6% at L1-L2, 36.4% at L2-L3, 48.0% at L3-L4, 57.3% at L4-L5, and 44.2% at L5-S1. Males were significantly more likely to have LFJ OA at several spinal levels (L1-L2 45.7% vs 18.9%, p < 0.001; L2-L3 46.9% vs 30.6%, p < 0.05; L4-L5 67.9% vs 51.4%, p < 0.05). LFJ OA was present in 50.0% of residents <50 years old, 68.4% at 50-59 years old, 86.3% at 60-69 years old, and 85.1% at ≥70 years old. Multiple logistic regression analysis showed no associations between LFJ OA and comorbidities. CONCLUSIONS: The prevalence of LFJ OA as evaluated by MRI was >85% at ≥60 years old and highest at the L4-L5 spinal level. Males were significantly more likely to have LFJ OA at several spinal levels. Comorbidities were not associated with LFJ OA.

Solo surgery in robot-assisted gastrectomy versus laparoscopic gastrectomy for gastric cancer: a propensity score-matched analysis.

BACKGROUND: Robot-assisted gastrectomy (RG) for gastric cancer is still not well standardized. This study aimed to explore the feasibility and effectiveness of solo surgery in robot-assisted gastrectomy (SRG) for gastric cancer compared to laparoscopic gastrectomy (LG). METHODS: This was a single-center retrospective comparative study between SRG and conventional LG. Between April 2015 and December 2022, 510 patients underwent gastrectomy, and data from a prospectively collected database were analyzed. We identified 372 patients who underwent LG (n = 267) and SRG (n = 105) and the remaining 138 patients were excluded because of remnant gastric cancer, esophagogastric junction cancer, open gastrectomy, concurrent surgery for concomitant malignancies, RG before starting SRG, or cases in which the author was unable to perform or supervise gastrectomy. Propensity score matching was performed at a ratio of 1:1 to reduce bias from confounding patient-related variables, and short-term outcomes were compared between the groups. RESULTS: After propensity score matching, 90 pairs of patients who underwent LG and SRG were selected. In the propensity-matched cohort, the operation time was significantly shorter in the SRG group than that in the LG group (SRG = 305.7 ± 74.0 min vs. LG = 340.3 ± 91.65 min, p < 0.0058), less estimated blood loss was observed in the SRG group than that in the LG group (SRG = 25.6 ± 50.6 mL vs. LG = 76.1 ± 104.2 mL, p < 0.0001) and postoperative hospital stay was shorter in the SRG group than that in the LG group (SRG = 7.1 ± 0.8 days vs. LG = 9.1 ± 7.7 days, p = 0.015). CONCLUSION: We found that SRG for gastric cancer was technically feasible and effective with favorable short-term outcomes, including shorter operative time, less estimated blood loss, shorter hospital stays, and lower postoperative morbidity than those in LG.

In situ scanning electron microscopy of hydrogen embrittlement by near atmospheric-pressure hydrogen microplasma jet.

Elucidation of microstructures responsible for hydrogen embrittlement is hoped for research and development of high-strength low-alloy steel. For this purpose, a novel in situ scanning electron microscopy method of hydrogen embrittlement was developed by using a near atmospheric-pressure hydrogen microplasma jet excited by pulsed glow discharge. By the developed method, propagations of hydrogen embrittlement cracks in typical martensitic steel, Japanese Industrial Standards SCM435 steel, were successfully observed at frame rates at least up to 10.2 Hz with the same image quality as in high vacuum. The hydrogen microplasma jet neither elevated the specimen temperature nor damaged the specimen surface. Strain evolution prior to the crack propagations was also successfully observed in conjunction with the digital image correlation technique. It was found that a small electron scattering cross section of the hydrogen molecule, a large density of hydrogen ions in the near atmospheric-pressure microplasma jet, and stabilization of the glow discharge by the electron beam of the scanning electron microscope play a crucial role in the realization of the in situ observations.

Presentation of External Ear Rosai-Dorfman Disease With Laryngeal Involvement.

Rosai-Dorfman disease (RDD) is a rare benign systemic histiocytic proliferation characterized by massive lymph node enlargement and sometimes associated with extranodal involvement. Even though it is considered to be benign, death can occur depending on the extent and location. Our case highlights a primary extranodal site of the right pinna with extension through the Eustachian tube to the subglottis. A previously healthy 15-year-old female presented with 1-year right pinna swelling, slowly enlarging and becoming more bothersome. An incisional biopsy was performed on the ear along with S100 staining yielding a diagnosis. After multidisciplinary case discussion, clofarabine monotherapy and systemic therapy for Langerhans cell histiocytosis has started. Rosai-Dorfman disease can be a general disorder, often affecting the lymph nodes. Unlike a nodal disease, extranodal disease could involve any site on the patient's anatomy. Head and neck lesions are the most common extranodal lesions. Rosai-Dorfman disease is self-limited in more than 20% of the cases with spontaneous regression without intervention; 70% of the patients have noticeable symptoms and vital organ involvement requiring treatments such as surgery, steroids, radiation, and chemotherapy. In our case, the patient had wide involvement and presented without any serious breathing difficulties; we decided to start with monotherapy with chemotherapy and systematic glucocorticoid treatment.

Clinical characteristics of early-stage lumbar spondylolysis detected by magnetic resonance imaging in male adolescent baseball players.

BACKGROUND: Many adolescent athletes experience low back pain; the most common cause is lumbar spondylolysis. Although early identification of lumbar spondylolysis in adolescent athletes is critical, few studies have focused on identifying the early stages of spondylolysis in baseball players. This study aimed to investigate the clinical characteristics of early-stage spondylolysis in male adolescent baseball players. METHODS: The participants comprised male junior and high school baseball players. Before magnetic resonance imaging, we recorded their demographic data, low back pain characteristics, and physical findings (lumbar flexion, extension, Kemp's test and the provocative tenderness of a spinous process). After the imaging evaluation, the association among low back pain characteristics, physical findings and the final diagnosis (early-stage spondylolysis or not) were investigated using univariate and multivariable analyses. RESULTS: A total of 171 players were included in this study. Univariate analyses indicated that the characteristics associated with early-stage spondylolysis were longer duration of low back pain (P = 0.0085), low back pain-related interference while running (P = 0.0022), low back pain starting with laterality (P = 0.0001), lumbar extension (P = 0.022), positive Kemp's test (P = 0.020), and the tenderness of a spinous process (P = 0.0003). After adjusting for confounding factors (age and position), we found that early-stage spondylolysis was significantly associated with low back pain duration ≥4 weeks (odds ratio 3.13, 95% confidence interval 1.42-6.92; P = 0.0048), low back pain-related interference while running (odds ratio 2.89, 95% confidence interval 1.30-6.46; P = 0.0094), low back pain starting with laterality (odds ratio 2.78, 95% confidence interval 1.24-6.27; P = 0.0133), and the tenderness of a spinous process (odds ratio 3.00, 95% confidence interval 1.36-6.57; P = 0.0062). CONCLUSIONS: Male adolescent baseball players with early-stage spondylolysis might have low back pain duration of more than four weeks, low back pain-related interference while running, and a history of low back pain starting with laterality. The tenderness of a spinous process might be helpful in the diagnosis of early-stage spondylolysis in male adolescent baseball players.

Regulators specifying cell fate activate cell cycle regulator genes to determine cell numbers in ascidian larval tissues.

In animal development, most cell types stop dividing before terminal differentiation; thus, cell cycle control is tightly linked to cell differentiation programmes. In ascidian embryos, cell lineages do not vary among individuals, and rounds of the cell cycle are determined according to cell lineages. Notochord and muscle cells stop dividing after eight or nine rounds of cell division depending on their lineages. In the present study, we showed that a Cdk inhibitor, Cdkn1.b, is responsible for stopping cell cycle progression in these lineages. Cdkn1.b is also necessary for epidermal cells to stop dividing. In contrast, mesenchymal and endodermal cells continue to divide even after hatching, and Myc is responsible for maintaining cell cycle progression in these tissues. Expression of Cdkn1.b in notochord and muscle is controlled by transcription factors that specify the developmental fate of notochord and muscle. Likewise, expression of Myc in mesenchyme and endoderm is under control of transcription factors that specify the developmental fate of mesenchyme and endoderm. Thus, cell fate specification and cell cycle control are linked by these transcription factors.

Evaluation of long-term chronic pain and outcomes for unilateral vs bilateral circular incision transabdominal preperitoneal inguinal hernia repair.

Aim: This study has two aims: to evaluate long-term chronic pain and complications after circular incision transabdominal preperitoneal inguinal hernia repair (C-TAPP) and compare outcomes of unilateral and bilateral inguinal hernia cases. Methods: A postoperative patient questionnaire was used to evaluate pain and complications in 1546 patients who underwent C-TAPP for simple inguinal hernia. Questions concerned satisfaction with surgery, pain at rest, pain at movement, mesh discomfort on a 10-point scale, and complications, such as recurrence. Patients were classified into unilateral (U Group) and bilateral (B Group) groups, and propensity score matching was performed to compare long-term chronic pain and complications. Results: The questionnaire return rates were 77.5% (1034 cases) and 79.9% (135 cases) in unilateral and bilateral cases. The frequency of moderate-to-severe (≥4 points) pain at rest, pain at movement, and mesh discomfort were 3.2%, 3.6%, and 4.5%, respectively. After propensity score matching, no significant differences in pain at rest (P = .726), at movement (P = .712), or mesh discomfort (P = .981) were detected between the U and B groups. Postoperative complications occurred in 2.1% of all patients, and the recurrence rate was 0.3%. In the post-match comparison, no differences in complications with Clavian-Dindo classification ≥III (U Group 0.7%, B Group 2.1%, P = .622) were detected. Conclusion: C-TAPP, which focuses on the layered structure, showed acceptable results for long-term chronic pain. Bilateral cases did not have worse pain or complications compared to unilateral cases.

Neural representations of others' traits predict social decisions.

To guide social interaction, people often rely on expectations about the traits of other people, based on markers of social group membership (i.e., stereotypes). Although the influence of stereotypes on social behavior is widespread, key questions remain about how traits inferred from social-group membership are instantiated in the brain and incorporated into neural computations that guide social behavior. Here, we show that the human lateral orbitofrontal cortex (OFC) represents the content of stereotypes about members of different social groups in the service of social decision-making. During functional MRI scanning, participants decided how to distribute resources across themselves and members of a variety of social groups in a modified Dictator Game. Behaviorally, we replicated our recent finding that inferences about others' traits, captured by a two-dimensional framework of stereotype content (warmth and competence), had dissociable effects on participants' monetary-allocation choices: recipients' warmth increased participants' aversion to advantageous inequity (i.e., earning more than recipients), and recipients' competence increased participants' aversion to disadvantageous inequity (i.e., earning less than recipients). Neurally, representational similarity analysis revealed that others' traits in the two-dimensional space were represented in the temporoparietal junction and superior temporal sulcus, two regions associated with mentalizing, and in the lateral OFC, known to represent inferred features of a decision context outside the social domain. Critically, only the latter predicted individual choices, suggesting that the effect of stereotypes on behavior is mediated by inference-based decision-making processes in the OFC.

Transient astrocytic mGluR5 expression drives synaptic plasticity and subsequent chronic pain in mice.

Activation of astrocytes has a profound effect on brain plasticity and is critical for the pathophysiology of several neurological disorders including neuropathic pain. Here, we show that metabotropic glutamate receptor 5 (mGluR5), which reemerges in astrocytes in a restricted time frame, is essential for these functions. Although mGluR5 is absent in healthy adult astrocytes, it transiently reemerges in astrocytes of the somatosensory cortex (S1). During a limited spatiotemporal time frame, astrocytic mGluR5 drives Ca2+ signals; upregulates multiple synaptogenic molecules such as Thrombospondin-1, Glypican-4, and Hevin; causes excess excitatory synaptogenesis; and produces persistent alteration of S1 neuronal activity, leading to mechanical allodynia. All of these events were abolished by the astrocyte-specific deletion of mGluR5. Astrocytes dynamically control synaptic plasticity by turning on and off a single molecule, mGluR5, which defines subsequent persistent brain functions, especially under pathological conditions.

Protein kinases and protein phosphatases encoded in the Ciona robusta genome.

Protein kinases (PKs) and protein phosphatases (PPs) regulate the phosphorylation of proteins that are involved in a variety of biological processes. To study such biological processes systematically, it is important to know the whole repertoire of PKs and PPs encoded in a genome. In the present study, we surveyed the genome of an ascidian (Ciona robusta or Ciona intestinalis type A) to comprehensively identify the genes that encoded PKs and PPs. Because ascidians belong to the sister group of vertebrates, a comparison of the whole repertoire of PKs and PPs of ascidians with those of vertebrates may help to delineate the complements of these proteins that were present in the last common ancestor of these two groups of animals. Our results show that the repertory of PPs was much more expanded in vertebrates than the repertory of PKs. We also showed that approximately 75% of PKs and PPs were expressed during development from eggs to larvae. Thus, the present study provides catalogs for PKs and PPs encoded in the ascidian genome. These catalogs will be useful for systematic studies of biological processes that involve phosphorylation and for evolutionary studies of the origin of vertebrates.

The visualization of low-molecule phenol (LMP) and copper naphthenate on treated wood using X-ray microtomography.

Recently, the plywood industry has been using low-molecule phenol (LMP) to enhance the dimensional stability of inferior-quality wood, along with copper naphthenate to increase veneer durability against staining fungi as a wood preservative. Non-destructive X-ray microtomography is a promising visualization method for reviewing the distribution of these materials. This study aimed to determine the applicability of X-ray microtomography for observing the distribution of LMP and Cu in two-and three-dimensional visualizations. The distribution mechanisms of these materials were investigated using X-ray images and image plot profiles. Six hardwood (wood from broad-leaved trees) and one softwood (wood from conifer trees) species were used for the experiments. An impregnation process was used to treat the wood samples with LMP, and copper naphthenate was added by dipping the wood in the compound for 1 s. A 10 mm2 sample of each wood species was scanned using X-ray microtomography, and the distribution of LMP and Cu was successfully visualized using X-ray microtomography with the same settings. The LMP was displayed approximately evenly throughout the veneer, whereas the copper naphthenate existed mainly on the veneer surface. The X-ray images successfully showed penetration at the microscopic scale.

Important risk factors for gallstones after laparoscopic gastrectomy: a retrospective study.

BACKGROUND: The frequency of gallstones is higher in patients who have undergone gastrectomy than in the general population. While there have been some studies of gallstone formation after open gastrectomy, there are few reports of gallstones after laparoscopic gastrectomy (LG). Therefore, this study aimed to evaluate the incidence of gallstones after LG. METHODS: We retrospectively reviewed the records of 184 patients who underwent LG between January 2011 and May 2016 at Saiseikai Utsunomiya Hospital. After gastrectomy, abdominal ultrasonography was generally performed every 6 months for 5 years. Patients who underwent cholecystectomy before LG, underwent simultaneous cholecystectomy, and did not undergo abdominal ultrasonography, with an observation period of < 24 months, were excluded from the study. Finally, 90 patients were analyzed. Laparoscopic cholecystectomy was performed whenever biliary complications occurred. Patient characteristics were compared using the two-tailed Fisher's exact test or Chi-square test. In addition, the risk factors for postoperative gallstones were analyzed using logistic regression analysis. RESULTS: Among the 90 patients included in this study, 60 were men (78%), and the mean age was 65.5 years. Laparoscopic total gastrectomy was performed for 15 patients and laparoscopic distal gastrectomy for 75 patients. D2 lymph node dissection was performed for 8 patients (9%), whereas 68 patients underwent LG with Roux-en-Y reconstruction (76%). Gallstones were detected after LG in 27 of the 90 (30%) patients. Multivariate analysis identified Roux-en-Y reconstruction and male sex as significant risk factors of gallstones after gastrectomy. The incidence of gallstones was significantly higher (53%) in male patients who underwent Roux-en-Y reconstruction. Symptomatic gallstones after laparoscopic cholecystectomy were found in 6 cases (6/27, 22%), and all patients underwent laparoscopic cholecystectomy. CONCLUSION: Roux-en-Y reconstruction and male sex were identified as significant risk factors for gallstones after LG.

Perioperative clinical parameters associated with short-term mortality after colorectal perforation.

PURPOSE: Although early prediction of mortality is useful for the management of patients with colorectal perforations, no significant perioperative predictive factors have been identified. The purpose of this study was to identify useful prognostic factors for patients with colorectal perforation. METHODS: This single-center retrospective study included consecutive patients undergoing emergency surgery for colorectal perforation from January 2012 to December 2019. The primary outcome was combined 30 day and in-hospital mortality. Patient- and disease-related factors obtained perioperatively were evaluated for mortality prediction. A scoring system was developed to enhance clinical utility. RESULTS: Overall, 146 patients were included and 20 (14%) died after surgery. Multivariate logistic regression identified five predictive factors: age, hemodialysis, uncommon perforation etiology, plasma albumin level, and decreased platelet count. The area under the receiver operating curve for the scoring system using these parameters was 0.894 (95% CI 0.835-0.952). Patients at high-risk of mortality were classified by the proposed score with a sensitivity of 90.0% and negative predictive value of 98.0%. CONCLUSION: This study identified five perioperative factors significantly associated with mortality of patients with colorectal perforation. Although these parameters predict mortality of patients with colorectal perforation using a score with high discrimination, further study is required to confirm these findings.

Dynamic Representation of the Subjective Value of Information.

To improve future decisions, people should seek information based on the value of information (VOI), which depends on the current evidence and the reward structure of the upcoming decision. When additional evidence is supplied, people should update the VOI to adjust subsequent information seeking, but the neurocognitive mechanisms of this updating process remain unknown. We used a modified beads task to examine how the VOI is represented and updated in the human brain of both sexes. We theoretically derived, and empirically verified, a normative prediction that the VOI depends on decision evidence and is biased by reward asymmetry. Using fMRI, we found that the subjective VOI is represented in the right dorsolateral prefrontal cortex (DLPFC). Critically, this VOI representation was updated when additional evidence was supplied, showing that the DLPFC dynamically tracks the up-to-date VOI over time. These results provide new insights into how humans adaptively seek information in the service of decision-making.SIGNIFICANCE STATEMENT For adaptive decision-making, people should seek information based on what they currently know and the extent to which additional information could improve the decision outcome, formalized as the VOI. Doing so requires dynamic updating of VOI according to outcome values and newly arriving evidence. We formalize these principles using a normative model and show that information seeking in people adheres to them. Using fMRI, we show that the underlying subjective VOI is represented in the dorsolateral prefrontal cortex and, critically, that it is updated in real time according to newly arriving evidence. Our results reveal the computational and neural dynamics through which evidence and values are combined to inform constantly evolving information-seeking decisions.

Excited-State Symmetry Breaking in a Multiple Multipolar Chromophore Probed by Single-Molecule Fluorescence Imaging and Spectroscopy.

Excited-state symmetry breaking (ESB) has attracted much attention because it is often observed in symmetric multipolar chromophores designed as two-photon absorption/emission materials. Herein, we report an ensemble and single-molecule fluorescence imaging and spectroscopy investigation of ESB in hexakis[4-(p-dioctylaminostyryl)phenylethynyl]benzene(DB6), a two-photon absorber possessing a C6-symmetric π-D6 structure (π = hexaethynylbenzene, D = (p-dioctylaminostyryl)phenyl group) consisting of three equivalent D-π-D moieties. Ensemble and single-molecule measurements and theoretical calculations revealed that DB6 undergoes a photoabsorption process with two orthogonal transition dipole moments, whereas it fluoresces with a single transition dipole moment after one- or two-step ESB upon photoexcitation, depending on the environmental polarity. In nonpolar solvents and polymer films, one of the three D-π-D sites becomes planar, and the excited state is localized on this moiety: a [Dδ+-πδ--Dδ+]* quadrupolar state is formed. In polar solvents, the symmetry is further broken within the planarized D-π-D moiety, and the excited state is localized on one of the two D-π sites; i.e., a D-[πδ--Dδ+]* dipolar state is generated. Hence, DB6 can behave like a multichromophore with multiple emission sites in the molecule, which was demonstrated by stepwise photobleaching under photon antibunching conditions.