Light-induced structural changes and the site of O=O bond formation in PSII caught by XFEL.

Photosystem II (PSII) is a huge membrane-protein complex consisting of 20 different subunits with a total molecular mass of 350 kDa for a monomer. It catalyses light-driven water oxidation at its catalytic centre, the oxygen-evolving complex (OEC). The structure of PSII has been analysed at 1.9 Å resolution by synchrotron radiation X-rays, which revealed that the OEC is a Mn4CaO5 cluster organized in an asymmetric, 'distorted-chair' form. This structure was further analysed with femtosecond X-ray free electron lasers (XFEL), providing the 'radiation damage-free' structure. The mechanism of O=O bond formation, however, remains obscure owing to the lack of intermediate-state structures. Here we describe the structural changes in PSII induced by two-flash illumination at room temperature at a resolution of 2.35 Å using time-resolved serial femtosecond crystallography with an XFEL provided by the SPring-8 ångström compact free-electron laser. An isomorphous difference Fourier map between the two-flash and dark-adapted states revealed two areas of apparent changes: around the QB/non-haem iron and the Mn4CaO5 cluster. The changes around the QB/non-haem iron region reflected the electron and proton transfers induced by the two-flash illumination. In the region around the OEC, a water molecule located 3.5 Å from the Mn4CaO5 cluster disappeared from the map upon two-flash illumination. This reduced the distance between another water molecule and the oxygen atom O4, suggesting that proton transfer also occurred. Importantly, the two-flash-minus-dark isomorphous difference Fourier map showed an apparent positive peak around O5, a unique µ4-oxo-bridge located in the quasi-centre of Mn1 and Mn4 (refs 4,5). This suggests the insertion of a new oxygen atom (O6) close to O5, providing an O=O distance of 1.5 Å between these two oxygen atoms. This provides a mechanism for the O=O bond formation consistent with that proposed previously.

Initial evaluation of a novel electrocardiography sensor-embedded fabric wear during a full marathon.

Sudden cardiac accident (SCA) during a marathon is a concern due to the popularity of the sport. Preventive strategies, such as cardiac screening and deployment of automated external defibrillators have controversial cost-effectiveness. We investigated the feasibility of use of a new electrocardiography (ECG) sensor-embedded fabric wear (SFW) during a marathon as a novel preventive strategy against SCA. Twenty healthy volunteers participated in a full marathon race. They were equipped with a SFW hitoe® with a transmitter connected via Bluetooth to a standard smartphone for continuous ECG recording. All data were stored in a smartphone and used to analyze the data acquisition rate. The adequate data acquisition rate was > 90% in 13, 30-90% in 3, and < 10% in 4 runners. All of 4 runners with poorly recorded data were female. Inadequate data acquisition was significantly associated with the early phase of the race compared with the mid phase (P = 0.007). Except for 3 runners with poor heart rate data, automated software calculation was significantly associated with manual analysis for both the mean (P < 0.001) and maximum (P = 0.014) heart rate. We tested the feasibility of continuously recording cardiac data during a marathon using a new ECG sensor-embedded wearable device. Although data from 65% of runners were adequately recorded, female runners and the early phase of the race tended to have poor data acquisition. Further improvements in device ergonomics and software are necessary to improve ability to detect abnormal ECGs that may precede SCA.

Genome-Wide Association Study in Asians Identifies Novel Loci for High Myopia and Highlights a Nervous System Role in Its Pathogenesis.

PURPOSE: To identify novel susceptibility loci for high myopia. DESIGN: Genome-wide association study (GWAS) followed by replication and meta-analysis. PARTICIPANTS: A total of 14 096 samples from East and Southeast Asian populations (2549 patients with high myopia and 11 547 healthy controls). METHODS: We performed a GWAS in 3269 Japanese individuals (1668 with high myopia and 1601 control participants), followed by replication analysis in a total of 10 827 additional samples (881 with high myopia and 9946 control participants) from Japan, Singapore, and Taiwan. To confirm the biological role of the identified loci in the pathogenesis of high myopia, we performed functional annotation and Gene Ontology (GO) analyses. MAIN OUTCOME MEASURES: We evaluated the association of single nucleotide polymorphisms with high myopia and GO terms enriched among genes identified in the current study. RESULTS: We identified 9 loci with genome-wide significance (P < 5.0 × 10-8). Three loci were previously reported myopia-related loci (ZC3H11B on 1q41, GJD2 on 15q14, and RASGRF1 on 15q25.1), and the other 6 were novel (HIVEP3 on 1p34.2, NFASC/CNTN2 on 1q32.1, CNTN4/CNTN6 on 3p26.3, FRMD4B on 3p14.1, LINC02418 on 12q24.33, and AKAP13 on 15q25.3). The GO analysis revealed a significant role of the nervous system related to synaptic signaling, neuronal development, and Ras/Rho signaling in the pathogenesis of high myopia. CONCLUSIONS: The current study identified 6 novel loci associated with high myopia and demonstrated an important role of the nervous system in the disease pathogenesis. Our findings give new insight into the genetic factors underlying myopia, including high myopia, by connecting previous findings and allowing for a clarified interpretation of the cause and pathophysiologic features of myopia at the molecular level.

Common variants in the COL2A1 gene are associated with lattice degeneration of the retina in a Japanese population.

Purpose: Lattice degeneration of the retina is a vitreoretinal disorder characterized by a visible fundus lesion that predisposes the patient to retinal detachment. It has been suggested that collagen type II alpha 1 (COL2A1) gene variants may contribute to the development of disorders associated with retinal detachment. Here we investigated whether COL2A1 gene variants were associated with the risk of lattice degeneration of the retina. Methods: We recruited 634 Japanese patients with lattice degeneration of the retina and 1694 Japanese healthy controls. We genotyped 13 tagging single-nucleotide polymorphisms (SNPs) in COL2A1. We also performed imputation analysis to evaluate the potential association of un-genotyped COL2A1 SNPs, involving the imputation of 65 SNPs. Results: Two intronic SNPs-rs1793954 and rs1635533-were significantly associated with lattice degeneration of the retina. The SNP rs1793954 showed the strongest association, with its C allele carrying an increased disease risk (p = 0.0016, corrected p = 0.021, OR = 1.25). The rs1793954 and rs1635533 SNPs were in strong linkage disequilibrium with each other (r 2 = 0.99), and conditional analysis revealed that rs1793954 could account for the association between rs1635533 and the disease. Conclusions: Our results suggested that COL2A1 gene variants may contribute to the development of lattice degeneration of the retina. Further genetic and functional analyses of COL2A1 variants are needed to clarify the present findings.

The ocular involvement did not accompany with the genital ulcer or the gastrointestinal symptoms at the early stage of Behçet's disease.

OBJECTIVES: This study aimed to identify patients with high-probability of ocular involvement of Behçet's disease (BD). METHODS: The Japanese Ministry of Health, Labour and Welfare provided dataset of ongoing nationwide BD registration project. A patient who had confirmed BD and who was suspected to have BD was registered. We mainly analyzed newly registered patients who had the data for all demographic and diagnostic parameters regardless of fulfilment of any diagnostic criteria. RESULTS: Among 3213 patients with confirmed or possible BD, 1382 (43.0%) were men and 1831 (57.0%) were women with a median age of 38 years (interquartile range (IQR) 30-49 years). The median duration between onset and registration was 0 year (IQR 0-3). A binomial multivariable logistic regression analysis revealed that being female (odds ratio (OR) 0.63, 95% confidence interval (CI) 0.53-0.75, p < .001), duration since onset (OR 1.33 per 10 years, 95% CI 1.18-1.51, p < .001), genital ulceration (OR 0.28, 95% CI 0.23-0.34, p < .001), and gastrointestinal symptoms (OR 0.36, 95% CI 0.30-0.44, p < .001) were related to the ocular lesion. Analyses based on data of 2800 patients who satisfied International criteria of BD, age-, sex-, duration-based subgroup analyses, analyses targeting iridocyclitis and retino-uveitis, and analysis including patients with missing data confirmed that the four factors were associated with the probability of eye involvement. CONCLUSION: The ocular involvement did not accompany with genital ulcer or gastrointestinal symptoms at the early stage of BD.

Clinical features of early-stage possible Behçet's disease patients with a variant-type major organ involvement in Japan.

Background: Clinical data of patients with entro-, vasculo-, and neuro-variant possible Behçet's disease (BD) based on Japanese criteria has not yet comprehensively reported. Methods: This ongoing nation-wide registration has been carried out by the Japanese Ministry of Health, Labour and Welfare. The Ministry asked physicians who diagnosed a patient with confirmed or possible BD to register the patient data by filling out a registration form. The Ministry provided us with the dataset after unlinkable anonymization. We analyzed 2003-2014 database generated from the early stage new cases. Results: Among the 7950 analyzable cases, 694 (8.7%) had variant-type possible BD without satisfying complete/incomplete criteria. Of the 694 patients, 479, 46, and 169 had entero-, vasculo-, and neuro-variant possible BD, respectively. Out of these 694 patients, 35 (5.0%) and 154 (22.2%) satisfied the International Study Group criteria and the International Criteria of BD, respectively. Entero-variant possible patients rarely (1.8%) had ocular lesions. Patients with vasculo-variant possible BD were featured by low genital ulceration risk (6.8%) and frequent positive HLA-B51 (60.0%). Neuro-variant possible BD was featured by high median age at registration (48 year). Vasculo- (69.6%) and neuro-variant (68.6%) BD patients showed clear male dominance. Epididymitis was very rare among variant-type possible BD men. Conclusion: We analyzed 694 early-stage variant-type possible BD cases. We believe the data from our study will contribute to further international discussion regarding BD diagnostic criteria and clarification of the clinical presentations of the Japanese variant-type possible BD patients.

Clinical manifestations of Behçet's disease depending on sex and age: results from Japanese nationwide registration.

Objective: This report aimed to scrutinize the prevalence of Behçet's disease (BD)-related clinical manifestations based on age- and sex-specific subgroups using a Japanese nationwide registration database. Methods: The database of newly registered BD was obtained from the Japanese Ministry of Health, Labour and Welfare. Patients who met the International Criteria for Behçet's Disease were selected and analysed. Results: Among 6627 International Criteria for Behçet's Disease cases, 2651 (40.0%) were men and 3976 (60.0%) were women with a median age of 39 years (interquartile range: 31-50 years). Ocular lesion was more common in male [odds ratio (male: female) 2.64 (95% CI: 2.35, 2.95, P < 0.001)] and genital ulceration was more common in female (odds ratio = 0.29, 95% CI: 0.25, 0.32, P < 0.001). Ocular lesion (P < 0.001), arthritis (P < 0.001) and vascular lesions (P < 0.001) were more frequently observed in elderly registered patients. Contrarily, genital ulceration (P < 0.001), epididymitis of males (P = 0.023) and oral ulceration (P = 0.003) were more common in younger patients. Simultaneous assessment of sex and age revealed that male predominance of ocular involvement was found in the young adult generation, but not in patients over 70 year of age. A female predominance of genital ulcer was prominently observed in patients 20-59 year of age; however, the sex difference was not found in patients over 60 years of age. Sensitivity analysis using International Study Group criteria replicated the results. Conclusion: We showed that clinical phenotype in early phase of BD was different depending on onset age and sex.

[Sense making affects stress response processes in parents of children with developmental disorders].

This study examined the stress-buffering effects of sense making among parents of children with developmental disorders. A model assuming that social support is related to sense making and that coping strategy mediates sense making and stress response was examined via a questionnaire survey of mothers of children with developmental disorders (N = 245). The results of structural equation modeling analysis suggested the following: (a) the stress-buffering effects of sense making were mediated through an emotional approach coping strategy and sense making was positively related to stress response mediated through an active coping strategy; (b) seeking a meaning directly increased one's stress response, which was indirectly mediated by an avoidant coping strategy; and (c) the effects of social support on sense making and coping strategy, as well as stress response, varied with the kind of social resources from whom mothers anticipated support. These results suggest that sense making affects stress response in mothers of children with developmental disorders through the social support they anticipate and the coping strategies they adopt.

[Stress-buffering effects of benefit finding on the psychological stress' response in mothers of children with developmental disorders].

This study describes the development and evaluation of the Benefit Finding Scale in Developmental Disorder Parenting (BFS-DDP). Using this scale, we examined the stress-buffering effects of identifying positive implications and benefits of having a child with developmental disorders in parents of such children. The BFS- DDP was developed from a questionnaire survey of mothers (N = 265) of children with developmental disorders. Exploratory and confirmatory analysis identified four factors: (a) "deepened relationships," (b) "changed life," (c) "changed life philosophy," and (d) "personal strength." These factors had high degrees of internal consistency. Furthermore, BFS-DDP scores significantly correlated with measuring optimism and meaningfulness, indicating good convergent validity. Hierarchical regression analysis showed that benefit finding significantly decreased stress response in the presence of high stressors. These results suggest that benefit finding may have a stress-buffering effect.

What is a Good Mother of Children with Autism? A Cross-Cultural Comparison Between the U.S. and Japan.

This study compared the characteristics of 'good mothers' of children with ASD (Autism Spectrum Disorder) as perceived by mothers of children with ASD in two countries-the U.S. and Japan. Grounded in the theory of culturally-influenced construal of the self, we hypothesized that U.S. mothers would prioritize fostering self-reliance and advocating for their child's well-being while Japanese mothers would prioritize maintaining close and harmonious relationships with their child. We conducted semi-structured interviews with 52 U.S. and 51 Japanese mothers of children with ASD about the characteristics of a good mother of a child with ASD (GMA) and characteristics of a good mother in general (GMG) and compared the frequencies of 'good mother' categories emerging from thematic analysis. Mothers of children with ASD in both countries viewed guiding children as the most important characteristic for both GMG and GMA. As hypothesized, U.S mothers tended to emphasize a mother's active role in advocating for her children, getting her child services and intervention, and educating herself about ASD. In contrast, Japanese mothers tended to value a mother's ability to accept her child, know her child well, and provide adequate support for her child based on a child-oriented perspective. The mother's role of advocating for her child and educating herself emerged more frequently in responses regarding GMA than GMG in the U.S. sample. The study revealed cultural differences in characterization of GMA, suggesting that more indirect models of instruction may be effective for different cultural groups.

[Developmental Disorder Parenting Stressor Index (DDPSI): reliability and validity].

This study describes the development and evaluation of the Developmental Disorder Parenting Stressor Index (DDPSI). The DDPSI items were developed from a questionnaire survey of mothers (N = 255) of children with developmental disorders. A factor analysis identified four factors: (a) difficulty understanding the child and coping with the child's needs, (b) anxiety about the child's future and independence, (c) inadequate understanding of the child's disorder, and (d) conflicting emotions with regard to the child's disorder. These factors had high degrees of internal consistency. The concurrent validity of the DDPSI was examined. The DDPSI scores significantly correlated with the Stress Response Scale-18 and the Handicapped Child Parenting Stress Scale. The results of structural equation modeling analysis suggested that social support for the mothers mitigated the stressors' effect and reduced their psychological stress responses. The DDPSI is sufficiently reliable and valid to measure the stressors of parents of children with developmental disorders.

Ophthalmic features of CHARGE syndrome with CHD7 mutations.

Coloboma and various ocular abnormalities have been described in CHARGE syndrome, although the severity of visual impairment varies from case to case. We conducted a multicenter study to clarify the ophthalmic features of patients with molecularly confirmed CHARGE syndrome. Thirty-eight eyes in 19 patients with CHARGE syndrome and confirmed CHD7 mutations treated at four centers were retrospectively studied. Colobomata affected the posterior segment of 35 eyes in 18 patients. Both retinochoroidal and optic disk colobomata were bilaterally observed in 15 patients and unilaterally observed in 3 patients. The coloboma involved the macula totally or partially in 21 eyes of 13 patients. We confirmed that bilateral large retinochoroidal colobomata represents a typical ophthalmic feature of CHARGE syndrome in patients with confirmed CHD7 mutations; however, even eyes with large colobomata can form maculas. The anatomical severity of the eye defect was graded according to the presence of colobomata, macula defect, and microphthalmos. A comparison of the severity in one eye with that in the other eye revealed a low-to-moderate degree of agreement between the two eyes, reflecting the general facial asymmetry of patients with CHARGE syndrome. The location of protein truncation and the anatomical severity of the eyes were significantly correlated. We suggested that the early diagnosis of retinal morphology and function may be beneficial to patients, since such attention may determine whether treatment for amblyopia, such as optical correction and patching, will be effective in facilitating the visual potential or whether care for poor vision will be needed.

The impact of gender differences, school adjustment, social interactions, and social activities on emotional and behavioral reactions to the COVID-19 pandemic among Japanese school children.

The COVID-19 pandemic has had negative psychological effects, such as increased depression, anxiety, and suicide, on children worldwide, including in Japan. To effectively mitigate the negative impact of the pandemic among Japanese children, it is necessary to increase understanding of the culturally specific psychological effects on Japanese children, including age and gender differences, as well as related risk and protective factors. However, no previous research has quantitatively evaluated changes in Japanese children's emotional functioning before and after the pandemic began. The present study examined changes in Japanese children's emotional functioning with pre- and mid-pandemic questionnaires, particularly focusing on age and gender differences. The present study also explored the effects of school adjustment, social interactions, and lifestyle activities on children's emotional and behavioral functioning during the pandemic. Data were analyzed from 293 children from the southwestern region in Japan. The pre-pandemic questionnaire assessed emotional and behavioral functioning and school adjustment, while the mid-pandemic questionnaire assessed emotional and behavioral functioning, social interactions, and lifestyle activities. The results indicated that the COVID-19 pandemic negatively impacted the emotional functioning of Japanese children, especially younger boys. Pre-pandemic school adjustment negatively influenced emotional functioning. Spending time alone, spending little time with one's mother, poor sleep regulation, a lack of exercise, and a high frequency of playing video games were related to poor emotional and behavioral functioning. The findings imply that Japanese children, especially younger boys, may benefit from psychological interventions that promote social interactions, especially with their mothers, regulated sleep patterns, adequate exercise, and that support children in managing video game engagement, to mitigate the pandemic's negative psychological impact.

Longitudinal analysis of 5-year refractive changes in a large Japanese population.

Refractive changes are reportedly affected by age, sex, and current refractive error. To clarify the pattern of refractive changes in a Japanese population, we conducted a 5-year follow-up longitudinal analysis of spherical equivalent (SE) refractive changes with stratification by sex, age, and SE in 593,273 eyes from Japanese individuals ages 3-91 years. The 5-year SE change with myopic shift dramatically increased over time after age 4 years, and the largest change was observed in both males and females who were age 8 years at baseline [males: - 2.654 ± 0.048 diopters (D); females: - 3.110 ± 0.038 D]. During school age, the 5-year myopic change was greater in females than in males, and emmetropic and low-to-moderate myopic eyes underwent larger myopic changes than hyperopic and high-to-severe myopic eyes. After the peak at age 8 years, the 5-year myopic change gradually declined with age and fell below - 0.25 D at age 27 in males and age 26 years in females. The 5-year SE changes transitioned from a myopic to a hyperopic shift at age 51 in both sexes, and hyperopization advanced more quickly in hyperopic eyes. Our findings highlight the importance of myopia prevention in school-aged children.

Two Cases of Thyrotoxicosis and Euglycemic Diabetic Ketoacidosis Under Sodium-glucose Transport Protein 2 Inhibitor Treatment.

Thyrotoxicosis and sodium-glucose transport protein 2 inhibitors (SGLT2is) are associated with the induction of euglycemic diabetic ketoacidosis (euDKA). We herein report two cases of euDKA in patients with diabetes mellitus wherein both thyrotoxicosis and SGLT2i treatment were the underlying causes. One patient developed thyrotoxicosis during the course of type 2 diabetes mellitus, whereas the other patient was suspected of developing slowly progressive insulin-dependent diabetes mellitus during the course of Graves' disease. Although such cases are rare, there is some concern that similar cases may occur because of the increased frequency of SGLT2i use in recent years.

Longitudinal psychometric evaluation of the developmental disorder parenting stressor index with Japanese parents of children with autism.

LAY ABSTRACT: Parents of children with autism experience high rates of parenting stress. Assessing parenting stress in them has crucial clinical implications because increased parental stress is associated with psychological disorders and personal distress, which can result in worse child-parent relationships. Theorists have proposed that a person's cognitive appraisal determines whether or not a situation or an encounter is personally stressful. However, prior scales merely measure the outcomes of parental stress as a stress response: little the scales were designed to assess events and cognitive appraisal-related parenting stressors of parents of children with autism. We investigated whether a new index for assessing parenting stressors-the Developmental Disorder Parenting Stressor Index is a valid measure to assess parenting stressors of parents of children with autism using longitudinal online surveys at three times. Participants were 212 Japanese parents of children with autism aged 2-18 years who completed the Developmental Disorder Parenting Stressor Index and measures of autism symptoms and stress response . Overall, the findings indicated that the Developmental Disorder Parenting Stressor Index can be reliably used to measure both experiences and cognitive appraisal of parenting stressors among parents of children with autism. Moreover, the Developmental Disorder Parenting Stressor Index has several advantages and is a valuable measurement tool to be able to evaluate parenting stressors in clinical settings; Developmental Disorder Parenting Stressor Index is shorter, easier to complete, and can evaluate both viewpoints of parenting stressors.

Simple Wearable Device to Reduce Stress When Delivering a Speech without Pre-training.

OBJECTIVE: There are many occasions in modern life when people must deliver presentations in front of audiences. Most people feel nervous before and while giving a speech. If there were a simple way to ease their stress, speakers would be able to perform better and their quality of life would improve. Consequently, this study aimed to alleviate the stress of speakers giving speeches by regulating breathing using a simple device. METHODS: To achieve this goal, a popular device, the Apple Watch, was chosen. Twenty-eight participants were divided into two groups: the Breathe app group and the non-Breathe app group. The Breathe app group regulated their breathing using the Breathe app installed on an Apple Watch before speech preparation. The non-Breathe app group listened to an explanation of the experiment so that they could not undertake their own stress-easing strategies. Participants prepared speeches about themselves and delivered them in front of the researcher. RESULTS: The Breathe app exercise eased stress during the exercise itself and the preparation phase of the speech task based on participants' cardiac activity. However, stress was not alleviated during speech delivery. CONCLUSIONS: Based on the experimental setting and results of this study, together with the findings of previous studies, introducing pre-training sessions and performing stress-easing tasks before and/or during a speech, such as sending vibrations to participants' wearable devices, might be an effective way to reduce stress when delivering speeches immediately after the breath-regulating task.

An open-label, prospective, single-arm study of switching from infliximab to cyclosporine for refractory uveitis in patients with Behçet's disease in long-term remission.

PURPOSE: Although infliximab (IFX) decreases the risk of blindness due to refractory uveitis in patients with Behçet's disease (BD), there are no standard criteria for IFX switching or withdrawal. To evaluate the effect of IFX switching in patients with BD in long-term remission, a prospective, single-arm intervention trial was conducted, switching from IFX to cyclosporine A (CYA). STUDY DESIGN: A prospective open-label study. METHODS: Eligible patients met the following criteria: administration of IFX without concomitant immunosuppressants for more than 5 years with no episodes of ocular attacks, no retinal vasculitis on fluorescein fundus angiography, negative C-reactive protein in serum, and no extraocular lesions at the time of IFX withdrawal. CYA 5 mg/kg/day was administered from 6 weeks after IFX withdrawal. The primary outcome was the rate of readministration of tumor necrosis factor inhibitors at 1 year after IFX withdrawal. RESULTS: Three of 45 BD patients treated with IFX for refractory uveitis were included in the study. At 1 year after withdrawal of IFX, no patient had experienced any ocular attacks or needed readministation of IFX. However, extraocular lesions, such as recurrent oral ulcers, folliculitis, and recurrent fevers, occurred in all patients. Liver or renal dysfunction, which may have been caused by CYA, was also observed in all patients. CONCLUSIONS: Although no ocular attacks were observed for at least 1 year after IFX withdrawal, this prospective study indicates that IFX withdrawal should be considered carefully, even for patients in long term remission of ocular and extraocular lesions.

Capturing structural changes of the S1 to S2 transition of photosystem II using time-resolved serial femtosecond crystallography.

Photosystem II (PSII) catalyzes light-induced water oxidation through an S i -state cycle, leading to the generation of di-oxygen, protons and electrons. Pump-probe time-resolved serial femtosecond crystallography (TR-SFX) has been used to capture structural dynamics of light-sensitive proteins. In this approach, it is crucial to avoid light contamination in the samples when analyzing a particular reaction intermediate. Here, a method for determining a condition that avoids light contamination of the PSII microcrystals while minimizing sample consumption in TR-SFX is described. By swapping the pump and probe pulses with a very short delay between them, the structural changes that occur during the S1-to-S2 transition were examined and a boundary of the excitation region was accurately determined. With the sample flow rate and concomitant illumination conditions determined, the S2-state structure of PSII could be analyzed at room temperature, revealing the structural changes that occur during the S1-to-S2 transition at ambient temperature. Though the structure of the manganese cluster was similar to previous studies, the behaviors of the water molecules in the two channels (O1 and O4 channels) were found to be different. By comparing with the previous studies performed at low temperature or with a different delay time, the possible channels for water inlet and structural changes important for the water-splitting reaction were revealed.

Structure-based drug design of tricyclic 8H-indeno[1,2-d][1,3]thiazoles as potent FBPase inhibitors.

With the goal of improving metabolic stability and further enhancing FBPase inhibitory activity, a series of tricyclic 8H-indeno[1,2-d][1,3]thiazoles was designed and synthesized with the aid of structure-based drug design. Extensive SAR studies led to the discovery of 19a with an IC(50) value of 1nM against human FBPase. X-ray crystallographic studies revealed that high affinity of 19a was due to the hydrophobic interaction arising from better shape complementarity and to the hydrogen bonding network involving the side chain on the tricyclic scaffold.