Modified t-butyl in tetradentate platinum (II) complexes enables exceptional lifetime for blue-phosphorescent organic light-emitting diodes.

In blue phosphorescent dopants, the tetradentate platinum(II) complex is a promising material showing high efficiency and stability in devices. However, metal-metal-to-ligand charge transfer (MMLCT) formation leads to low photo-luminescence quantum yields (PLQYs), wide spectra, and intermolecular interaction. To suppress MMLCT, PtON-tb-TTB and PtON-tb-DTB are designed using theoretical simulation by modifying t-butyl in PtON-TBBI. Both materials effectively suppress MMLCT and exhibit high PLQYs of 99% and 78% in 5 wt% doped film, respectively. The PtON-tb-TTB and PtON-tb-DTB devices have maximum external quantum efficiencies of 26.3% and 20.9%, respectively. Additionally, the PtON-tb-DTB device has an extended lifetime of 169.3 h with an initial luminescence of 1200 nit, which is 8.5 times greater than the PtON-TBBI device. Extended lifetime because of suppressed MMLCT and smaller displacement between the lowest triplet and triplet metal-centered states compared to other dopants. The study provides an effective approach to designing platinum(II) complexes for long device lifetimes.

NLRX1 knockdown attenuates pro-apoptotic signaling and cell death in pulmonary hyperoxic acute injury.

Hyperoxia is frequently used for treating acute respiratory failure, but it can cause acute lung injury. Nucleotide-binding domain and leucine-rich-repeat-containing family member X1 (NLRX1) is localized in mitochondria and involved in production of reactive oxygen species, inflammation, and apoptosis, which are the features of hyperoxic acute lung injury (HALI). The contribution of NLRX1 to HALI has not previously been addressed. Thus, to investigate the role of NLRX1 in hyperoxia, we generated a murine model of HALI in wild-type (WT) and NLRX1-/- mice by exposure to > 95% oxygen for 72 h. As a result, NLRX1 expression was elevated in mice exposed to hyperoxia. In acute lung injury, levels of inflammatory cells, protein leakage, cell cytotoxicity, and pro-inflammatory cytokines were diminished in NLRX1-/- mice compared to WT mice. In a survival test, NLRX1-/- mice showed reduced mortality under hyperoxic conditions, and apoptotic cell death and caspase expression and activity were also lower in NLRX1-/- mice. Furthermore, levels of the MAPK signaling proteins ERK 1/2, JNK, and p38 were decreased in NLRX1-deficient mice than in WT mice exposed to hyperoxia. The study shows that a genetic deficit in NLRX1 can suppress hyperoxia-induced apoptosis, suggesting that NLRX1 acts as a pivotal regulator of HALI.

A Comparative Immunohistochemical Study of Wound Healing after Dental Diode Laser Treatment in the Rat Oral Mucosa.

This study aimed to examine the differences in healing patterns using two types of diode laser devices (laser A and laser B) and a steel scalpel for periodontal surgery through histological and immunohistochemical methods. Twenty 12-week-old male rats were assigned to three groups (3, 7, and 14 days). Square-shaped erosion wounds (2 × 2 mm2 diameter) were created on the hard palate of each rat. Two wounds were created using Laser A and a steel scalpel (Bard-Parker No. 15) on the right palate and using Laser B and a steel scalpel on the left side. Rats were sacrificed after 3, 7, and 14 days. Tissues were collected with a margin of 1 mm from the border of the erosional wound of the maxillary hard palate. Histological and immunohistochemical analyses were performed on the tissue samples after 3, 7, and 14 days. The tissue healing pattern and expression of inducible nitric oxide synthase (iNOS) and cluster of differentiation (CD) were observed under a light microscope. Statistical analysis was conducted using the Kruskal−Wallis H test for comparison among the groups (α = 0.05). In comparison to the wounds made with the scalpel, wounds treated with lasers A and B showed delayed healing patterns. There was no significant difference between the two laser treatment groups (p > 0.05). The expression of iNOS and CD68 was not significantly different among the three groups after 3 and 7 days (p > 0.05). On day 14, the groups treated with the dental diode lasers showed higher expression than the group treated with the steel scalpel, but no significant difference was observed (p > 0.05). Laser-induced wounds tended to heal slower than surgical wounds performed using a steel scalpel, but histological and immunohistochemical results showed no significant difference between the dental diode laser and scalpel groups.

Interleukin-18 Receptor α Modulates the T Cell Response in Food Allergy.

PURPOSE: The prevalence of food allergy, triggered by T-helper type 2 (Th2) cell-mediated inflammation, is increasing worldwide. Interleukin (IL)-18 plays an important role in inflammatory diseases by binding with the IL-18 receptor. IL-18/IL-18 receptor α (IL-18Rα) is a cofactor for immunoglobulin E (IgE) production and Th2 cell development. Studies have not investigated the association between the IL-18/IL-18Rα signaling pathway and food allergy. Here, we investigated the role of IL-18Rα in food allergy induction and development. METHODS: Wild-type (WT) and IL-18Rα-null mutant (IL-18Rα-/-) C57BL/6 mice were sensitized and challenged using ovalbumin (OVA) for food allergy induction. Food allergy symptoms, T cell-mediated immune responses, and signal transducer and activator of transcription (STAT)/suppressors of cytokine signaling (SOCS) pathways were analyzed in mice. RESULTS: IL-18Rα expression was increased in WT mouse intestines after OVA treatment. Food allergy-induced IL-18Rα-/- mice showed attenuated systemic food allergic reactions, OVA-specific IgE and mouse mast cell protease-1 production, inflammatory cell infiltration, and T cell activation. Ex vivo experiments showed that cell proliferation and Th2 cytokine production were lower in IL-18Rα-/- mouse splenocytes than in WT mouse splenocytes. IL-18Rα blockade in WT splenocytes attenuated cell proliferation and Th2 cytokine production. Moreover, STAT3 phosphorylation was reduced in IL-18Rα-/- mice, and SOCS3 and SOCS1 activation were diminished in IL-18Rα-/- intestinal T cells. CONCLUSIONS: IL-18Rα regulates allergic reactions and immune responses by regulating T cell responses in food allergies. Moreover, IL-18Rα is involved in the STAT/SOCS signaling pathways. Targeting IL-18Rα signaling might be a novel therapeutic strategy for food allergy.

Neuron-recognizable characteristics of peptides recombined using a neuronal binding domain of botulinum neurotoxin.

Recombinant peptides were designed using the C-terminal domain (receptor binding domain, RBD) and its subdomain (peptide A2) of a heavy chain of botulinum neurotoxin A-type 1 (BoNT/A1), which can bind to the luminal domain of synaptic vesicle glycoprotein 2C (SV2C-LD). Peptide A2- or RBD-containing recombinant peptides linked to an enhanced green fluorescence protein (EGFP) were prepared by expression in Escherichia coli. A pull-down assay using SV2C-LD-covered resins showed that the recombinant peptides for CDC297 BoNT/A1, referred to EGFP-A2' and EGFP-RBD', exhibited ≥ 2.0-times stronger binding affinity to SV2C-LD than those for the wild-type BoNT/A1. Using bio-layer interferometry, an equilibrium dissociation rate constant (KD) of EGFP-RBD' to SV2C-LD was determined to be 5.45 µM, which is 33.87- and 15.67-times smaller than the KD values for EGFP and EGFP-A2', respectively. Based on confocal laser fluorescence micrometric analysis, the adsorption/absorption of EGFP-RBD' to/in differentiated PC-12 cells was 2.49- and 1.29-times faster than those of EGFP and EGFP-A2', respectively. Consequently, the recombinant peptides acquired reasonable neuron-specific binding/internalizing ability through the recruitment of RBD'. In conclusion, RBDs of BoNTs are versatile protein domains that can be used to mark neural systems and treat a range of disorders in neural systems.

Product Inspection Methodology via Deep Learning: An Overview.

In this study, we present a framework for product quality inspection based on deep learning techniques. First, we categorize several deep learning models that can be applied to product inspection systems. In addition, we explain the steps for building a deep-learning-based inspection system in detail. Second, we address connection schemes that efficiently link deep learning models to product inspection systems. Finally, we propose an effective method that can maintain and enhance a product inspection system according to improvement goals of the existing product inspection systems. The proposed system is observed to possess good system maintenance and stability owing to the proposed methods. All the proposed methods are integrated into a unified framework and we provide detailed explanations of each proposed method. In order to verify the effectiveness of the proposed system, we compare and analyze the performance of the methods in various test scenarios. We expect that our study will provide useful guidelines to readers who desire to implement deep-learning-based systems for product inspection.

Clusterin Deficiency Exacerbates Hyperoxia-Induced Acute Lung Injury.

Exposure to high oxygen concentrations leads to generation of excessive reactive oxygen species, causing cellular injury and multiple organ dysfunctions and is associated with a high mortality rate. Clusterin (CLU) is a heterodimeric glycoprotein that mediates several intracellular signaling pathways, including cell death and inflammation. However, the role of CLU in the pathogenesis of hyperoxic acute lung injury (HALI) is unknown. Wild-type (WT) and CLU-deficient mice and cultured human airway epithelial cells were used. Changes in cell death- and inflammation-related molecules with or without hyperoxia exposure in cells and animals were determined. Hyperoxia induced an increase in CLU expression in mouse lungs and human airway epithelial cells. Mice lacking CLU had increased HALI and mortality rate compared with WT mice. In vitro, CLU-disrupted cells showed enhanced release of cytochrome c, Bax translocation, cell death and inflammatory cytokine expression. However, treatment with recombinant CLU attenuated hyperoxia-induced apoptosis. Moreover, the Kyoto Encyclopedia of Genes and Genomes and Gene Ontology analyses revealed metabolic pathways, hematopoietic cell lineage, response to stress and localization and regulation of immune system that were differentially regulated between WT and CLU-/- mice. These results demonstrate that prolonged hyperoxia-induced lung injury is associated with CLU expression and that CLU replenishment may alleviate hyperoxia-induced cell death.

Evaluation of the clinical efficacy of a TW3-based fully automated bone age assessment system using deep neural networks.

PURPOSE: The aim of this study was to evaluate the clinical efficacy of a Tanner-Whitehouse 3 (TW3)-based fully automated bone age assessment system on hand-wrist radiographs of Korean children and adolescents. MATERIALS AND METHODS: Hand-wrist radiographs of 80 subjects (40 boys and 40 girls, 7-15 years of age) were collected. The clinical efficacy was evaluated by comparing the bone ages that were determined using the system with those from the reference standard produced by 2 oral and maxillofacial radiologists. Comparisons were conducted using the paired t-test and simple regression analysis. RESULTS: The bone ages estimated with this bone age assessment system were not significantly different from those obtained with the reference standard (P>0.05) and satisfied the equivalence criterion of 0.6 years within the 95% confidence interval (- 0.07 to 0.22), demonstrating excellent performance of the system. Similarly, in the comparisons of gender subgroups, no significant difference in bone age between the values produced by the system and the reference standard was observed (P>0.05 for both boys and girls). The determination coefficients obtained via regression analysis were 0.962, 0.945, and 0.952 for boys, girls, and overall, respectively (P=0.000); hence, the radiologist-determined bone ages and the system-determined bone ages were strongly correlated. CONCLUSION: This TW3-based system can be effectively used for bone age assessment based on hand-wrist radiographs of Korean children and adolescents.

Reduction of focal sweating by lipid nanoparticle-delivered myricetin.

Myricetin-a flavonoid capable of inhibiting the SNARE complex formation in neurons-reduces focal sweating after skin-application when delivers as encapsulated in lipid nanoparticles (M-LNPs). The stability of M-LNP enables efficient delivery of myricetin to sudomotor nerves located underneath sweat glands through transappendageal pathways while free myricetin just remained on the skin. Furthermore, release of myricetin from M-LNP is accelerated through lipase-/esterase-induced lipolysis in the skin-appendages, enabling uptake of myricetin by the surrounding cells. The amount of sweat is reduced by 55% after application of M-LNP (0.8 mg kg-1) on the mouse footpad. This is comparable to that of subcutaneously injected anticholinergic agents [0.25 mg kg-1 glycopyrrolate; 0.8 U kg-1 botulinum neurotoxin-A-type (BoNT/A)]. M-LNP neither shows a distal effect after skin-application nor induced cellular/ocular toxicity. In conclusion, M-LNP is an efficient skin-applicable antiperspirant. SNARE-inhibitory small molecules with suitable delivery systems have the potential to replace many BoNT/A interventions for which self-applications are preferred.

Characterization of Ginkgo biloba Leaf Flavonoids as Neuroexocytosis Regulators.

Ginkgo biloba leaf (GBL) is known as a potential source of bioactive flavonoids, such as quercetin, arresting the neuronal soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE)-zippering. Here, the GBL flavonoids were isolated in two different manners and then examined for their bioactivity, physicochemical stability, and biocompatibility. The majority of flavonoids in the non-hydrolyzed and acidolyzed isolates, termed non-hydrolyzed isolate (NI) and acidolyzed isolate (AI) hereafter, were rich in flavonol glycosides and aglycones, respectively. Glycosidic/aglyconic quercetin and kaempferol were abundant in both NI and AI, whereas a little of apigenin, luteolin, and isorhamnetin were found in AI. NI was more thermostable in all pH ranges than quercetin, kaempferol, and AI. NI and AI both inhibited neurotransmitter release from differentiated neuronal PC-12 cells. NI and AI showed 1/2-1/3 lower EC50/CC50 values than quercetin and kaempferol. The NI and AI exhibited no toxicity assessed by the tests on chorioallantoic membranes of hen's eggs, removing toxicological concerns of irritation potential. Moreover, GBL isolates, particularly AI, showed antioxidant and anti-inflammatory activities in the use below the CC50 levels. Taken together, these results suggest that GBL isolates that are rich in antioxidant flavonoids are effective anti-neuroexocytotic agents with high stability and low toxicity.

Development of a quantitative assay for 2´-fucosyllactose via one-pot reaction with α1,2-fucosidase and l-fucose dehydrogenase.

2'-Fucosyllactose (2'-FL) is the most abundant milk oligosaccharide in human breast milk and it has several benefits for infant health. The quantification of 2'-FL in breast milk or in samples from other sources generally requires lengthy analyses. These methods cannot be used to simultaneously detect 2'-FL in numerous samples, which would be more time-efficient. In this study, two genes, namely α1,2-fucosidase from Xanthomonas manihotis and l-fucose dehydrogenase from Pseudomonas sp. no. 1143, were identified, cloned and overexpressed in E. coli. The recombinant enzymes were produced as 6 × His-tagged proteins and were purified to homogeneity using Ni2+ affinity chromatography. The purified α1,2-fucosidase and l-fucose dehydrogenase are monomers with molecular masses of 63 kDa and 36 kDa, respectively. Both enzymes have sufficiently high activities in phosphate-buffered saline (pH 7.0) at 37 °C, making it possible to develop a coupled enzyme reaction in a single buffer system for the quantitative determination of 2'-FL in a large number of samples simultaneously. This method can be used to quantify 2'-FL in infant formulas and in samples collected from different phases of the biotechnological production of this oligosaccharide. Furthermore, the method is applicable for the rapid screening of active variants during the development of microbial strains producing 2'-FL.

Recurrence Rates and Characteristics of Phyllodes Tumors Diagnosed by Ultrasound-guided Vacuum-assisted Breast Biopsy (VABB).

BACKGROUND/AIM: Recently, the development of ultrasonography (US)-guided vacuum-assisted breast biopsy (VABB) has enabled the excision of benign breast tumors with normal surrounding breast tissues; thus, complete excision is possible without residual tumor tissue. We sought to identify the clinicopathological characteristics and recurrence rates of benign phyllodes tumors diagnosed by US-guided VABB. PATIENTS AND METHODS: Data from 11,221 US-guided VABBs performed at the Gangnam Cha Medical Center over 12 years were analyzed. Eighty-three lesions were diagnosed as benign phyllodes tumors; 67 with >24 months of follow-up data were investigated. All lesions were excised using an 8-gauge probe without residual tissue; patients underwent follow-up US every 3-6 months. RESULTS: Five patients (7.46%) experienced local recurrence during a mean follow-up period of 27.8 months; no distant metastases occurred. The mean tumor size was 3.0 cm in the recurrence group and 1.87 cm in the non-recurrence group (p=0.05). CONCLUSION: Benign phyllodes tumors excised and diagnosed using VABB showed a low recurrence rate during the follow-up period; thus, these tumors, particularly those <3 cm, can be safely monitored with ultrasonography instead of performing immediate re-excision.

Histopathology findings of non-mass cancers on breast ultrasound.

BACKGROUND: There is little research done on non-mass cancers (NMCs) on breast ultrasound (US). PURPOSE: To evaluate large-sectional histopathology findings of NMCs on breast US. MATERIAL AND METHODS: The mammographic and histopathology features of biopsy proven 36 breast cancers which showed pure non-mass lesions on US were retrospectively reviewed. RESULTS: The most common mammographic finding was microcalcification (23/35, 65.7%); fine pleomorphic microcalcification was predominant (18/23, 78.3%). The main tumor type was pure ductal carcinoma in situ (DCIS) (14/36, 38.9%) and DCIS with micro- or minimal invasion (11/36, 30.6%). Among the 25 DCIS, histologic grade was high in 15 (60.0%) and intermediate in nine (36%); comedo necrosis was seen in 17 (68%). Immunohistochemical analysis was available in 27 lesions and showed HER2-overexpression in 12 (44.4%) and triple-negative in two (7.4%). CONCLUSION: According to our limited patient sample, NMCs on breast US were mainly associated with high-grade DCIS.

Clinicopathological Analysis of Ultrasound-guided Vacuum-assisted Breast Biopsy for the Diagnosis and Treatment of Breast Disease.

BACKGROUND/AIM: To evaluate the usefulness and safety of vacuum-assisted breast biopsy (VABB) for breast lesion diagnosis and treatment. PATIENTS AND METHODS: Clinical and histopathological data of 8,748 patients, who underwent 11,221 VABB procedures were analyzed. RESULTS: Most patients (58.2%) were <40 years old. Most lesions (39.6%) were 0.6-1.0 cm in diameter while 3.2% were ≥3.0 cm; fibroadenomas were the most common (46.6%). Eight (14% of 57) cases of atypical ductal hyperplasia were underestimated. The positive predictive values (PPVs) of breast imaging reporting and data system (BI-RADS) ultrasound category were 0.6%, 3.4%, 34.8%, 66.2%, and 93.8% for category 3, 4a, 4b, 4c, and 5 lesions, respectively. The mean number of core specimens was 9.5±8.8; the mean procedure time was 3.4±2.7 min. No residual lesions were found in 94.4% of the 7,480 patients. CONCLUSION: VABB could replace ultrasound-guided core biopsy and surgical excisional biopsy for the diagnosis of breast disease and the treatment of benign breast lesions.

How social information can improve estimation accuracy in human groups.

In our digital and connected societies, the development of social networks, online shopping, and reputation systems raises the questions of how individuals use social information and how it affects their decisions. We report experiments performed in France and Japan, in which subjects could update their estimates after having received information from other subjects. We measure and model the impact of this social information at individual and collective scales. We observe and justify that, when individuals have little prior knowledge about a quantity, the distribution of the logarithm of their estimates is close to a Cauchy distribution. We find that social influence helps the group improve its properly defined collective accuracy. We quantify the improvement of the group estimation when additional controlled and reliable information is provided, unbeknownst to the subjects. We show that subjects' sensitivity to social influence permits us to define five robust behavioral traits and increases with the difference between personal and group estimates. We then use our data to build and calibrate a model of collective estimation to analyze the impact on the group performance of the quantity and quality of information received by individuals. The model quantitatively reproduces the distributions of estimates and the improvement of collective performance and accuracy observed in our experiments. Finally, our model predicts that providing a moderate amount of incorrect information to individuals can counterbalance the human cognitive bias to systematically underestimate quantities and thereby improve collective performance.

Diagnosis of Grave's disease with pulmonary hypertension on chest CT.

OBJECTIVE: To evaluate the diagnostic accuracy of chest CT findings to diagnose Grave's disease in pulmonary hypertension. METHODS: We retrospectively evaluated chest CT and the medical records of 13 patients with Grave's disease with (n=6) or without pulmonary hypertension (n=7) and in 17 control patients. RESULTS: Presence of iso-attenuation of diffusely enlarged thyroid glands compared with adjacent neck muscle on non-enhanced CT as a diagnostic clue of Grave's disease, and assessment of pulmonary hypertension on CT has high diagnostic accuracy. CONCLUSION: Chest CT has the potential to diagnose Grave's disease with pulmonary hypertension in the absence of other information.

Mammography, US, and MRI for Preoperative Prediction of Extensive Intraductal Component of Invasive Breast Cancer: Interobserver Variability and Performances.

BACKGROUND: Interobserver variability and performances of imaging studies for predicting an extensive intraductal component (EIC) of invasive breast cancer have not been well established. MATERIALS AND METHODS: Two independent readers retrospectively reviewed every preoperative mammography, ultrasonography (US), and magnetic resonance imaging (MRI) studies of 145 breast cancers in 144 patients with surgically confirmed EIC status and recorded the EIC presence for each study, using our own descriptors referred to in prior articles. Agreement and performance of each study for the prediction of an EIC were assessed. The reference standard was surgical pathologic findings. RESULTS: Of 145 breast cancers, an EIC was present in 49 cancers (33.8%) in 49 patients. Overall agreement was perfect on mammography (κ = 0.944), and substantial in US (κ = 0.691) or in MRI (κ = 0.627), and moderate to perfect agreement was found on most descriptors (κ = 0.443-0.81), except some US descriptors (κ = 0.23-0.396). The sensitivity of each study showed no significant differences in both readers (0.73-0.82). For the specificity, mammography was better than US in 2 readers (0.69/0.5; P = .001; 0.72/0.6; P = .007, respectively), and MRI better than US in 1 reader (0.79/0.5; P = .039). Performances between the readers showed no significant differences in each study. CONCLUSION: According to our data, mammography, US, and MRI are valid and reproducible methods for the preoperative prediction of an EIC of invasive breast cancer. However, US shows low agreement on some descriptors and lower performance than mammography or MRI.

Presence of subpleural pulmonary interstitial emphysema as an indication of single or multiple alveolar ruptures on CT in patients with spontaneous pneumomediastinum.

Background There are no previous reports regarding the computed tomography (CT) findings of subpleural pulmonary interstitial emphysema (PIE) in patients with spontaneous pneumomediastinum. Purpose To evaluate CT findings of subpleural PIE that may indicate a direct site of terminal alveolar rupture. Material and Methods We retrospectively evaluated chest CT and the medical records of 34 patients with spontaneous pneumomediastinum. Subpleural PIE was defined as the presence of an interstitial air collection in the subpleural portion of the lungs excluding the bronchovascular bundle. Results Subpleural PIE on CT was identified in six of 34 patients (17.6%) with spontaneous pneumomediastinum. In four of these (66.7%), subpleural PIE was present in multiple lobes suggesting multiple simultaneous ruptures of terminal alveoli. The shape of subpleural PIE was elongated linear (4/6), branching and linear (1/6), and elliptical (1/6). Conclusion The presence of subpleural PIE on CT suggests an origin of pneumomediastinal air from alveolar rupture.

A Case of Complete Unroofed Coronary Sinus Syndrome Combined With Coronary Sinus Stenosis Leading to Asymptomatic Presentation.

We describe a patient with an asymptomatic complete unroofed coronary sinus (CS) syndrome associated with the CS stenosis in the absence of a persistent left superior vena cava (SVC) as identified on coronary computed tomography angiography. There was a large defect between the CS and the left atrium (i.e. a large left-to-right shunt), but an unusual combination of the absence of a persistent left SVC (i.e. no risk for brain abscess due to the absence of a right-to-left shunt) and the CS stenosis (i.e. a markedly reduced degree of a left-to-right shunt), resulting in an asymptomatic presentation.

Human collective intelligence under dual exploration-exploitation dilemmas.

The exploration-exploitation dilemma is a recurrent adaptive problem for humans as well as non-human animals. Given a fixed time/energy budget, every individual faces a fundamental trade-off between exploring for better resources and exploiting known resources to optimize overall performance under uncertainty. Colonies of eusocial insects are known to solve this dilemma successfully via evolved coordination mechanisms that function at the collective level. For humans and other non-eusocial species, however, this dilemma operates within individuals as well as between individuals, because group members may be motivated to take excessive advantage of others' exploratory findings through social learning. Thus, even though social learning can reduce collective exploration costs, the emergence of disproportionate "information scroungers" may severely undermine its potential benefits. We investigated experimentally whether social learning opportunities might improve the performance of human participants working on a "multi-armed bandit" problem in groups, where they could learn about each other's past choice behaviors. Results showed that, even though information scroungers emerged frequently in groups, social learning opportunities reduced total group exploration time while increasing harvesting from better options, and consequentially improved collective performance. Surprisingly, enriching social information by allowing participants to observe others' evaluations of chosen options (e.g., Amazon's 5-star rating system) in addition to choice-frequency information had a detrimental impact on performance compared to the simpler situation with only the choice-frequency information. These results indicate that humans groups can handle the fundamental "dual exploration-exploitation dilemmas" successfully, and that social learning about simple choice-frequencies can help produce collective intelligence.