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Imidazole-containing dipeptides (IDPs), such as carnosine and anserine, are found exclusively in various animal tissues, especially in the skeletal muscles and nerves. IDPs have antioxidant activity because of their metal-chelating and free radical-scavenging properties. However, the underlying mechanisms that would fully explain IDP antioxidant effects remain obscure. Here, using HPLC–electrospray ionization–tandem MS analyses, we comprehensively investigated carnosine and its related small peptides in the soluble fractions of mouse tissue homogenates and ubiquitously detected 2-oxo-histidine–containing dipeptides (2-oxo-IDPs) in all examined tissues. We noted enhanced production of the 2-oxo-IDPs in the brain of a mouse model of sepsis-associated encephalopathy. Moreover, in SH-SY5Y human neuroblastoma cells stably expressing carnosine synthase, H(2)O(2) exposure resulted in the intracellular production of 2-oxo-carnosine, which was associated with significant inhibition of the H(2)O(2) cytotoxicity. Notably, 2-oxo-carnosine showed a better antioxidant activity than endogenous antioxidants such as GSH and ascorbate. Mechanistic studies indicated that carnosine monooxygenation is mediated through the formation of a histidyl-imidazole radical, followed by the addition of molecular oxygen. Our findings reveal that 2-oxo-IDPs are metal-catalyzed oxidation products present in vivo and provide a revised paradigm for understanding the antioxidant effects of the IDPs.

Background The aim of this randomized controlled trial (RCT) is to investigate whether Spiral-thread sutures are superior to conventional sutures (0-Vicryl) for preventing uterine scar thinning following elective cesarean section. Methods This multicenter, parallel-group RCT will be conducted in four hospitals across three medical regions in Japan to assess 200 women (≥20 years old) with singleton pregnancies who are scheduled to undergo cesarean sections. Eligible women will be randomly assigned (1:1 ratio) to receive either the conventional uterine suture continuous absorption thread, which is most commonly used in Japan, or the Spiral thread. The primary endpoint is the degree of scar thinning, measured by transvaginal ultrasonography 6–7 months postoperatively, to evaluate the position of the uterus (anterior or posterior tilt) and myometrial wound thickness. The degree of thinning will be compared between the groups, and four measurements (mm) of the thinning area, including caudal distance, depth of the depression, remaining thickness of the myometrium on the serous side of the most depressed area, and width of the depression, will be recorded in the sagittal view on transvaginal ultrasound. Secondary endpoints will include total operative time, suture application time (from birth to the end of uterine suturing), operative blood loss, number of additional Z-sutures or continuous sutures required to stop bleeding, maternal abnormality frequency (surgical complications and postoperative infections), surgeon's years of experience, and clinical interpretation of individual subscale scores. Discussion This study shall provide important evidence on the optimal suture for preventing hysterotomy wound thinning after the first cesarean section. Trial registration National Institute of Public Health, Japan: jRCT1062200001 (May 7, 2020; https://rctportal.niph.go.jp/en/detail?trial_id=jRCT1062200001 ) and Okayama University Certified Review Board: CRB6180001 (April 9, 2020, version 3.0).

There is increasing interest in finding the relation between solar activity and climate change. In general, fractal properties may be observed in the time series of the dynamics of complex systems, such as solar activity and climate. This study investigates the relations among solar activity, geomagnetic activity, and climatic regime shift by performing a multifractal analysis. To investigate the change in multifractality, we apply a wavelet transform to time series. The change in fractality of the sunspot number (SSN) correlates closely with that of the solar polar field strength. For the SSN and solar polar field strength, a weak multifractality or monofractality is present at the maximum SSN, minimum SSN, and maximum solar polar field strength. A strong multifractality is present two years before the maximum SSN. The climatic regime shift occurs when the SSN increases and the disturbance of the geomagnetic activity is large. At the climatic regime shift, the changes in the fractality of the Pacific Decadal Oscillation (PDO) index and changes in that of the solar activity indices corresponded with each other. From the fractals point of view, we clarify the relations among solar activity, geomagnetic activity, and climatic regime shift. The formation of the magnetic field of the sunspots is correlated with the solar polar field strength. The solar activity seems to influence the climatic regime shift. These findings will contribute to investigating the relation between solar activity and climate change.

A pathogenicity island within the genome of a multi-host plant bacterium, Pseudomonas cichorii strain SPC9018, comprises the hrp genes encoding a type III secretion system and the pat gene encoding an N-acetyltransferase proposed to play a role in virulence. However, the function of the N-acetyltransferase remains poorly characterized. Interestingly, limiting the iron condition using a phytosiderophore, mugineic acid, resulted in reduced virulence of strain SPC9018 on respective host plants, including eggplant, similar to the reduced virulence observed with a pat gene-deletion mutant. Spectroscopic analyses showed that the pat deletion reduced the concentration of pyoverdine, which is the main siderophore produced by strain SPC9018, leading to a reduction in pyoverdine-mediated iron acquisition. Furthermore, the pat gene deletion mutant showed enhanced expression of the fecA, pvdL, and pvdR genes, whose expression is induced under deficient siderophore-mediated iron uptake. The pat-deletion mutant showed a hyper-swarming phenotype, and the addition of iron decreased this swarming motility. The pat deletion also reduced the adhesion ability of the bacteria, similar to the effect of iron-limited conditions. Furthermore, deletion of the pat gene enhanced expression of the hrp genes. These findings suggested that the pat gene encoding the N-acetyltransferase may be implicated in iron acquisition, contributing to host specificity of P. cichorii strain SPC9018 and its virulence.

Ceilometers are durable compact backscatter lidars widely used to detect cloud base height. They are also useful for measuring aerosols. We introduced a ceilometer (CL51) for observing dust in a source region in Mongolia. For retrieving aerosol profiles with a backscatter lidar, the molecular backscatter signal in the aerosol free heights or system constant of the lidar is required. Although the system constant of the ceilometer is calibrated by the manufacturer, it is not necessarily accurate enough for the aerosol retrieval. We determined a correction factor, which is defined as the ratio of true attenuated backscattering coefficient to the measured attenuated backscattering coefficient, for the CL51 ceilometer using a dual-wavelength Mie-scattering lidar in Tsukuba, Japan before moving the ceilometer to Dalanzadgad, Mongolia. The correction factor determined by minimizing the difference between the ceilometer and lidar backscattering coefficients was approximately 1.2±0.1. Applying the correction to the CL51 signals, the aerosol optical depth (AOD) agreed well with the sky-radiometer AOD during the observation period (13–17 February 2013) in Tsukuba ( 9 × 10 − 3 of mean square error). After moving the ceilometer to Dalanzadgad, however, the AOD observed with the CL51 (calibrated by the correction factor determined in Tsukuba) was approximately 60% of the AErosol RObotic NETwork (AERONET) sun photometer AOD. The possible causes of the lower AOD results are as follows: (1) the limited height range of extinction integration ( 3 km ); (2) change in the correction factor during the ceilometer transportation or with the window contamination in Mongolia. In both cases, on-site calibrations by dual-wavelength lidar are needed. As an alternative method, we showed that the backward inversion method was useful for retrieving extinction coefficients if the AOD was larger than 1.5. This retrieval method does not require the system constant and molecular backscatter signals, and can be applied to severe dust and air pollution aerosol cases in East Asia.

Increasing our understanding of the Earth-atmosphere system has been a scientific and political priority for the last few decades. This system not only touches on environmental science, but it has applicability to our broader understanding of planetary atmospheres in general. While this issue focuses primarily on electromagnetics, other fundamental fields of science, including fluid and thermodynamics play major roles. In recent years, significant research efforts have led to advances in the fields of radiative transfer and electromagnetic scattering from irregularly shaped particles. Recently, several workshops and small conferences have taken place to promote the fusion of these efforts. Late in 2013, for instance, two such meetings took place. The Optical Characterization of Atmospheric Aerosols (OCAA) meeting took place in Smolenice, Slovakia to promote a better understanding of microphysical properties of aerosol particles, and the characterization of such atmospheric particles using optical techniques. A complementary conference was organized in Nagoya, Japan, the 3rd International Symposium on Atmospheric Light Scattering and Remote Sensing (ISALSaRS), whose goal is to fuse the advances achieved in particle characterization with remote-sensing techniques. While the focus of these meetings is slightly different, they represent the same aspects of this rapidly growing field. This Topical Issue is the first of two parts. Within this issue we analyze different aspects of the problem of atmospheric characterization and present a broad overview of the topical area. Research includes theory and experiment, ranging from fundamental microphysical properties of individual aerosol particles to broad characterizations of atmospheric properties. Since this is an active field, we also have encouraged the submission of ideas for new methodologies that may represent the future of the field.

The α-ketol oxylipin (12Z,15Z)-9-hydroxy-10-oxooctadeca-12,15-dienoic acid (1) reacts with epinephrine (2) to afford unique cycloadducts, KE1 (3) and KE2 (4), both of which strongly induce flowering in Lemna paucicostata. Here we isolate compound 5 from the reaction mixture and identify it as a Michael-type adduct of 1 with adrenochrome (6), an oxidized form of 2. Compound 5 was gradually converted into KEs in aqueous solution, suggesting that the compound is an intermediate of KEs. From these results, we newly propose the reaction mechanism of the cycloaddition between 1 and 2.

N -Acylhomoserine lactones (AHLs) are the conserved quorum-sensing signal molecules in Gram-negative bacteria. ( Z )- N -(4-Decenoyl)homoserine lactone ( 1 ), a new AHL, was isolated from the culture broth of the fungus Mortierella alpina A-178 harboring bacterial endosymbionts, called endobacteria. The structure and absolute configuration of 1 were elucidated by EI-MS, chemical synthesis, and chiral GC analysis. The compound induced the expression of a QS-regulated reporter gene in Agrobacterium tumefaciens NTL4, although its activity was lower than that of N -decanoylhomoserine lactone ( 6 ).

Oxylipin glucosides (2–4) were isolated from Lemna paucicostata with their structures and absolute configurations elucidated by spectroscopic and chemical methods. Compounds 2–4 were glucosides of C14 oxylipin which were synthesized from α-linolenic acid via the 9-lipoxygenase pathway.

(12Z,15Z)-9-Hydroxy-10-oxooctadeca-12,15-dienoic acid (1) and norepinephrine (2) undergo cycloaddition to afford FN1 (3) and FN2 (4), both of which induce flowering in Lemna paucicostata. Although the derivatives of 1 were suggested to also yield FN-like compounds after reacting with 2, their structures have not been elucidated. In this report, we investigated the structure and stereochemistry of seven novel FN analogs. These analogs were shown to be formed in the same regio- and stereocontrolled manner as FNs. Moreover, the activity of FN analogs on flowering induction was investigated, and we determined that all analogs, except for compound 8, were effective flowering inducers for L. paucicostata.

FN1 (1) and FN2 (2), cycloadducts of α-ketol octadecadienoic acid (3) with norepinephrine (NE), induce flowering in Lemna paucicostata. In order to broaden our understanding of structural requirements of FN for flower induction, nine analogs of 3 (4–12) were synthesized and reacted with NE under basic conditions. These analogs, except for 8, 10, and 12, exhibited significant activity regarding to floral induction in L. paucicostata. Similar experiments were carried out by using 3 and epinephrine, and it was demonstrated that these products also possessed biological activity.

α-Ketol of octadecadienoic acid (KODA, 1 ) has been suggested to play a role in the photoperiod-regulated flowering in Pharbitis nil . The level of 1 in cotyledons is temporarily controlled during short-day conditions. The biosynthesis of 1 is well studied in plants; however, its in vivo conversion is less understood. We have investigated this issue by studying the metabolism of exogenously-applied [U- 13 C]- 1 , [1- 14 C]- 1 , and non-labeled 1 in P. nil seedlings by the spectroscopic methods and identified six major metabolites ( 4 – 9 ). We have also found that the enantiomers of 1 are differentially metabolized in P. nil seedlings.

A search was made for conjugates of indole-3-acetic acid (IAA) in rice (Oryza sativa) using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) in order to elucidate unknown metabolic pathways for IAA. N-beta-d-Glucopyranosyl indole-3-acetic acid (IAA-N-Glc) was found in an alkaline hydrolysate of rice extract. A quantitative analysis of 3-week-old rice demonstrated that the total amount of IAA-N-Glc was equal to that of IAA. A LC-ESI-MS/MS-based analysis established that the major part of IAA-N-Glc was present as bound forms with aspartate and glutamate. Their levels were in good agreement with the total amount of IAA-N-Glc during the vegetative growth of rice. Further detailed analysis showed that both conjugates highly accumulated in the root. The free form of IAA-N-Glc accounted for 60% of the total in seeds but could not be detected in the vegetative tissue. An incorporation study using deuterium-labeled compounds showed that the amino acid conjugates of IAA-N-Glc were biosynthesized from IAA-amino acids. IAA-N-Glc and/or its conjugates were also found in extracts of Arabidopsis, Lotus japonicus, and maize, suggesting that N-glucosylation of indole can be the common metabolic pathway of IAA in plants.

From the evening of 25 March 2003 until 27 March an Asian dust event (Kosa) was observed at a total of 37 routine meteorological observatories in Japan, although no significant dust storms had been observed in the arid regions of China and Mongolia. A numerical simulation with a three-dimensional global aerosol transport model and meteorological observations reveal that the observed mineral dust particles were generated through dust storms in North Africa and the Middle East on 19 March. The simulation predicted that dust particles generated in the Sahara Desert and Arabian Peninsula on 19 March would be transported north of the Tien Shan Mountains in China and arrive over Japan in about 6–7 days. It also indicated that over 50% of the dust particles in Japan on 26–27 March came from North Africa, about 30% from the Middle East, and only about 10% from China in the boundary layer. The simulated result is consistent with polarization lidar and sky radiometer observations, indicating that the simulation is realistic. The simulation indicates that the Kosa phenomenon was caused by a mixture of transported dust and anthropogenic pollutants. The simulation of this dust event suggests the possible importance of dust transport from the Sahara and the Arabian Peninsula to East Asia.

Aerosol particles were collected in the situation of the widespread dust suspension on 21 February 1991 at Qira in the southern edge of the Taklamakan Desert, western China. The collected particles were examined by a transmission electron microscope equipped with an energy-dispersive X-ray (EDX) analyzer in order to obtain the size and elemental composition of individual mineral particles. On the basis of EDX analyses for 386 particles, mineral particles were present in high number fractions (>99%) of particles in the radius range of 0.1–4 μm. Particles mainly composed of silicates comprised 76% of mineral particles. “Ca-rich” particles were detected in 7% of all the particles. Ca in the particles would be present not only as CaCO3 but also as an internal mixture of CaCO3 and CaSO4. Particles containing halite (NaCl) were detected in number proportions of about 10% and were mainly present in the radius range of ⩾0.5 μm. Some halite particles would be modified by chemical reactions with sulfuric acid.

Two cyclic peptides, PF1171F ( 1 ) and PF1171G ( 2 ), were isolated from okara fermented with the unidentified ascomycete OK-128, and their structures were determined by NMR, MS, and Marfey amino acid analysis. Both peptides showed paralytic activity against silkworms.

Aerosol particles were collected at China and Japan in the same spring Asian dust-storm event of 1991 in order to study the change in composition of mineral aerosol particles during long range transport. It was found on the basis of a microchemical analysis that dust particles containing Mg, Al, Si, K, Ca and Fe were a major fraction of the aerosol particles collected at Hohhot and Beijing, China, and Nagasaki, Japan. A large fraction of the mineral aerosol particles was internally mixed with sea salt in Nagasaki. Present study suggests that the internal mixed particles were mainly produced by cloud processes through droplet coalescence.