Search

Recipient depression before kidney transplantation needs to be treated to reduce poor posttransplant outcomes. For recipients who receive living kidney transplantation, feelings of guilt for potential donors may be factors related to the presence of depressive symptoms. This study aimed to examine the association between recipients' feelings of guilt for the donor and depressive symptoms before living kidney transplantation.Participants included 178 patients in Sapporo City General Hospital, Hokkaido, Japan, who completed a questionnaire before having living kidney transplantation from April 2009 to May 2016. Feelings of guilt for the donor, depressive symptoms using the Beck Depression Inventory-II (BDI-II), relationship to the donor, dialysis period, and socio-demographic characteristics were assessed via a questionnaire. Multivariate regression analyses were performed to examine the association between feelings of guilt for the donor and BDI-II score after multiple imputations.The results showed that feelings of guilt for donors were associated with depressive symptoms, especially cognitive factors.These findings indicate that medical staff needs to address recipients' feelings of guilt for donors before living kidney transplantation.

Further advances in magnesium ion batteries (MIBs) require the development of electrolyte solutions with highly optimized properties. Here we report the design, synthesis and electrolytic properties of a new family of Mg salts of carba-closo-dodecaborate anions (CCAs). Detailed calculations suggested that modification at the boron vertices, previously considered inappropriate for MIB electrolytes, would be effective. Experimental studies showed that simple halogenation at the 12-B vertex of CCA drastically improves the solubility in low viscosity solvents without compromising the chemical and redox stability, and the ionic conductivity reached 6.2 mS/cm. The synthesized electrolytes showed low overpotential (≤200 mV) for Mg deposition and excellent reversible magnesium deposition/stripping with high Coulombic efficiency (≥95%).

With the increasing importance of fluorine to medicinal chemistry and other areas, methods to access various fluorinated compounds are needed. Herein, we report the synthesis of difluoropropargyl vinyl ethers from ketones and aldehydes using difluoropropargyl bromide dicobalt complexes. We applied difluoropropargyl vinyl ethers to the synthesis of difluorodienone or difluoroallene under thermal conditions and trifluoro-pyran under acid-catalyzed conditions.

Lolitrems are tremorgenic indole diterpenes that exhibit a unique 5/6 bicyclic system of the indole moiety. Although genetic analysis has indicated that the prenyltransferase LtmE and the cytochrome P450 LtmJ are involved in the construction of this unique structure, the detailed mechanism remains to be elucidated. Herein, we report the reconstitution of the biosynthetic pathway for lolitrems employing a recently established genome-editing technique for the expression host Aspergillus oryzae. Heterologous expression and bioconversion of the various intermediates revealed that LtmJ catalyzes multistep oxidation to furnish the lolitrem core. We also isolated the key reaction intermediate with an epoxyalcohol moiety. This observation allowed us to establish the mechanism of radical-induced cyclization, which was firmly supported by density functional theory calculations and a model experiment with a synthetic analogue.

Sterically hindered three-dimensional (3D) alkyl halides are promising precursors for various reactions; however, they are difficult to synthesize via conventional reactions. We present an efficient and practical method for decarboxylative bromination of sterically hindered 3D aliphatic carboxylic acids using commercially available (diacetoxyiodo)­benzene and potassium bromide, one of the most stable and cheapest bromine sources in nature. The present method features a metal-free/Br2-free system, mild reaction conditions, one-pot operation under air at room temperature, wide functional group compatibility, and gram-scale synthetic capability. This highly efficient reaction cleanly converts a broad range of carboxylic acids, the most inexpensive and readily available sources of highly strained/naturally occurring/drug-related scaffolds, into the corresponding alkyl bromides in good to high yields.

We report the first stereoselective synthesis of stable (E)- and (Z)-β-chlorovinyl-λ3-chlorane via direct mesitylation of 1,2-dichloroethylene with mesityldiazonium tetrakis(pentafluorophenyl)borat...

Transition-metal-catalyzed cycloisomerization reactions with skeletal rearrangement of 1,n-enynes to afford cyclic dienes (particularly exo-cyclization products) have been well studied. However, there are few reports on the nonmetal-catalyzed skeletal rearrangement of enynes and skeletal rearrangement of electron-deficient enynes such as n-en-2-ynones. Here, we describe BF3·MeCN-catalyzed synthesis of 3-alkylidenecyclohexenes from 7-en-2-ynones, representing the first nonmetal-catalyzed skeletal rearrangement of 1,6-enynes to endo-type cyclic dienes.

Background We aimed to explore the overall network structure of problematic smartphone use symptoms assessed by smartphone addiction scale-short version (SAS-SV) and to identify which items could play important roles in the network. Methods 487 college and university students filled out the study questionnaire, including SAS-SV. We constructed a regularized partial correlation network among the 10 items of SAS-SV. We calculated three indices of node centrality: strength, closeness, and betweenness, to quantify the importance of each SAS-SV item. Results We identified 34 edges in the estimated network. In the given network, one item pertaining to withdrawal symptom hadthe highest strength and high closeness centrality. Additionally, one item related to preoccupation was also found to have high centrality indices. Conclusion Our results indicating the central role of one withdrawal symptom and one preoccupation symptom in the symptom network of problematic smartphone use in young adults were in line with a previous study targeting school-age children. Longitudinal study designs are required to elicit the role of these central items on the formation and maintenance of this behavioral problem.

Shimalactones A and B are neuritogenic polyketides possessing characteristic oxabicyclo[2.2.1]heptane and bicyclo[4.2.0]octadiene ring systems that are produced by the marine fungus Emericella variecolor GF10. We identified a candidate biosynthetic gene cluster and conducted heterologous expression analysis. Expression of ShmA polyketide synthase in Aspergillus oryzae resulted in the production of preshimalactone. Aspergillus oryzae and Saccharomyces cerevisiae transformants expressing ShmA and ShmB produced shimalactones A and B, thus suggesting that the double bicyclo-ring formation reactions proceed non-enzymatically from preshimalactone epoxide. DFT calculations strongly support the idea that oxabicyclo-ring formation and 8π-6π electrocyclization proceed spontaneously after opening of the preshimalactone epoxide ring through protonation. We confirmed the formation of preshimalactone epoxide in vitro, followed by its non-enzymatic conversion to shimalactones in the dark.

The silaboration of [1.1.1]propellane enables direct introduction of B and Si functional groups onto the bicyclo[1.1.1]pentane (BCP) scaffold in high yield under mild, additive-free conditions. The silaborated BCP can be obtained on a gram-scale in a single step without the need for column-chromatographic purification, and is storable and easy to handle, providing a versatile synthetic intermediate for BCP derivatives. We also describe various conversions of the C-B/C-Si bonds on the BCP scaffold, including development of a modified Suzuki-Miyaura cross-coupling reaction at the highly sterically hindered bridgehead sp3 carbon center of the BCP skeleton using a combination of highly activated BCP boronic esters, copper(I) oxide, and a PdCl2 (dppf) catalyst system.

With the increasing importance of fluorine to medicinal chemistry and other areas, methods to access various fluorinated compounds are needed. Herein, we report the synthesis of difluoropropargyl vinyl ethers from ketones and aldehydes using difluoropropargyl bromide dicobalt complexes. We applied difluoropropargyl vinyl ethers to the synthesis of difluorodienone or difluoroallene under thermal conditions and trifluoro-pyran under acid-catalyzed conditions.

The bicyclo[1.1.1]pentane (BCP) scaffold is useful in medicinal chemistry, and many protocols are available for synthesizing BCP derivatives from [1.1.1]propellane. However, little progress has been made in the preparation of [1.1.1]propellane since the first practical synthesis in 1985. Here, we report the α-cyclodextrin (α-CD) encapsulation of BCP derivatives, affording a stable, readily storable material from which BCPs can be easily and quantitatively recovered. We have also developed new and simple protocols for deiodination reaction of 1,3-diiodo BCP to afford [1.1.1]propellane in protic/aprotic/polar/non-polar solvents. The combination of these methodologies enables simple, on-demand preparation of [1.1.1]propellane in various solvents under mild conditions from α-CD capsules containing 1,3-diiodo BCP.

Brasilane-type sesquiterpenes have been known for a long time, but their biosynthetic pathways and mechanisms remain elusive. Recently, two groups independently characterized a Trichoderma terpene cyclase that produces trichobrasilenol, a brasilane-type sesquiterpene, and a plausible biosynthetic pathway was proposed based on isotopic labeling experiments. In the proposed mechanism, the characteristic brasilane-type 5/6 bicyclic skeleton is synthesized from a 5/7/3 tricyclic intermediate via a complicated concerted reaction, including six chemical events of C-C σ bond metathesis and rearrangements, ring-contraction, π bond formation, and regioselective hydroxylation. However, our density functional theory (DFT) calculations do not support this mechanism. On the basis of DFT calculations, we propose a new pathway for trichobrasilenol biosynthesis, involving a multistep carbocation cascade in which cyclopropylcarbinyl cations in equilibrium with homoallyl cations play a pivotal role. This pathway and mechanism is in good agreement with previous biosynthetic studies on brasilane-type compounds and related terpenoids, including isotope-labeling experiments and byproducts analysis.

A potent cross-coupling methodology that enables efficient carbon–carbon bond formation at sterically hindered sp2- and sp3-carbons has been developed., We describe a powerful, broadly applicable cross-coupling protocol that enables carbon–carbon bond formation at highly sterically hindered carbon centers (both sp2 and sp3) by employing organocopper reagents under palladium catalysis. Experimental studies and theoretical calculations indicated that the key to the unique reactivity of copper is the relatively low activation energy of the compact transmetalation transition state, due to Cu(i)–Pd(ii) interaction, which is associated with small values of deformation energy of the reactants. This reaction is applicable to a variety of bulky substrates, including compounds inert to previous cross-coupling chemistry and has high functional group tolerance.

A formal total synthesis of pactamycin (1) has been accomplished by face-selective and regioselective nitroso Diels–Alder (NDA) reaction of acyl nitroso compound 14, which contains a camphorsultam ...

We report the first stereoselective synthesis of stable (

Transition-metal-catalyzed cycloisomerization reactions with skeletal rearrangement of 1,n-enynes to afford cyclic dienes (particularly

Utilization of three-dimensional cyclic scaffolds is important in modern drug discovery, both to provide greater opportunities for optimizing drug candidates and to expand the available chemical space of drugs. Among these scaffolds, bicyclo[1.1.1]pentane (BCP) is a high-value bioisostere for 1,4-disubstituted phenyl rings, internal alkynes, and the tert-butyl group, generally offering high passive permeability, high water solubility, and improved metabolic stability. However, the lack of methods for functionalizing BCP remains a significant challenge, and in particular, a versatile strategy for synthesizing a wide range of unsymmetrically 1,3-difunctionalized BCP derivatives has been lacking. In this account, we review recent advances in the synthetic chemistry of BCP, focusing especially on our recently developed radical multicomponent carboamination of [1.1.1]propellane.1 Introduction2 Overview of the Synthetic Chemistry of [1.1.1]Propellane, the Most Promising Precursor of Bicyclo[1.1.1]pentane3 Recent Advances in the Synthetic Chemistry of Unsymmetrically 1,3-Disubstituted Bicyclo[1.1.1]pentane Derivatives4 Radical Multicomponent Carboamination of [1.1.1]Propellane Permits Direct Synthesis of 3-Substituted Bicyclo[1.1.1]pent-1-ylamine Derivatives5 Conclusion

Objectives Previous studies have reported that internet addiction (IA) is associated with attention-deficit/hyperactivity disorder (ADHD) consistently. However, in terms of gender, there are controversial findings. We aimed to investigate the relation between IA and self-acknowledged ADHD traits among female college students in Japan. Methods The study questionnaire consisted of questions about demographics, Adult ADHD Self-Report Scale-V1.1 Part A (ADHD screener) and Young's Internet Addiction Test (IAT). When four or more items are more frequent than the cut-off on ADHD screener, the subject was categorized into students with a positive ADHD screen. We defined students with total IAT score of 70 and higher as IA. Results A total number of respondents was 369 (mean age: 19.0±0.7 years). Seventy-seven subjects were screened positive on ADHD screener (20.9%). Students with a positive ADHD screen scored significantly higher on the IAT (54.2±14.2 vs. 42.5±11.3). The rates of IA in students with and without a positive ADHD screen were 18.2% and 1.0%, respectively. Conclusion Results of this study demonstrated the relation between IA and self-evaluated ADHD traits among female college students in Japan. Appropriate education for students on how to use the internet properly will be necessary to prevent IA.

Three-dimensional, small-ring scaffolds are very important in modern drug discovery to expand the available drug-like chemical space and to optimize drug candidates. Among them, bicyclo[1.1.1]pentane (BCP) is regarded as a high-value bioisostere for a phenyl ring or tert-butyl group; it provides an option to generate drug-like molecules with good passive permeability, high aqueous solubility, and improved metabolic stability, though the lack of methodology to functionalize BCP remains a significant challenge. Here we present an efficient method, developed with the aid of density functional theory calculations, for the synthesis of multifunctionalized BCP derivatives by means of a radical multicomponent carboamination of [1.1.1]propellane. This reaction features mild conditions, one-pot operation, and gram-scale synthetic capability, and opens up a unique and highly efficient route for the synthesis of multifunctionalized BCP derivatives, including synthetically useful 3-substituted BCP-amines.

The Weiss Functional Impairment Rating Scale Self-Report has been translated into nine languages and has been widely used in assessing functional impairment of adults with ADHD. This study is a psychometric validation of the WFIRS-S in Japanese. The WFIRS-S-J and other questionnaires were administered to 46 adults with attention-deficit-hyperactivity disorder (ADHD), 104 control adults, and 889 university students. ADHD diagnoses were made using the Japanese semi-structured diagnostic interview for adult ADHD, which is compatible with the DSM-5. All subscales of the WFIRS-S-J had Cronbach's α values of around 0.80. Total scores on the WFIRS-S-J had high test-retest reliability after a 2-week interval. The total score, subscale scores, and 59 of the individual item scores of the 70 items in the WFIRS-S-J were significantly higher in the ADHD group than in the other two groups, although more than half of the items in subdomain G (risk) showed floor effects and did not reach significance. Generally WFIRS-S-J subdomain scores were moderately correlated with scores on the Japanese version of Conners' Adult ADHD Rating Scales Self-Report subscales. WFIRS-S-J scores were also correlated (albeit more weakly; 0.31 ≤ r ≤ 0.55) with Beck Depression Inventory II total scores. The WFIRS-S-J showed acceptable psychometric properties, although further study is necessary.

This Concept article focuses on the rapid growth in studies of the chemistry of the monocarba-closo-dodecaborate(-) anion (C1 carborane anion). As one of the most stable anions known, the C1 carborane anion has been useful for exploring the chemistry of highly reactive cations. On the other hand, development of novel functional molecules utilizing the unique properties of C1 carborane anion (e.g., σ-aromaticity, rigid spherical skeleton) has progressed more slowly. The main reason for this is the relatively undeveloped state of synthetic chemistry in this area. Recent advances in the synthetic chemistry of C1 carborane anion are highlighted in this Concept article, focusing on cross-coupling reactions at the carbon vertex, direct conversion of B-H bonds, and the synthesis of multivalent weakly coordinating anions. These progressions move this species beyond its well-established role of highly stable "counter" monocharged anion.

Conjugation between σ- and π-aromatic moieties in 1-C-arylated monocarba-closo-dodecaborate anion derivatives 2 has been identified by means of kinetic experimental studies combined with theoretical calculations. We found that the reaction rate of iodination at the 12-B vertex of the carborane anion cage was affected by distal substituents on the benzene ring connected at the antipodal carbon vertex. Hammett and Yukawa-Tsuno plots indicated that substantial resonance effects are involved. Density functional theory calculations enabled detailed interpretation of the electronic interaction.

A cross-coupling reaction of lithium species of monocarba-closo-dodecaborate {[closo-CHB11H11]–} at the carbon vertex under palladium catalysis was developed. The properties of a metal–carborate complex in a transmetalation step were important to achieve the cross-coupling process with aryl halides, and the use of lithiated monocarba-closo-dodecaborate was found to promote the carbon–carbon bond formation to provide a series of C-arylated monocarba-closo-dodecaborate derivatives. Mechanistic investigations with DFT calculations suggested the efficient transmetalation with the lithium reagent.

A cross-coupling reaction at the carbon vertex of a monocarba-closo-dodecaborate has been developed to allow introduction of various aryl groups and other sp(2)/sp-hybridized carbon centers. A copper(I) complex facilitated the coupling process with a wide range of electrophiles at room temperature. The reaction was successfully used to prepare a series of C-arylated caborane anion derivatives, some of which showed potent androgen-receptor binding activity and excellent mesogenic properties.

Background This study was conducted to investigate the relationship between symptoms of gambling problems, gambling behaviours, and cognitive distortions among a university student population in Japan ages 20 to 29 years. We aimed to address the gap in knowledge of gambling disorders and treatment for this population. Methods Data were obtained from 1471 Japanese undergraduate students from 19 universities in Japan. Descriptive statistics and hierarchical multivariate regression analysis were used to investigate whether the factors of gambling cognitive distortions would have predictive effects on gambling disorder symptoms. Results Results indicated that 5.1% of the participants are classifiable as probable disordered gamblers. The bias of the gambling type to pachinko and pachislot was unique to gamblers in Japan. Of the students sampled, 342 self-reported gambling symptoms via the South Oaks Gambling Screen. Hierarchical multivariate regression analysis indicated that one domain of gambling cognitive distortions was associated significantly with gambling symptoms among the 342 symptomatic participants: gambling expectancy (β = 0.19, p Conclusion This study successfully contributed to the sparse research on university student gambling in Japan. Specifically, our results indicated a statistically significant relationship between gambling cognitive distortions and gambling disorder symptoms. These results can inform the development of preventive education and treatment for university students with gambling disorder in Japan. The report also describes needs for future research of university students with gambling disorder.

Ion pairs 2[Pyr] and 3[Pyr] containing [closo-1-CB11H11-1-Ph]− as the structural element were synthesized and their liquid crystalline properties were investigated by thermal and optical methods. Their mesogenic behavior was compared to that of the analogous series 1[Pyr] having a COO linking group between the benzene ring and the cluster, and the observed structure–property relationships are discussed in the context of general trends in related non-ionic liquid crystals.

a counterion for the isolation of reactive cations, and for activation of catalysts in organic synthesis. Its unique electronic and molecular structures render 1 as an attractive starting material for the construction of various functional molecules and bioactive/pharmaceutical building blocks. However, progress in the synthesis of such materials is hindered by the lack of methods for the functionalization of 1. In particular, no efficient general methods are available for introduction of aryl and sp/sp-hybridized carbon centers at the carbon vertex of C1-carborane. A cross-coupling reaction is an obvious method for the introduction of aryl groups and sp/sp-hybridized carbon centers at the carbon vertex of C1-carborane derivatives, but has not yet been successful. 10] The intrinsic difficulty appears to be associated mainly with the sterically hindered and hypervalent nature of the vertex carbon atom in 1. We report herein a general and efficient copper-mediated C C cross-coupling reaction of 1 under palladium catalysis that yields a variety of C-functionalized C1-carborane derivatives and provides a basic architecture for pharmacophores and functional materials. The reaction is demonstrated not only for the parent C1-carborane but also its B-halogenated derivatives. To demonstrate utility of the method and the resulting new class of compounds, we describe the synthesis of multivalent anions and disclose preliminary results of the biological activity and liquid crystal behavior of selected derivatives. We commenced our studies by screening for a suitable metal species at the C1-carborane carbon vertex for crosscoupling reaction with aryl iodide 2a under palladium catalysis (Table 1). Reactions of various zinc carborate derivatives 1a (i.e. Negishi-type reaction), including zincate complexes, were unsuccessful (Table 1, entry 1). The Suzuki–Miyaura-type cross-coupling with pinacol borate 1b was also examined under a variety of conditions, but failed to give the desired product, affording only halogenated C1carboranes, with most of the pinacol borate moiety remaining intact (Table 1, entry 2). These results imply that the nature of the vertex carbon atom with respect to transmetalation is quite different from that of typical aryl or alkyl carbon atoms. After extensive screening of other systems, we found that a combination of copper(I) carborate 1c and a palladium catalyst promoted the coupling reaction with 2a at room temperature to give the desired product 3a (Table 1, Scheme 1. C1-carborane (1).

This study aimed to develop and test the Japanese version of the Gambling Related Cognitions Scale (GRCS-J) to investigate its reliability and validity for assessing gambling cognitions in a Japanese sample. Five hundred and thirty-six participants (351 male, 185 female; Mean age = 29.75 years) from a community sample living in Japan were included in the analyses. The results of a confirmatory factor analysis confirmed that a five-factor model was appropriate for the data (goodness of fit index = .87, comparative fit index = .90, root mean square error of approximation = .07). The Cronbach’s alpha coefficient was .94 for the total scale and ranged from .74 to .85 for the subscales. The concurrent validities for the GRCS-J were also good. Further, the results of a t-test revealed significant gender differences in the GRCS-J subscale scores and the total score. These results indicated that the GRCS-J was a valid and reliable measure for assessing gambling cognitions in a non-clinical Japanese sample.